3DS: Improve framebuffer support

src/video/n3ds/SDL_n3dsframebuffer.c

@@ -34,7 +34,9 @@ typedef struct
     int width, height;
 } Dimensions;
 
-static void CopyFramebuffertoN3DS(u32 *dest, const Dimensions dest_dim, const u32 *source, const Dimensions source_dim);
+static void CopyFramebuffertoN3DS_16(u16 *dest, const Dimensions dest_dim, const u16 *source, const Dimensions source_dim);
+static void CopyFramebuffertoN3DS_24(u8  *dest, const Dimensions dest_dim, const u8  *source, const Dimensions source_dim);
+static void CopyFramebuffertoN3DS_32(u32 *dest, const Dimensions dest_dim, const u32 *source, const Dimensions source_dim);
 static int GetDestOffset(int x, int y, int dest_width);
 static int GetSourceOffset(int x, int y, int source_width);
 static void FlushN3DSBuffer(const void *buffer, u32 bufsize, gfxScreen_t screen);
@@ -43,17 +45,21 @@ static void FlushN3DSBuffer(const void *buffer, u32 bufsize, gfxScreen_t screen)
 int SDL_N3DS_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, SDL_PixelFormatEnum *format, void **pixels, int *pitch)
 {
     SDL_Surface *framebuffer;
+    const SDL_DisplayMode *mode;
     int w, h;
 
+    SDL_N3DS_DestroyWindowFramebuffer(_this, window);
+
+    mode = SDL_GetCurrentDisplayMode(SDL_GetDisplayForWindow(window));
     SDL_GetWindowSizeInPixels(window, &w, &h);
-    framebuffer = SDL_CreateSurface(w, h, FRAMEBUFFER_FORMAT);
+    framebuffer = SDL_CreateSurface(w, h, mode->format);
 
     if (!framebuffer) {
         return -1;
     }
 
     SDL_SetSurfaceProperty(SDL_GetWindowProperties(window), N3DS_SURFACE, framebuffer);
-    *format = FRAMEBUFFER_FORMAT;
+    *format = mode->format;
     *pixels = framebuffer->pixels;
     *pitch = framebuffer->pitch;
     return 0;
@@ -64,7 +70,7 @@ int SDL_N3DS_UpdateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window,
     SDL_WindowData *drv_data = window->driverdata;
     SDL_Surface *surface;
     u16 width, height;
-    u32 *framebuffer;
+    void *framebuffer;
     u32 bufsize;
 
     surface = (SDL_Surface *)SDL_GetProperty(SDL_GetWindowProperties(window), N3DS_SURFACE, NULL);
@@ -73,26 +79,60 @@ int SDL_N3DS_UpdateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window,
     }
 
     /* Get the N3DS internal framebuffer and its size */
-    framebuffer = (u32 *)gfxGetFramebuffer(drv_data->screen, GFX_LEFT, &width, &height);
+    framebuffer = gfxGetFramebuffer(drv_data->screen, GFX_LEFT, &width, &height);
     bufsize = width * height * 4;
 
-    CopyFramebuffertoN3DS(framebuffer, (Dimensions){ width, height },
-                          surface->pixels, (Dimensions){ surface->w, surface->h });
+    if (surface->format->bytes_per_pixel == 2)
+        CopyFramebuffertoN3DS_16(framebuffer, (Dimensions){ width, height },
+                                 surface->pixels, (Dimensions){ surface->w, surface->h });
+    else if (surface->format->bytes_per_pixel == 3)
+        CopyFramebuffertoN3DS_24(framebuffer, (Dimensions){ width, height },
+                                 surface->pixels, (Dimensions){ surface->w, surface->h });
+    else
+        CopyFramebuffertoN3DS_32(framebuffer, (Dimensions){ width, height },
+                                 surface->pixels, (Dimensions){ surface->w, surface->h });
     FlushN3DSBuffer(framebuffer, bufsize, drv_data->screen);
 
     return 0;
 }
 
-static void CopyFramebuffertoN3DS(u32 *dest, const Dimensions dest_dim, const u32 *source, const Dimensions source_dim)
+static void CopyFramebuffertoN3DS_16(u16 *dest, const Dimensions dest_dim, const u16 *source, const Dimensions source_dim)
+{
+    int rows = SDL_min(dest_dim.width, source_dim.height);
+    int cols = SDL_min(dest_dim.height, source_dim.width);
+    for (int y = 0; y < rows; ++y) {
+        for (int x = 0; x < cols; ++x) {
+            const u16 *s = source + GetSourceOffset(x, y, source_dim.width);
+            u16 *d = dest + GetDestOffset(x, y, dest_dim.width);
+            *d = *s;
+        }
+    }
+}
+
+static void CopyFramebuffertoN3DS_24(u8 *dest, const Dimensions dest_dim, const u8 *source, const Dimensions source_dim)
+{
+    int rows = SDL_min(dest_dim.width, source_dim.height);
+    int cols = SDL_min(dest_dim.height, source_dim.width);
+    for (int y = 0; y < rows; ++y) {
+        for (int x = 0; x < cols; ++x) {
+            const u8 *s = source + GetSourceOffset(x, y, source_dim.width) * 3;
+            u8 *d = dest + GetDestOffset(x, y, dest_dim.width) * 3;
+            d[0] = s[0];
+            d[1] = s[1];
+            d[2] = s[2];
+        }
+    }
+}
+
+static void CopyFramebuffertoN3DS_32(u32 *dest, const Dimensions dest_dim, const u32 *source, const Dimensions source_dim)
 {
     int rows = SDL_min(dest_dim.width, source_dim.height);
     int cols = SDL_min(dest_dim.height, source_dim.width);
     for (int y = 0; y < rows; ++y) {
         for (int x = 0; x < cols; ++x) {
-            SDL_memcpy(
-                dest + GetDestOffset(x, y, dest_dim.width),
-                source + GetSourceOffset(x, y, source_dim.width),
-                4);
+            const u32 *s = source + GetSourceOffset(x, y, source_dim.width);
+            u32 *d = dest + GetDestOffset(x, y, dest_dim.width);
+            *d = *s;
         }
     }
 }

src/video/n3ds/SDL_n3dsvideo.c

@@ -35,6 +35,8 @@ static int AddN3DSDisplay(gfxScreen_t screen);
 
 static int N3DS_VideoInit(SDL_VideoDevice *_this);
 static void N3DS_VideoQuit(SDL_VideoDevice *_this);
+static int N3DS_GetDisplayModes(SDL_VideoDevice *_this, SDL_VideoDisplay *display);
+static int N3DS_SetDisplayMode(SDL_VideoDevice *_this, SDL_VideoDisplay *display, SDL_DisplayMode *mode);
 static int N3DS_GetDisplayBounds(SDL_VideoDevice *_this, SDL_VideoDisplay *display, SDL_Rect *rect);
 static int N3DS_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window, SDL_PropertiesID create_props);
 static void N3DS_DestroyWindow(SDL_VideoDevice *_this, SDL_Window *window);
@@ -44,6 +46,23 @@ struct SDL_DisplayData
     gfxScreen_t screen;
 };
 
+struct SDL_DisplayModeData
+{
+    GSPGPU_FramebufferFormat fmt;
+};
+
+static const struct
+{
+    SDL_PixelFormatEnum pixfmt;
+    GSPGPU_FramebufferFormat gspfmt;
+} format_map[] = {
+    { SDL_PIXELFORMAT_RGBA8888, GSP_RGBA8_OES },
+    { SDL_PIXELFORMAT_BGR24, GSP_BGR8_OES },
+    { SDL_PIXELFORMAT_RGB565, GSP_RGB565_OES },
+    { SDL_PIXELFORMAT_RGBA5551, GSP_RGB5_A1_OES },
+    { SDL_PIXELFORMAT_RGBA4444, GSP_RGBA4_OES }
+};
+
 /* N3DS driver bootstrap functions */
 
 static void N3DS_DeleteDevice(SDL_VideoDevice *device)
@@ -76,6 +95,8 @@ static SDL_VideoDevice *N3DS_CreateDevice(void)
     device->VideoInit = N3DS_VideoInit;
     device->VideoQuit = N3DS_VideoQuit;
 
+    device->GetDisplayModes = N3DS_GetDisplayModes;
+    device->SetDisplayMode = N3DS_SetDisplayMode;
     device->GetDisplayBounds = N3DS_GetDisplayBounds;
 
     device->CreateSDLWindow = N3DS_CreateWindow;
@@ -93,6 +114,8 @@ static SDL_VideoDevice *N3DS_CreateDevice(void)
 
     device->free = N3DS_DeleteDevice;
 
+    device->device_caps = VIDEO_DEVICE_CAPS_FULLSCREEN_ONLY;
+
     return device;
 }
 
@@ -117,6 +140,7 @@ static int N3DS_VideoInit(SDL_VideoDevice *_this)
 static int AddN3DSDisplay(gfxScreen_t screen)
 {
     SDL_DisplayMode mode;
+    SDL_DisplayModeData *modedata;
     SDL_VideoDisplay display;
     SDL_DisplayData *display_driver_data = SDL_calloc(1, sizeof(SDL_DisplayData));
     if (!display_driver_data) {
@@ -128,10 +152,17 @@ static int AddN3DSDisplay(gfxScreen_t screen)
 
     display_driver_data->screen = screen;
 
+    modedata = SDL_malloc(sizeof(SDL_DisplayModeData));
+    if (!modedata) {
+        return -1;
+    }
+
     mode.w = (screen == GFX_TOP) ? GSP_SCREEN_HEIGHT_TOP : GSP_SCREEN_HEIGHT_BOTTOM;
     mode.h = GSP_SCREEN_WIDTH;
     mode.refresh_rate = 60.0f;
-    mode.format = FRAMEBUFFER_FORMAT;
+    mode.format = SDL_PIXELFORMAT_RGBA8888;
+    mode.driverdata = modedata;
+    modedata->fmt = GSP_RGBA8_OES;
 
     display.name = (screen == GFX_TOP) ? "N3DS top screen" : "N3DS bottom screen";
     display.desktop_mode = mode;
@@ -149,6 +180,43 @@ static void N3DS_VideoQuit(SDL_VideoDevice *_this)
     gfxExit();
 }
 
+static int N3DS_GetDisplayModes(SDL_VideoDevice *_this, SDL_VideoDisplay *display)
+{
+    SDL_DisplayData *displaydata = display->driverdata;
+    SDL_DisplayModeData *modedata;
+    SDL_DisplayMode mode;
+    int i;
+
+    for (i = 0; i < SDL_arraysize(format_map); i++) {
+        modedata = SDL_malloc(sizeof(SDL_DisplayModeData));
+        if (!modedata)
+            continue;
+
+        SDL_zero(mode);
+        mode.w = (displaydata->screen == GFX_TOP) ? GSP_SCREEN_HEIGHT_TOP : GSP_SCREEN_HEIGHT_BOTTOM;
+        mode.h = GSP_SCREEN_WIDTH;
+        mode.refresh_rate = 60;
+        mode.format = format_map[i].pixfmt;
+        mode.driverdata = modedata;
+        modedata->fmt = format_map[i].gspfmt;
+
+        if (!SDL_AddFullscreenDisplayMode(display, &mode)) {
+            SDL_free(modedata);
+        }
+    }
+
+    return 0;
+}
+
+static int N3DS_SetDisplayMode(SDL_VideoDevice *_this, SDL_VideoDisplay *display, SDL_DisplayMode *mode)
+{
+    SDL_DisplayData *displaydata = display->driverdata;
+    SDL_DisplayModeData *modedata = mode->driverdata;
+
+    gfxSetScreenFormat(displaydata->screen, modedata->fmt);
+    return 0;
+}
+
 static int N3DS_GetDisplayBounds(SDL_VideoDevice *_this, SDL_VideoDisplay *display, SDL_Rect *rect)
 {
     SDL_DisplayData *driver_data = display->driverdata;

src/video/n3ds/SDL_n3dsvideo.h

@@ -38,6 +38,4 @@ struct SDL_WindowData
     gfxScreen_t screen; /**< Keeps track of which N3DS screen is targeted */
 };
 
-#define FRAMEBUFFER_FORMAT SDL_PIXELFORMAT_RGBA8888
-
 #endif /* SDL_n3dsvideo_h_ */