Implement Guest Touch-Screen Support

app/CMakeLists.txt

@@ -48,6 +48,7 @@ add_library(skyline SHARED
         ${source_DIR}/skyline/input.cpp
         ${source_DIR}/skyline/input/npad.cpp
         ${source_DIR}/skyline/input/npad_device.cpp
+        ${source_DIR}/skyline/input/touch.cpp
         ${source_DIR}/skyline/os.cpp
         ${source_DIR}/skyline/loader/loader.cpp
         ${source_DIR}/skyline/loader/nro.cpp

app/src/main/cpp/emu_jni.cpp

@@ -131,3 +131,19 @@ extern "C" JNIEXPORT void JNICALL Java_emu_skyline_EmulationActivity_setAxisValu
         // We don't mind if we miss axis updates while input hasn't been initialized
     }
 }
+
+extern "C" JNIEXPORT void JNICALL Java_emu_skyline_EmulationActivity_setTouchState(JNIEnv *env, jobject, jintArray pointsJni) {
+    try {
+        using Point = skyline::input::TouchScreenPoint;
+
+        auto input = inputWeak.lock();
+        jboolean isCopy{false};
+
+        std::span<Point> points(reinterpret_cast<Point *>(env->GetIntArrayElements(pointsJni, &isCopy)), env->GetArrayLength(pointsJni) / (sizeof(Point) / sizeof(jint)));
+        input->touch.SetState(points);
+
+        env->ReleaseIntArrayElements(pointsJni, reinterpret_cast<jint *>(points.data()), JNI_ABORT);
+    } catch (const std::bad_weak_ptr &) {
+        // We don't mind if we miss axis updates while input hasn't been initialized
+    }
+}

app/src/main/cpp/skyline/common.h

@@ -31,7 +31,7 @@ namespace skyline {
      */
     union Result {
         u32 raw{};
-        struct {
+        struct __attribute__((packed)) {
             u16 module : 9;
             u16 id : 12;
         };
@@ -39,7 +39,7 @@ namespace skyline {
         /**
          * @note Success is 0, 0 - it is the only error that's not specific to a module
          */
-        Result() {}
+        Result() = default;
 
         constexpr Result(u16 module, u16 id) {
             this->module = module;

app/src/main/cpp/skyline/input.cpp

@@ -4,5 +4,5 @@
 #include "input.h"
 
 namespace skyline::input {
-    Input::Input(const DeviceState &state) : state(state), kHid(std::make_shared<kernel::type::KSharedMemory>(state, NULL, sizeof(HidSharedMemory), memory::Permission(true, false, false))), hid(reinterpret_cast<HidSharedMemory *>(kHid->kernel.address)), npad(state, hid) {}
+    Input::Input(const DeviceState &state) : state(state), kHid(std::make_shared<kernel::type::KSharedMemory>(state, NULL, sizeof(HidSharedMemory), memory::Permission(true, false, false))), hid(reinterpret_cast<HidSharedMemory *>(kHid->kernel.address)), npad(state, hid), touch(state, hid) {}
 }

app/src/main/cpp/skyline/input.h

@@ -7,6 +7,7 @@
 #include "kernel/types/KSharedMemory.h"
 #include "input/shared_mem.h"
 #include "input/npad.h"
+#include "input/touch.h"
 
 namespace skyline::input {
     /**
@@ -20,7 +21,8 @@ namespace skyline::input {
         std::shared_ptr<kernel::type::KSharedMemory> kHid; //!< The kernel shared memory object for HID Shared Memory
         HidSharedMemory *hid; //!< A pointer to HID Shared Memory on the host
 
-        NpadManager npad; //!< This manages all the NPad controllers
+        NpadManager npad;
+        TouchManager touch;
 
         Input(const DeviceState &state);
     };

app/src/main/cpp/skyline/input/sections/TouchScreen.h

@@ -18,10 +18,10 @@ namespace skyline::input {
         u32 positionX; //!< The X position of this touch
         u32 positionY; //!< The Y position of this touch
 
-        u32 diameterX; //!< The diameter of the touch on the X-axis
+        u32 minorAxis; //!< The diameter of the touch cross-section on the minor-axis in pixels
-        u32 diameterY; //!< The diameter of the touch on the Y-axis
+        u32 majorAxis; //!< The diameter of the touch cross-section on the major-axis in pixels
 
-        u32 angle; //!< The angle of the touch
+        i32 angle; //!< The angle of the touch in degrees (from -89 to 90 [-90 and 90 aren't distinguishable]. On the Switch, this has limited resolution with only 90, -67, -45, 0, 45, 67, 90 being values)
         u32 _pad1_;
     };
     static_assert(sizeof(TouchScreenStateData) == 0x28);

app/src/main/cpp/skyline/input/touch.cpp

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)
+
+#include <input.h>
+#include "touch.h"
+
+namespace skyline::input {
+    TouchManager::TouchManager(const DeviceState &state, input::HidSharedMemory *hid) : state(state), section(hid->touchScreen) {
+        Activate();
+    }
+
+    void TouchManager::Activate() {
+        activated = true;
+        SetState({});
+    }
+
+    void TouchManager::SetState(const std::span<TouchScreenPoint> &points) {
+        if (!activated)
+            return;
+
+        const auto& lastEntry = section.entries[section.header.currentEntry];
+        auto entryIndex = (section.header.currentEntry != constant::HidEntryCount - 1) ? section.header.currentEntry + 1 : 0;
+        auto& entry = section.entries[entryIndex];
+        entry.globalTimestamp = lastEntry.globalTimestamp + 1;
+        entry.localTimestamp = lastEntry.localTimestamp + 1;
+        entry.touchCount = points.size();
+
+        for (size_t i{}; i < points.size(); i++) {
+            const auto& host = points[i];
+            auto& guest = entry.data[i];
+            guest.index = i;
+            guest.positionX = host.x;
+            guest.positionY = host.y;
+            guest.minorAxis = host.minor;
+            guest.majorAxis = host.major;
+            guest.angle = host.angle;
+        }
+
+        section.header.timestamp = util::GetTimeTicks();
+        section.header.entryCount = std::min(static_cast<u8>(section.header.entryCount + 1), constant::HidEntryCount);
+        section.header.currentEntry = entryIndex;
+    }
+}

app/src/main/cpp/skyline/input/touch.h

@@ -0,0 +1,42 @@
+// SPDX-License-Identifier: MPL-2.0
+// Copyright © 2020 Skyline Team and Contributors (https://github.com/skyline-emu/)
+
+#pragma once
+
+#include <common.h>
+#include "shared_mem.h"
+
+namespace skyline::input {
+    /*
+     * @brief A description of a point being touched on the screen
+     * @note All members are jint as it is treated as a jint array in Kotlin
+     * @note This structure corresponds to TouchScreenStateData, see that for details
+     */
+    struct TouchScreenPoint {
+        jint x;
+        jint y;
+        jint minor;
+        jint major;
+        jint angle;
+    };
+
+    /**
+     * @brief This class is used to manage the shared memory responsible for touch-screen data
+     */
+    class TouchManager {
+      private:
+        const DeviceState &state;
+        bool activated{};
+        TouchScreenSection &section;
+
+      public:
+        /**
+         * @param hid A pointer to HID Shared Memory on the host
+         */
+        TouchManager(const DeviceState &state, input::HidSharedMemory *hid);
+
+        void Activate();
+
+        void SetState(const std::span<TouchScreenPoint> &points);
+    };
+}

app/src/main/java/emu/skyline/EmulationActivity.kt

@@ -20,7 +20,7 @@ import kotlinx.android.synthetic.main.emu_activity.*
 import java.io.File
 import kotlin.math.abs
 
-class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback {
+class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback, View.OnTouchListener {
     init {
         System.loadLibrary("skyline") // libskyline.so
     }
@@ -142,6 +142,13 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback {
      */
     private external fun setAxisValue(index : Int, axis : Int, value : Int)
 
+    /**
+     * This sets the values of the points on the guest touch-screen
+     *
+     * @param points An array of skyline::input::TouchScreenPoint in C++ represented as integers
+     */
+    private external fun setTouchState(points : IntArray)
+
     /**
      * This initializes all of the controllers from [input] on the guest
      */
@@ -235,6 +242,8 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback {
         @Suppress("DEPRECATION") val display = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) display!! else windowManager.defaultDisplay
         display?.supportedModes?.maxBy { it.refreshRate + (it.physicalHeight * it.physicalWidth) }?.let { window.attributes.preferredDisplayModeId = it.modeId }
 
+        game_view.setOnTouchListener(this)
+
         executeApplication(intent.data!!)
     }
 
@@ -390,6 +399,30 @@ class EmulationActivity : AppCompatActivity(), SurfaceHolder.Callback {
         return super.onGenericMotionEvent(event)
     }
 
+    @SuppressLint("ClickableViewAccessibility")
+    override fun onTouch(view : View, event : MotionEvent) : Boolean {
+        val count = if(event.action != MotionEvent.ACTION_UP && event.action != MotionEvent.ACTION_CANCEL) event.pointerCount else 0
+        val points = IntArray(count * 5) // This is an array of skyline::input::TouchScreenPoint in C++ as that allows for efficient transfer of values to it
+        var offset = 0
+        for (index in 0 until count) {
+            val pointer = MotionEvent.PointerCoords()
+            event.getPointerCoords(index, pointer)
+
+            val x = 0f.coerceAtLeast(pointer.x * 1280 / view.width).toInt()
+            val y = 0f.coerceAtLeast(pointer.y * 720 / view.height).toInt()
+
+            points[offset++] = x
+            points[offset++] = y
+            points[offset++] = pointer.touchMinor.toInt()
+            points[offset++] = pointer.touchMajor.toInt()
+            points[offset++] = (pointer.orientation * 180 / Math.PI).toInt()
+        }
+
+        setTouchState(points)
+
+        return true
+    }
+
     @SuppressLint("WrongConstant")
     fun vibrateDevice(index : Int, timing : LongArray, amplitude : IntArray) {
         val vibrator = if (vibrators[index] != null) {