Mirrors_Framework/SDL
1
0
Fork 0
mirror of https://github.com/libsdl-org/SDL.git synced 2026-05-27 19:19:41 +08:00
Code Issues Actions 6 Packages Projects Releases Wiki Activity

Improved color accuracy blitting floating point surfaces to 8-bit indexed surfaces

Browse Source
This commit is contained in:
Sam Lantinga
2024-08-12 11:00:42 -07:00
parent e87647c351
commit 375f303d97
1 changed files with 24 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/video/SDL_blit_slow.c
+24 -12
View File
@@ -281,7 +281,7 @@ void SDL_Blit_Slow(SDL_BlitInfo *info)
switch (dst_access) { switch (dst_access) {
case SlowBlitPixelAccess_Index8: case SlowBlitPixelAccess_Index8:
dstpixel = (dstR << 24 | dstG << 16 | dstB << 8 | dstA); dstpixel = ((dstR << 24) | (dstG << 16) | (dstB << 8) | dstA);
if (dstpixel != last_pixel) { if (dstpixel != last_pixel) {
last_pixel = dstpixel; last_pixel = dstpixel;
last_index = SDL_LookupRGBAColor(palette_map, dstpixel, dst_pal); last_index = SDL_LookupRGBAColor(palette_map, dstpixel, dst_pal);
@@ -583,7 +583,7 @@ static void ReadFloatPixel(Uint8 *pixels, SlowBlitPixelAccess access, const SDL_
*outA = fA; *outA = fA;
} }
static void WriteFloatPixel(Uint8 *pixels, SlowBlitPixelAccess access, const SDL_PixelFormatDetails *fmt, Uint8 *table, SDL_Colorspace colorspace, float SDR_white_point, static void WriteFloatPixel(Uint8 *pixels, SlowBlitPixelAccess access, const SDL_PixelFormatDetails *fmt, SDL_Colorspace colorspace, float SDR_white_point,
float fR, float fG, float fB, float fA) float fR, float fG, float fB, float fA)
{ {
Uint32 R, G, B, A; Uint32 R, G, B, A;
@@ -614,15 +614,8 @@ static void WriteFloatPixel(Uint8 *pixels, SlowBlitPixelAccess access, const SDL
switch (access) { switch (access) {
case SlowBlitPixelAccess_Index8: case SlowBlitPixelAccess_Index8:
R = (Uint8)SDL_roundf(SDL_clamp(fR, 0.0f, 1.0f) * 7.0f); // This should never happen, checked before this call
G = (Uint8)SDL_roundf(SDL_clamp(fG, 0.0f, 1.0f) * 7.0f); SDL_assert(0);
B = (Uint8)SDL_roundf(SDL_clamp(fB, 0.0f, 1.0f) * 3.0f);
pixel = (R << 5) | (G << 2) | B;
if (table) {
*pixels = table[pixel];
} else {
*pixels = pixel;
}
break; break;
case SlowBlitPixelAccess_RGB: case SlowBlitPixelAccess_RGB:
R = (Uint8)SDL_roundf(SDL_clamp(fR, 0.0f, 1.0f) * 255.0f); R = (Uint8)SDL_roundf(SDL_clamp(fR, 0.0f, 1.0f) * 255.0f);
@@ -828,6 +821,7 @@ void SDL_Blit_Slow_Float(SDL_BlitInfo *info)
const SDL_Palette *src_pal = info->src_pal; const SDL_Palette *src_pal = info->src_pal;
const SDL_PixelFormatDetails *dst_fmt = info->dst_fmt; const SDL_PixelFormatDetails *dst_fmt = info->dst_fmt;
const SDL_Palette *dst_pal = info->dst_pal; const SDL_Palette *dst_pal = info->dst_pal;
SDL_HashTable *palette_map = info->palette_map;
int srcbpp = src_fmt->bytes_per_pixel; int srcbpp = src_fmt->bytes_per_pixel;
int dstbpp = dst_fmt->bytes_per_pixel; int dstbpp = dst_fmt->bytes_per_pixel;
SlowBlitPixelAccess src_access; SlowBlitPixelAccess src_access;
@@ -842,6 +836,8 @@ void SDL_Blit_Slow_Float(SDL_BlitInfo *info)
float dst_headroom; float dst_headroom;
float src_headroom; float src_headroom;
SDL_TonemapContext tonemap; SDL_TonemapContext tonemap;
Uint32 last_pixel = 0;
Uint8 last_index = 0;
src_colorspace = info->src_surface->internal->colorspace; src_colorspace = info->src_surface->internal->colorspace;
dst_colorspace = info->dst_surface->internal->colorspace; dst_colorspace = info->dst_surface->internal->colorspace;
@@ -892,6 +888,9 @@ void SDL_Blit_Slow_Float(SDL_BlitInfo *info)
src_access = GetPixelAccessMethod(src_fmt->format); src_access = GetPixelAccessMethod(src_fmt->format);
dst_access = GetPixelAccessMethod(dst_fmt->format); dst_access = GetPixelAccessMethod(dst_fmt->format);
if (dst_access == SlowBlitPixelAccess_Index8) {
last_index = SDL_LookupRGBAColor(palette_map, last_pixel, dst_pal);
}
incy = ((Uint64)info->src_h << 16) / info->dst_h; incy = ((Uint64)info->src_h << 16) / info->dst_h;
incx = ((Uint64)info->src_w << 16) / info->dst_w; incx = ((Uint64)info->src_w << 16) / info->dst_w;
@@ -972,7 +971,20 @@ void SDL_Blit_Slow_Float(SDL_BlitInfo *info)
break; break;
} }
WriteFloatPixel(dst, dst_access, dst_fmt, info->table, dst_colorspace, dst_white_point, dstR, dstG, dstB, dstA); if (dst_access == SlowBlitPixelAccess_Index8) {
Uint32 R = (Uint8)SDL_roundf(SDL_clamp(SDL_sRGBfromLinear(dstR), 0.0f, 1.0f) * 255.0f);
Uint32 G = (Uint8)SDL_roundf(SDL_clamp(SDL_sRGBfromLinear(dstG), 0.0f, 1.0f) * 255.0f);
Uint32 B = (Uint8)SDL_roundf(SDL_clamp(SDL_sRGBfromLinear(dstB), 0.0f, 1.0f) * 255.0f);
Uint32 A = (Uint8)SDL_roundf(SDL_clamp(dstA, 0.0f, 1.0f) * 255.0f);
Uint32 dstpixel = ((R << 24) | (G << 16) | (B << 8) | A);
if (dstpixel != last_pixel) {
last_pixel = dstpixel;
last_index = SDL_LookupRGBAColor(palette_map, dstpixel, dst_pal);
}
*dst = last_index;
} else {
WriteFloatPixel(dst, dst_access, dst_fmt, dst_colorspace, dst_white_point, dstR, dstG, dstB, dstA);
}
posx += incx; posx += incx;
dst += dstbpp; dst += dstbpp;