Add runtime blargg NTSC filter option

Makefile.libretro

@@ -1,4 +1,3 @@
-NTSC = 0
 DEBUG = 0
 LOGSOUND = 0
 FRONTEND_SUPPORTS_RGB565 = 1
@@ -53,7 +52,7 @@ else ifeq ($(platform), ios)
 else ifeq ($(platform), qnx)
    TARGET := genesis_plus_gx_libretro.so
    fpic := -fPIC
-   SHARED := -shared -Wl,--version-script=libretro/link.T -Wl,--no-undefined -lz
+   SHARED := -lm -shared -Wl,--version-script=libretro/link.T -Wl,--no-undefined -lz
    ENDIANNESS_DEFINES := -DLSB_FIRST
    PLATFORM_DEFINES := -DHAVE_ZLIB
 	CC = qcc -Vgcc_ntoarmv7le
@@ -105,10 +104,6 @@ else
    PLATFORM_DEFINES := -DHAVE_ZLIB
 endif
 
-ifeq ($(NTSC), 1)
-    CFLAGS += -DUSE_NTSC
-endif
-
 ifeq ($(DEBUG), 1)
    CFLAGS += -O0 -g
 else

libretro/libretro.c

@@ -36,7 +36,18 @@ static retro_input_state_t input_state_cb;
 static retro_environment_t environ_cb;
 static retro_audio_sample_batch_t audio_batch_cb;
 
-void retro_set_environment(retro_environment_t cb) { environ_cb = cb; }
+void retro_set_environment(retro_environment_t cb)
+{
+   environ_cb = cb;
+
+   static const struct retro_variable vars[] = {
+      { "blargg_ntsc_filter", "Blargg NTSC filter; disabled|enabled" },
+      { NULL, NULL },
+   };
+
+   cb(RETRO_ENVIRONMENT_SET_VARIABLES, (void*)vars);
+}
+
 void retro_set_video_refresh(retro_video_refresh_t cb) { video_cb = cb; }
 void retro_set_audio_sample(retro_audio_sample_t cb) { (void)cb; }
 void retro_set_audio_sample_batch(retro_audio_sample_batch_t cb) { audio_batch_cb = cb; }
@@ -242,9 +253,7 @@ static void config_default(void)
    config.aspect   = 0;
    config.overscan = 0; /* 3 == FULL */
    config.gg_extra = 0; /* 1 = show extended Game Gear screen (256x192) */
-#if defined(USE_NTSC)
+   config.ntsc     = 0;
-   config.ntsc     = 1;
-#endif
    config.vsync    = 1; /* AUTO */
 
    config.render   = 0;
@@ -783,7 +792,6 @@ static void retro_set_viewport_dimensions(void)
 
    retro_reset();
 
-#if defined(USE_NTSC)
    if (config.ntsc)
    {
       if (system_hw & SYSTEM_MD)
@@ -791,7 +799,6 @@ static void retro_set_viewport_dimensions(void)
       else
          vwidth = SMS_NTSC_OUT_WIDTH(vwidth);
    }
-#endif
 
    geom.aspect_ratio = 4.0 / 3.0;
    geom.base_width = vwidth;
@@ -838,6 +845,22 @@ static bool LoadFile(char * filename)
    return size > 0;
 }
 
+static void check_variables(void)
+{
+   struct retro_variable var = {0};
+   var.key = "blargg_ntsc_filter";
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
+   {
+      if (strcmp(var.value, "disabled") == 0)
+         config.ntsc = 0;
+      else if (strcmp(var.value, "enabled") == 0)
+         config.ntsc = 1;
+
+      retro_set_viewport_dimensions();
+   }
+}
+
 bool retro_load_game(const struct retro_game_info *info)
 {
    const char *full_path;
@@ -911,6 +934,8 @@ bool retro_load_game(const struct retro_game_info *info)
 
    retro_set_viewport_dimensions();
 
+   check_variables();
+
    return TRUE;
 }
 
@@ -963,12 +988,10 @@ size_t retro_get_memory_size(unsigned id)
 void retro_init(void)
 {
    unsigned level, rgb565;
-#if defined(USE_NTSC)
    sms_ntsc = calloc(1, sizeof(sms_ntsc_t));
    md_ntsc  = calloc(1, sizeof(md_ntsc_t));
    sms_ntsc_init(sms_ntsc, &sms_ntsc_composite);
    md_ntsc_init(md_ntsc,   &md_ntsc_composite);
-#endif
 
    level = 1;
    environ_cb(RETRO_ENVIRONMENT_SET_PERFORMANCE_LEVEL, &level);
@@ -983,10 +1006,8 @@ void retro_init(void)
 void retro_deinit(void)
 {
    audio_shutdown();
-#if defined(USE_NTSC)
    free(md_ntsc);
    free(sms_ntsc);
-#endif
 }
 
 void retro_reset(void) { system_reset(); }
@@ -1099,13 +1120,13 @@ void retro_run(void)
    else
       system_frame_sms(0);
 
-#if defined(USE_NTSC)
    video_cb(bitmap.data, config.ntsc ? vwidth : (bitmap.viewport.w + (bitmap.viewport.x * 2)), bitmap.viewport.h + (bitmap.viewport.y * 2), bitmap.pitch);
-#else
-   video_cb(bitmap.data, bitmap.viewport.w + (bitmap.viewport.x * 2), bitmap.viewport.h + (bitmap.viewport.y * 2), bitmap.pitch);
-#endif
 
    aud = audio_update(soundbuffer) << 1;
    audio_batch_cb(soundbuffer, aud >> 1);
+
+   bool updated = false;
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) && updated)
+      check_variables();
 }
 

libretro/libretro.h

@@ -19,7 +19,7 @@ extern "C" {
 #endif
 
 // Used for checking API/ABI mismatches that can break libretro implementations.
-// It is not incremented for compatible changes.
+// It is not incremented for compatible changes to the API.
 #define RETRO_API_VERSION         1
 
 // Libretro's fundamental device abstractions.
@@ -50,6 +50,28 @@ extern "C" {
 // Only use ANALOG type when polling for analog values of the axes.
 #define RETRO_DEVICE_ANALOG       5
 
+// Abstracts the concept of a pointing mechanism, e.g. touch.
+// This allows libretro to query in absolute coordinates where on the screen a mouse (or something similar) is being placed.
+// For a touch centric device, coordinates reported are the coordinates of the press.
+//
+// Coordinates in X and Y are reported as:
+// [-0x7fff, 0x7fff]: -0x7fff corresponds to the far left/top of the screen,
+// and 0x7fff corresponds to the far right/bottom of the screen.
+// The "screen" is here defined as area that is passed to the frontend and later displayed on the monitor.
+// The frontend is free to scale/resize this screen as it sees fit, however,
+// (X, Y) = (-0x7fff, -0x7fff) will correspond to the top-left pixel of the game image, etc.
+//
+// To check if the pointer coordinates are valid (e.g. a touch display actually being touched),
+// PRESSED returns 1 or 0.
+// If using a mouse, PRESSED will usually correspond to the left mouse button.
+// PRESSED will only return 1 if the pointer is inside the game screen.
+//
+// For multi-touch, the index variable can be used to successively query more presses.
+// If index = 0 returns true for _PRESSED, coordinates can be extracted
+// with _X, _Y for index = 0. One can then query _PRESSED, _X, _Y with index = 1, and so on.
+// Eventually _PRESSED will return false for an index. No further presses are registered at this point.
+#define RETRO_DEVICE_POINTER      6
+
 // These device types are specializations of the base types above.
 // They should only be used in retro_set_controller_type() to inform libretro implementations
 // about use of a very specific device type.
@@ -101,6 +123,11 @@ extern "C" {
 #define RETRO_DEVICE_ID_LIGHTGUN_PAUSE    5
 #define RETRO_DEVICE_ID_LIGHTGUN_START    6
 
+// Id values for POINTER.
+#define RETRO_DEVICE_ID_POINTER_X         0
+#define RETRO_DEVICE_ID_POINTER_Y         1
+#define RETRO_DEVICE_ID_POINTER_PRESSED   2
+
 // Returned from retro_get_region().
 #define RETRO_REGION_NTSC  0
 #define RETRO_REGION_PAL   1
@@ -285,9 +312,30 @@ enum retro_key
    RETROK_EURO           = 321,
    RETROK_UNDO           = 322,
 
-   RETROK_LAST
+   RETROK_LAST,
+
+   RETROK_DUMMY          = INT_MAX // Ensure sizeof(enum) == sizeof(int)
 };
 
+enum retro_mod
+{
+   RETROKMOD_NONE       = 0x0000,
+
+   RETROKMOD_SHIFT      = 0x01,
+   RETROKMOD_CTRL       = 0x02,
+   RETROKMOD_ALT        = 0x04,
+   RETROKMOD_META       = 0x08,
+
+   RETROKMOD_NUMLOCK    = 0x10,
+   RETROKMOD_CAPSLOCK   = 0x20,
+   RETROKMOD_SCROLLOCK  = 0x40,
+
+   RETROKMOD_DUMMY = INT_MAX // Ensure sizeof(enum) == sizeof(int)
+};
+
+// If set, this call is not part of the public libretro API yet. It can change or be removed at any time.
+#define RETRO_ENVIRONMENT_EXPERIMENTAL 0x10000
+
 // Environment commands.
 #define RETRO_ENVIRONMENT_SET_ROTATION  1  // const unsigned * --
                                            // Sets screen rotation of graphics.
@@ -302,18 +350,7 @@ enum retro_key
                                            // Boolean value whether or not frontend supports frame duping,
                                            // passing NULL to video frame callback.
                                            //
-#define RETRO_ENVIRONMENT_GET_VARIABLE  4  // struct retro_variable * --
+// Environ 4, 5 are no longer supported (GET_VARIABLE / SET_VARIABLES), and reserved to avoid possible ABI clash.
-                                           // Interface to aquire user-defined information from environment
-                                           // that cannot feasibly be supported in a multi-system way.
-                                           // Mostly used for obscure,
-                                           // specific features that the user can tap into when neseccary.
-                                           //
-#define RETRO_ENVIRONMENT_SET_VARIABLES 5  // const struct retro_variable * --
-                                           // Allows an implementation to signal the environment
-                                           // which variables it might want to check for later using GET_VARIABLE.
-                                           // 'data' points to an array of retro_variable structs terminated by a { NULL, NULL } element.
-                                           // retro_variable::value should contain a human readable description of the key.
-                                           //
 #define RETRO_ENVIRONMENT_SET_MESSAGE   6  // const struct retro_message * --
                                            // Sets a message to be displayed in implementation-specific manner for a certain amount of 'frames'.
                                            // Should not be used for trivial messages, which should simply be logged to stderr.
@@ -366,7 +403,151 @@ enum retro_key
                                            // It is up to the frontend to present this in a usable way.
                                            // The array is terminated by retro_input_descriptor::description being set to NULL.
                                            // This function can be called at any time, but it is recommended to call it as early as possible.
+#define RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK 12
+                                           // const struct retro_keyboard_callback * --
+                                           // Sets a callback function used to notify core about keyboard events.
+                                           //
+#define RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE 13
+                                           // const struct retro_disk_control_callback * --
+                                           // Sets an interface which frontend can use to eject and insert disk images.
+                                           // This is used for games which consist of multiple images and must be manually
+                                           // swapped out by the user (e.g. PSX).
+#define RETRO_ENVIRONMENT_SET_HW_RENDER    (14 | RETRO_ENVIRONMENT_EXPERIMENTAL)
+                                           // struct retro_hw_render_callback * --
+                                           // NOTE: This call is currently very experimental, and should not be considered part of the public API.
+                                           // The interface could be changed or removed at any time.
+                                           // Sets an interface to let a libretro core render with hardware acceleration.
+                                           // Should be called in retro_load_game().
+                                           // If successful, libretro cores will be able to render to a frontend-provided framebuffer.
+                                           // The size of this framebuffer will be at least as large as max_width/max_height provided in get_av_info().
+                                           // If HW rendering is used, pass only RETRO_HW_FRAME_BUFFER_VALID or NULL to retro_video_refresh_t.
+#define RETRO_ENVIRONMENT_GET_VARIABLE 15
+                                           // struct retro_variable * --
+                                           // Interface to aquire user-defined information from environment
+                                           // that cannot feasibly be supported in a multi-system way.
+                                           // 'key' should be set to a key which has already been set by SET_VARIABLES.
+                                           // 'data' will be set to a value or NULL.
+                                           //
+#define RETRO_ENVIRONMENT_SET_VARIABLES 16
+                                           // const struct retro_variable * --
+                                           // Allows an implementation to signal the environment
+                                           // which variables it might want to check for later using GET_VARIABLE.
+                                           // This allows the frontend to present these variables to a user dynamically.
+                                           // This should be called as early as possible (ideally in retro_set_environment).
+                                           //
+                                           // 'data' points to an array of retro_variable structs terminated by a { NULL, NULL } element.
+                                           // retro_variable::key should be namespaced to not collide with other implementations' keys. E.g. A core called 'foo' should use keys named as 'foo_option'.
+                                           // retro_variable::value should contain a human readable description of the key as well as a '|' delimited list of expected values.
+                                           // The number of possible options should be very limited, i.e. it should be feasible to cycle through options without a keyboard.
+                                           // First entry should be treated as a default.
+                                           //
+                                           // Example entry:
+                                           // { "foo_option", "Speed hack coprocessor X; false|true" }
+                                           //
+                                           // Text before first ';' is description. This ';' must be followed by a space, and followed by a list of possible values split up with '|'.
+                                           // Only strings are operated on. The possible values will generally be displayed and stored as-is by the frontend.
+                                           //
+#define RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE 17
+                                           // bool * --
+                                           // Result is set to true if some variables are updated by
+                                           // frontend since last call to RETRO_ENVIRONMENT_GET_VARIABLE.
+                                           // Variables should be queried with GET_VARIABLE.
 
+// Pass this to retro_video_refresh_t if rendering to hardware.
+// Passing NULL to retro_video_refresh_t is still a frame dupe as normal.
+#define RETRO_HW_FRAME_BUFFER_VALID ((void*)-1)
+
+// Invalidates the current HW context.
+// If called, all GPU resources must be reinitialized.
+// Usually called when frontend reinits video driver.
+// Also called first time video driver is initialized, allowing libretro core to init resources.
+typedef void (*retro_hw_context_reset_t)(void);
+// Gets current framebuffer which is to be rendered to. Could change every frame potentially.
+typedef uintptr_t (*retro_hw_get_current_framebuffer_t)(void);
+
+// Get a symbol from HW context.
+typedef void (*retro_proc_address_t)(void);
+typedef retro_proc_address_t (*retro_hw_get_proc_address_t)(const char *sym);
+
+enum retro_hw_context_type
+{
+   RETRO_HW_CONTEXT_NONE = 0,
+   RETRO_HW_CONTEXT_OPENGL, // OpenGL 2.x. Latest version available before 3.x+.
+   RETRO_HW_CONTEXT_OPENGLES2, // GLES 2.0
+
+   RETRO_HW_CONTEXT_DUMMY = INT_MAX
+};
+
+struct retro_hw_render_callback
+{
+   enum retro_hw_context_type context_type; // Which API to use. Set by libretro core.
+   retro_hw_context_reset_t context_reset; // Set by libretro core.
+   retro_hw_get_current_framebuffer_t get_current_framebuffer; // Set by frontend.
+   retro_hw_get_proc_address_t get_proc_address; // Set by frontend.
+   bool depth; // Set if render buffers should have depth component attached.
+};
+
+// Callback type passed in RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK. Called by the frontend in response to keyboard events.
+// down is set if the key is being pressed, or false if it is being released.
+// keycode is the RETROK value of the char.
+// character is the text character of the pressed key. (UTF-32).
+// key_modifiers is a set of RETROKMOD values or'ed together.
+typedef void (*retro_keyboard_event_t)(bool down, unsigned keycode, uint32_t character, uint16_t key_modifiers);
+
+struct retro_keyboard_callback
+{
+    retro_keyboard_event_t callback;
+};
+
+// Callbacks for RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE.
+// Should be set for implementations which can swap out multiple disk images in runtime.
+// If the implementation can do this automatically, it should strive to do so.
+// However, there are cases where the user must manually do so.
+//
+// Overview: To swap a disk image, eject the disk image with set_eject_state(true).
+// Set the disk index with set_image_index(index). Insert the disk again with set_eject_state(false).
+
+// If ejected is true, "ejects" the virtual disk tray.
+// When ejected, the disk image index can be set.
+typedef bool (*retro_set_eject_state_t)(bool ejected);
+// Gets current eject state. The initial state is 'not ejected'.
+typedef bool (*retro_get_eject_state_t)(void);
+// Gets current disk index. First disk is index 0.
+// If return value is >= get_num_images(), no disk is currently inserted.
+typedef unsigned (*retro_get_image_index_t)(void);
+// Sets image index. Can only be called when disk is ejected.
+// The implementation supports setting "no disk" by using an index >= get_num_images().
+typedef bool (*retro_set_image_index_t)(unsigned index);
+// Gets total number of images which are available to use.
+typedef unsigned (*retro_get_num_images_t)(void);
+//
+// Replaces the disk image associated with index.
+// Arguments to pass in info have same requirements as retro_load_game().
+// Virtual disk tray must be ejected when calling this.
+// Replacing a disk image with info = NULL will remove the disk image from the internal list.
+// As a result, calls to get_image_index() can change.
+//
+// E.g. replace_image_index(1, NULL), and previous get_image_index() returned 4 before.
+// Index 1 will be removed, and the new index is 3.
+struct retro_game_info;
+typedef bool (*retro_replace_image_index_t)(unsigned index, const struct retro_game_info *info);
+// Adds a new valid index (get_num_images()) to the internal disk list.
+// This will increment subsequent return values from get_num_images() by 1.
+// This image index cannot be used until a disk image has been set with replace_image_index.
+typedef bool (*retro_add_image_index_t)(void);
+
+struct retro_disk_control_callback
+{
+   retro_set_eject_state_t set_eject_state;
+   retro_get_eject_state_t get_eject_state;
+
+   retro_get_image_index_t get_image_index;
+   retro_set_image_index_t set_image_index;
+   retro_get_num_images_t  get_num_images;
+
+   retro_replace_image_index_t replace_image_index;
+   retro_add_image_index_t add_image_index;
+};
 
 enum retro_pixel_format
 {