Commit bf8aa1edaea84997a2b27ee87a2bd1bb373bf58a
2020-02-23T22:38:08
Fix regression: when a palette + colorkey is converted, it needs a blend mode. - Regression of test_1.c of bug 3827, after fix from bug 4798. - Blending is also needed when the palette contains alpha value, but not necessarily colorkey. - Clean up SDL_ConvertColorkeyToAlpha which doesn't seem to need 'ignore_alpha' parameter any-more. (see bug 3827)
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diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c
index c3b4d56..d108415 100644
--- a/src/video/SDL_surface.c
+++ b/src/video/SDL_surface.c
@@ -964,6 +964,7 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
int ret;
int palette_ck_transform = 0;
int palette_ck_value = 0;
+ int palette_has_alpha = SDL_FALSE;
if (!surface) {
SDL_InvalidParamError("surface");
@@ -1029,6 +1030,7 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
if (copy_flags & SDL_COPY_COLORKEY) {
if (surface->format->palette && !format->palette) {
palette_ck_transform = 1;
+ palette_has_alpha = SDL_TRUE;
palette_ck_value = surface->format->palette->colors[surface->map->info.colorkey].a;
surface->format->palette->colors[surface->map->info.colorkey].a = SDL_ALPHA_TRANSPARENT;
}
@@ -1066,7 +1068,6 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
if (copy_flags & SDL_COPY_COLORKEY) {
SDL_bool set_colorkey_by_color = SDL_FALSE;
- SDL_bool ignore_alpha = SDL_TRUE; /* Ignore, or not, alpha in colorkey comparison */
if (surface->format->palette) {
if (format->palette &&
@@ -1077,9 +1078,6 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
SDL_SetColorKey(convert, 1, surface->map->info.colorkey);
} else if (!format->palette) {
/* Was done by 'palette_ck_transform' */
- }else if (format->Amask) {
- set_colorkey_by_color = SDL_TRUE;
- ignore_alpha = SDL_FALSE;
} else {
set_colorkey_by_color = SDL_TRUE;
}
@@ -1120,14 +1118,27 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
SDL_SetColorKey(convert, 1, converted_colorkey);
/* This is needed when converting for 3D texture upload */
- SDL_ConvertColorkeyToAlpha(convert, ignore_alpha);
+ SDL_ConvertColorkeyToAlpha(convert, SDL_TRUE);
}
}
SDL_SetClipRect(convert, &surface->clip_rect);
+ /* Source surface has a palette with alpha. Will need blend mode */
+ if (palette_has_alpha == SDL_FALSE && surface->format->palette) {
+ int i;
+ for (i = 0; i < surface->format->palette->ncolors; i++) {
+ Uint8 alpha_value = surface->format->palette->colors[i].a;
+ if (alpha_value != 0 && alpha_value != SDL_ALPHA_OPAQUE) {
+ palette_has_alpha = SDL_TRUE;
+ break;
+ }
+ }
+ }
+
/* Enable alpha blending by default if the new surface has an
* alpha channel or alpha modulation */
if ((surface->format->Amask && format->Amask) ||
+ (palette_has_alpha && format->Amask) ||
(copy_flags & SDL_COPY_MODULATE_ALPHA)) {
SDL_SetSurfaceBlendMode(convert, SDL_BLENDMODE_BLEND);
}