render: Fix texture format selection for color-keyed indexed surfaces

015cc6a broke texture format selection for this kind of surface if the
renderer's first texture format doesn't happen to have an alpha
channel. This happens for on-screen software renderers on Windows,
whose preferred format is the window's own `SDL_PIXELFORMAT_XRGB8888`.
This fixed check also cover the intent behind 015cc6a, assuming that
indexed and alpha formats are mutually exclusive.
This commit is contained in:
nmlgc
2025-10-14 23:34:32 +02:00
committed by Sam Lantinga
parent 705ced8cf5
commit 2ffabb5150

View File

@@ -1844,10 +1844,13 @@ SDL_Texture *SDL_CreateTextureFromSurface(SDL_Renderer *renderer, SDL_Surface *s
}
}
// Indexed formats don't support the transparency needed for color-keyed surfaces
bool preferIndexed = SDL_ISPIXELFORMAT_INDEXED(surface->format) && !needAlpha;
for (i = 0; i < renderer->num_texture_formats; ++i) {
if (!SDL_ISPIXELFORMAT_FOURCC(renderer->texture_formats[i]) &&
SDL_ISPIXELFORMAT_ALPHA(renderer->texture_formats[i]) == needAlpha &&
SDL_ISPIXELFORMAT_INDEXED(renderer->texture_formats[i]) == SDL_ISPIXELFORMAT_INDEXED(surface->format)) {
SDL_ISPIXELFORMAT_INDEXED(renderer->texture_formats[i]) == preferIndexed) {
format = renderer->texture_formats[i];
break;
}