Fix: set to opaque when a palette surface is converted to an alpha format.

This commit is contained in:
Sylvain Becker 2020-02-23 23:07:15 +01:00
parent bf8aa1edae
commit f485766005

View file

@ -402,6 +402,64 @@ SDL_ConvertColorkeyToAlpha(SDL_Surface * surface, SDL_bool ignore_alpha)
SDL_SetSurfaceBlendMode(surface, SDL_BLENDMODE_BLEND);
}
static void
SDL_ConvertSetOpaque(SDL_Surface * surface)
{
int x, y;
if (!surface) {
return;
}
if (!surface->format->Amask) {
return;
}
SDL_LockSurface(surface);
switch (surface->format->BytesPerPixel) {
case 2:
{
Uint16 *row, *spot;
Uint16 mask = (Uint16) (surface->format->Amask);
row = (Uint16 *) surface->pixels;
for (y = surface->h; y--;) {
spot = row;
for (x = surface->w; x--;) {
*spot |= mask;
++spot;
}
row += surface->pitch / 2;
}
}
break;
case 3:
/* FIXME */
break;
case 4:
{
Uint32 *row, *spot;
Uint32 mask = surface->format->Amask;
row = (Uint32 *) surface->pixels;
for (y = surface->h; y--;) {
spot = row;
for (x = surface->w; x--;) {
*spot |= mask;
++spot;
}
row += surface->pitch / 4;
}
}
break;
}
SDL_UnlockSurface(surface);
}
int
SDL_SetSurfaceColorMod(SDL_Surface * surface, Uint8 r, Uint8 g, Uint8 b)
{
@ -962,9 +1020,9 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
SDL_Color copy_color;
SDL_Rect bounds;
int ret;
int palette_ck_transform = 0;
SDL_bool palette_ck_transform = SDL_FALSE;
int palette_ck_value = 0;
int palette_has_alpha = SDL_FALSE;
SDL_bool palette_has_alpha = SDL_FALSE;
if (!surface) {
SDL_InvalidParamError("surface");
@ -1029,7 +1087,7 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
/* Transform colorkey to alpha. for cases where source palette has duplicate values, and colorkey is one of them */
if (copy_flags & SDL_COPY_COLORKEY) {
if (surface->format->palette && !format->palette) {
palette_ck_transform = 1;
palette_ck_transform = SDL_TRUE;
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;
@ -1135,6 +1193,26 @@ SDL_ConvertSurface(SDL_Surface * surface, const SDL_PixelFormat * format,
}
}
/* Source surface has a palette with no alpha nor colorkey.
* Destination format has alpha.
* We may need to set the alpha channel to opaque. */
if (surface->format->palette && format->Amask && palette_has_alpha == SDL_FALSE) {
SDL_bool need_opaque = SDL_FALSE;
int i;
for (i = 0; i < surface->format->palette->ncolors; i++) {
Uint8 alpha_value = surface->format->palette->colors[i].a;
if (alpha_value == 0) {
need_opaque = SDL_TRUE;
break;
}
}
if (need_opaque) {
SDL_ConvertSetOpaque(convert);
}
}
/* Enable alpha blending by default if the new surface has an
* alpha channel or alpha modulation */
if ((surface->format->Amask && format->Amask) ||