1 files changed, 161 insertions, 0 deletions

diff --git a/contrib/SDL-3.2.8/src/video/n3ds/SDL_n3dsframebuffer.c b/contrib/SDL-3.2.8/src/video/n3ds/SDL_n3dsframebuffer.c
new file mode 100644
index 0000000..d632545
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/video/n3ds/SDL_n3dsframebuffer.c
@@ -0,0 +1,161 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "SDL_internal.h"
+
+#ifdef SDL_VIDEO_DRIVER_N3DS
+
+#include "../SDL_sysvideo.h"
+#include "../../SDL_properties_c.h"
+#include "SDL_n3dsframebuffer_c.h"
+#include "SDL_n3dsvideo.h"
+
+#define N3DS_SURFACE "SDL.internal.window.surface"
+
+typedef struct
+{
+    int width, height;
+} Dimensions;
+
+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);
+
+
+bool SDL_N3DS_CreateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, SDL_PixelFormat *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, mode->format);
+
+    if (!framebuffer) {
+        return false;
+    }
+
+    SDL_SetSurfaceProperty(SDL_GetWindowProperties(window), N3DS_SURFACE, framebuffer);
+    *format = mode->format;
+    *pixels = framebuffer->pixels;
+    *pitch = framebuffer->pitch;
+    return true;
+}
+
+bool SDL_N3DS_UpdateWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window, const SDL_Rect *rects, int numrects)
+{
+    SDL_WindowData *drv_data = window->internal;
+    SDL_Surface *surface;
+    u16 width, height;
+    void *framebuffer;
+    u32 bufsize;
+
+    surface = (SDL_Surface *)SDL_GetPointerProperty(SDL_GetWindowProperties(window), N3DS_SURFACE, NULL);
+    if (!surface) {
+        return SDL_SetError("%s: Unable to get the window surface.", __func__);
+    }
+
+    // Get the N3DS internal framebuffer and its size
+    framebuffer = gfxGetFramebuffer(drv_data->screen, GFX_LEFT, &width, &height);
+    bufsize = width * height * 4;
+
+    if (SDL_BYTESPERPIXEL(surface->format) == 2)
+        CopyFramebuffertoN3DS_16(framebuffer, (Dimensions){ width, height },
+                                 surface->pixels, (Dimensions){ surface->w, surface->h });
+    else if (SDL_BYTESPERPIXEL(surface->format) == 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 true;
+}
+
+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) {
+            const u32 *s = source + GetSourceOffset(x, y, source_dim.width);
+            u32 *d = dest + GetDestOffset(x, y, dest_dim.width);
+            *d = *s;
+        }
+    }
+}
+
+static int GetDestOffset(int x, int y, int dest_width)
+{
+    return dest_width - y - 1 + dest_width * x;
+}
+
+static int GetSourceOffset(int x, int y, int source_width)
+{
+    return x + y * source_width;
+}
+
+static void FlushN3DSBuffer(const void *buffer, u32 bufsize, gfxScreen_t screen)
+{
+    GSPGPU_FlushDataCache(buffer, bufsize);
+    gfxScreenSwapBuffers(screen, false);
+}
+
+void SDL_N3DS_DestroyWindowFramebuffer(SDL_VideoDevice *_this, SDL_Window *window)
+{
+    SDL_ClearProperty(SDL_GetWindowProperties(window), N3DS_SURFACE);
+}
+
+#endif // SDL_VIDEO_DRIVER_N3DS