hidpi test

app/src/scrcpy.c

@@ -35,6 +35,21 @@ static struct input_manager input_manager = {
     .screen = &screen,
 };
 
+static void hidpi_fix_coordinates(Sint32 *x, Sint32 *y) {
+    struct screen_sizes sizes = screen_get_sizes(&screen);
+    Uint16 ww = sizes.window_size.width;
+    Uint16 wh = sizes.window_size.height;
+    Uint16 dw = sizes.drawable_size.width;
+    Uint16 dh = sizes.drawable_size.height;
+    printf("window=%dx%d; drawable=%dx%d\n", (int) ww, (int) wh, (int) dw, (int) dh);
+    if (dw && dw != ww) {
+        *x = ((Sint64) *x) * ww / dw;
+    }
+    if (dh && dh != wh) {
+        *y = ((Sint64) *y) * wh / dh;
+    }
+}
+
 static void event_loop(void) {
     SDL_Event event;
     while (SDL_WaitEvent(&event)) {
@@ -72,14 +87,17 @@ static void event_loop(void) {
                 input_manager_process_key(&input_manager, &event.key);
                 break;
             case SDL_MOUSEMOTION:
+                hidpi_fix_coordinates(&event.motion.x, &event.motion.y);
                 input_manager_process_mouse_motion(&input_manager, &event.motion);
                 break;
             case SDL_MOUSEWHEEL: {
+                hidpi_fix_coordinates(&event.wheel.x, &event.wheel.y);
                 input_manager_process_mouse_wheel(&input_manager, &event.wheel);
                 break;
             }
             case SDL_MOUSEBUTTONDOWN:
             case SDL_MOUSEBUTTONUP: {
+                hidpi_fix_coordinates(&event.button.y, &event.button.y);
                 input_manager_process_mouse_button(&input_manager, &event.button);
                 break;
             }

app/src/screen.c

@@ -45,6 +45,27 @@ static struct size get_native_window_size(SDL_Window *window) {
     return size;
 }
 
+// get the size of the window underlying drawable in pixels
+// may differ from get_native_window_size() if hi-dpi is enabled
+static struct size get_native_drawable_size(SDL_Window *window) {
+    int width;
+    int height;
+    SDL_GL_GetDrawableSize(window, &width, &height);
+
+    struct size size;
+    size.width = width;
+    size.height = height;
+    return size;
+}
+
+// return both the native window size and native drawable size
+struct screen_sizes screen_get_sizes(const struct screen *screen) {
+    struct screen_sizes sizes;
+    sizes.window_size = get_native_window_size(screen->window);
+    sizes.drawable_size = get_native_drawable_size(screen->window);
+    return sizes;
+}
+
 // get the windowed window size
 static struct size get_window_size(const struct screen *screen) {
     if (screen->fullscreen) {
@@ -141,7 +162,8 @@ SDL_bool screen_init_rendering(struct screen *screen, const char *device_name, s
 
     struct size window_size = get_initial_optimal_size(frame_size);
     screen->window = SDL_CreateWindow(device_name, SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
-                                      window_size.width, window_size.height, SDL_WINDOW_HIDDEN | SDL_WINDOW_RESIZABLE);
+                                      window_size.width, window_size.height,
+                                      SDL_WINDOW_HIDDEN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
     if (!screen->window) {
         LOGC("Could not create window: %s", SDL_GetError());
         return SDL_FALSE;

app/src/screen.h

@@ -34,6 +34,15 @@ struct screen {
     .fullscreen = SDL_FALSE,  \
 }
 
+// the window and drawable size may differ if hi-dpi is enabled
+struct screen_sizes {
+    // the size of the window client area, as reported by SDL_GetWindowSize()
+    struct size window_size;
+    // the size of the window underlying drawable, as reported by
+    // SDL_GL_GetDrawableSize()
+    struct size drawable_size;
+};
+
 // init SDL and set appropriate hints
 SDL_bool sdl_init_and_configure(void);
 
@@ -66,4 +75,6 @@ void screen_resize_to_fit(struct screen *screen);
 // resize window to 1:1 (pixel-perfect)
 void screen_resize_to_pixel_perfect(struct screen *screen);
 
+struct screen_sizes screen_get_sizes(const struct screen *screen);
+
 #endif