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SDL_ReadSurfacePixel() now supports large pixel formats

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This commit is contained in:
Sam Lantinga
2024-02-05 09:43:36 -08:00
parent 9755e490c0
commit 809f02e89e
1 changed files with 24 additions and 10 deletions
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34
src/video/SDL_surface.c
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@@ -1733,6 +1733,7 @@ int SDL_ReadSurfacePixel(SDL_Surface *surface, int x, int y, Uint8 *r, Uint8 *g,
size_t bytes_per_pixel; size_t bytes_per_pixel;
Uint8 unused; Uint8 unused;
Uint8 *p; Uint8 *p;
int result = -1;
if (!surface || !surface->format || !surface->pixels) { if (!surface || !surface->format || !surface->pixels) {
return SDL_InvalidParamError("surface"); return SDL_InvalidParamError("surface");
@@ -1764,28 +1765,41 @@ int SDL_ReadSurfacePixel(SDL_Surface *surface, int x, int y, Uint8 *r, Uint8 *g,
bytes_per_pixel = surface->format->BytesPerPixel; bytes_per_pixel = surface->format->BytesPerPixel;
if (bytes_per_pixel > sizeof(pixel)) {
return SDL_InvalidParamError("surface->format->BytesPerPixel");
}
if (SDL_MUSTLOCK(surface)) { if (SDL_MUSTLOCK(surface)) {
SDL_LockSurface(surface); SDL_LockSurface(surface);
} }
p = (Uint8 *)surface->pixels + y * surface->pitch + x * bytes_per_pixel; p = (Uint8 *)surface->pixels + y * surface->pitch + x * bytes_per_pixel;
/* Fill the appropriate number of least-significant bytes of pixel,
* leaving the most-significant bytes set to zero */ if (bytes_per_pixel > sizeof(pixel)) {
/* This is really slow, but it gets the job done */
Uint8 rgba[4];
SDL_Colorspace colorspace;
if (SDL_GetSurfaceColorspace(surface, &colorspace) == 0 &&
SDL_ConvertPixelsAndColorspace(1, 1, surface->format->format, colorspace, p, surface->pitch, SDL_PIXELFORMAT_RGBA32, SDL_COLORSPACE_SRGB, rgba, sizeof(rgba)) == 0) {
*r = rgba[0];
*g = rgba[1];
*b = rgba[2];
*a = rgba[3];
result = 0;
}
} else {
/* Fill the appropriate number of least-significant bytes of pixel,
* leaving the most-significant bytes set to zero */
#if SDL_BYTEORDER == SDL_BIG_ENDIAN #if SDL_BYTEORDER == SDL_BIG_ENDIAN
SDL_memcpy(((Uint8 *) &pixel) + (sizeof(pixel) - bytes_per_pixel), p, bytes_per_pixel); SDL_memcpy(((Uint8 *)&pixel) + (sizeof(pixel) - bytes_per_pixel), p, bytes_per_pixel);
#else #else
SDL_memcpy(&pixel, p, bytes_per_pixel); SDL_memcpy(&pixel, p, bytes_per_pixel);
#endif #endif
SDL_GetRGBA(pixel, surface->format, r, g, b, a); SDL_GetRGBA(pixel, surface->format, r, g, b, a);
result = 0;
}
if (SDL_MUSTLOCK(surface)) { if (SDL_MUSTLOCK(surface)) {
SDL_UnlockSurface(surface); SDL_UnlockSurface(surface);
} }
return 0; return result;
} }
/* /*