Documentation and minor refactors

.gitignore

@@ -10,8 +10,10 @@
 *.pfs0
 *.smdh
 .gdb_history
-build.*/
-ftpd
-romfs.3ds/*.t3x
-romfs.switch/*.zst
-romfs.switch/shaders/*.dksh
+3ds/build
+3ds/romfs/*.t3x
+linux/build
+linux/ftpd
+switch/build
+switch/romfs/*.zst
+switch/romfs/shaders/*.dksh

Makefile

@@ -17,19 +17,19 @@ all: 3dsx nro linux
 nxlink:
 	@$(MAKE) -f Makefile.switch nxlink
 
-3dslink: 3dsx
-	@/opt/devkitpro/tools/bin/3dslink $(TARGET)-3ds.3dsx
+3dslink:
+	@$(MAKE) -f Makefile.3ds 3dslink
 
 format:
 	@clang-format -style=file -i $(filter-out \
 		include/imgui.h \
-		source/pc/imgui_impl_glfw.cpp \
-		source/pc/imgui_impl_glfw.h \
-		source/pc/imgui_impl_opengl3.cpp \
-		source/pc/imgui_impl_opengl3.h \
-		source/pc/KHR/khrplatform.h \
-		source/pc/glad.c \
-		source/pc/glad/glad.h \
+		source/linux/imgui_impl_glfw.cpp \
+		source/linux/imgui_impl_glfw.h \
+		source/linux/imgui_impl_opengl3.cpp \
+		source/linux/imgui_impl_opengl3.h \
+		source/linux/KHR/khrplatform.h \
+		source/linux/glad.c \
+		source/linux/glad/glad.h \
 		source/imgui/imgui.cpp \
 		source/imgui/imgui_demo.cpp \
 		source/imgui/imgui_draw.cpp \
@@ -41,9 +41,9 @@ format:
 		$(shell find source include -type f -name \*.c -o -name \*.cpp -o -name \*.h))
 
 release: release-3ds release-nro
-	@xz -c <$(TARGET)-3ds.3dsx >ftpd.3dsx.xz
-	@echo xz -c <$(TARGET)-3ds.cia >ftpd.cia.xz
-	@echo xz -c <$(TARGET)-nx.nro >ftpd.nro.xz
+	@xz -c <3ds/$(TARGET).3dsx >ftpd.3dsx.xz
+	@xz -c <3ds/$(TARGET).cia >ftpd.cia.xz
+	@xz -c <switch/$(TARGET).nro >ftpd.nro.xz
 
 nro:
 	@$(MAKE) -f Makefile.switch all
@@ -64,7 +64,7 @@ release-cia: release-3dsx
 	@$(MAKE) DEFINES=-NDEBUG -f Makefile.3ds cia
 
 release-3ds:
-	# can't let these three run in parallel with each other due to using same
+	# can't let these run in parallel with each other due to using same
 	# .elf file name
 	@$(MAKE) DEFINES=-DNDEBUG -f Makefile.3ds 3dsx
 	@$(MAKE) DEFINES=-DNDEBUG -f Makefile.3ds cia

Makefile.3ds

@@ -31,13 +31,13 @@ include $(DEVKITARM)/3ds_rules
 #     - icon.png
 #     - <libctru folder>/default_icon.png
 #---------------------------------------------------------------------------------
-TARGET   := $(notdir $(CURDIR))-3ds
-BUILD    := build.3ds
+TARGET   := 3ds/$(notdir $(CURDIR))
+BUILD    := 3ds/build
 SOURCES  := source source/3ds source/imgui
 DATA     := data
 INCLUDES := include
-GRAPHICS := gfx.3ds
-ROMFS    := romfs.3ds
+GRAPHICS := 3ds/gfx
+ROMFS    := 3ds/romfs
 GFXBUILD := $(ROMFS)
 
 APP_TITLE       := ftpd
@@ -66,7 +66,7 @@ CFLAGS   +=  $(INCLUDE) -DARM11 -D_3DS \
 CXXFLAGS := $(CFLAGS) -fno-rtti -fno-exceptions -std=gnu++17
 
 ASFLAGS  := -g $(ARCH)
-LDFLAGS   = -specs=3dsx.specs -g $(ARCH) -Wl,-Map,$(TARGET).map $(OPTIMIZE)
+LDFLAGS   = -specs=3dsx.specs -g $(ARCH) -Wl,-Map,$(notdir $*.map) $(OPTIMIZE)
 
 LIBS     := -lcitro3d -lctru -lm
 
@@ -81,7 +81,7 @@ LIBDIRS  := $(CTRULIB)
 # no real need to edit anything past this point unless you need to add additional
 # rules for different file extensions
 #---------------------------------------------------------------------------------
-ifneq ($(BUILD),$(notdir $(CURDIR)))
+ifneq ($(TOPDIR)/$(BUILD),$(CURDIR))
 #---------------------------------------------------------------------------------
 
 export OUTPUT  :=  $(CURDIR)/$(TARGET)
@@ -165,7 +165,7 @@ ifneq ($(ROMFS),)
   export _3DSXFLAGS += --romfs=$(CURDIR)/$(ROMFS)
 endif
 
-.PHONY: $(BUILD) clean all 3dsx cia
+.PHONY: $(BUILD) clean all 3dsx cia 3dslink
 
 #---------------------------------------------------------------------------------
 all: $(BUILD) $(GFXBUILD) $(DEPSDIR) $(ROMFS_T3XFILES) $(T3XHFILES)
@@ -196,6 +196,9 @@ $(GFXBUILD)/%.t3x $(BUILD)/%.h: %.t3s
 cia: $(BUILD) $(GFXBUILD) $(DEPSDIR) $(ROMFS_T3XFILES) $(T3XHFILES)
 	@$(MAKE) --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile.3ds cia
 
+3dslink: 3dsx
+	@3dslink $(OUTPUT).3dsx
+
 #---------------------------------------------------------------------------------
 clean:
 	@echo clean ...

Makefile.linux

@@ -1,12 +1,12 @@
-TARGET  := ftpd
-BUILD   := build.linux
+TARGET  := linux/ftpd
+BUILD   := linux/build
 
-CFILES    := $(wildcard source/pc/*.c)
+CFILES    := $(wildcard source/linux/*.c)
 OFILES    := $(patsubst source/%,$(BUILD)/%,$(CFILES:.c=.c.o))
-CXXFILES  := $(wildcard source/*.cpp source/imgui/*.cpp source/pc/*.cpp)
+CXXFILES  := $(wildcard source/*.cpp source/imgui/*.cpp source/linux/*.cpp)
 OXXFILES  := $(patsubst source/%,$(BUILD)/%,$(CXXFILES:.cpp=.cpp.o))
 
-CPPFLAGS  := -g -Wall -pthread -Iinclude -Isource/pc \
+CPPFLAGS  := -g -Wall -pthread -Iinclude -Isource/linux \
              `pkg-config --cflags gl glfw3` \
              -DSTATUS_STRING="\"ftpd v$(VERSION)\"" \
              -DIMGUI_DISABLE_INCLUDE_IMCONFIG_H=1 \

Makefile.switch

@@ -42,13 +42,13 @@ APP_AUTHOR	:=	mtheall, TuxSH, WinterMute
 ICON		:=	meta/ftpd.jpg
 APP_VERSION	:=	$(VERSION)
 
-TARGET		:=	$(notdir $(CURDIR))-nx
-BUILD		:=	build.switch
-SOURCES		:=	source source/imgui source/nx
+TARGET		:=	switch/$(notdir $(CURDIR))
+BUILD		:=	switch/build
+SOURCES		:=	source source/imgui source/switch
 DATA		:=	data
 INCLUDES	:=	include
-GRAPHICS	:=	gfx.switch
-ROMFS		:=	romfs.switch
+GRAPHICS	:=	switch/gfx
+ROMFS		:=	switch/romfs
 
 # Output folders for autogenerated files in romfs
 OUT_SHADERS	:=	shaders
@@ -85,7 +85,7 @@ LIBDIRS	:= $(PORTLIBS) $(LIBNX)
 # no real need to edit anything past this point unless you need to add additional
 # rules for different file extensions
 #---------------------------------------------------------------------------------
-ifneq ($(BUILD),$(notdir $(CURDIR)))
+ifneq ($(TOPDIR)/$(BUILD),$(CURDIR))
 #---------------------------------------------------------------------------------
 
 export OUTPUT	:=	$(CURDIR)/$(TARGET)
@@ -193,7 +193,7 @@ all: $(ROMFS_TARGETS) | $(BUILD)
 	@$(MAKE) --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile.switch
 
 nxlink: all
-	@$(MAKE) --no-print-directory -C $(BUILD) -f $(CURDIR)/Makefile.switch nxlink
+	@nxlink -s $(OUTPUT).nro
 
 $(BUILD):
 	@mkdir -p $@
@@ -260,9 +260,6 @@ ifeq ($(strip $(APP_JSON)),)
 
 all	:	$(OUTPUT).nro
 
-nxlink: $(OUTPUT).nro
-	@nxlink -s $(OUTPUT).nro
-
 ifeq ($(strip $(NO_NACP)),)
 $(OUTPUT).nro	:	$(OUTPUT).elf $(OUTPUT).nacp $(ROMFS_DEPS)
 else

include/fs.h

@@ -29,8 +29,11 @@
 
 namespace fs
 {
+/// \brief Print size in human-readable format (KiB, MiB, etc)
+/// \param size_ Size to print
 std::string printSize (std::uint64_t size_);
 
+/// \brief File I/O object
 class File
 {
 public:
@@ -40,51 +43,97 @@ public:
 
 	File (File const &that_) = delete;
 
+	/// \brief Move constructor
+	/// \param that_ Object to move from
 	File (File &&that_);
 
 	File &operator= (File const &that_) = delete;
 
+	/// \brief Move assignment
+	/// \param that_ Object to move from
 	File &operator= (File &&that_);
 
-	operator bool () const;
-	operator FILE * () const;
+	/// \brief bool cast operator
+	explicit operator bool () const;
 
+	/// \brief std::FILE* cast operator
+	operator std::FILE * () const;
+
+	/// \brief Set buffer size
+	/// \param size_ Buffer size
 	void setBufferSize (std::size_t size_);
 
+	/// \brief Open file
+	/// \param path_ Path to open
+	/// \param mode_ Access mode (\sa std::fopen)
 	bool open (char const *path_, char const *mode_ = "rb");
+
+	/// \brief Close file
 	void close ();
 
+	/// \brief Seek to file position
+	/// \param pos_ File position
+	/// \param origin_ Reference position (\sa std::fseek)
 	ssize_t seek (std::size_t pos_, int origin_);
 
+	/// \brief Read data
+	/// \param data_ Output buffer
+	/// \param size_ Size to read
+	/// \note Can return partial reads
 	ssize_t read (void *data_, std::size_t size_);
+
+	/// \brief Read data
+	/// \param data_ Output buffer
+	/// \param size_ Size to read
+	/// \note Fails on partial reads and errors
 	bool readAll (void *data_, std::size_t size_);
 
+	/// \brief Write data
+	/// \param data_ Input data
+	/// \param size_ Size to write
+	/// \note Can return partial writes
 	ssize_t write (void const *data_, std::size_t size_);
+
+	/// \brief Write data
+	/// \param data_ Input data
+	/// \param size_ Size to write
+	/// \note Fails on partials writes and errors
 	bool writeAll (void const *data_, std::size_t size_);
 
+	/// \brief Read data
+	/// \tparam T Type to read
 	template <typename T>
 	T read ()
 	{
 		T data;
-		if (read (&data, sizeof (data)) != sizeof (data))
+		if (!readAll (&data, sizeof (data)))
 			std::abort ();
 
 		return data;
 	}
 
+	/// \brief Write data
+	/// \tparam T type to write
+	/// \param data_ Data to write
 	template <typename T>
 	void write (T const &data_)
 	{
-		if (write (&data_, sizeof (data_)) != sizeof (data_))
+		if (!writeAll (&data_, sizeof (data_)))
 			std::abort ();
 	}
 
 private:
+	/// \brief Underlying std::FILE*
 	std::unique_ptr<std::FILE, int (*) (std::FILE *)> m_fp{nullptr, nullptr};
+
+	/// \brief Buffer
 	std::unique_ptr<char[]> m_buffer;
+
+	/// \brief Buffer size
 	std::size_t m_bufferSize = 0;
 };
 
+/// Directory object
 class Dir
 {
 public:
@@ -94,20 +143,35 @@ public:
 
 	Dir (Dir const &that_) = delete;
 
+	/// \brief Move constructor
+	/// \param that_ Object to move from
 	Dir (Dir &&that_);
 
 	Dir &operator= (Dir const &that_) = delete;
 
+	/// \brief Move assignment
+	/// \param that_ Object to move from
 	Dir &operator= (Dir &&that_);
 
-	operator bool () const;
+	/// \brief bool cast operator
+	explicit operator bool () const;
+
+	/// \brief DIR* cast operator
 	operator DIR * () const;
 
+	/// \brief Open directory
+	/// \param path_ Path to open
 	bool open (char const *const path_);
+
+	/// \brief Close directory
 	void close ();
+
+	/// \brief Read a directory entry
+	/// \note Returns nullptr on end-of-directory or error; check errno
 	struct dirent *read ();
 
 private:
+	/// \brief Underlying DIR*
 	std::unique_ptr<DIR, int (*) (DIR *)> m_dp{nullptr, nullptr};
 };
 }

include/ftpServer.h

@@ -34,40 +34,63 @@
 class FtpServer;
 using UniqueFtpServer = std::unique_ptr<FtpServer>;
 
+/// \brief FTP server
 class FtpServer
 {
 public:
 	~FtpServer ();
 
+	/// \brief Draw server and all of its sessions
 	void draw ();
 
+	/// \brief Create server
+	/// \param port_ Port to listen on
 	static UniqueFtpServer create (std::uint16_t port_);
 
+	/// \brief Update free space
 	static void updateFreeSpace ();
 
+	/// \brief Server start time
 	static std::time_t startTime ();
 
 private:
+	/// \brief Paramterized constructor
+	/// \param port_ Port to listen on
 	FtpServer (std::uint16_t port_);
 
+	/// \brief Handle when start button is pressed
 	void handleStartButton ();
+
+	/// \brief Handle when stop button is pressed
 	void handleStopButton ();
 
+	/// \brief Server loop
 	void loop ();
+
+	/// \brief Thread entry point
 	void threadFunc ();
 
+	/// \brief Thread
 	platform::Thread m_thread;
+
+	/// \brief Mutex
 	platform::Mutex m_lock;
 
+	/// \brief Listen socket
 	UniqueSocket m_socket;
 
+	/// \brief ImGui window name
 	std::string m_name;
 
+	/// \brief Log
 	SharedLog m_log;
 
+	/// \brief Sessions
 	std::vector<UniqueFtpSession> m_sessions;
 
-	std::uint16_t m_port;
+	/// \brief Port to listen on
+	std::uint16_t const m_port;
 
+	/// \brief Whether thread should quit
 	std::atomic<bool> m_quit;
 };

include/ftpSession.h

@@ -34,33 +34,54 @@
 class FtpSession;
 using UniqueFtpSession = std::unique_ptr<FtpSession>;
 
+/// \brief FTP session
 class FtpSession
 {
 public:
 	~FtpSession ();
 
+	/// \brief Whether session sockets are all inactive
 	bool dead ();
 
+	/// \brief Draw session status
 	void draw ();
 
+	/// \brief Create session
+	/// \param commandSocket_ Command socket
 	static UniqueFtpSession create (UniqueSocket commandSocket_);
 
+	/// \brief Poll for activity
+	/// \param sessions_ Sessions to poll
 	static void poll (std::vector<UniqueFtpSession> const &sessions_);
 
 private:
-	constexpr static auto COMMAND_BUFFERSIZE  = 4096;
+	/// \brief Command buffer size
+	constexpr static auto COMMAND_BUFFERSIZE = 4096;
+
+	/// \brief Response buffer size
 	constexpr static auto RESPONSE_BUFFERSIZE = 32768;
-	constexpr static auto XFER_BUFFERSIZE     = 65536;
-	constexpr static auto FILE_BUFFERSIZE     = 4 * XFER_BUFFERSIZE;
+
+	/// \brief Transfer buffersize
+	constexpr static auto XFER_BUFFERSIZE = 65536;
+
+	/// \brief File buffersize
+	constexpr static auto FILE_BUFFERSIZE = 4 * XFER_BUFFERSIZE;
 
 #ifdef _3DS
-	constexpr static auto SOCK_BUFFERSIZE  = 32768;
+	/// \brief Socket buffer size
+	constexpr static auto SOCK_BUFFERSIZE = 32768;
+
+	/// \brief Amount of file position history to keep
 	constexpr static auto POSITION_HISTORY = 100;
 #else
-	constexpr static auto SOCK_BUFFERSIZE  = XFER_BUFFERSIZE;
+	/// \brief Socket buffer size
+	constexpr static auto SOCK_BUFFERSIZE = XFER_BUFFERSIZE;
+
+	/// \brief Amount of file position history to keep
 	constexpr static auto POSITION_HISTORY = 300;
 #endif
 
+	/// \brief Session state
 	enum class State
 	{
 		COMMAND,
@@ -68,6 +89,7 @@ private:
 		DATA_TRANSFER,
 	};
 
+	/// \brief Transfer file mode
 	enum class XferFileMode
 	{
 		RETR,
@@ -75,6 +97,7 @@ private:
 		APPE,
 	};
 
+	/// \brief Transfer directory mode
 	enum class XferDirMode
 	{
 		LIST,
@@ -84,122 +107,322 @@ private:
 		STAT,
 	};
 
+	/// \brief Parameterized constructor
+	/// \param commandSocket_ Command socket
 	FtpSession (UniqueSocket commandSocket_);
 
+	/// \brief Set session state
+	/// \param state_ State to set
+	/// \param closePasv_ Whether to close listening socket
+	/// \param closeData_ Whether to close data socket
 	void setState (State state_, bool closePasv_, bool closeData_);
 
+	/// \brief Close data socket
 	void closeData ();
 
+	/// \brief Change working directory
 	bool changeDir (char const *args_);
 
+	/// \brief Accept connection as data socket
 	bool dataAccept ();
+
+	/// \brief Connect data socket
 	bool dataConnect ();
 
-	void updateFreeSpace ();
-
+	/// \brief Fill directory entry
+	/// \param st_ Entry status
+	/// \param path_ Path name
+	/// \param type_ MLST type
 	int fillDirent (struct stat const &st_, std::string_view path_, char const *type_ = nullptr);
+
+	/// \brief Fill directory entry
+	/// \param path_ Path name
+	/// \param type_ MLST type
 	int fillDirent (std::string const &path_, char const *type_ = nullptr);
+
+	/// \brief Transfer file
+	/// \param args_ Command arguments
+	/// \param mode_ Transfer file mode
 	void xferFile (char const *args_, XferFileMode mode_);
+
+	/// \brief Transfer directory
+	/// \param args_ Command arguments
+	/// \param mode_ Transfer directory mode
 	void xferDir (char const *args_, XferDirMode mode_, bool workaround_);
 
+	/// \brief Read command
+	/// \param events_ Poll events
 	void readCommand (int events_);
+
+	/// \brief Write response
 	void writeResponse ();
 
+	/// \brief Send response
+	/// \param fmt_ Message format
 	__attribute__ ((format (printf, 2, 3))) void sendResponse (char const *fmt_, ...);
+
+	/// \brief Send response
+	/// \param response_ Response message
 	void sendResponse (std::string_view response_);
 
+	/// \brief Transfer function
 	bool (FtpSession::*m_transfer) () = nullptr;
 
+	/// \brief Transfer directory list
 	bool listTransfer ();
+
+	/// \brief Transfer download
 	bool retrieveTransfer ();
+
+	/// \brief Transfer upload
 	bool storeTransfer ();
 
+	/// \brief Mutex
 	platform::Mutex m_lock;
 
+	/// \brief Command socket
 	SharedSocket m_commandSocket;
+
+	/// \brief Data listen socker
 	UniqueSocket m_pasvSocket;
+
+	/// \brief Data socket
 	SharedSocket m_dataSocket;
+
+	/// \brief Sockets pending close
 	std::vector<SharedSocket> m_pendingCloseSocket;
 
+	/// \brief Command buffer
 	IOBuffer m_commandBuffer;
+
+	/// \brief Response buffer
 	IOBuffer m_responseBuffer;
+
+	/// \brief Transfer buffer
 	IOBuffer m_xferBuffer;
 
-	SockAddr m_pasvAddr;
+	/// \brief Address from last PORT command
 	SockAddr m_portAddr;
 
+	/// \brief Current working directory
 	std::string m_cwd = "/";
+
+	/// \brief List working directory
 	std::string m_lwd;
+
+	/// \brief Path from RNFR command
 	std::string m_rename;
+
+	/// \brief Current work item
 	std::string m_workItem;
 
+	/// \brief ImGui window name
 	std::string m_windowName;
+
+	/// \brief ImGui plot widget name
 	std::string m_plotName;
 
+	/// \brief Position from REST command
 	std::uint64_t m_restartPosition = 0;
-	std::uint64_t m_filePosition    = 0;
-	std::uint64_t m_fileSize        = 0;
 
+	/// \brief Current file position
+	std::uint64_t m_filePosition = 0;
+
+	/// \brief File size of current transfer
+	std::uint64_t m_fileSize = 0;
+
+	/// \brief Last file position update timestamp
 	platform::steady_clock::time_point m_filePositionTime;
+
+	/// \brief File position history
 	std::uint64_t m_filePositionHistory[POSITION_HISTORY];
+
+	/// \brief File position history deltas
 	float m_filePositionDeltas[POSITION_HISTORY];
+
+	/// \brief Transfer rate (EWMA low-pass filtered)
 	float m_xferRate;
 
+	/// \brief Session state
 	State m_state = State::COMMAND;
 
+	/// \brief File being transferred
 	fs::File m_file;
+
+	/// \brief Directory being transferred
 	fs::Dir m_dir;
 
+	/// \brief Directory transfer mode
 	XferDirMode m_xferDirMode;
 
+	/// \brief Whether previous command was PASV
 	bool m_pasv : 1;
+	/// \brief Whether previous command was PORT
 	bool m_port : 1;
+	/// \brief Whether receiving data
 	bool m_recv : 1;
+	/// \brief Whether sending data
 	bool m_send : 1;
+	/// \brief Whether urgent (out-of-band) data is on the way
 	bool m_urgent : 1;
 
+	/// \brief Whether MLST type fact is enabled
 	bool m_mlstType : 1;
+	/// \brief Whether MLST size fact is enabled
 	bool m_mlstSize : 1;
+	/// \brief Whether MLST modify fact is enabled
 	bool m_mlstModify : 1;
+	/// \brief Whether MLST perm fact is enabled
 	bool m_mlstPerm : 1;
+	/// \brief Whether MLST unix.mode fact is enabled
 	bool m_mlstUnixMode : 1;
 
+	/// \brief Abort a transfer
+	/// \param args_ Command arguments
 	void ABOR (char const *args_);
+
+	/// \brief Allocate space
+	/// \param args_ Command arguments
 	void ALLO (char const *args_);
+
+	/// \brief Append data to a file
+	/// \param args_ Command arguments
 	void APPE (char const *args_);
+
+	/// \brief CWD to parent directory
+	/// \param args_ Command arguments
 	void CDUP (char const *args_);
+
+	/// \brief Change working directory
+	/// \param args_ Command arguments
 	void CWD (char const *args_);
+
+	/// \brief Delete a file
+	/// \param args_ Command arguments
 	void DELE (char const *args_);
+
+	/// \brief List server features
+	/// \param args_ Command arguments
 	void FEAT (char const *args_);
+
+	/// \brief Print server help
+	/// \param args_ Command arguments
 	void HELP (char const *args_);
+
+	/// \brief List directory
+	/// \param args_ Command arguments
 	void LIST (char const *args_);
+
+	/// \brief Last modification time
+	/// \param args_ Command arguments
 	void MDTM (char const *args_);
+
+	/// \brief Create a directory
+	/// \param args_ Command arguments
 	void MKD (char const *args_);
+
+	/// \brief Machine list directory
+	/// \param args_ Command arguments
 	void MLSD (char const *args_);
+
+	/// \brief Machine list
+	/// \param args_ Command arguments
 	void MLST (char const *args_);
+
+	/// \brief Set transfer mode
+	/// \param args_ Command arguments
 	void MODE (char const *args_);
+
+	/// \brief Name list
+	/// \param args_ Command arguments
 	void NLST (char const *args_);
+
+	/// \brief No-op
+	/// \param args_ Command arguments
 	void NOOP (char const *args_);
+
+	/// \brief Set server options
+	/// \param args_ Command arguments
 	void OPTS (char const *args_);
+
+	/// \brief Password
+	/// \param args_ Command arguments
 	void PASS (char const *args_);
+
+	/// \brief Request an address to connect to for data transfers
+	/// \param args_ Command arguments
 	void PASV (char const *args_);
+
+	/// \brief Provide an address to connect to for data transfers
+	/// \param args_ Command arguments
 	void PORT (char const *args_);
+
+	/// \brief Print working directory
+	/// \param args_ Command arguments
 	void PWD (char const *args_);
+
+	/// \brief Terminate session
+	/// \param args_ Command arguments
 	void QUIT (char const *args_);
+
+	/// \brief Restart a file transfer
+	/// \param args_ Command arguments
 	void REST (char const *args_);
+
+	/// \brief Retrieve a file
+	/// \param args_ Command arguments
+	/// \note Requires a PASV or PORT connection
 	void RETR (char const *args_);
+
+	/// \brief Remove a directory
+	/// \param args_ Command arguments
 	void RMD (char const *args_);
+
+	/// \brief Rename from
+	/// \param args_ Command arguments
 	void RNFR (char const *args_);
+
+	/// \brief Rename to
+	/// \param args_ Command arguments
 	void RNTO (char const *args_);
+
+	/// \brief Get file size
+	/// \param args_ Command arguments
 	void SIZE (char const *args_);
+
+	/// \brief Get status
+	/// \param args_ Command arguments
+	/// \note If no argument is supplied, and a transfer is occurring, get the current transfer
+	/// status. If no argument is supplied, and no transfer is occurring, get the server status. If
+	/// an argument is supplied, this is equivalent to LIST, except the data is sent over the
+	/// command socket.
 	void STAT (char const *args_);
+
+	/// \brief Store a file
+	/// \param args_ Command arguments
 	void STOR (char const *args_);
+
+	/// \brief Store a unique file
+	/// \param args_ Command arguments
 	void STOU (char const *args_);
+
+	/// \brief Set file structure
+	/// \param args_ Command arguments
 	void STRU (char const *args_);
+
+	/// \brief Identify system
+	/// \param args_ Command arguments
 	void SYST (char const *args_);
+
+	/// \brief Set representation type
+	/// \param args_ Command arguments
 	void TYPE (char const *args_);
+
+	/// \brief User name
+	/// \param args_ Command arguments
 	void USER (char const *args_);
 
+	/// \brief Map of command handlers
 	static std::vector<std::pair<std::string_view, void (FtpSession::*) (char const *)>> const
 	    handlers;
 };

include/ioBuffer.h

@@ -23,29 +23,66 @@
 #include <cstddef>
 #include <memory>
 
+/// \brief I/O buffer
+/// [unusable][usedArea][freeArea]
 class IOBuffer
 {
 public:
 	~IOBuffer ();
 
+	/// \brief Parameterized constructor
+	/// \param size_ Buffer size
 	IOBuffer (std::size_t size_);
 
+	/// \brief Get pointer to writable area
 	char *freeArea () const;
+	/// \brief Get size of writable area
 	std::size_t freeSize () const;
-	void markFree (std::size_t size_);
 
+	/// \brief Get pointer to readable area
 	char *usedArea () const;
+	/// \brief Get size of readable area
 	std::size_t usedSize () const;
+
+	/// \brief Consume data from the beginning of usedArea
+	/// \param size_ Size to consume
+	/// [unusable][+++++usedArea][freeArea]
+	///   becomes
+	/// [unusable+++++][usedArea][freeArea]
+	void markFree (std::size_t size_);
+	/// \brief Produce data to the end of usedArea from freeArea
+	/// [unusable][usedArea][++++++freeArea]
+	///   becomes
+	/// [unusable][usedArea++++++][freeArea]
 	void markUsed (std::size_t size_);
 
+	/// \brief Whether usedArea is empty
 	bool empty () const;
+
+	/// \brief Get buffer capacity
 	std::size_t capacity () const;
+
+	/// \brief Clear buffer; usedArea becomes empty
+	/// [unusable][usedArea][++++++freeArea]
+	///  becomes
+	/// [freeArea++++++++++++++++++++++++++]
 	void clear ();
+
+	/// \brief Move usedArea to the beginning of the buffer
+	/// [unusable][usedArea][freeArea]
+	///  becomes
+	/// [usedArea][freeArea++++++++++]
 	void coalesce ();
 
 private:
+	/// \brief Buffer
 	std::unique_ptr<char[]> m_buffer;
+
+	/// \brief Buffer size
 	std::size_t const m_size;
+
+	/// \brief Start of usedArea
 	std::size_t m_start = 0;
-	std::size_t m_end   = 0;
+	/// \brief Start of freeArea
+	std::size_t m_end = 0;
 };

include/log.h

@@ -32,9 +32,11 @@ class Log;
 using SharedLog = std::shared_ptr<Log>;
 using WeakLog   = std::weak_ptr<Log>;
 
+/// \brief Log object
 class Log
 {
 public:
+	/// \brief Log level
 	enum Level
 	{
 		DEBUG,
@@ -46,36 +48,72 @@ public:
 
 	~Log ();
 
+	/// \brief Draw log
 	void draw ();
 
+	/// \brief Create log
 	static SharedLog create ();
+
+	/// \brief Bind log
+	/// \param log_ Log to bind
 	static void bind (SharedLog log_);
 
+	/// \brief Add debug message to bound log
+	/// \param fmt_ Message format
 	__attribute__ ((format (printf, 1, 2))) static void debug (char const *fmt_, ...);
+	/// \brief Add info message to bound log
+	/// \param fmt_ Message format
 	__attribute__ ((format (printf, 1, 2))) static void info (char const *fmt_, ...);
+	/// \brief Add error message to bound log
+	/// \param fmt_ Message format
 	__attribute__ ((format (printf, 1, 2))) static void error (char const *fmt_, ...);
+	/// \brief Add command message to bound log
+	/// \param fmt_ Message format
 	__attribute__ ((format (printf, 1, 2))) static void command (char const *fmt_, ...);
+	/// \brief Add response message to bound log
+	/// \param fmt_ Message format
 	__attribute__ ((format (printf, 1, 2))) static void response (char const *fmt_, ...);
 
+	/// \brief Add log message to bound log
+	/// \param level_ Log level
+	/// \param fmt_ Message format
+	/// \param ap_ Message arguments
 	static void log (Level level_, char const *fmt_, va_list ap_);
+
+	/// \brief Add log message to bound log
+	/// \param level_ Log level
+	/// \param message_ Message to log
 	static void log (Level level_, std::string_view message_);
 
 private:
 	Log ();
 
+	/// \brief Add log message
+	/// \param level_ Log level
+	/// \param fmt_ Message format
+	/// \param ap_ Message arguments
 	void _log (Level level_, char const *fmt_, va_list ap_);
 
+	/// \brief Log message
 	struct Message
 	{
+		/// \brief Parameterized constructor
+		/// \param level_ Log level
+		/// \param message_ Log message
 		Message (Level const level_, std::string message_)
 		    : level (level_), message (std::move (message_))
 		{
 		}
 
+		/// \brief Log level
 		Level level;
+		/// \brief Log message
 		std::string message;
 	};
 
+	/// \brief Log messages
 	std::vector<Message> m_messages;
+
+	/// \brief Log lock
 	platform::Mutex m_lock;
 };

include/platform.h

@@ -31,65 +31,102 @@
 
 namespace platform
 {
+/// \brief Initialize platform
 bool init ();
+
+/// \brief Platform loop
 bool loop ();
+
+/// \brief Platform render
 void render ();
+
+/// \brief Deinitialize platform
 void exit ();
 
 #ifdef _3DS
+/// \brief Steady clock
 struct steady_clock
 {
-	using rep        = std::uint64_t;
-	using period     = std::ratio<1, SYSCLOCK_ARM11>;
-	using duration   = std::chrono::duration<rep, period>;
+	/// \brief Type representing number of ticks
+	using rep = std::uint64_t;
+
+	/// \brief Type representing ratio of clock period in seconds
+	using period = std::ratio<1, SYSCLOCK_ARM11>;
+
+	/// \brief Duration type
+	using duration = std::chrono::duration<rep, period>;
+
+	/// \brief Timestamp type
 	using time_point = std::chrono::time_point<steady_clock>;
 
+	/// \brief Whether clock is steady
 	constexpr static bool is_steady = true;
+
+	/// \brief Current timestamp
 	static time_point now () noexcept
 	{
 		return time_point (duration (svcGetSystemTick ()));
 	}
 };
 #else
+/// \brief Steady clock
 using steady_clock = std::chrono::steady_clock;
 #endif
 
+/// \brief Platform thread
 class Thread
 {
 public:
 	~Thread ();
 	Thread ();
 
+	/// \brief Parameterized constructor
+	/// \param func_ Thread entrypoint
 	Thread (std::function<void ()> func_);
 
 	Thread (Thread const &that_) = delete;
 
+	/// \brief Move constructor
+	/// \param that_ Object to move from
 	Thread (Thread &&that_);
 
 	Thread &operator= (Thread const &that_) = delete;
 
+	/// \brief Move assignment
+	/// \param that_ Object to move from
 	Thread &operator= (Thread &&that_);
 
+	/// \brief Join thread
 	void join ();
 
+	/// \brief Suspend current thread
+	/// \param timeout_ Minimum time to sleep
 	static void sleep (std::chrono::milliseconds timeout_);
 
 private:
 	class privateData_t;
+
+	/// \brief pimpl
 	std::unique_ptr<privateData_t> m_d;
 };
 
+/// \brief Platform mutex
 class Mutex
 {
 public:
 	~Mutex ();
 	Mutex ();
 
+	/// \brief Lock mutex
 	void lock ();
+
+	/// \brief Unlock mutex
 	void unlock ();
 
 private:
 	class privateData_t;
+
+	/// \brief pimpl
 	std::unique_ptr<privateData_t> m_d;
 };
 }

include/sockAddr.h

@@ -25,6 +25,7 @@
 
 #include <cstdint>
 
+/// \brief Socket address
 class SockAddr
 {
 public:
@@ -32,39 +33,72 @@ public:
 
 	SockAddr ();
 
+	/// \brief Copy constructor
+	/// \param that_ Object to copy
 	SockAddr (SockAddr const &that_);
 
+	/// \brief Move constructor
+	/// \param that_ Object to move from
 	SockAddr (SockAddr &&that_);
 
+	/// \brief Copy assignment
+	/// \param that_ Object to copy
 	SockAddr &operator= (SockAddr const &that_);
 
+	/// \brief Move assignment
+	/// \param that_ Object to move from
 	SockAddr &operator= (SockAddr &&that_);
 
+	/// \param Parameterized constructor
+	/// \param addr_ Address
 	SockAddr (struct sockaddr const &addr_);
 
+	/// \param Parameterized constructor
+	/// \param addr_ Address
 	SockAddr (struct sockaddr_in const &addr_);
 
 #ifndef _3DS
+	/// \param Parameterized constructor
+	/// \param addr_ Address
 	SockAddr (struct sockaddr_in6 const &addr_);
 #endif
 
+	/// \param Parameterized constructor
+	/// \param addr_ Address
 	SockAddr (struct sockaddr_storage const &addr_);
 
+	/// \param sockaddr_in cast operator
 	operator struct sockaddr_in const & () const;
 
 #ifndef _3DS
+	/// \param sockaddr_in6 cast operator
 	operator struct sockaddr_in6 const & () const;
 #endif
 
+	/// \param sockaddr_storage cast operator
 	operator struct sockaddr_storage const & () const;
 
+	/// \param sockaddr* cast operator
 	operator struct sockaddr * ();
+	/// \param sockaddr const* cast operator
 	operator struct sockaddr const * () const;
 
+	/// \brief Address port
 	std::uint16_t port () const;
+
+	/// \brief Address name
+	/// \param buffer_
+	/// \param size_ Size of buffer_
+	/// \retval buffer_ success
+	/// \retval nullptr failure
 	char const *name (char *buffer_, std::size_t size_) const;
+
+	/// \brief Address name
+	/// \retval nullptr failure
+	/// \note This function is not reentrant
 	char const *name () const;
 
 private:
+	/// \brief Address storage
 	struct sockaddr_storage m_addr = {};
 };

include/socket.h

@@ -30,53 +30,115 @@ class Socket;
 using UniqueSocket = std::unique_ptr<Socket>;
 using SharedSocket = std::shared_ptr<Socket>;
 
+/// \brief Socket object
 class Socket
 {
 public:
+	/// \brief Poll info
 	struct PollInfo
 	{
+		/// \brief Socket to poll
 		std::reference_wrapper<Socket> socket;
+
+		/// \brief Input events
 		int events;
+
+		/// \brief Output events
 		int revents;
 	};
 
 	~Socket ();
 
+	/// \brief Accept connection
 	UniqueSocket accept ();
+
+	/// \brief Whether socket is at out-of-band mark
 	int atMark ();
+
+	/// \brief Bind socket to address
+	/// \param addr_ Address to bind
 	bool bind (SockAddr const &addr_);
+
+	/// \brief Connect to a peer
+	/// \param addr_ Peer address
 	bool connect (SockAddr const &addr_);
+
+	/// \brief Listen for connections
+	/// \param backlog_ Queue size for incoming connections
 	bool listen (int backlog_);
+
+	/// \brief Shutdown socket
+	/// \param how_ Type of shutdown (\sa ::shutdown)
 	bool shutdown (int how_);
 
+	/// \brief Set linger option
+	/// \param enable_ Whether to enable linger
+	/// \param time_ Linger timeout
 	bool setLinger (bool enable_, std::chrono::seconds time_);
+
+	/// \brief Set non-blocking
+	/// \param nonBlocking_ Whether to set non-blocking
 	bool setNonBlocking (bool nonBlocking_ = true);
+
+	/// \brief Set reuse address in subsequent bind
+	/// \param reuse_ Whether to reuse address
 	bool setReuseAddress (bool reuse_ = true);
+
+	/// \brief Set recv buffer size
+	/// \param size_ Buffer size
 	bool setRecvBufferSize (std::size_t size_);
+
+	/// \brief Set send buffer size
+	/// \param size_ Buffer size
 	bool setSendBufferSize (std::size_t size_);
 
+	/// \brief Read data
+	/// \param buffer_ Output buffer
+	/// \param size_ Size to read
+	/// \param oob_ Whether to read from out-of-band
 	ssize_t read (void *buffer_, std::size_t size_, bool oob_ = false);
+
+	/// \brief Read data
+	/// \param buffer_ Output buffer
+	/// \param size_ Size to read
+	/// \param oob_ Whether to read from out-of-band
 	ssize_t read (IOBuffer &buffer_, bool oob_ = false);
+
+	/// \brief Write data
+	/// \param buffer_ Input buffer
+	/// \param size_ Size to write
 	ssize_t write (void const *buffer_, std::size_t size_);
+
+	/// \brief Write data
+	/// \param buffer_ Input buffer
+	/// \param size_ Size to write
 	ssize_t write (IOBuffer &buffer_);
 
+	/// \brief Local name
 	SockAddr const &sockName () const;
+	/// \brief Peer name
 	SockAddr const &peerName () const;
 
+	/// \brief Create socket
 	static UniqueSocket create ();
 
+	/// \brief Poll sockets
+	/// \param info_ Poll info
+	/// \param count_ Number of poll entries
+	/// \param timeout_ Poll timeout
 	static int poll (PollInfo *info_, std::size_t count_, std::chrono::milliseconds timeout_);
 
-	int fd () const
-	{
-		return m_fd;
-	}
-
 private:
 	Socket () = delete;
 
+	/// \brief Parameterized constructor
+	/// \param fd_ Socket fd
 	Socket (int fd_);
 
+	/// \brief Parameterized constructor
+	/// \param fd_ Socket fd
+	/// \param sockName_ Local name
+	/// \param peerName_ Peer name
 	Socket (int fd_, SockAddr const &sockName_, SockAddr const &peerName_);
 
 	Socket (Socket const &that_) = delete;
@@ -87,11 +149,17 @@ private:
 
 	Socket &operator= (Socket &&that_) = delete;
 
+	/// \param Local name
 	SockAddr m_sockName;
+	/// \param Peer name
 	SockAddr m_peerName;
 
+	/// \param Socket fd
 	int const m_fd;
 
+	/// \param Whether listening
 	bool m_listening : 1;
+
+	/// \param Whether connected
 	bool m_connected : 1;
 };

source/3ds/imgui_citro3d.cpp

@@ -33,37 +33,59 @@
 
 namespace
 {
+/// \brief 3DS font glyph ranges
 std::vector<ImWchar> s_fontRanges;
 
+/// \brief Clear color
 constexpr auto CLEAR_COLOR = 0x204B7AFF;
 
+/// \brief Display transfer flags
 constexpr auto DISPLAY_TRANSFER_FLAGS =
     GX_TRANSFER_FLIP_VERT (0) | GX_TRANSFER_OUT_TILED (0) | GX_TRANSFER_RAW_COPY (0) |
     GX_TRANSFER_IN_FORMAT (GX_TRANSFER_FMT_RGBA8) | GX_TRANSFER_OUT_FORMAT (GX_TRANSFER_FMT_RGB8) |
     GX_TRANSFER_SCALING (GX_TRANSFER_SCALE_NO);
 
-C3D_RenderTarget *s_top    = nullptr;
+/// \brief Top screen render target
+C3D_RenderTarget *s_top = nullptr;
+/// \brief Bottom screen render target
 C3D_RenderTarget *s_bottom = nullptr;
 
+/// \brief Vertex shader
 DVLB_s *s_vsh = nullptr;
+/// \brief Vertex shader program
 shaderProgram_s s_program;
 
+/// \brief Projection matrix uniform location
 int s_projLocation;
+/// \brief Top screen projection matrix
 C3D_Mtx s_projTop;
+/// \brief Bottom screen projection matrix
 C3D_Mtx s_projBottom;
 
+/// \brief System font textures
 std::vector<C3D_Tex> s_fontTextures;
+/// \brief Text scale
 float s_textScale;
 
+/// \brief Scissor test bounds
 std::uint32_t s_boundScissor[4];
+/// \brief Currently bound vertex data
 ImDrawVert *s_boundVtxData;
+/// \brief Currently bound texture
 C3D_Tex *s_boundTexture;
 
+/// \brief Vertex data buffer
 ImDrawVert *s_vtxData = nullptr;
+/// \brief Size of vertex data buffer
 std::size_t s_vtxSize = 0;
-ImDrawIdx *s_idxData  = nullptr;
+/// \brief Index data buffer
+ImDrawIdx *s_idxData = nullptr;
+/// \brief Size of index data buffer
 std::size_t s_idxSize = 0;
 
+/// \brief Get code point from glyph index
+/// \param font_ Font to search
+/// \param glyphIndex_ Glyph index
 std::uint32_t fontCodePointFromGlyphIndex (CFNT_s *const font_, int const glyphIndex_)
 {
 	for (auto cmap = fontGetInfo (font_)->cmap; cmap; cmap = cmap->next)
@@ -100,8 +122,11 @@ std::uint32_t fontCodePointFromGlyphIndex (CFNT_s *const font_, int const glyphI
 	return 0;
 }
 
+/// \brief Setup render state
+/// \param screen_ Whether top or bottom screen
 void setupRenderState (gfxScreen_t const screen_)
 {
+	// disable face culling
 	C3D_CullFace (GPU_CULL_NONE);
 
 	// configure attributes for user with vertex shader
@@ -111,14 +136,18 @@ void setupRenderState (gfxScreen_t const screen_)
 	AttrInfo_AddLoader (attrInfo, 1, GPU_FLOAT, 2);         // v1 = inUv
 	AttrInfo_AddLoader (attrInfo, 2, GPU_UNSIGNED_BYTE, 4); // v2 = inColor
 
+	// clear bindings
 	std::memset (s_boundScissor, 0xFF, sizeof (s_boundScissor));
 	s_boundVtxData = nullptr;
 	s_boundTexture = nullptr;
 
+	// bind program
 	C3D_BindProgram (&s_program);
 
+	// enable depth test
 	C3D_DepthTest (true, GPU_GREATER, GPU_WRITE_COLOR);
 
+	// enable alpha blending
 	C3D_AlphaBlend (GPU_BLEND_ADD,
 	    GPU_BLEND_ADD,
 	    GPU_SRC_ALPHA,
@@ -126,6 +155,7 @@ void setupRenderState (gfxScreen_t const screen_)
 	    GPU_SRC_ALPHA,
 	    GPU_ONE_MINUS_SRC_ALPHA);
 
+	// apply projection matrix
 	if (screen_ == GFX_TOP)
 		C3D_FVUnifMtx4x4 (GPU_VERTEX_SHADER, s_projLocation, &s_projTop);
 	else
@@ -135,36 +165,46 @@ void setupRenderState (gfxScreen_t const screen_)
 
 void imgui::citro3d::init ()
 {
-	// Setup back-end capabilities flags
+	// setup back-end capabilities flags
 	ImGuiIO &io = ImGui::GetIO ();
 
 	io.BackendRendererName = "citro3d";
 	io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;
 
+	// initialize citro3d
 	C3D_Init (C3D_DEFAULT_CMDBUF_SIZE);
 
+	// create top screen render target
 	s_top = C3D_RenderTargetCreate (240, 400, GPU_RB_RGBA8, GPU_RB_DEPTH24_STENCIL8);
 	C3D_RenderTargetSetOutput (s_top, GFX_TOP, GFX_LEFT, DISPLAY_TRANSFER_FLAGS);
 
+	// create bottom screen render target
 	s_bottom = C3D_RenderTargetCreate (240, 320, GPU_RB_RGBA8, GPU_RB_DEPTH24_STENCIL8);
 	C3D_RenderTargetSetOutput (s_bottom, GFX_BOTTOM, GFX_LEFT, DISPLAY_TRANSFER_FLAGS);
 
+	// load vertex shader
 	s_vsh = DVLB_ParseFile (
 	    const_cast<std::uint32_t *> (reinterpret_cast<std::uint32_t const *> (vshader_shbin)),
 	    vshader_shbin_size);
+
+	// initialize vertex shader program
 	shaderProgramInit (&s_program);
 	shaderProgramSetVsh (&s_program, &s_vsh->DVLE[0]);
 
+	// get projection matrix uniform location
 	s_projLocation = shaderInstanceGetUniformLocation (s_program.vertexShader, "proj");
 
+	// initialize projection matrices
 	Mtx_OrthoTilt (&s_projTop, 0.0f, 800.0f, 480.0f, 0.0f, -1.0f, 1.0f, false);
 	Mtx_OrthoTilt (&s_projBottom, 80.0f, 720.0f, 960.0f, 480.0f, -1.0f, 1.0f, false);
 
+	// allocate vertex data buffer
 	s_vtxSize = 65536;
 	s_vtxData = reinterpret_cast<ImDrawVert *> (linearAlloc (sizeof (ImDrawVert) * s_vtxSize));
 	if (!s_vtxData)
 		svcBreak (USERBREAK_PANIC);
 
+	// allocate index data buffer
 	s_idxSize = 65536;
 	s_idxData = reinterpret_cast<ImDrawIdx *> (linearAlloc (sizeof (ImDrawIdx) * s_idxSize));
 	if (!s_idxData)
@@ -184,6 +224,7 @@ void imgui::citro3d::init ()
 
 	s_textScale = 30.0f / glyphInfo->cellHeight;
 
+	// use system font sheets as citro3d textures
 	for (unsigned i = 0; i < glyphInfo->nSheets; ++i)
 	{
 		auto &tex = s_fontTextures[i];
@@ -201,9 +242,11 @@ void imgui::citro3d::init ()
 	}
 
 	{
+		// create texture for ImGui's white pixel
 		auto &tex = s_fontTextures[glyphInfo->nSheets];
 		C3D_TexInit (&tex, 8, 8, GPU_A4);
 
+		// fill texture with full alpha
 		std::uint32_t size;
 		auto data = C3D_Tex2DGetImagePtr (&tex, 0, &size);
 		if (!data || !size)
@@ -211,10 +254,12 @@ void imgui::citro3d::init ()
 		std::memset (data, 0xFF, size);
 	}
 
+	// get alternate character glyph
 	ImWchar alterChar = fontCodePointFromGlyphIndex (font, fontInfo->alterCharIndex);
 	if (!alterChar)
 		alterChar = '?';
 
+	// collect character map
 	std::vector<ImWchar> charSet;
 	for (auto cmap = fontInfo->cmap; cmap; cmap = cmap->next)
 	{
@@ -242,9 +287,11 @@ void imgui::citro3d::init ()
 	if (charSet.empty ())
 		svcBreak (USERBREAK_PANIC);
 
+	// deduplicate character map
 	std::sort (std::begin (charSet), std::end (charSet));
 	charSet.erase (std::unique (std::begin (charSet), std::end (charSet)), std::end (charSet));
 
+	// fill in font glyph ranges
 	auto it       = std::begin (charSet);
 	ImWchar start = *it++;
 	ImWchar prev  = start;
@@ -262,8 +309,11 @@ void imgui::citro3d::init ()
 	}
 	s_fontRanges.emplace_back (start);
 	s_fontRanges.emplace_back (prev);
+
+	// terminate glyph ranges
 	s_fontRanges.emplace_back (0);
 
+	// initialize font atlas
 	auto const atlas = ImGui::GetIO ().Fonts;
 	atlas->Clear ();
 	atlas->TexWidth        = glyphInfo->sheetWidth;
@@ -272,6 +322,7 @@ void imgui::citro3d::init ()
 	atlas->TexUvWhitePixel = ImVec2 (0.5f / 8.0f, glyphInfo->nSheets + 0.5f / 8.0f);
 	atlas->TexPixelsAlpha8 = static_cast<unsigned char *> (IM_ALLOC (1)); // dummy allocation
 
+	// initialize font config
 	ImFontConfig config;
 	config.FontData             = nullptr;
 	config.FontDataSize         = 0;
@@ -292,19 +343,20 @@ void imgui::citro3d::init ()
 	config.EllipsisChar         = 0x2026;
 	std::memset (config.Name, 0, sizeof (config.Name));
 
+	// create font
 	auto const imFont = IM_NEW (ImFont);
 	config.DstFont    = imFont;
 
+	// add config and font to atlas
 	atlas->ConfigData.push_back (config);
 	atlas->Fonts.push_back (imFont);
-	// atlas->CustomRectIds[0] = atlas->AddCustomRectRegular (0x80000000, 108 * 2 + 1, 27);
-	// atlas->CustomRects[0].X = 0;
-	// atlas->CustomRects[0].Y = 0;
 	atlas->SetTexID (s_fontTextures.data ());
 
+	// initialize font metrics
 	imFont->FallbackAdvanceX = fontInfo->defaultWidth.charWidth;
 	imFont->FontSize         = fontInfo->lineFeed;
 
+	// add glyphs to font
 	fontGlyphPos_s glyphPos;
 	for (auto const &code : charSet)
 	{
@@ -312,6 +364,7 @@ void imgui::citro3d::init ()
 		if (glyphIndex < 0)
 			svcBreak (USERBREAK_PANIC);
 
+		// calculate glyph metrics
 		fontCalcGlyphPos (&glyphPos,
 		    font,
 		    glyphIndex,
@@ -319,8 +372,8 @@ void imgui::citro3d::init ()
 		    1.0f,
 		    1.0f);
 
+		// convert to ImGui font metrics
 		ImFontGlyph glyph;
-
 		glyph.Codepoint = code;
 		glyph.AdvanceX  = glyphPos.xAdvance;
 		glyph.X0        = glyphPos.vtxcoord.left;
@@ -332,41 +385,48 @@ void imgui::citro3d::init ()
 		glyph.U1        = glyphPos.texcoord.right;
 		glyph.V1        = glyphPos.sheetIndex + glyphPos.texcoord.bottom;
 
+		// add glyph to font
 		imFont->Glyphs.push_back (glyph);
 		imFont->MetricsTotalSurface +=
 		    static_cast<int> ((glyph.U1 - glyph.U0) * atlas->TexWidth + 1.99f) *
 		    static_cast<int> ((glyph.V1 - glyph.V0) * atlas->TexHeight + 1.99f);
 	}
 
+	// build lookup table
 	imFont->BuildLookupTable ();
 
+	// finalize font
 	imFont->DisplayOffset.x = 0.0f;
 	imFont->DisplayOffset.y = fontInfo->ascent;
-
 	imFont->ContainerAtlas  = atlas;
 	imFont->ConfigData      = &atlas->ConfigData[0];
 	imFont->ConfigDataCount = 1;
 	imFont->FallbackChar    = alterChar;
 	imFont->EllipsisChar    = config.EllipsisChar;
-	imFont->Scale           = 1.0f;
+	imFont->Scale           = s_textScale;
 	imFont->Ascent          = fontInfo->ascent;
 	imFont->Descent         = 0.0f;
 }
 
 void imgui::citro3d::exit ()
 {
+	// free vertex/index data buffers
 	linearFree (s_idxData);
 	linearFree (s_vtxData);
 
+	// delete ImGui white pixel texture
 	assert (!s_fontTextures.empty ());
 	C3D_TexDelete (&s_fontTextures.back ());
 
+	// free shader program
 	shaderProgramFree (&s_program);
 	DVLB_Free (s_vsh);
 
+	// free render targets
 	C3D_RenderTargetDelete (s_bottom);
 	C3D_RenderTargetDelete (s_top);
 
+	// deinitialize citro3d
 	C3D_Fini ();
 }
 
@@ -377,9 +437,12 @@ void imgui::citro3d::newFrame ()
 void imgui::citro3d::render ()
 {
 	C3D_FrameBegin (C3D_FRAME_SYNCDRAW);
+
+	// clear frame/depth buffers
 	C3D_RenderTargetClear (s_top, C3D_CLEAR_ALL, CLEAR_COLOR, 0);
 	C3D_RenderTargetClear (s_bottom, C3D_CLEAR_ALL, CLEAR_COLOR, 0);
 
+	// get draw data
 	auto const drawData = ImGui::GetDrawData ();
 	if (drawData->CmdListsCount <= 0)
 	{
@@ -387,6 +450,7 @@ void imgui::citro3d::render ()
 		return;
 	}
 
+	// get framebuffer dimensions
 	unsigned width  = drawData->DisplaySize.x * drawData->FramebufferScale.x;
 	unsigned height = drawData->DisplaySize.y * drawData->FramebufferScale.y;
 	if (width <= 0 || height <= 0)
@@ -395,6 +459,7 @@ void imgui::citro3d::render ()
 		return;
 	}
 
+	// check if we need to grow vertex data buffer
 	if (s_vtxSize < static_cast<std::size_t> (drawData->TotalVtxCount))
 	{
 		linearFree (s_vtxData);
@@ -406,6 +471,7 @@ void imgui::citro3d::render ()
 			svcBreak (USERBREAK_PANIC);
 	}
 
+	// check if we need to grow index data buffer
 	if (s_idxSize < static_cast<std::size_t> (drawData->TotalIdxCount))
 	{
 		// add 10% to avoid growing many frames in a row
@@ -415,7 +481,7 @@ void imgui::citro3d::render ()
 			svcBreak (USERBREAK_PANIC);
 	}
 
-	// Will project scissor/clipping rectangles into framebuffer space
+	// will project scissor/clipping rectangles into framebuffer space
 	// (0,0) unless using multi-viewports
 	auto const clipOff = drawData->DisplayPos;
 	// (1,1) unless using retina display which are often (2,2)
@@ -427,11 +493,14 @@ void imgui::citro3d::render ()
 	for (int i = 0; i < drawData->CmdListsCount; ++i)
 	{
 		auto const &cmdList = *drawData->CmdLists[i];
+
+		// double check that we don't overrun vertex/index data buffers
 		if (s_vtxSize - offsetVtx < static_cast<std::size_t> (cmdList.VtxBuffer.Size))
 			svcBreak (USERBREAK_PANIC);
 		if (s_idxSize - offsetIdx < static_cast<std::size_t> (cmdList.IdxBuffer.Size))
 			svcBreak (USERBREAK_PANIC);
 
+		// copy vertex/index data into buffers
 		std::memcpy (&s_vtxData[offsetVtx],
 		    cmdList.VtxBuffer.Data,
 		    sizeof (ImDrawVert) * cmdList.VtxBuffer.Size);
@@ -455,7 +524,7 @@ void imgui::citro3d::render ()
 		offsetVtx = 0;
 		offsetIdx = 0;
 
-		// Render command lists
+		// render command lists
 		for (int i = 0; i < drawData->CmdListsCount; ++i)
 		{
 			auto const &cmdList = *drawData->CmdLists[i];
@@ -463,7 +532,7 @@ void imgui::citro3d::render ()
 			{
 				if (cmd.UserCallback)
 				{
-					// User callback, registered via ImDrawList::AddCallback()
+					// user callback, registered via ImDrawList::AddCallback()
 					// (ImDrawCallback_ResetRenderState is a special callback value used by the user
 					// to request the renderer to reset render state.)
 					if (cmd.UserCallback == ImDrawCallback_ResetRenderState)
@@ -473,7 +542,7 @@ void imgui::citro3d::render ()
 				}
 				else
 				{
-					// Project scissor/clipping rectangles into framebuffer space
+					// project scissor/clipping rectangles into framebuffer space
 					ImVec4 clip;
 					clip.x = (cmd.ClipRect.x - clipOff.x) * clipScale.x;
 					clip.y = (cmd.ClipRect.y - clipOff.y) * clipScale.y;
@@ -486,6 +555,10 @@ void imgui::citro3d::render ()
 						clip.x = 0.0f;
 					if (clip.y < 0.0f)
 						clip.y = 0.0f;
+					if (clip.z > width)
+						clip.z = width;
+					if (clip.w > height)
+						clip.z = height;
 
 					if (screen == GFX_TOP)
 					{
@@ -493,12 +566,22 @@ void imgui::citro3d::render ()
 						if (clip.y > 240.0f)
 							continue;
 
+						// convert from framebuffer space to screen space (3DS screen rotation)
 						auto const x1 = std::clamp<unsigned> (240.0f - clip.w, 0, 240);
 						auto const y1 = std::clamp<unsigned> (400.0f - clip.z, 0, 400);
 						auto const x2 = std::clamp<unsigned> (240.0f - clip.y, 0, 240);
 						auto const y2 = std::clamp<unsigned> (400.0f - clip.x, 0, 400);
 
-						C3D_SetScissor (GPU_SCISSOR_NORMAL, x1, y1, x2, y2);
+						// check if scissor needs to be updated
+						if (s_boundScissor[0] != x1 || s_boundScissor[1] != y1 ||
+						    s_boundScissor[2] != x2 || s_boundScissor[3] != y2)
+						{
+							s_boundScissor[0] = x1;
+							s_boundScissor[1] = y1;
+							s_boundScissor[2] = x2;
+							s_boundScissor[3] = y2;
+							C3D_SetScissor (GPU_SCISSOR_NORMAL, x1, y1, x2, y2);
+						}
 					}
 					else
 					{
@@ -514,11 +597,14 @@ void imgui::citro3d::render ()
 						if (clip.x > 360.0f)
 							continue;
 
+						// convert from framebuffer space to screen space
+						// (3DS screen rotation + bottom screen offset)
 						auto const x1 = std::clamp<unsigned> (480.0f - clip.w, 0, 240);
 						auto const y1 = std::clamp<unsigned> (360.0f - clip.z, 0, 320);
 						auto const x2 = std::clamp<unsigned> (480.0f - clip.y, 0, 240);
 						auto const y2 = std::clamp<unsigned> (360.0f - clip.x, 0, 320);
 
+						// check if scissor needs to be updated
 						if (s_boundScissor[0] != x1 || s_boundScissor[1] != y1 ||
 						    s_boundScissor[2] != x2 || s_boundScissor[3] != y2)
 						{
@@ -530,36 +616,41 @@ void imgui::citro3d::render ()
 						}
 					}
 
+					// check if we need to update vertex data binding
 					auto const vtxData = &s_vtxData[cmd.VtxOffset + offsetVtx];
 					if (vtxData != s_boundVtxData)
 					{
-						s_boundVtxData     = &s_vtxData[cmd.VtxOffset + offsetVtx];
+						s_boundVtxData     = vtxData;
 						auto const bufInfo = C3D_GetBufInfo ();
 						BufInfo_Init (bufInfo);
-						BufInfo_Add (bufInfo, s_boundVtxData, sizeof (ImDrawVert), 3, 0x210);
+						BufInfo_Add (bufInfo, vtxData, sizeof (ImDrawVert), 3, 0x210);
 					}
 
+					// check if we need to update texture binding
 					auto tex = static_cast<C3D_Tex *> (cmd.TextureId);
 					if (tex == s_fontTextures.data ())
 					{
 						assert (cmd.ElemCount % 3 == 0);
 
-						// TODO get by idx not consecutive vtx
+						// get sheet number from uv coords
 						auto const getSheet = [] (auto const vtx_, auto const idx_) {
 							unsigned const sheet = std::min (
 							    {vtx_[idx_[0]].uv.y, vtx_[idx_[1]].uv.y, vtx_[idx_[2]].uv.y});
+
+							// assert that these three vertices use the same sheet
 							for (unsigned i = 0; i < 3; ++i)
 								assert (vtx_[idx_[i]].uv.y - sheet <= 1.0f);
 							return sheet;
 						};
 
+						// initialize texture binding
 						unsigned boundSheet = getSheet (&s_vtxData[cmd.VtxOffset + offsetVtx],
 						    &s_idxData[cmd.IdxOffset + offsetIdx]);
+						C3D_TexBind (0, &s_fontTextures[boundSheet]);
 
 						unsigned offset = 0;
 
-						C3D_TexBind (0, &s_fontTextures[boundSheet]);
-
+						// update texture environment for non-image drawing
 						auto const env = C3D_GetTexEnv (0);
 						C3D_TexEnvInit (env);
 						C3D_TexEnvSrc (
@@ -569,23 +660,30 @@ void imgui::citro3d::render ()
 						    env, C3D_Alpha, GPU_TEXTURE0, GPU_PRIMARY_COLOR, GPU_PRIMARY_COLOR);
 						C3D_TexEnvFunc (env, C3D_Alpha, GPU_MODULATE);
 
+						// process one triangle at a time
 						for (unsigned i = 3; i < cmd.ElemCount; i += 3)
 						{
+							// get sheet for this triangle
 							unsigned const sheet = getSheet (&s_vtxData[cmd.VtxOffset + offsetVtx],
 							    &s_idxData[cmd.IdxOffset + offsetIdx + i]);
+
+							// check if we're changing textures
 							if (boundSheet != sheet)
 							{
+								// draw everything up until now
 								C3D_DrawElements (GPU_TRIANGLES,
 								    i - offset,
 								    C3D_UNSIGNED_SHORT,
 								    &s_idxData[cmd.IdxOffset + offsetIdx + offset]);
 
+								// bind texture for next draw call
 								boundSheet = sheet;
 								offset     = i;
 								C3D_TexBind (0, &s_fontTextures[boundSheet]);
 							}
 						}
 
+						// draw the final set of triangles
 						assert ((cmd.ElemCount - offset) % 3 == 0);
 						C3D_DrawElements (GPU_TRIANGLES,
 						    cmd.ElemCount - offset,
@@ -594,9 +692,13 @@ void imgui::citro3d::render ()
 					}
 					else
 					{
+						// drawing an image; check if we need to change texture binding
 						if (tex != s_boundTexture)
 						{
+							// bind new texture
 							C3D_TexBind (0, tex);
+
+							// update texture environment for drawing images
 							auto const env = C3D_GetTexEnv (0);
 							C3D_TexEnvInit (env);
 							C3D_TexEnvSrc (
@@ -604,6 +706,7 @@ void imgui::citro3d::render ()
 							C3D_TexEnvFunc (env, C3D_Both, GPU_MODULATE);
 						}
 
+						// draw triangles
 						C3D_DrawElements (GPU_TRIANGLES,
 						    cmd.ElemCount,
 						    C3D_UNSIGNED_SHORT,

source/3ds/imgui_citro3d.h

@@ -24,10 +24,14 @@ namespace imgui
 {
 namespace citro3d
 {
+/// \brief Initialize citro3d
 void init ();
+/// \brief Deinitialize citro3d
 void exit ();
 
+/// \brief Prepare citro3d for a new frame
 void newFrame ();
+/// \brief Render ImGui draw list
 void render ();
 }
 }

source/3ds/imgui_ctru.cpp

@@ -23,6 +23,7 @@
 #include "imgui.h"
 
 #include "fs.h"
+#include "platform.h"
 
 #include <3ds.h>
 
@@ -35,32 +36,45 @@ using namespace std::chrono_literals;
 
 namespace
 {
-constexpr auto SCREEN_WIDTH  = 400.0f;
+/// \brief Screen width
+constexpr auto SCREEN_WIDTH = 400.0f;
+/// \brief Screen height
 constexpr auto SCREEN_HEIGHT = 480.0f;
 
+/// \brief Clipboard
 std::string s_clipboard;
 
+/// \brief Get clipboard text callback
+/// \param userData_ User data
 char const *getClipboardText (void *const userData_)
 {
 	(void)userData_;
 	return s_clipboard.c_str ();
 }
 
+/// \brief Set clipboard text callback
+/// \param userData_ User data
+/// \param text_ Clipboard text
 void setClipboardText (void *const userData_, char const *const text_)
 {
 	(void)userData_;
 	s_clipboard = text_;
 }
 
+/// \brief Update touch position
+/// \param io_ ImGui IO
 void updateTouch (ImGuiIO &io_)
 {
-	if (!((hidKeysDown () | hidKeysHeld ()) & KEY_TOUCH))
+	// check if touchpad was touched
+	if (!(hidKeysHeld () & KEY_TOUCH))
 	{
+		// set mouse cursor off-screen
 		io_.MousePos     = ImVec2 (-10.0f, -10.0f);
 		io_.MouseDown[0] = false;
 		return;
 	}
 
+	// read touch position
 	touchPosition pos;
 	hidTouchRead (&pos);
 
@@ -69,8 +83,11 @@ void updateTouch (ImGuiIO &io_)
 	io_.MouseDown[0] = true;
 }
 
+/// \brief Update gamepad inputs
+/// \param io_ ImGui IO
 void updateGamepads (ImGuiIO &io_)
 {
+	// clear navigation inputs
 	std::memset (io_.NavInputs, 0, sizeof (io_.NavInputs));
 
 	auto const buttonMapping = {
@@ -88,6 +105,7 @@ void updateGamepads (ImGuiIO &io_)
 	    std::make_pair (KEY_DLEFT, ImGuiNavInput_DpadLeft),
 	};
 
+	// read buttons from 3DS
 	auto const keys = hidKeysHeld ();
 	for (auto const &[in, out] : buttonMapping)
 	{
@@ -95,6 +113,7 @@ void updateGamepads (ImGuiIO &io_)
 			io_.NavInputs[out] = 1.0f;
 	}
 
+	// update joystick
 	circlePosition cpad;
 	auto const analogMapping = {
 	    std::make_tuple (std::ref (cpad.dx), ImGuiNavInput_LStickLeft, -0.3f, -0.9f),
@@ -103,12 +122,12 @@ void updateGamepads (ImGuiIO &io_)
 	    std::make_tuple (std::ref (cpad.dy), ImGuiNavInput_LStickDown, -0.3f, -0.9f),
 	};
 
+	// read left joystick from circle pad
 	hidCircleRead (&cpad);
 	for (auto const &[in, out, min, max] : analogMapping)
 	{
 		auto const value   = in / static_cast<float> (0x9C);
-		auto const v       = std::min (1.0f, (value - min) / (max - min));
-		io_.NavInputs[out] = std::max (io_.NavInputs[out], v);
+		io_.NavInputs[out] = std::clamp ((value - min) / (max - min), 0.0f, 1.0f);
 	}
 }
 }
@@ -117,17 +136,21 @@ bool imgui::ctru::init ()
 {
 	ImGuiIO &io = ImGui::GetIO ();
 
+	// disable imgui.ini file
 	io.IniFilename = nullptr;
 
+	// setup config flags
 	io.ConfigFlags |= ImGuiConfigFlags_IsTouchScreen;
 	io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;
 
+	// setup platform backend
 	io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
+	io.BackendPlatformName = "3DS";
 
-	io.BackendPlatformName = "3ds";
-
+	// disable mouse cursor
 	io.MouseDrawCursor = false;
 
+	// clipboard callbacks
 	io.SetClipboardTextFn = setClipboardText;
 	io.GetClipboardTextFn = getClipboardText;
 	io.ClipboardUserData  = nullptr;
@@ -139,19 +162,21 @@ void imgui::ctru::newFrame ()
 {
 	ImGuiIO &io = ImGui::GetIO ();
 
+	// check that font was built
 	IM_ASSERT (io.Fonts->IsBuilt () &&
 	           "Font atlas not built! It is generally built by the renderer back-end. Missing call "
 	           "to renderer _NewFrame() function?");
 
+	// setup display metrics
 	io.DisplaySize             = ImVec2 (SCREEN_WIDTH * 2.0f, SCREEN_HEIGHT * 2.0f);
 	io.DisplayFramebufferScale = ImVec2 (0.5f, 0.5f);
 
-	// Setup time step
-	static auto const start = svcGetSystemTick ();
+	// time step
+	static auto const start = platform::steady_clock::now ();
 	static auto prev        = start;
-	auto const now          = svcGetSystemTick ();
+	auto const now          = platform::steady_clock::now ();
 
-	io.DeltaTime = (now - prev) / static_cast<float> (SYSCLOCK_ARM11);
+	io.DeltaTime = std::chrono::duration<float> (now - prev).count ();
 	prev         = now;
 
 	updateTouch (io);

source/3ds/imgui_ctru.h

@@ -24,9 +24,12 @@ namespace imgui
 {
 namespace ctru
 {
+/// \brief Initialize 3ds platform
 bool init ();
+/// \brief Deinitialize 3ds platform
 void exit ();
 
+/// \brief Prepare 3ds for a new frame
 void newFrame ();
 }
 }

source/3ds/platform.cpp

@@ -41,33 +41,45 @@
 
 namespace
 {
-constexpr auto STACK_SIZE      = 32768;
-constexpr auto SOCU_ALIGN      = 0x1000;
+/// \brief Thread stack size
+constexpr auto STACK_SIZE = 0x8000;
+/// \brief soc:u buffer alignment
+constexpr auto SOCU_ALIGN = 0x1000;
+/// \brief soc:u buffer size
 constexpr auto SOCU_BUFFERSIZE = 0x100000;
 
 static_assert (SOCU_BUFFERSIZE % SOCU_ALIGN == 0);
 
+/// \brief Whether soc:u is active
 bool s_socuActive = false;
+/// \brief soc:u buffer
 u32 *s_socuBuffer = nullptr;
 
+/// \brief Texture atlas
 C3D_Tex s_gfxTexture;
+/// \brief Texture atlas metadata
 Tex3DS_Texture s_gfxT3x;
 
+/// \brief Start network
 void startNetwork ()
 {
+	// check if already active
 	if (s_socuActive)
 		return;
 
+	// get wifi status
 	std::uint32_t wifi = 0;
 	if (R_FAILED (ACU_GetWifiStatus (&wifi)) || !wifi)
 		return;
 
+	// allocate soc:u buffer
 	if (!s_socuBuffer)
 		s_socuBuffer = static_cast<u32 *> (::memalign (SOCU_ALIGN, SOCU_BUFFERSIZE));
 
 	if (!s_socuBuffer)
 		return;
 
+	// initialize soc:u service
 	if (R_FAILED (socInit (s_socuBuffer, SOCU_BUFFERSIZE)))
 		return;
 
@@ -75,27 +87,34 @@ void startNetwork ()
 	Log::info ("Wifi connected\n");
 }
 
+/// \brief Draw citro3d logo
 void drawLogo ()
 {
+	// get citro3d logo subtexture
 	auto subTex = Tex3DS_GetSubTexture (s_gfxT3x, gfx_c3dlogo_idx);
 
+	// get framebuffer metrics
 	ImGuiIO &io             = ImGui::GetIO ();
 	auto const screenWidth  = io.DisplaySize.x;
 	auto const screenHeight = io.DisplaySize.y;
 	auto const logoWidth    = subTex->width / io.DisplayFramebufferScale.x;
 	auto const logoHeight   = subTex->height / io.DisplayFramebufferScale.y;
 
+	// calculate top screen coords
 	auto const x1 = (screenWidth - logoWidth) / 2.0f;
 	auto const x2 = x1 + logoWidth;
 	auto const y1 = (screenHeight / 2.0f - logoHeight) / 2.0f;
 	auto const y2 = y1 + logoHeight;
 
+	// calculate uv coords
 	auto const uv1 = ImVec2 (subTex->left, subTex->top);
 	auto const uv2 = ImVec2 (subTex->right, subTex->bottom);
 
+	// draw to top screen
 	ImGui::GetBackgroundDrawList ()->AddImage (
 	    &s_gfxTexture, ImVec2 (x1, y1), ImVec2 (x2, y2), uv1, uv2);
 
+	// draw to bottom screen
 	ImGui::GetBackgroundDrawList ()->AddImage (&s_gfxTexture,
 	    ImVec2 (x1, y1 + screenHeight / 2.0f),
 	    ImVec2 (x2, y2 + screenHeight / 2.0f),
@@ -103,6 +122,7 @@ void drawLogo ()
 	    uv2);
 }
 
+/// \brief Draw status
 void drawStatus ()
 {
 	constexpr unsigned batteryLevels[] = {
@@ -121,6 +141,7 @@ void drawStatus ()
 	    gfx_wifi3_idx,
 	};
 
+	// get battery charging state or level
 	static u8 charging = 0;
 	static u8 level    = 5;
 	PTMU_GetBatteryChargeState (&charging);
@@ -136,33 +157,43 @@ void drawStatus ()
 
 	auto const screenWidth = io.DisplaySize.x;
 
+	// calculate battery icon metrics
 	auto const battery =
 	    Tex3DS_GetSubTexture (s_gfxT3x, charging ? gfx_batteryCharge_idx : batteryLevels[level]);
 	auto const batteryWidth  = battery->width / io.DisplayFramebufferScale.x;
 	auto const batteryHeight = battery->height / io.DisplayFramebufferScale.y;
 
+	// calculate battery icon position
 	auto const p1 = ImVec2 (screenWidth - batteryWidth, 0.0f);
 	auto const p2 = ImVec2 (screenWidth, batteryHeight);
 
+	// calculate battery icon uv coords
 	auto const uv1 = ImVec2 (battery->left, battery->top);
 	auto const uv2 = ImVec2 (battery->right, battery->bottom);
 
+	// draw battery icon
 	ImGui::GetForegroundDrawList ()->AddImage (&s_gfxTexture, p1, p2, uv1, uv2);
 
+	// get wifi strength
 	auto const wifiStrength = osGetWifiStrength ();
 
+	// calculate wifi icon metrics
 	auto const wifi       = Tex3DS_GetSubTexture (s_gfxT3x, wifiLevels[wifiStrength]);
 	auto const wifiWidth  = wifi->width / io.DisplayFramebufferScale.x;
 	auto const wifiHeight = wifi->height / io.DisplayFramebufferScale.y;
 
+	// calculate wifi icon position
 	auto const p3 = ImVec2 (p1.x - wifiWidth - 4.0f, 0.0f);
 	auto const p4 = ImVec2 (p1.x - 4.0f, wifiHeight);
 
+	// calculate wifi icon uv coords
 	auto const uv3 = ImVec2 (wifi->left, wifi->top);
 	auto const uv4 = ImVec2 (wifi->right, wifi->bottom);
 
+	// draw wifi icon
 	ImGui::GetForegroundDrawList ()->AddImage (&s_gfxTexture, p3, p4, uv3, uv4);
 
+	// draw current timestamp
 	char buffer[64];
 	auto const now = std::time (nullptr);
 	std::strftime (buffer, sizeof (buffer), "%H:%M:%S", std::localtime (&now));
@@ -173,6 +204,7 @@ void drawStatus ()
 
 bool platform::init ()
 {
+	// enable New 3DS speedup
 	osSetSpeedupEnable (true);
 
 	acInit ();
@@ -187,18 +219,13 @@ bool platform::init ()
 	std::setvbuf (stderr, nullptr, _IOLBF, 0);
 #endif
 
-	IMGUI_CHECKVERSION ();
-	ImGui::CreateContext ();
-
 	if (!imgui::ctru::init ())
-	{
-		ImGui::DestroyContext ();
 		return false;
-	}
 
 	imgui::citro3d::init ();
 
 	{
+		// load texture atlas
 		fs::File file;
 		if (!file.open ("romfs:/gfx.t3x"))
 			svcBreak (USERBREAK_PANIC);
@@ -206,9 +233,9 @@ bool platform::init ()
 		s_gfxT3x = Tex3DS_TextureImportStdio (file, &s_gfxTexture, nullptr, true);
 		if (!s_gfxT3x)
 			svcBreak (USERBREAK_PANIC);
-	}
 
-	C3D_TexSetFilter (&s_gfxTexture, GPU_LINEAR, GPU_LINEAR);
+		C3D_TexSetFilter (&s_gfxTexture, GPU_LINEAR, GPU_LINEAR);
+	}
 
 	return true;
 }
@@ -247,8 +274,6 @@ void platform::exit ()
 	Tex3DS_TextureFree (s_gfxT3x);
 	C3D_TexDelete (&s_gfxTexture);
 
-	ImGui::DestroyContext ();
-
 	imgui::citro3d::exit ();
 	imgui::ctru::exit ();
 
@@ -262,6 +287,7 @@ void platform::exit ()
 }
 
 ///////////////////////////////////////////////////////////////////////////
+/// \brief Platform thread pimpl
 class platform::Thread::privateData_t
 {
 public:
@@ -271,6 +297,8 @@ public:
 			threadFree (thread);
 	}
 
+	/// \brief Parameterized constructor
+	/// \param func_ Thread entry point
 	privateData_t (std::function<void ()> func_) : thread (nullptr)
 	{
 		s32 priority = 0x30;
@@ -280,13 +308,18 @@ public:
 		assert (thread);
 	}
 
+	/// \brief Underlying thread entry point
+	/// \param arg_ Thread pimpl object
 	static void threadFunc (void *const arg_)
 	{
+		// call passed-in entry point
 		auto const t = static_cast<privateData_t *> (arg_);
 		t->func ();
 	}
 
+	/// \brief Underlying thread
 	::Thread thread = nullptr;
+	/// \brief Thread entry point
 	std::function<void ()> func;
 };
 
@@ -323,9 +356,11 @@ void platform::Thread::sleep (std::chrono::milliseconds const timeout_)
 }
 
 ///////////////////////////////////////////////////////////////////////////
+/// \brief Platform mutex pimpl
 class platform::Mutex::privateData_t
 {
 public:
+	/// \brief Underlying mutex
 	LightLock mutex;
 };
 

source/3ds/vshader.v.pica

@@ -18,26 +18,28 @@
 ; You should have received a copy of the GNU General Public License
 ; along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-; Example PICA200 vertex shader
+; ImGui PICA200 vertex shader
 
-; Uniforms
+; uniforms
+; Projection matrix
 .fvec proj[4]
 
-; Constants
+; constants
+; [1.0, 0.0, 1.0/255.0, 0.0]
 .constf constants(1.0, 0.0, 0.00392156862745, 0.0)
 
-; Outputs
+; outputs
 .out outPos   position
 .out outUv    texcoord0
 .out outColor color
 
-; Inputs (defined as aliases for convenience)
+; inputs (defined as aliases for convenience)
 .alias inPos   v0
 .alias inUv    v1
 .alias inColor v2
 
 .proc main
-	; Force inPos.z = 0.0, inPos.w = 1.0
+	; force inPos.z = 0.0, inPos.w = 1.0
 	mov r0.xy, inPos.xy
 	mov r0.zw, constants.yx
 
@@ -56,6 +58,6 @@
 	; outColor = inColor
 	mov outColor, r1
 
-	; We're finished
+	; we're finished
 	end
 .end

source/fs.cpp

@@ -45,28 +45,34 @@ std::string fs::printSize (std::uint64_t const size_)
 	         // clang-format on
 	     })
 	{
+		// get the integral portion of the number
 		auto const whole = size_ / bin;
 		if (size_ >= 100 * bin)
 		{
+			// >= 100, print xxxXiB
 			std::sprintf (buffer, "%" PRIu64 "%s", whole, name);
 			return buffer;
 		}
 
+		// get the fractional portion of the number
 		auto const frac = size_ - whole * bin;
 		if (size_ >= 10 * bin)
 		{
+			// >= 10, print xx.xXiB
 			std::sprintf (buffer, "%" PRIu64 ".%" PRIu64 "%s", whole, frac * 10 / bin, name);
 			return buffer;
 		}
 
 		if (size_ >= 1000 * (bin / KiB))
 		{
+			// >= 1000 of lesser bin, print x.xxXiB
 			std::sprintf (buffer, "%" PRIu64 ".%02" PRIu64 "%s", whole, frac * 100 / bin, name);
 			return buffer;
 		}
 	}
 
-	std::sprintf (buffer, "%" PRIu64, size_);
+	// < 1KiB, just print the number
+	std::sprintf (buffer, "%" PRIu64 "B", size_);
 	return buffer;
 }
 
@@ -207,5 +213,6 @@ void fs::Dir::close ()
 
 struct dirent *fs::Dir::read ()
 {
+	errno = 0;
 	return ::readdir (m_dp.get ());
 }

source/ftpServer.cpp

@@ -36,6 +36,7 @@
 using namespace std::chrono_literals;
 
 #ifndef _3DS
+/// \todo Investigate multithreading on 3DS
 #define MULTITHREADED 1
 #else
 #define MULTITHREADED 0
@@ -43,17 +44,24 @@ using namespace std::chrono_literals;
 
 namespace
 {
-auto const s_startTime = std::chrono::system_clock::to_time_t (std::chrono::system_clock::now ());
+/// \brief Application start time
+auto const s_startTime = std::time (nullptr);
+
+/// \brief Mutex for s_freeSpace
 platform::Mutex s_lock;
+
+/// \brief Free space string
 std::string s_freeSpace;
 }
 
 ///////////////////////////////////////////////////////////////////////////
 FtpServer::~FtpServer ()
 {
+#if MULTITHREADED
 	m_quit = true;
 
 	m_thread.join ();
+#endif
 }
 
 FtpServer::FtpServer (std::uint16_t const port_)
@@ -118,6 +126,7 @@ void FtpServer::draw ()
 	ImGui::Separator ();
 
 #ifdef _3DS
+	// Fill rest of top screen window
 	ImGui::BeginChild ("Logs", ImVec2 (0, 0), false, ImGuiWindowFlags_HorizontalScrollbar);
 #else
 	ImGui::BeginChild ("Logs", ImVec2 (0, 200), false, ImGuiWindowFlags_HorizontalScrollbar);
@@ -214,6 +223,7 @@ void FtpServer::handleStopButton ()
 void FtpServer::loop ()
 {
 	{
+		// poll listen socket
 		auto const lock = std::scoped_lock (m_lock);
 		if (m_socket)
 		{
@@ -227,6 +237,7 @@ void FtpServer::loop ()
 		}
 	}
 
+	// remove dead sessions
 	for (auto it = std::begin (m_sessions); it != std::end (m_sessions);)
 	{
 		auto const &session = *it;
@@ -236,9 +247,11 @@ void FtpServer::loop ()
 			++it;
 	}
 
+	// poll sessions
 	if (!m_sessions.empty ())
 		FtpSession::poll (m_sessions);
 #if MULTITHREADED
+	// avoid busy polling in background thread
 	else
 		platform::Thread::sleep (16ms);
 #endif
@@ -246,6 +259,7 @@ void FtpServer::loop ()
 
 void FtpServer::threadFunc ()
 {
+	// bind log for this thread
 	Log::bind (m_log);
 
 	while (!m_quit)

source/ftpSession.cpp

@@ -55,8 +55,13 @@ using namespace std::chrono_literals;
 
 namespace
 {
+/// \brief Parse command
+/// \param buffer_ Buffer to parse
+/// \param size_ Size of buffer
+/// \returns {delimiterPos, nextPos}
 std::pair<char *, char *> parseCommand (char *const buffer_, std::size_t const size_)
 {
+	// look for \r\n or \n delimiter
 	auto const end = &buffer_[size_];
 	for (auto p = buffer_; p < end; ++p)
 	{
@@ -70,6 +75,9 @@ std::pair<char *, char *> parseCommand (char *const buffer_, std::size_t const s
 	return {nullptr, nullptr};
 }
 
+/// \brief Decode path
+/// \param buffer_ Buffer to decode
+/// \param size_ Size of buffer
 void decodePath (char *const buffer_, std::size_t const size_)
 {
 	auto const end = &buffer_[size_];
@@ -81,6 +89,9 @@ void decodePath (char *const buffer_, std::size_t const size_)
 	}
 }
 
+/// \brief Encode path
+/// \param buffer_ Buffer to encode
+/// \param quotes_ Whether to encode quotes
 std::string encodePath (std::string_view const buffer_, bool const quotes_ = false)
 {
 	// check if the buffer has \n
@@ -104,13 +115,16 @@ std::string encodePath (std::string_view const buffer_, bool const quotes_ = fal
 		} while (p);
 	}
 
+	// if nothing needs escaping, return it as-is
 	if (!lf && !numQuotes)
 		return std::string (buffer_);
 
+	// reserve output buffer
 	std::string path (buffer_.size () + numQuotes, '\0');
 	auto in  = buffer_.data ();
 	auto out = path.data ();
 
+	// encode into the output buffer
 	while (in < end)
 	{
 		if (*in == '\n')
@@ -132,6 +146,8 @@ std::string encodePath (std::string_view const buffer_, bool const quotes_ = fal
 	return path;
 }
 
+/// \brief Get parent directory name of a path
+/// \param path_ Path to get parent of
 std::string dirName (std::string_view const path_)
 {
 	// remove last path component
@@ -142,6 +158,8 @@ std::string dirName (std::string_view const path_)
 	return dir;
 }
 
+/// \brief Resolve path
+/// \param path_ Path to resolve
 std::string resolvePath (std::string_view const path_)
 {
 	assert (!path_.empty ());
@@ -209,6 +227,9 @@ std::string resolvePath (std::string_view const path_)
 	return outPath;
 }
 
+/// \brief Build path from a parent and child
+/// \param cwd_ Parent directory
+/// \param args_ Child component
 std::string buildPath (std::string_view const cwd_, std::string_view const args_)
 {
 	// absolute path
@@ -222,6 +243,9 @@ std::string buildPath (std::string_view const cwd_, std::string_view const args_
 	return std::string (cwd_) + '/' + std::string (args_);
 }
 
+/// \brief Build resolved path from a parent and child
+/// \param cwd_ Parent directory
+/// \param args_ Child component
 std::string buildResolvedPath (std::string_view const cwd_, std::string_view const args_)
 {
 	return resolvePath (buildPath (cwd_, args_));

source/ioBuffer.cpp

@@ -29,6 +29,7 @@ IOBuffer::~IOBuffer () = default;
 IOBuffer::IOBuffer (std::size_t const size_)
     : m_buffer (std::make_unique<char[]> (size_)), m_size (size_)
 {
+	assert (size_ > 0);
 }
 
 char *IOBuffer::freeArea () const

source/linux/platform.cpp

@@ -36,8 +36,13 @@
 
 namespace
 {
+/// \brief GLFW main window
 std::unique_ptr<GLFWwindow, void (*) (GLFWwindow *)> s_mainWindow (nullptr, glfwDestroyWindow);
 
+/// \brief Window resize callback
+/// \param window_ GLFW window
+/// \param width_ New window width
+/// \param height_ New window height
 void windowResize (GLFWwindow *const window_, int const width_, int const height_)
 {
 	(void)window_;
@@ -49,6 +54,13 @@ void windowResize (GLFWwindow *const window_, int const width_, int const height
 }
 
 #ifndef NDEBUG
+/// \brief GL log callback
+/// \param source_ Message source
+/// \param type_ Message type
+/// \param id_ Message id
+/// \param severity_ Message severity
+/// \param length_ Message length
+/// \param userParam_ User parameter
 void logCallback (GLenum const source_,
     GLenum const type_,
     GLuint const id_,
@@ -63,19 +75,21 @@ void logCallback (GLenum const source_,
 	(void)severity_;
 	(void)length_;
 	(void)userParam_;
-	// std::fprintf (stderr, "%s\n", message_);
+	std::fprintf (stderr, "%s\n", message_);
 }
 #endif
 }
 
 bool platform::init ()
 {
+	// initialize GLFW
 	if (!glfwInit ())
 	{
 		std::fprintf (stderr, "Failed to initialize GLFW\n");
 		return false;
 	}
 
+	// use OpenGL 4.3 Core Profile
 	glfwWindowHint (GLFW_CONTEXT_VERSION_MAJOR, 4);
 	glfwWindowHint (GLFW_CONTEXT_VERSION_MINOR, 3);
 	glfwWindowHint (GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
@@ -87,6 +101,7 @@ bool platform::init ()
 	glfwWindowHint (GLFW_DEPTH_BITS, 24);
 	glfwWindowHint (GLFW_STENCIL_BITS, 8);
 
+	// create GLFW window
 	s_mainWindow.reset (glfwCreateWindow (1280, 720, "Test Game", nullptr, nullptr));
 	if (!s_mainWindow)
 	{
@@ -95,12 +110,14 @@ bool platform::init ()
 		return false;
 	}
 
+	// enable vsync
 	glfwSwapInterval (1);
 
 	// create context
 	glfwMakeContextCurrent (s_mainWindow.get ());
 	glfwSetFramebufferSizeCallback (s_mainWindow.get (), windowResize);
 
+	// load OpenGL
 	if (!gladLoadGL ())
 	{
 		std::fprintf (stderr, "gladLoadGL: failed\n");
@@ -134,12 +151,10 @@ bool platform::init ()
 	std::printf ("Renderer:       %s\n", glGetString (GL_RENDERER));
 	std::printf ("OpenGL Version: %s\n", glGetString (GL_VERSION));
 
-	IMGUI_CHECKVERSION ();
-	ImGui::CreateContext ();
-
 	ImGui_ImplGlfw_InitForOpenGL (s_mainWindow.get (), true);
 	ImGui_ImplOpenGL3_Init ("#version 150");
 
+	// disable imgui.ini file
 	ImGuiIO &io    = ImGui::GetIO ();
 	io.IniFilename = nullptr;
 
@@ -169,10 +184,6 @@ void platform::render ()
 {
 	ImGui::Render ();
 
-	int width;
-	int height;
-	glfwGetFramebufferSize (s_mainWindow.get (), &width, &height);
-	glViewport (0, 0, width, height);
 	glClearColor (0.45f, 0.55f, 0.60f, 1.00f);
 	glClear (GL_COLOR_BUFFER_BIT);
 
@@ -183,22 +194,24 @@ void platform::render ()
 
 void platform::exit ()
 {
-	ImGui::DestroyContext ();
-
 	s_mainWindow.reset ();
 	glfwTerminate ();
 }
 
 ///////////////////////////////////////////////////////////////////////////
+/// \brief Platform thread pimpl
 class platform::Thread::privateData_t
 {
 public:
 	privateData_t () = default;
 
+	/// \brief Parameterized constructor
+	/// \param func_ Thread entry point
 	privateData_t (std::function<void ()> func_) : thread (func_)
 	{
 	}
 
+	/// \brief Underlying thread object
 	std::thread thread;
 };
 
@@ -235,9 +248,11 @@ void platform::Thread::sleep (std::chrono::milliseconds const timeout_)
 }
 
 ///////////////////////////////////////////////////////////////////////////
+/// \brief Platform mutex pimpl
 class platform::Mutex::privateData_t
 {
 public:
+	/// \brief Underlying mutex
 	std::mutex mutex;
 };
 

source/log.cpp

@@ -27,12 +27,17 @@
 namespace
 {
 #ifdef _3DS
+/// \brief Maximum number of log messages to keep
 constexpr auto MAX_LOGS = 250;
 #else
+/// \brief Maximum number of log messages to keep
 constexpr auto MAX_LOGS = 10000;
 #endif
+
+/// \brief Bound log
 thread_local WeakLog s_log;
 
+/// \brief Message prefix
 static char const *const s_prefix[] = {
     [Log::DEBUG]    = "[DEBUG]",
     [Log::INFO]     = "[INFO]",
@@ -59,19 +64,11 @@ void Log::draw ()
 	}
 
 	static ImVec4 const s_colors[] = {
-	    [Log::DEBUG]    = ImVec4 (1.0f, 1.0f, 0.4f, 1.0f),
-	    [Log::INFO]     = ImVec4 (1.0f, 1.0f, 1.0f, 1.0f),
-	    [Log::ERROR]    = ImVec4 (1.0f, 0.4f, 0.4f, 1.0f),
-	    [Log::COMMAND]  = ImVec4 (0.4f, 1.0f, 0.4f, 1.0f),
-	    [Log::RESPONSE] = ImVec4 (0.4f, 1.0f, 1.0f, 1.0f),
-	};
-
-	static char const *const s_prefix[] = {
-	    [Log::DEBUG]    = "[DEBUG]",
-	    [Log::INFO]     = "[INFO]",
-	    [Log::ERROR]    = "[ERROR]",
-	    [Log::COMMAND]  = "[COMMAND]",
-	    [Log::RESPONSE] = "[RESPONSE]",
+	    [Log::DEBUG]    = ImVec4 (1.0f, 1.0f, 0.4f, 1.0f), // yellow
+	    [Log::INFO]     = ImVec4 (1.0f, 1.0f, 1.0f, 1.0f), // white
+	    [Log::ERROR]    = ImVec4 (1.0f, 0.4f, 0.4f, 1.0f), // red
+	    [Log::COMMAND]  = ImVec4 (0.4f, 1.0f, 0.4f, 1.0f), // green
+	    [Log::RESPONSE] = ImVec4 (0.4f, 1.0f, 1.0f, 1.0f), // cyan
 	};
 
 	for (auto const &message : m_messages)
@@ -83,7 +80,7 @@ void Log::draw ()
 		ImGui::PopStyleColor ();
 	}
 
-	// auto scroll if scroll bar is at end
+	// auto-scroll if scroll bar is at end
 	if (ImGui::GetScrollY () >= ImGui::GetScrollMaxY ())
 		ImGui::SetScrollHereY (1.0f);
 }
@@ -183,6 +180,7 @@ void Log::log (Level const level_, std::string_view const message_)
 	auto msg = std::string (message_);
 	for (auto &c : msg)
 	{
+		// replace nul-characters with ? to avoid truncation
 		if (c == '\0')
 			c = '?';
 	}

source/main.cpp

@@ -29,14 +29,21 @@
 
 int main (int argc_, char *argv_[])
 {
+	IMGUI_CHECKVERSION ();
+	ImGui::CreateContext ();
+
 	if (!platform::init ())
+	{
+		ImGui::DestroyContext ();
 		return EXIT_FAILURE;
+	}
 
 	auto &style          = ImGui::GetStyle ();
 	style.WindowRounding = 0.0f;
 
 #ifdef _3DS
-	style.Colors[ImGuiCol_WindowBg].w = 0.5f;
+	// citro3d logo doesn't quite show with the default transparency
+	style.Colors[ImGuiCol_WindowBg].w = 0.8f;
 #endif
 
 	auto server = FtpServer::create (5000);
@@ -48,5 +55,7 @@ int main (int argc_, char *argv_[])
 		platform::render ();
 	}
 
+	server.reset ();
 	platform::exit ();
+	ImGui::DestroyContext ();
 }

source/sockAddr.cpp

@@ -23,6 +23,7 @@
 #include <arpa/inet.h>
 
 #include <cassert>
+#include <cstdlib>
 #include <cstring>
 
 ///////////////////////////////////////////////////////////////////////////
@@ -51,18 +52,24 @@ SockAddr::SockAddr (struct sockaddr const &addr_)
 		std::memcpy (&m_addr, &addr_, sizeof (struct sockaddr_in6));
 		break;
 #endif
+
+	default:
+		std::abort ();
+		break;
 	}
 }
 
 SockAddr::SockAddr (struct sockaddr_in const &addr_)
     : SockAddr (reinterpret_cast<struct sockaddr const &> (addr_))
 {
+	assert (m_addr.ss_family == AF_INET);
 }
 
 #ifndef _3DS
 SockAddr::SockAddr (struct sockaddr_in6 const &addr_)
     : SockAddr (reinterpret_cast<struct sockaddr const &> (addr_))
 {
+	assert (m_addr.ss_family == AF_INET6);
 }
 #endif
 
@@ -111,9 +118,11 @@ std::uint16_t SockAddr::port () const
 	case AF_INET6:
 		return ntohs (reinterpret_cast<struct sockaddr_in6 const *> (&m_addr)->sin6_port);
 #endif
-	}
 
-	return 0;
+	default:
+		std::abort ();
+		break;
+	}
 }
 
 char const *SockAddr::name (char *buffer_, std::size_t size_) const
@@ -133,9 +142,11 @@ char const *SockAddr::name (char *buffer_, std::size_t size_) const
 		    buffer_,
 		    size_);
 #endif
-	}
 
-	return nullptr;
+	default:
+		std::abort ();
+		break;
+	}
 }
 
 char const *SockAddr::name () const

source/socket.cpp

@@ -38,8 +38,10 @@ Socket::~Socket ()
 {
 	if (m_listening)
 		Log::info ("Stop listening on [%s]:%u\n", m_sockName.name (), m_sockName.port ());
+
 	if (m_connected)
 		Log::info ("Closing connection to [%s]:%u\n", m_peerName.name (), m_peerName.port ());
+
 	if (::close (m_fd) != 0)
 		Log::error ("close: %s\n", std::strerror (errno));
 }
@@ -66,7 +68,7 @@ UniqueSocket Socket::accept ()
 	if (fd < 0)
 	{
 		Log::error ("accept: %s\n", std::strerror (errno));
-		return {nullptr, {}};
+		return nullptr;
 	}
 
 	Log::info ("Accepted connection from [%s]:%u\n", addr.name (), addr.port ());
@@ -112,6 +114,7 @@ bool Socket::bind (SockAddr const &addr_)
 
 	if (addr_.port () == 0)
 	{
+		// get socket name due to request for ephemeral port
 		socklen_t addrLen = sizeof (struct sockaddr_storage);
 		if (::getsockname (m_fd, m_sockName, &addrLen) != 0)
 			Log::error ("getsockname: %s\n", std::strerror (errno));
@@ -200,7 +203,7 @@ bool Socket::setNonBlocking (bool const nonBlocking_)
 
 	if (::fcntl (m_fd, F_SETFL, flags) != 0)
 	{
-		Log::error ("fcntl(F_SETFL): %s\n", std::strerror (errno));
+		Log::error ("fcntl(F_SETFL, %d): %s\n", flags, std::strerror (errno));
 		return false;
 	}
 
@@ -212,7 +215,8 @@ bool Socket::setReuseAddress (bool const reuse_)
 	int reuse = reuse_;
 	if (::setsockopt (m_fd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof (reuse)) != 0)
 	{
-		Log::error ("setsockopt(SO_REUSEADDR, %u): %s\n", reuse_, std::strerror (errno));
+		Log::error (
+		    "setsockopt(SO_REUSEADDR, %s): %s\n", reuse_ ? "yes" : "no", std::strerror (errno));
 		return false;
 	}
 

source/switch/imgui_deko3d.cpp

@@ -48,27 +48,39 @@
 
 namespace
 {
-constexpr auto LOGO_WIDTH  = 500;
+/// \brief deko3d logo width
+constexpr auto LOGO_WIDTH = 500;
+/// \brief deko3d logo height
 constexpr auto LOGO_HEIGHT = 493;
 
+/// \brief Number of framebuffers
 constexpr auto FB_NUM = 2u;
 
-constexpr auto CMDBUF_SIZE   = 1024 * 1024;
-constexpr auto DATABUF_SIZE  = 1024 * 1024;
+/// \brief Command buffer size
+constexpr auto CMDBUF_SIZE = 1024 * 1024;
+/// \brief Data buffer size
+constexpr auto DATABUF_SIZE = 1024 * 1024;
+/// \brief Index buffer size
 constexpr auto INDEXBUF_SIZE = 1024 * 1024;
+/// \brief Image buffer size
 constexpr auto IMAGEBUF_SIZE = 16 * 1024 * 1024;
 
+/// \brief Vertex shader UBO
 struct VertUBO
 {
+	/// \brief Projection matrix
 	glm::mat4 projMtx;
 };
 
+/// \brief Fragment shader UBO
 struct FragUBO
 {
+	/// \brief Whether drawing a font or not
 	std::uint32_t font;
 };
 
-constexpr std::array VertexAttribState = {
+/// \brief Vertex attribute state
+constexpr std::array VERTEX_ATTRIB_STATE = {
     // clang-format off
     DkVtxAttribState{0, 0, offsetof (ImDrawVert, pos), DkVtxAttribSize_2x32, DkVtxAttribType_Float, 0},
     DkVtxAttribState{0, 0, offsetof (ImDrawVert, uv),  DkVtxAttribSize_2x32, DkVtxAttribType_Float, 0},
@@ -76,58 +88,95 @@ constexpr std::array VertexAttribState = {
     // clang-format on
 };
 
-constexpr std::array VertexBufferState = {
+/// \brief Vertex buffer state
+constexpr std::array VERTEX_BUFFER_STATE = {
     DkVtxBufferState{sizeof (ImDrawVert), 0},
 };
 
+/// \brief deko3d device
 dk::UniqueDevice s_device;
 
+/// \brief Depth buffer memblock
 dk::UniqueMemBlock s_depthMemBlock;
+/// \brief Depth buffer image
 dk::Image s_depthBuffer;
 
+/// \brief Framebuffer memblock
 dk::UniqueMemBlock s_fbMemBlock;
+/// \brief Framebuffer images
 dk::Image s_frameBuffers[FB_NUM];
 
+/// \brief Font image
 dk::Image s_fontTexture;
+/// \brief deko3d logo image
 dk::Image s_logoTexture;
 
+/// \brief deko3d swapchain
 dk::UniqueSwapchain s_swapchain;
 
+/// \brief Shader code memblock
 dk::UniqueMemBlock s_codeMemBlock;
+/// \brief Shaders (vertex, fragment)
 dk::Shader s_shaders[2];
 
+/// \brief UBO memblock
 dk::UniqueMemBlock s_uboMemBlock;
 
+/// \brief Vertex data memblock
 dk::UniqueMemBlock s_vtxMemBlock[FB_NUM];
+/// \brief Index data memblock
 dk::UniqueMemBlock s_idxMemBlock[FB_NUM];
+/// \brief Command buffer memblock
 dk::UniqueMemBlock s_cmdMemBlock[FB_NUM];
+/// \brief Command buffers
 dk::UniqueCmdBuf s_cmdBuf[FB_NUM];
 
+/// \brief Image memblock
 dk::UniqueMemBlock s_imageMemBlock;
+/// \brief Image/Sampler descriptor memblock
 dk::UniqueMemBlock s_descriptorMemBlock;
 
+/// \brief deko3d queue
 dk::UniqueQueue s_queue;
 
-constexpr auto MAX_SAMPLERS                 = 1;
-constexpr auto MAX_IMAGES                   = 2;
+/// \brief Maximum number of samplers
+constexpr auto MAX_SAMPLERS = 1;
+/// \brief Maximum number of images
+constexpr auto MAX_IMAGES = 2;
+/// \brief Sample descriptors
 dk::SamplerDescriptor *s_samplerDescriptors = nullptr;
-dk::ImageDescriptor *s_imageDescriptors     = nullptr;
+/// \brief Image descriptors
+dk::ImageDescriptor *s_imageDescriptors = nullptr;
 
+/// \brief Currently bound image descriptor
 std::uintptr_t s_boundDescriptor = 0;
 
-unsigned s_width  = 0;
+/// \brief Framebuffer width
+unsigned s_width = 0;
+/// \brief Framebuffer height
 unsigned s_height = 0;
 
+/// \brief Align value
+/// \tparam T Value type
+/// \tparam U Alignment type
+/// \param size_ Value to align
+/// \param align_ Alignment
 template <typename T, typename U>
 constexpr inline std::uint32_t align (T const &size_, U const &align_)
 {
 	return static_cast<std::uint32_t> (size_ + align_ - 1) & ~(align_ - 1);
 }
 
+/// \brief Rebuild swapchain
+/// \param width_ Framebuffer width
+/// \param height_ Framebuffer height
+/// \note This assumes the first call is the largest a framebuffer will ever be
 void rebuildSwapchain (unsigned const width_, unsigned const height_)
 {
+	// destroy old swapchain
 	s_swapchain = nullptr;
 
+	// create new depth buffer image layout
 	dk::ImageLayout depthLayout;
 	dk::ImageLayoutMaker{s_device}
 	    .setFlags (DkImageFlags_UsageRender | DkImageFlags_HwCompression)
@@ -138,6 +187,7 @@ void rebuildSwapchain (unsigned const width_, unsigned const height_)
 	auto const depthAlign = depthLayout.getAlignment ();
 	auto const depthSize  = depthLayout.getSize ();
 
+	// create depth buffer memblock
 	if (!s_depthMemBlock)
 	{
 		s_depthMemBlock = dk::MemBlockMaker{s_device,
@@ -148,6 +198,7 @@ void rebuildSwapchain (unsigned const width_, unsigned const height_)
 
 	s_depthBuffer.initialize (depthLayout, s_depthMemBlock, 0);
 
+	// create framebuffer image layout
 	dk::ImageLayout fbLayout;
 	dk::ImageLayoutMaker{s_device}
 	    .setFlags (
@@ -159,6 +210,7 @@ void rebuildSwapchain (unsigned const width_, unsigned const height_)
 	auto const fbAlign = fbLayout.getAlignment ();
 	auto const fbSize  = fbLayout.getSize ();
 
+	// create framebuffer memblock
 	if (!s_fbMemBlock)
 	{
 		s_fbMemBlock = dk::MemBlockMaker{s_device,
@@ -167,6 +219,7 @@ void rebuildSwapchain (unsigned const width_, unsigned const height_)
 		                   .create ();
 	}
 
+	// initialize swapchain images
 	std::array<DkImage const *, FB_NUM> swapchainImages;
 	for (unsigned i = 0; i < FB_NUM; ++i)
 	{
@@ -174,18 +227,26 @@ void rebuildSwapchain (unsigned const width_, unsigned const height_)
 		s_frameBuffers[i].initialize (fbLayout, s_fbMemBlock, i * fbSize);
 	}
 
+	// create swapchain
 	s_swapchain = dk::SwapchainMaker{s_device, nwindowGetDefault (), swapchainImages}.create ();
 }
 
+/// \brief Load shader code
 void loadShaders ()
 {
+	/// \brief Shader file descriptor
 	struct ShaderFile
 	{
+		/// \brief Parameterized constructor
+		/// \param shader_ Shader object
+		/// \param path_ Path to source code
 		ShaderFile (dk::Shader &shader_, char const *const path_)
 		    : shader (shader_), path (path_), size (getSize (path_))
 		{
 		}
 
+		/// \brief Get size of a file
+		/// \param path_ Path to file
 		static std::size_t getSize (char const *const path_)
 		{
 			struct stat st;
@@ -199,14 +260,18 @@ void loadShaders ()
 			return st.st_size;
 		}
 
+		/// \brief Shader object
 		dk::Shader &shader;
+		/// \brief Path to source code
 		char const *const path;
+		/// \brief Source code file size
 		std::size_t const size;
 	};
 
 	auto shaderFiles = {ShaderFile{s_shaders[0], "romfs:/shaders/imgui_vsh.dksh"},
 	    ShaderFile{s_shaders[1], "romfs:/shaders/imgui_fsh.dksh"}};
 
+	// calculate total size of shaders
 	auto const codeSize = std::accumulate (std::begin (shaderFiles),
 	    std::end (shaderFiles),
 	    DK_SHADER_CODE_UNUSABLE_SIZE,
@@ -214,6 +279,7 @@ void loadShaders ()
 		    return sum_ + align (file_.size, DK_SHADER_CODE_ALIGNMENT);
 	    });
 
+	// create shader code memblock
 	s_codeMemBlock = dk::MemBlockMaker{s_device, align (codeSize, DK_MEMBLOCK_ALIGNMENT)}
 	                     .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached |
 	                                DkMemBlockFlags_Code)
@@ -222,6 +288,7 @@ void loadShaders ()
 	auto const addr    = static_cast<std::uint8_t *> (s_codeMemBlock.getCpuAddr ());
 	std::size_t offset = 0;
 
+	// read shaders into memblock
 	for (auto &file : shaderFiles)
 	{
 		std::uint32_t const codeOffset = offset;
@@ -245,13 +312,18 @@ void loadShaders ()
 	}
 }
 
+/// \brief Setup render state
+/// \param slot_ Swapchain slot
+/// \param drawData_ Data to draw
+/// \param width_ Framebuffer width
+/// \param height_ Framebuffer height
 DkCmdList setupRenderState (int const slot_,
     ImDrawData *const drawData_,
     unsigned const width_,
     unsigned const height_)
 {
-	// Setup viewport, orthographic projection matrix
-	// Our visible imgui space lies from drawData_->DisplayPos (top left) to
+	// setup viewport, orthographic projection matrix
+	// our visible imgui space lies from drawData_->DisplayPos (top left) to
 	// drawData_->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single
 	// viewport apps.
 	auto const L = drawData_->DisplayPos.x;
@@ -262,6 +334,7 @@ DkCmdList setupRenderState (int const slot_,
 	VertUBO vertUBO;
 	vertUBO.projMtx = glm::orthoRH_ZO (L, R, B, T, -1.0f, 1.0f);
 
+	// create command buffer to initialize/reset render state
 	s_cmdBuf[slot_].setViewports (0, DkViewport{0.0f, 0.0f, width_, height_});
 	s_cmdBuf[slot_].bindShaders (DkStageFlag_GraphicsMask, {&s_shaders[0], &s_shaders[1]});
 	s_cmdBuf[slot_].bindUniformBuffer (DkStage_Vertex,
@@ -286,8 +359,8 @@ DkCmdList setupRenderState (int const slot_,
 	        DkBlendFactor_InvSrcAlpha,
 	        DkBlendFactor_InvSrcAlpha,
 	        DkBlendFactor_Zero));
-	s_cmdBuf[slot_].bindVtxAttribState (VertexAttribState);
-	s_cmdBuf[slot_].bindVtxBufferState (VertexBufferState);
+	s_cmdBuf[slot_].bindVtxAttribState (VERTEX_ATTRIB_STATE);
+	s_cmdBuf[slot_].bindVtxBufferState (VERTEX_BUFFER_STATE);
 
 	return s_cmdBuf[slot_].finishList ();
 }
@@ -295,17 +368,21 @@ DkCmdList setupRenderState (int const slot_,
 
 void imgui::deko3d::init ()
 {
-	// Setup back-end capabilities flags
+	// setup back-end capabilities flags
 	ImGuiIO &io = ImGui::GetIO ();
 
 	io.BackendRendererName = "deko3d";
 	io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;
+
+	// defer initialization to first newFrame ()
 }
 
 void imgui::deko3d::exit ()
 {
+	// wait for queue to be idle
 	s_queue.waitIdle ();
 
+	// clean up all of the deko3d objects
 	s_queue              = nullptr;
 	s_descriptorMemBlock = nullptr;
 	s_imageMemBlock      = nullptr;
@@ -331,12 +408,16 @@ void imgui::deko3d::newFrame ()
 	if (s_device)
 		return;
 
+	// create deko3d device
 	s_device = dk::DeviceMaker{}.create ();
 
+	// initialize swapchain with maximum resolution
 	rebuildSwapchain (1920, 1080);
 
+	// load shader code
 	loadShaders ();
 
+	// create UBO memblock
 	s_uboMemBlock = dk::MemBlockMaker{s_device,
 	    align (align (sizeof (VertUBO), DK_UNIFORM_BUF_ALIGNMENT) +
 	               align (sizeof (FragUBO), DK_UNIFORM_BUF_ALIGNMENT),
@@ -344,32 +425,38 @@ void imgui::deko3d::newFrame ()
 	                    .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
 	                    .create ();
 
+	// create memblocks for each framebuffer slot
 	for (std::size_t i = 0; i < FB_NUM; ++i)
 	{
+		// create vertex data memblock
 		s_vtxMemBlock[i] = dk::MemBlockMaker{s_device, align (DATABUF_SIZE, DK_MEMBLOCK_ALIGNMENT)}
 		                       .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
 		                       .create ();
 
+		// create index data memblock
 		s_idxMemBlock[i] = dk::MemBlockMaker{s_device, align (INDEXBUF_SIZE, DK_MEMBLOCK_ALIGNMENT)}
 		                       .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
 		                       .create ();
 
+		// create command buffer memblock
 		s_cmdMemBlock[i] = dk::MemBlockMaker{s_device, align (CMDBUF_SIZE, DK_MEMBLOCK_ALIGNMENT)}
 		                       .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
 		                       .create ();
 
+		// create command buffer
 		s_cmdBuf[i] = dk::CmdBufMaker{s_device}.create ();
-
 		s_cmdBuf[i].addMemory (s_cmdMemBlock[i], 0, s_cmdMemBlock[i].getSize ());
 	}
 
+	// create queue
 	s_queue = dk::QueueMaker{s_device}.setFlags (DkQueueFlags_Graphics).create ();
 
+	// create image memblock
 	s_imageMemBlock = dk::MemBlockMaker{s_device, align (IMAGEBUF_SIZE, DK_MEMBLOCK_ALIGNMENT)}
 	                      .setFlags (DkMemBlockFlags_GpuCached | DkMemBlockFlags_Image)
 	                      .create ();
 
-	// Build texture atlas
+	// get texture atlas
 	ImGuiIO &io = ImGui::GetIO ();
 	io.Fonts->SetTexID (nullptr);
 	unsigned char *pixels;
@@ -377,12 +464,14 @@ void imgui::deko3d::newFrame ()
 	int height;
 	io.Fonts->GetTexDataAsAlpha8 (&pixels, &width, &height);
 
+	// create memblock for transfer
 	dk::UniqueMemBlock memBlock =
 	    dk::MemBlockMaker{s_device, align (width * height, DK_MEMBLOCK_ALIGNMENT)}
 	        .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
 	        .create ();
 	std::memcpy (memBlock.getCpuAddr (), pixels, width * height);
 
+	// create image/sampler memblock
 	static_assert (sizeof (dk::ImageDescriptor) == DK_IMAGE_DESCRIPTOR_ALIGNMENT);
 	static_assert (sizeof (dk::SamplerDescriptor) == DK_SAMPLER_DESCRIPTOR_ALIGNMENT);
 	static_assert (DK_IMAGE_DESCRIPTOR_ALIGNMENT == DK_SAMPLER_DESCRIPTOR_ALIGNMENT);
@@ -391,17 +480,22 @@ void imgui::deko3d::newFrame ()
 	                           .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
 	                           .create ();
 
+	// get cpu address for descriptors
 	s_samplerDescriptors =
 	    static_cast<dk::SamplerDescriptor *> (s_descriptorMemBlock.getCpuAddr ());
 	s_imageDescriptors =
 	    reinterpret_cast<dk::ImageDescriptor *> (&s_samplerDescriptors[MAX_SAMPLERS]);
 
+	// initialize sampler descriptor
 	s_samplerDescriptors[0].initialize (
 	    dk::Sampler{}
 	        .setFilter (DkFilter_Linear, DkFilter_Linear)
 	        .setWrapMode (DkWrapMode_ClampToEdge, DkWrapMode_ClampToEdge, DkWrapMode_ClampToEdge));
 
+	// use command buffer 0 for initialization
 	auto &cmdBuf = s_cmdBuf[0];
+
+	// initialize texture atlas image layout
 	dk::ImageLayout layout;
 	dk::ImageLayoutMaker{s_device}
 	    .setFlags (0)
@@ -409,21 +503,25 @@ void imgui::deko3d::newFrame ()
 	    .setDimensions (width, height)
 	    .initialize (layout);
 
+	// initialize font texture atlas image descriptor
 	s_fontTexture.initialize (layout, s_imageMemBlock, 0);
 	s_imageDescriptors[0].initialize (s_fontTexture);
 
+	// copy font texture atlas to image view
 	dk::ImageView imageView{s_fontTexture};
 	cmdBuf.copyBufferToImage ({memBlock.getGpuAddr ()}, imageView, {0, 0, 0, width, height, 1});
 
+	// bind image/sampler descriptors
 	cmdBuf.bindSamplerDescriptorSet (s_descriptorMemBlock.getGpuAddr (), MAX_SAMPLERS);
 	cmdBuf.bindImageDescriptorSet (
 	    s_descriptorMemBlock.getGpuAddr () + MAX_SAMPLERS * sizeof (dk::SamplerDescriptor),
 	    MAX_IMAGES);
 
+	// submit commands while we get the next image ready to transfer
 	s_queue.submitCommands (cmdBuf.finishList ());
-	s_queue.waitIdle ();
 
 	{
+		// read the deko3d logo
 		auto const path = "romfs:/deko3d.rgba.zst";
 
 		struct stat st;
@@ -456,10 +554,13 @@ void imgui::deko3d::newFrame ()
 			std::abort ();
 		}
 
-		memBlock = dk::MemBlockMaker{s_device, align (size, DK_MEMBLOCK_ALIGNMENT)}
-		               .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
-		               .create ();
+		// create memblock for transfer
+		dk::UniqueMemBlock memBlock =
+		    dk::MemBlockMaker{s_device, align (size, DK_MEMBLOCK_ALIGNMENT)}
+		        .setFlags (DkMemBlockFlags_CpuUncached | DkMemBlockFlags_GpuCached)
+		        .create ();
 
+		// decompress into transfer memblock
 		auto const decoded =
 		    ZSTD_decompress (memBlock.getCpuAddr (), size, buffer.data (), st.st_size);
 		if (ZSTD_isError (decoded))
@@ -468,6 +569,7 @@ void imgui::deko3d::newFrame ()
 			std::abort ();
 		}
 
+		// initialize deko3d logo texture image layout
 		dk::ImageLayout layout;
 		dk::ImageLayoutMaker{s_device}
 		    .setFlags (0)
@@ -475,32 +577,41 @@ void imgui::deko3d::newFrame ()
 		    .setDimensions (LOGO_WIDTH, LOGO_HEIGHT)
 		    .initialize (layout);
 
+		// initialize deko3d logo texture image descriptor
 		auto const offset = align (width * height, DK_IMAGE_LINEAR_STRIDE_ALIGNMENT);
 		s_logoTexture.initialize (layout, s_imageMemBlock, offset);
 		s_imageDescriptors[1].initialize (s_logoTexture);
 
+		// copy deko3d logo texture to image view
 		dk::ImageView imageView{s_logoTexture};
 		cmdBuf.copyBufferToImage (
 		    {memBlock.getGpuAddr ()}, imageView, {0, 0, 0, LOGO_WIDTH, LOGO_HEIGHT, 1});
 
+		// submit commands to transfer deko3d logo texture
 		s_queue.submitCommands (cmdBuf.finishList ());
+
+		// wait for commands to complete before releasing memblocks
 		s_queue.waitIdle ();
 	}
 
+	// reset command buffer
 	cmdBuf.clear ();
 }
 
 void imgui::deko3d::render ()
 {
+	// get ImGui draw data
 	auto const drawData = ImGui::GetDrawData ();
 	if (drawData->CmdListsCount <= 0)
 		return;
 
+	// get framebuffer dimensions
 	unsigned width  = drawData->DisplaySize.x * drawData->FramebufferScale.x;
 	unsigned height = drawData->DisplaySize.y * drawData->FramebufferScale.y;
 	if (width <= 0 || height <= 0)
 		return;
 
+	// check if we need to rebuild the swapchain
 	if (width != s_width || height != s_height)
 	{
 		s_width  = width;
@@ -510,9 +621,11 @@ void imgui::deko3d::render ()
 		rebuildSwapchain (width, height);
 	}
 
+	// get image from queue
 	auto const slot = s_queue.acquireImage (s_swapchain);
 	s_cmdBuf[slot].clear ();
 
+	// bind frame/depth buffers and clear them
 	dk::ImageView colorTarget{s_frameBuffers[slot]};
 	dk::ImageView depthTarget{s_depthBuffer};
 	s_cmdBuf[slot].bindRenderTargets (&colorTarget, &depthTarget);
@@ -520,21 +633,22 @@ void imgui::deko3d::render ()
 	s_cmdBuf[slot].clearDepthStencil (true, 1.0f, 0xFF, 0);
 	s_queue.submitCommands (s_cmdBuf[slot].finishList ());
 
-	// Setup desired render state
+	// setup desired render state
 	auto const setupCmd = setupRenderState (slot, drawData, width, height);
 	s_queue.submitCommands (setupCmd);
 
+	// start with bogus descriptor binding so it'll be updated before first draw call
 	s_boundDescriptor = ~static_cast<std::uintptr_t> (0);
 
-	// Will project scissor/clipping rectangles into framebuffer space
+	// will project scissor/clipping rectangles into framebuffer space
 	// (0,0) unless using multi-viewports
 	auto const clipOff = drawData->DisplayPos;
 	// (1,1) unless using retina display which are often (2,2)
 	auto const clipScale = drawData->FramebufferScale;
 
+	// check if we need to grow vertex data memblock
 	if (s_vtxMemBlock[slot].getSize () < drawData->TotalVtxCount * sizeof (ImDrawVert))
 	{
-		s_vtxMemBlock[slot] = nullptr;
 		s_vtxMemBlock[slot] =
 		    dk::MemBlockMaker{s_device,
 		        align (drawData->TotalVtxCount * sizeof (ImDrawVert), DK_MEMBLOCK_ALIGNMENT)}
@@ -542,9 +656,9 @@ void imgui::deko3d::render ()
 		        .create ();
 	}
 
+	// check if we need to grow index data memblock
 	if (s_idxMemBlock[slot].getSize () < drawData->TotalIdxCount * sizeof (ImDrawIdx))
 	{
-		s_idxMemBlock[slot] = nullptr;
 		s_idxMemBlock[slot] =
 		    dk::MemBlockMaker{s_device,
 		        align (drawData->TotalIdxCount * sizeof (ImDrawIdx), DK_MEMBLOCK_ALIGNMENT)}
@@ -552,20 +666,24 @@ void imgui::deko3d::render ()
 		        .create ();
 	}
 
+	// get base cpu addresses
 	auto const cpuVtx = static_cast<std::uint8_t *> (s_vtxMemBlock[slot].getCpuAddr ());
 	auto const cpuIdx = static_cast<std::uint8_t *> (s_idxMemBlock[slot].getCpuAddr ());
 
+	// get base gpu addresses
 	auto const gpuVtx = s_vtxMemBlock[slot].getGpuAddr ();
 	auto const gpuIdx = s_idxMemBlock[slot].getGpuAddr ();
 
+	// get memblock sizes
 	auto const sizeVtx = s_vtxMemBlock[slot].getSize ();
 	auto const sizeIdx = s_idxMemBlock[slot].getSize ();
 
+	// bind vertex/index data memblocks
 	static_assert (sizeof (ImDrawIdx) == 2);
 	s_cmdBuf[slot].bindVtxBuffer (0, gpuVtx, sizeVtx);
 	s_cmdBuf[slot].bindIdxBuffer (DkIdxFormat_Uint16, gpuIdx);
 
-	// Render command lists
+	// render command lists
 	std::size_t offsetVtx = 0;
 	std::size_t offsetIdx = 0;
 	for (int i = 0; i < drawData->CmdListsCount; ++i)
@@ -575,6 +693,7 @@ void imgui::deko3d::render ()
 		auto const vtxSize = cmdList.VtxBuffer.Size * sizeof (ImDrawVert);
 		auto const idxSize = cmdList.IdxBuffer.Size * sizeof (ImDrawIdx);
 
+		// double check that we don't overrun vertex data memblock
 		if (sizeVtx - offsetVtx < vtxSize)
 		{
 			std::fprintf (stderr, "Not enough vertex buffer\n");
@@ -582,6 +701,7 @@ void imgui::deko3d::render ()
 			continue;
 		}
 
+		// double check that we don't overrun index data memblock
 		if (sizeIdx - offsetIdx < idxSize)
 		{
 			std::fprintf (stderr, "Not enough index buffer\n");
@@ -589,6 +709,7 @@ void imgui::deko3d::render ()
 			continue;
 		}
 
+		// copy vertex/index data into memblocks
 		std::memcpy (cpuVtx + offsetVtx, cmdList.VtxBuffer.Data, vtxSize);
 		std::memcpy (cpuIdx + offsetIdx, cmdList.IdxBuffer.Data, idxSize);
 
@@ -596,9 +717,10 @@ void imgui::deko3d::render ()
 		{
 			if (cmd.UserCallback)
 			{
+				// submit commands to preserve ordering
 				s_queue.submitCommands (s_cmdBuf[slot].finishList ());
 
-				// User callback, registered via ImDrawList::AddCallback()
+				// user callback, registered via ImDrawList::AddCallback()
 				// (ImDrawCallback_ResetRenderState is a special callback value used by the user to
 				// request the renderer to reset render state.)
 				if (cmd.UserCallback == ImDrawCallback_ResetRenderState)
@@ -608,53 +730,65 @@ void imgui::deko3d::render ()
 			}
 			else
 			{
-				// Project scissor/clipping rectangles into framebuffer space
+				// project scissor/clipping rectangles into framebuffer space
 				ImVec4 clip;
 				clip.x = (cmd.ClipRect.x - clipOff.x) * clipScale.x;
 				clip.y = (cmd.ClipRect.y - clipOff.y) * clipScale.y;
 				clip.z = (cmd.ClipRect.z - clipOff.x) * clipScale.x;
 				clip.w = (cmd.ClipRect.w - clipOff.y) * clipScale.y;
 
-				if (clip.x < width && clip.y < height && clip.z >= 0.0f && clip.w >= 0.0f)
+				if (clip.x >= width || clip.y >= height || clip.z < 0.0f || clip.w < 0.0f)
+					continue;
+
+				// keep scissor coordinates inside viewport
+				if (clip.x < 0.0f)
+					clip.x = 0.0f;
+				if (clip.y < 0.0f)
+					clip.y = 0.0f;
+				if (clip.z > width)
+					clip.z = width;
+				if (clip.w > height)
+					clip.z = height;
+
+				// apply scissor boundaries
+				s_cmdBuf[slot].setScissors (
+				    0, DkScissor{clip.x, clip.y, clip.z - clip.x, clip.w - clip.y});
+
+				// get image descriptor
+				auto const descriptor = reinterpret_cast<std::uintptr_t> (cmd.TextureId);
+				if (descriptor >= MAX_IMAGES)
+					continue;
+
+				// check if we need to bind a new texture
+				if (descriptor != s_boundDescriptor)
 				{
-					if (clip.x < 0.0f)
-						clip.x = 0.0f;
-					if (clip.y < 0.0f)
-						clip.y = 0.0f;
+					s_boundDescriptor = descriptor;
 
-					s_cmdBuf[slot].setScissors (
-					    0, DkScissor{clip.x, clip.y, clip.z - clip.x, clip.w - clip.y});
+					// bind the new texture
+					s_cmdBuf[slot].bindTextures (
+					    DkStage_Fragment, 0, dkMakeTextureHandle (descriptor, 0));
 
-					auto const descriptor = reinterpret_cast<std::uintptr_t> (cmd.TextureId);
-					if (descriptor >= MAX_IMAGES)
-						continue;
+					// check if this is the font texture atlas image descriptor
+					FragUBO fragUBO;
+					fragUBO.font = (descriptor == 0);
 
-					if (descriptor != s_boundDescriptor)
-					{
-						s_boundDescriptor = descriptor;
-
-						s_cmdBuf[slot].bindTextures (
-						    DkStage_Fragment, 0, dkMakeTextureHandle (descriptor, 0));
-
-						FragUBO fragUBO;
-						fragUBO.font = (descriptor == 0);
-
-						s_cmdBuf[slot].pushConstants (
-						    s_uboMemBlock.getGpuAddr () +
-						        align (sizeof (VertUBO), DK_UNIFORM_BUF_ALIGNMENT),
-						    align (sizeof (FragUBO), DK_UNIFORM_BUF_ALIGNMENT),
-						    0,
-						    sizeof (FragUBO),
-						    &fragUBO);
-					}
-
-					s_cmdBuf[slot].drawIndexed (DkPrimitive_Triangles,
-					    cmd.ElemCount,
-					    1,
-					    cmd.IdxOffset + offsetIdx / sizeof (ImDrawIdx),
-					    cmd.VtxOffset + offsetVtx / sizeof (ImDrawVert),
-					    0);
+					// update fragment shader UBO
+					s_cmdBuf[slot].pushConstants (
+					    s_uboMemBlock.getGpuAddr () +
+					        align (sizeof (VertUBO), DK_UNIFORM_BUF_ALIGNMENT),
+					    align (sizeof (FragUBO), DK_UNIFORM_BUF_ALIGNMENT),
+					    0,
+					    sizeof (FragUBO),
+					    &fragUBO);
 				}
+
+				// draw the draw list
+				s_cmdBuf[slot].drawIndexed (DkPrimitive_Triangles,
+				    cmd.ElemCount,
+				    1,
+				    cmd.IdxOffset + offsetIdx / sizeof (ImDrawIdx),
+				    cmd.VtxOffset + offsetVtx / sizeof (ImDrawVert),
+				    0);
 			}
 		}
 
@@ -662,10 +796,14 @@ void imgui::deko3d::render ()
 		offsetIdx += idxSize;
 	}
 
+	// wait for fragments to be completed before discarding depth/stencil buffer
 	s_cmdBuf[slot].barrier (DkBarrier_Fragments, 0);
 	s_cmdBuf[slot].discardDepthStencil ();
+
+	// submit final commands
 	s_queue.submitCommands (s_cmdBuf[slot].finishList ());
 
+	// present image
 	s_queue.presentImage (s_swapchain, slot);
 }
 

source/switch/imgui_fsh.glsl

@@ -33,6 +33,7 @@ layout (location = 0) out vec4 outColor;
 
 void main()
 {
+	// font texture is single-channel (alpha)
 	if (ubo.font != 0)
 	    outColor = vtxColor * vec4 (vec3 (1.0), texture (tex, vtxUv).r);
 	else

source/switch/imgui_nx.cpp

@@ -23,6 +23,7 @@
 #include "imgui.h"
 
 #include "fs.h"
+#include "platform.h"
 
 #include <switch.h>
 
@@ -35,23 +36,32 @@ using namespace std::chrono_literals;
 
 namespace
 {
+/// \brief Font atlas cache file
 constexpr auto FONT_ATLAS_BIN = "ftpd-font.bin";
 
-bool s_mouseJustPressed[IM_ARRAYSIZE (ImGuiIO::MouseDown)];
-
-std::chrono::high_resolution_clock::time_point s_lastMouseUpdate;
+/// \brief Last mouse update timestamp
+std::chrono::steady_clock::time_point s_lastMouseUpdate;
 
+/// \brief Whether application is focused
 bool s_focused = true;
-float s_width  = 1280.0f;
+
+/// \brief Framebuffer width
+float s_width = 1280.0f;
+/// \brief Framebuffer height
 float s_height = 720.0f;
 
+/// \brief Whether to show mouse
 float s_showMouse = false;
+/// \brief Mouse position
 ImVec2 s_mousePos = ImVec2 (0.0f, 0.0f);
 
+/// \brief Clipboard
 std::string s_clipboard;
 
+/// \brief Applet hook cookie
 AppletHookCookie s_appletHookCookie;
 
+/// \brief System font glyph ranges
 ImWchar const nxFontRanges[] = {
     // clang-format off
 	0x0020, 0x007e, 0x00a0, 0x017f, 0x0192, 0x0192, 0x01c0, 0x01c0,
@@ -1189,12 +1199,16 @@ ImWchar const nxFontRanges[] = {
     // clang-format on
 };
 
+/// \brief Handle applet hook
+/// \param hook_ Callback reason
+/// \param param_ User param
 void handleAppletHook (AppletHookType const hook_, void *const param_)
 {
 	(void)param_;
 	switch (hook_)
 	{
 	case AppletHookType_OnFocusState:
+		// grab focus state
 		s_focused = (appletGetFocusState () == AppletFocusState_Focused);
 		break;
 
@@ -1203,15 +1217,18 @@ void handleAppletHook (AppletHookType const hook_, void *const param_)
 		{
 		default:
 		case AppletOperationMode_Handheld:
+			// use handheld mode resolution (720p)
 			s_width  = 1280.0f;
 			s_height = 720.0f;
 			break;
 
 		case AppletOperationMode_Docked:
+			// use docked mode resolution (1080p)
 #if 0
 			s_width  = 1920.0f;
 			s_height = 1080.0f;
 #else
+			/// \todo check if we'd rather use framebuffer scale
 			s_width  = 1280.0f;
 			s_height = 720.0f;
 #endif
@@ -1224,30 +1241,43 @@ void handleAppletHook (AppletHookType const hook_, void *const param_)
 	}
 }
 
+/// \brief Get clipboard text callback
+/// \param userData_ User data
 char const *getClipboardText (void *const userData_)
 {
 	(void)userData_;
 	return s_clipboard.c_str ();
 }
 
+/// \brief Set clipboard text callback
+/// \param userData_ User data
+/// \param text_ Clipboard text
 void setClipboardText (void *const userData_, char const *const text_)
 {
 	(void)userData_;
 	s_clipboard = text_;
 }
 
+/// \brief Move mouse cursor
+/// \param io_ ImGui IO
+/// \param pos_ New mouse position
+/// \param force_ Whether to ignore prior mouse position
 void moveMouse (ImGuiIO &io_, ImVec2 const &pos_, bool const force_ = false)
 {
-	auto const now = std::chrono::high_resolution_clock::now ();
+	// get update timestamp
+	auto const now = std::chrono::steady_clock::now ();
 
+	// check if the mouse position has been updated
 	if (!force_ && pos_.x == s_mousePos.x && pos_.y == s_mousePos.y)
 	{
+		// stop displaying mouse cursor after inactivity timeout
 		if (now - s_lastMouseUpdate > 1s)
 			s_showMouse = false;
 
 		return;
 	}
 
+	// update mouse position
 	s_showMouse       = true;
 	s_lastMouseUpdate = now;
 	s_mousePos        = pos_;
@@ -1255,27 +1285,27 @@ void moveMouse (ImGuiIO &io_, ImVec2 const &pos_, bool const force_ = false)
 	io_.MousePos = s_mousePos;
 }
 
+/// \brief Update mouse buttons
+/// \param io_ ImGui IO
 void updateMouseButtons (ImGuiIO &io_)
 {
+	// read mouse buttons
 	auto const buttons = hidMouseButtonsHeld ();
 
 	for (std::size_t i = 0; i < IM_ARRAYSIZE (io_.MouseDown); ++i)
 	{
-		// If a mouse press event came, always pass it as "mouse held this frame", so we don't miss
-		// click-release events that are shorter than 1 frame.
-		io_.MouseDown[i]      = s_mouseJustPressed[i] || (buttons & BIT (i));
-		s_mouseJustPressed[i] = false;
+		io_.MouseDown[i] = buttons & BIT (i);
 
+		// force mouse cursor to show on click
 		if (io_.MouseDown[i])
 			moveMouse (io_, s_mousePos, true);
 	}
 }
 
+/// \brief Update mouse position
+/// \param io_ ImGui IO
 void updateMousePos (ImGuiIO &io_)
 {
-	if (!s_focused)
-		return;
-
 	MousePosition pos;
 	hidMouseRead (&pos);
 
@@ -1286,25 +1316,30 @@ void updateMousePos (ImGuiIO &io_)
 	    io_, ImVec2 (s_mousePos.x + 2.0f * pos.velocityX, s_mousePos.y + 2.0f * pos.velocityY));
 }
 
+/// \brief Update touch position
+/// \param io_ ImGui IO
 void updateTouch (ImGuiIO &io_)
 {
-	if (!s_focused)
-		return;
-
+	// read touch positions
 	auto const touchCount = hidTouchCount ();
 	if (touchCount < 1)
 		return;
 
+	// use first touch position
 	touchPosition pos;
 	hidTouchRead (&pos, 0);
 
+	// set mouse position to touch point; force hide mouse cursor
 	moveMouse (io_, ImVec2 (pos.px, pos.py));
 	io_.MouseDown[0] = true;
 	s_showMouse      = false;
 }
 
+/// \brief Update gamepad inputs
+/// \param io_ ImGui IO
 void updateGamepads (ImGuiIO &io_)
 {
+	// clear navigation inputs
 	std::memset (io_.NavInputs, 0, sizeof (io_.NavInputs));
 
 	auto const buttonMapping = {
@@ -1322,6 +1357,7 @@ void updateGamepads (ImGuiIO &io_)
 	    std::make_pair (KEY_DLEFT, ImGuiNavInput_DpadLeft),
 	};
 
+	// read buttons from primary controller
 	auto const keys = hidKeysHeld (CONTROLLER_P1_AUTO);
 	for (auto const &[in, out] : buttonMapping)
 	{
@@ -1329,7 +1365,7 @@ void updateGamepads (ImGuiIO &io_)
 			io_.NavInputs[out] = 1.0f;
 	}
 
-	// Use ZR/ZL as Mouse0/Mouse1, respectively
+	// use ZR/ZL as left-click/right-click, respectively
 	if (keys & KEY_ZR)
 	{
 		io_.MouseDown[0] = true;
@@ -1341,6 +1377,7 @@ void updateGamepads (ImGuiIO &io_)
 		moveMouse (io_, s_mousePos, true);
 	}
 
+	// update joystick
 	JoystickPosition js;
 	auto const analogMapping = {
 	    std::make_tuple (std::ref (js.dx), ImGuiNavInput_LStickLeft, -0.3f, -0.9f),
@@ -1349,15 +1386,15 @@ void updateGamepads (ImGuiIO &io_)
 	    std::make_tuple (std::ref (js.dy), ImGuiNavInput_LStickDown, -0.3f, -0.9f),
 	};
 
+	// read left joystick from primary controller
 	hidJoystickRead (&js, CONTROLLER_P1_AUTO, JOYSTICK_LEFT);
 	for (auto const &[in, out, min, max] : analogMapping)
 	{
 		auto const value   = in / static_cast<float> (JOYSTICK_MAX);
-		auto const v       = std::min (1.0f, (value - min) / (max - min));
-		io_.NavInputs[out] = std::max (io_.NavInputs[out], v);
+		io_.NavInputs[out] = std::clamp ((value - min) / (max - min), 0.0f, 1.0f);
 	}
 
-	// Use right stick as mouse
+	// use right stick as mouse
 	auto scale = 5.0f;
 	if (keys & KEY_L)
 		scale = 1.0f;
@@ -1365,37 +1402,41 @@ void updateGamepads (ImGuiIO &io_)
 		scale = 20.0f;
 	hidJoystickRead (&js, CONTROLLER_P1_AUTO, JOYSTICK_RIGHT);
 
+	// move mouse
 	moveMouse (io_,
 	    ImVec2 (s_mousePos.x + js.dx / static_cast<float> (JOYSTICK_MAX) * scale,
 	        s_mousePos.y - js.dy / static_cast<float> (JOYSTICK_MAX) * scale));
 }
 
+/// \brief Update keyboard inputs
+/// \param io_ ImGui IO
 void updateKeyboard (ImGuiIO &io_)
 {
 	io_.KeyCtrl =
 	    hidKeyboardModifierHeld (static_cast<HidKeyboardModifier> (KBD_MOD_LCTRL | KBD_MOD_RCTRL));
+
 	io_.KeyShift = hidKeyboardModifierHeld (
 	    static_cast<HidKeyboardModifier> (KBD_MOD_LSHIFT | KBD_MOD_RSHIFT));
+
 	io_.KeyAlt =
 	    hidKeyboardModifierHeld (static_cast<HidKeyboardModifier> (KBD_MOD_LALT | KBD_MOD_RALT));
+
 	io_.KeySuper =
 	    hidKeyboardModifierHeld (static_cast<HidKeyboardModifier> (KBD_MOD_LMETA | KBD_MOD_RMETA));
 
 	for (int i = 0; i < 256; ++i)
 		io_.KeysDown[i] = hidKeyboardHeld (static_cast<HidKeyboardScancode> (i));
-
-	if (!io_.WantTextInput)
-		return;
-
-	// io_.AddInputCharacter (c);
 }
 
+/// \brief Load font atlas cache from disk
 bool loadFontAtlas ()
 {
+	// open font atlas
 	fs::File fp;
 	if (!fp.open (FONT_ATLAS_BIN))
 		return false;
 
+	// initialize font atlas
 	auto const atlas = ImGui::GetIO ().Fonts;
 	atlas->Clear ();
 	atlas->TexWidth        = fp.read<std::uint16_t> ();
@@ -1405,9 +1446,11 @@ bool loadFontAtlas ()
 	atlas->TexPixelsAlpha8 =
 	    reinterpret_cast<unsigned char *> (IM_ALLOC (atlas->TexWidth * atlas->TexHeight));
 
+	// read pixel data
 	if (!fp.readAll (atlas->TexPixelsAlpha8, atlas->TexWidth * atlas->TexHeight))
 		return false;
 
+	// initialize font config
 	ImFontConfig config;
 	config.FontData             = nullptr;
 	config.FontDataSize         = 0;
@@ -1428,23 +1471,28 @@ bool loadFontAtlas ()
 	config.EllipsisChar         = 0x2026;
 	std::memset (config.Name, 0, sizeof (config.Name));
 
+	// create font
 	auto const font = IM_NEW (ImFont);
 	config.DstFont  = font;
 
+	// add config and font to atlas
 	atlas->ConfigData.push_back (config);
 	atlas->Fonts.push_back (font);
 	atlas->CustomRectIds[0] = atlas->AddCustomRectRegular (0x80000000, 108 * 2 + 1, 27);
 	atlas->CustomRects[0].X = 0;
 	atlas->CustomRects[0].Y = 0;
 
+	// read some font metrics
 	font->FallbackAdvanceX = fp.read<float> ();
 	font->FontSize         = fp.read<float> ();
 
+	// decode glyph metadata
 	auto const glyphCount = fp.read<std::uint16_t> ();
 	for (unsigned i = 0; i < glyphCount; ++i)
 	{
 		ImFontGlyph glyph;
 
+		// read glyph metadata
 		glyph.Codepoint = fp.read<ImWchar> ();
 		glyph.AdvanceX  = fp.read<float> ();
 		glyph.X0        = fp.read<float> ();
@@ -1456,17 +1504,21 @@ bool loadFontAtlas ()
 		glyph.U1        = fp.read<float> ();
 		glyph.V1        = fp.read<float> ();
 
+		// add glyph to font
 		font->Glyphs.push_back (glyph);
 		font->MetricsTotalSurface +=
 		    static_cast<int> ((glyph.U1 - glyph.U0) * atlas->TexWidth + 1.99f) *
 		    static_cast<int> ((glyph.V1 - glyph.V0) * atlas->TexHeight + 1.99f);
 	}
 
+	// build font lookup table
 	font->BuildLookupTable ();
 
+	// read display offsets
 	font->DisplayOffset.x = fp.read<float> ();
 	font->DisplayOffset.y = fp.read<float> ();
 
+	// finalize font atlas
 	font->ContainerAtlas  = atlas;
 	font->ConfigData      = &atlas->ConfigData[0];
 	font->ConfigDataCount = 1;
@@ -1479,6 +1531,7 @@ bool loadFontAtlas ()
 	return true;
 }
 
+/// \brief Store font atlas cache to disk
 bool saveFontAtlas ()
 {
 	auto const atlas = ImGui::GetIO ().Fonts;
@@ -1488,24 +1541,30 @@ bool saveFontAtlas ()
 	int height;
 	atlas->GetTexDataAsAlpha8 (&pixels, &width, &height);
 
+	// create font atlas cache
 	fs::File fp;
 	if (!fp.open (FONT_ATLAS_BIN, "wb"))
 		return false;
 
+	// save atlas dimensions
 	fp.write<std::uint16_t> (width);
 	fp.write<std::uint16_t> (height);
 
+	// write pixel data
 	if (!fp.writeAll (pixels, width * height))
 		return false;
 
 	auto const font = atlas->ConfigData[0].DstFont;
 
+	// write some font metrics
 	fp.write (font->FallbackAdvanceX);
 	fp.write (font->FontSize);
 
+	// encode glyph metadata
 	fp.write<std::uint16_t> (font->Glyphs.size ());
 	for (auto const &glyph : font->Glyphs)
 	{
+		// write glyph metadata
 		fp.write (glyph.Codepoint);
 		fp.write (glyph.AdvanceX);
 		fp.write (glyph.X0);
@@ -1518,6 +1577,7 @@ bool saveFontAtlas ()
 		fp.write (glyph.V1);
 	}
 
+	// write remaining font metrics
 	fp.write (font->DisplayOffset.x);
 	fp.write (font->DisplayOffset.y);
 	fp.write (font->Ascent);
@@ -1529,44 +1589,71 @@ bool saveFontAtlas ()
 
 bool imgui::nx::init ()
 {
-	u64 languageCode;
-	auto rc = setInitialize ();
-	if (R_FAILED (rc))
-		return false;
+	ImGuiIO &io = ImGui::GetIO ();
 
-	rc = setGetSystemLanguage (&languageCode);
-	if (R_FAILED (rc))
+	if (!loadFontAtlas ())
 	{
+		// get system language
+		u64 languageCode;
+		auto rc = setInitialize ();
+		if (R_FAILED (rc))
+			return false;
+
+		rc = setGetSystemLanguage (&languageCode);
+		if (R_FAILED (rc))
+		{
+			setExit ();
+			return false;
+		}
 		setExit ();
-		return false;
+
+		// get fonts for system language
+		std::vector<PlFontData> fonts (PlSharedFontType_Total);
+		s32 numFonts = 0;
+		rc           = plGetSharedFont (languageCode, fonts.data (), fonts.size (), &numFonts);
+		if (R_FAILED (rc))
+			return false;
+		fonts.resize (numFonts);
+
+		// add fonts
+		ImFontConfig config;
+		config.MergeMode            = false;
+		config.FontDataOwnedByAtlas = false;
+		for (auto const &font : fonts)
+		{
+			io.Fonts->AddFontFromMemoryTTF (font.address, font.size, 14.0f, &config, nxFontRanges);
+			config.MergeMode = true;
+		}
+
+		// build font atlas
+		io.Fonts->Flags |= ImFontAtlasFlags_NoPowerOfTwoHeight;
+		io.Fonts->Build ();
+
+		// save font atlas
+		saveFontAtlas ();
 	}
-	setExit ();
-
-	std::vector<PlFontData> fonts (PlSharedFontType_Total);
-	s32 numFonts = 0;
-	rc           = plGetSharedFont (languageCode, fonts.data (), fonts.size (), &numFonts);
-	if (R_FAILED (rc))
-		return false;
-	fonts.resize (numFonts);
+	else
+		std::printf ("Loaded font atlas from disk\n");
 
+	// initialize applet hooks
 	appletSetFocusHandlingMode (AppletFocusHandlingMode_NoSuspend);
 	appletHook (&s_appletHookCookie, handleAppletHook, nullptr);
 	handleAppletHook (AppletHookType_OnFocusState, nullptr);
 	handleAppletHook (AppletHookType_OnOperationMode, nullptr);
 
-	ImGuiIO &io = ImGui::GetIO ();
-
+	// disable imgui.ini file
 	io.IniFilename = nullptr;
 
+	// setup config flags
 	io.ConfigFlags |= ImGuiConfigFlags_IsTouchScreen;
 	io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;
 	io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
 
+	// setup platform backend
 	io.BackendFlags |= ImGuiBackendFlags_HasGamepad;
+	io.BackendPlatformName = "Switch";
 
-	io.BackendPlatformName = "switch";
-
-	// Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array.
+	// keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array.
 	io.KeyMap[ImGuiKey_Tab]         = KBD_TAB;
 	io.KeyMap[ImGuiKey_LeftArrow]   = KBD_LEFT;
 	io.KeyMap[ImGuiKey_RightArrow]  = KBD_RIGHT;
@@ -1590,66 +1677,58 @@ bool imgui::nx::init ()
 	io.KeyMap[ImGuiKey_Y]           = KBD_Y;
 	io.KeyMap[ImGuiKey_Z]           = KBD_Z;
 
+	// initially disable mouse cursor
 	io.MouseDrawCursor = false;
 
+	// clipboard callbacks
 	io.SetClipboardTextFn = setClipboardText;
 	io.GetClipboardTextFn = getClipboardText;
 	io.ClipboardUserData  = nullptr;
 
-	if (!loadFontAtlas ())
-	{
-		ImFontConfig config;
-		config.MergeMode            = false;
-		config.FontDataOwnedByAtlas = false;
-
-		for (auto const &font : fonts)
-		{
-			io.Fonts->AddFontFromMemoryTTF (font.address, font.size, 14.0f, &config, nxFontRanges);
-			config.MergeMode = true;
-		}
-		io.Fonts->Flags |= ImFontAtlasFlags_NoPowerOfTwoHeight;
-		io.Fonts->Build ();
-
-		saveFontAtlas ();
-	}
-	else
-		std::printf ("Loaded font atlas from disk\n");
-
 	return true;
 }
 
 void imgui::nx::newFrame ()
 {
 	ImGuiIO &io = ImGui::GetIO ();
+
+	// check that font was built
 	IM_ASSERT (io.Fonts->IsBuilt () &&
 	           "Font atlas not built! It is generally built by the renderer back-end. Missing call "
 	           "to renderer _NewFrame() function?");
 
+	// setup display metrics
 	io.DisplaySize             = ImVec2 (s_width, s_height);
 	io.DisplayFramebufferScale = ImVec2 (1.0f, 1.0f);
 
-	// Setup time step
-	static auto const start = std::chrono::high_resolution_clock::now ();
+	// time step
+	static auto const start = platform::steady_clock::now ();
 	static auto prev        = start;
-	auto const now          = std::chrono::high_resolution_clock::now ();
+	auto const now          = platform::steady_clock::now ();
 
 	io.DeltaTime = std::chrono::duration<float> (now - prev).count ();
 	prev         = now;
 
-	updateMouseButtons (io);
-	updateMousePos (io);
-	updateTouch (io);
-	updateGamepads (io);
-	updateKeyboard (io);
+	if (s_focused)
+	{
+		// update inputs
+		updateMouseButtons (io);
+		updateMousePos (io);
+		updateTouch (io);
+		updateGamepads (io);
+		updateKeyboard (io);
+	}
 
+	// whether to draw mouse cursor
 	io.MouseDrawCursor = s_showMouse;
 
-	// Clamp mouse to screen
+	// clamp mouse to screen
 	s_mousePos.x = std::clamp (s_mousePos.x, 0.0f, s_width);
 	s_mousePos.y = std::clamp (s_mousePos.y, 0.0f, s_height);
 }
 
 void imgui::nx::exit ()
 {
+	// deinitialize applet hooks
 	appletUnhook (&s_appletHookCookie);
 }

source/switch/init.c

@@ -23,9 +23,11 @@
 #include <unistd.h>
 
 #ifndef NDEBUG
+/// \brief nxlink socket fd
 static int s_fd = -1;
 #endif
 
+/// \brief Socket initialization configuration
 static SocketInitConfig const s_socketInitConfig = {
     .bsdsockets_version = 1,
 
@@ -43,10 +45,13 @@ static SocketInitConfig const s_socketInitConfig = {
     .bsd_service_type = BsdServiceType_User,
 };
 
+/// \brief Number of FS sessions
 u32 __nx_fs_num_sessions = 3;
 
+/// \brief Called before main ()
 void userAppInit ()
 {
+	// disable immediate app close
 	appletLockExit ();
 
 	romfsInit ();

source/switch/platform.cpp

@@ -32,14 +32,8 @@
 
 bool platform::init ()
 {
-	IMGUI_CHECKVERSION ();
-	ImGui::CreateContext ();
-
 	if (!imgui::nx::init ())
-	{
-		ImGui::DestroyContext ();
 		return false;
-	}
 
 	imgui::deko3d::init ();
 
@@ -77,20 +71,22 @@ void platform::exit ()
 {
 	imgui::nx::exit ();
 	imgui::deko3d::exit ();
-
-	ImGui::DestroyContext ();
 }
 
 ///////////////////////////////////////////////////////////////////////////
+/// \brief Platform thread pimpl
 class platform::Thread::privateData_t
 {
 public:
 	privateData_t () = default;
 
+	/// \brief Parameterized constructor
+	/// \param func_ Thread entry point
 	privateData_t (std::function<void ()> func_) : thread (func_)
 	{
 	}
 
+	/// \brief Underlying thread
 	std::thread thread;
 };
 
@@ -128,12 +124,16 @@ void platform::Thread::sleep (std::chrono::milliseconds const timeout_)
 
 ///////////////////////////////////////////////////////////////////////////
 #define USE_STD_MUTEX 1
+
+/// \brief Platform mutex pimpl
 class platform::Mutex::privateData_t
 {
 public:
 #if USE_STD_MUTEX
+	/// \brief Underlying mutex
 	std::mutex mutex;
 #else
+	/// \brief Underlying mutex
 	::Mutex mutex;
 #endif
 };