Comment mouse tracker actions

src/citra_libretro/input/mouse_tracker.cpp

@@ -74,12 +74,14 @@ void MouseTracker::Update(int bufferWidth, int bufferHeight,
     auto widthSpeed = (bottomScreen.GetWidth() / 20.0);
     auto heightSpeed = (bottomScreen.GetHeight() / 20.0);
 
+    // Read in and convert pointer values to absolute values on the canvas
     auto pointerX = LibRetro::CheckInput(0, RETRO_DEVICE_POINTER, 0, RETRO_DEVICE_ID_POINTER_X);
     auto pointerY = LibRetro::CheckInput(0, RETRO_DEVICE_POINTER, 0, RETRO_DEVICE_ID_POINTER_Y);
     auto newX = static_cast<int>((pointerX + 0x7fff) / (float)(0x7fff * 2) * bufferWidth);
     auto newY = static_cast<int>((pointerY + 0x7fff) / (float)(0x7fff * 2) * bufferHeight);
 
     if ((pointerX != 0 || pointerY != 0) && (newX != lastMouseX || newY != lastMouseY)) {
+        // Use mouse pointer movement
         lastMouseX = newX;
         lastMouseY = newY;
 
@@ -88,6 +90,7 @@ void MouseTracker::Update(int bufferWidth, int bufferHeight,
         y = std::max(static_cast<int>(bottomScreen.top), std::min(newY, static_cast<int>(bottomScreen.bottom))) -
                bottomScreen.top;
     } else if (LibRetro::settings.analog_function != LibRetro::CStickFunction::CStick) {
+        // Use controller movement
         float controllerX =
                 ((float) LibRetro::CheckInput(0, RETRO_DEVICE_ANALOG, RETRO_DEVICE_INDEX_ANALOG_RIGHT,
                                               RETRO_DEVICE_ID_ANALOG_X) /