mirrors
/
SDL
mirror of https://github.com/libsdl-org/SDL
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Improved color accuracy blitting to 8-bit indexed surfaces 

Fixes https://github.com/libsdl-org/SDL/issues/10519
This commit is contained in:
Sam Lantinga 2024-08-12 09:05:52 -07:00
parent 1a729251ad
commit 755e201aa5
5 changed files with 43 additions and 435 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
src/video/SDL_blit.h
View File

@ -23,6 +23,8 @@
#ifndef SDL_blit_h_
#define SDL_blit_h_
#include "../SDL_hashtable.h"
/* Table to do pixel byte expansion */
extern const Uint8 *SDL_expand_byte[9];
extern const Uint16 SDL_expand_byte_10[];
@ -70,6 +72,7 @@ typedef struct
const SDL_PixelFormatDetails *dst_fmt;
const SDL_Palette *dst_pal;
Uint8 *table;
SDL_HashTable *palette_map;
int flags;
Uint32 colorkey;
Uint8 r, g, b, a;

405
src/video/SDL_blit_N.c
View File

@ -933,234 +933,6 @@ static void Blit_RGB444_XRGB8888ARMSIMD(SDL_BlitInfo *info)
#define LO 1
#endif
/* Special optimized blit for RGB 8-8-8 --> RGB 3-3-2 */
#define RGB888_RGB332(dst, src) \
{ \
dst = (Uint8)((((src)&0x00E00000) >> 16) | \
(((src)&0x0000E000) >> 11) | \
(((src)&0x000000C0) >> 6)); \
}
static void Blit_XRGB8888_index8(SDL_BlitInfo *info)
{
#ifndef USE_DUFFS_LOOP
int c;
#endif
int width, height;
Uint32 *src;
const Uint8 *map;
Uint8 *dst;
int srcskip, dstskip;
/* Set up some basic variables */
width = info->dst_w;
height = info->dst_h;
src = (Uint32 *)info->src;
srcskip = info->src_skip / 4;
dst = info->dst;
dstskip = info->dst_skip;
map = info->table;
if (!map) {
while (height--) {
#ifdef USE_DUFFS_LOOP
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
RGB888_RGB332(*dst++, *src);
, width);
/* *INDENT-ON* */ /* clang-format on */
#else
for (c = width / 4; c; --c) {
/* Pack RGB into 8bit pixel */
++src;
RGB888_RGB332(*dst++, *src);
++src;
RGB888_RGB332(*dst++, *src);
++src;
RGB888_RGB332(*dst++, *src);
++src;
}
switch (width & 3) {
case 3:
RGB888_RGB332(*dst++, *src);
++src;
SDL_FALLTHROUGH;
case 2:
RGB888_RGB332(*dst++, *src);
++src;
SDL_FALLTHROUGH;
case 1:
RGB888_RGB332(*dst++, *src);
++src;
}
#endif /* USE_DUFFS_LOOP */
src += srcskip;
dst += dstskip;
}
} else {
int Pixel;
while (height--) {
#ifdef USE_DUFFS_LOOP
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
, width);
/* *INDENT-ON* */ /* clang-format on */
#else
for (c = width / 4; c; --c) {
/* Pack RGB into 8bit pixel */
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
}
switch (width & 3) {
case 3:
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
SDL_FALLTHROUGH;
case 2:
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
SDL_FALLTHROUGH;
case 1:
RGB888_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
}
#endif /* USE_DUFFS_LOOP */
src += srcskip;
dst += dstskip;
}
}
}
/* Special optimized blit for RGB 10-10-10 --> RGB 3-3-2 */
#define RGB101010_RGB332(dst, src) \
{ \
dst = (Uint8)((((src)&0x38000000) >> 22) | \
(((src)&0x000E0000) >> 15) | \
(((src)&0x00000300) >> 8)); \
}
static void Blit_RGB101010_index8(SDL_BlitInfo *info)
{
#ifndef USE_DUFFS_LOOP
int c;
#endif
int width, height;
Uint32 *src;
const Uint8 *map;
Uint8 *dst;
int srcskip, dstskip;
/* Set up some basic variables */
width = info->dst_w;
height = info->dst_h;
src = (Uint32 *)info->src;
srcskip = info->src_skip / 4;
dst = info->dst;
dstskip = info->dst_skip;
map = info->table;
if (!map) {
while (height--) {
#ifdef USE_DUFFS_LOOP
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
RGB101010_RGB332(*dst++, *src);
, width);
/* *INDENT-ON* */ /* clang-format on */
#else
for (c = width / 4; c; --c) {
/* Pack RGB into 8bit pixel */
++src;
RGB101010_RGB332(*dst++, *src);
++src;
RGB101010_RGB332(*dst++, *src);
++src;
RGB101010_RGB332(*dst++, *src);
++src;
}
switch (width & 3) {
case 3:
RGB101010_RGB332(*dst++, *src);
++src;
SDL_FALLTHROUGH;
case 2:
RGB101010_RGB332(*dst++, *src);
++src;
SDL_FALLTHROUGH;
case 1:
RGB101010_RGB332(*dst++, *src);
++src;
}
#endif /* USE_DUFFS_LOOP */
src += srcskip;
dst += dstskip;
}
} else {
int Pixel;
while (height--) {
#ifdef USE_DUFFS_LOOP
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
, width);
/* *INDENT-ON* */ /* clang-format on */
#else
for (c = width / 4; c; --c) {
/* Pack RGB into 8bit pixel */
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
}
switch (width & 3) {
case 3:
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
SDL_FALLTHROUGH;
case 2:
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
SDL_FALLTHROUGH;
case 1:
RGB101010_RGB332(Pixel, *src);
*dst++ = map[Pixel];
++src;
}
#endif /* USE_DUFFS_LOOP */
src += srcskip;
dst += dstskip;
}
}
}
/* Special optimized blit for RGB 8-8-8 --> RGB 5-5-5 */
#define RGB888_RGB555(dst, src) \
{ \
@ -2072,97 +1844,6 @@ static void Blit_RGB555_ARGB1555(SDL_BlitInfo *info)
}
}
static void BlitNto1(SDL_BlitInfo *info)
{
#ifndef USE_DUFFS_LOOP
int c;
#endif
int width, height;
Uint8 *src;
const Uint8 *map;
Uint8 *dst;
int srcskip, dstskip;
int srcbpp;
Uint32 Pixel;
int sR, sG, sB;
const SDL_PixelFormatDetails *srcfmt;
/* Set up some basic variables */
width = info->dst_w;
height = info->dst_h;
src = info->src;
srcskip = info->src_skip;
dst = info->dst;
dstskip = info->dst_skip;
map = info->table;
srcfmt = info->src_fmt;
srcbpp = srcfmt->bytes_per_pixel;
if (!map) {
while (height--) {
#ifdef USE_DUFFS_LOOP
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel,
sR, sG, sB);
if ( 1 ) {
/* Pack RGB into 8bit pixel */
*dst = (Uint8)(((sR>>5)<<(3+2)) | ((sG>>5)<<(2)) | ((sB>>6)<<(0)));
}
dst++;
src += srcbpp;
, width);
/* *INDENT-ON* */ /* clang-format on */
#else
for (c = width; c; --c) {
DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel, sR, sG, sB);
if (1) {
/* Pack RGB into 8bit pixel */
*dst = ((sR >> 5) << (3 + 2)) |
((sG >> 5) << (2)) | ((sB >> 6) << (0));
}
dst++;
src += srcbpp;
}
#endif
src += srcskip;
dst += dstskip;
}
} else {
while (height--) {
#ifdef USE_DUFFS_LOOP
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel,
sR, sG, sB);
if ( 1 ) {
/* Pack RGB into 8bit pixel */
*dst = map[((sR>>5)<<(3+2))|
((sG>>5)<<(2)) |
((sB>>6)<<(0)) ];
}
dst++;
src += srcbpp;
, width);
/* *INDENT-ON* */ /* clang-format on */
#else
for (c = width; c; --c) {
DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel, sR, sG, sB);
if (1) {
/* Pack RGB into 8bit pixel */
*dst = map[((sR >> 5) << (3 + 2)) |
((sG >> 5) << (2)) | ((sB >> 6) << (0))];
}
dst++;
src += srcbpp;
}
#endif /* USE_DUFFS_LOOP */
src += srcskip;
dst += dstskip;
}
}
}
/* blits 32 bit RGB<->RGBA with both surfaces having the same R,G,B fields */
static void Blit4to4MaskAlpha(SDL_BlitInfo *info)
{
@ -2474,71 +2155,6 @@ static void BlitNtoNCopyAlpha(SDL_BlitInfo *info)
}
}
static void BlitNto1Key(SDL_BlitInfo *info)
{
int width = info->dst_w;
int height = info->dst_h;
Uint8 *src = info->src;
int srcskip = info->src_skip;
Uint8 *dst = info->dst;
int dstskip = info->dst_skip;
const SDL_PixelFormatDetails *srcfmt = info->src_fmt;
const Uint8 *palmap = info->table;
Uint32 ckey = info->colorkey;
Uint32 rgbmask = ~srcfmt->Amask;
int srcbpp;
Uint32 Pixel;
unsigned sR, sG, sB;
/* Set up some basic variables */
srcbpp = srcfmt->bytes_per_pixel;
ckey &= rgbmask;
if (!palmap) {
while (height--) {
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
{
DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel,
sR, sG, sB);
if ( (Pixel & rgbmask) != ckey ) {
/* Pack RGB into 8bit pixel */
*dst = (Uint8)(((sR>>5)<<(3+2))|
((sG>>5)<<(2)) |
((sB>>6)<<(0)));
}
dst++;
src += srcbpp;
},
width);
/* *INDENT-ON* */ /* clang-format on */
src += srcskip;
dst += dstskip;
}
} else {
while (height--) {
/* *INDENT-OFF* */ /* clang-format off */
DUFFS_LOOP(
{
DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel,
sR, sG, sB);
if ( (Pixel & rgbmask) != ckey ) {
/* Pack RGB into 8bit pixel */
*dst = (Uint8)palmap[((sR>>5)<<(3+2))|
((sG>>5)<<(2)) |
((sB>>6)<<(0)) ];
}
dst++;
src += srcbpp;
},
width);
/* *INDENT-ON* */ /* clang-format on */
src += srcskip;
dst += dstskip;
}
}
}
static void Blit2to2Key(SDL_BlitInfo *info)
{
int width = info->dst_w;
@ -3343,22 +2959,7 @@ SDL_BlitFunc SDL_CalculateBlitN(SDL_Surface *surface)
switch (surface->internal->map.info.flags & ~SDL_COPY_RLE_MASK) {
case 0:
blitfun = NULL;
if (dstfmt->bits_per_pixel == 8) {
if ((srcfmt->bytes_per_pixel == 4) &&
(srcfmt->Rmask == 0x00FF0000) &&
(srcfmt->Gmask == 0x0000FF00) &&
(srcfmt->Bmask == 0x000000FF)) {
blitfun = Blit_XRGB8888_index8;
} else if ((srcfmt->bytes_per_pixel == 4) &&
(srcfmt->Rmask == 0x3FF00000) &&
(srcfmt->Gmask == 0x000FFC00) &&
(srcfmt->Bmask == 0x000003FF)) {
blitfun = Blit_RGB101010_index8;
} else {
blitfun = BlitNto1;
}
} else {
/* Now the meat, choose the blitter we want */
if (dstfmt->bits_per_pixel > 8) {
Uint32 a_need = NO_ALPHA;
if (dstfmt->Amask) {
a_need = srcfmt->Amask ? COPY_ALPHA : SET_ALPHA;
@ -3418,15 +3019,13 @@ SDL_BlitFunc SDL_CalculateBlitN(SDL_Surface *surface)
if (srcfmt->bytes_per_pixel == 2 && surface->internal->map.identity != 0) {
return Blit2to2Key;
} else if (dstfmt->bytes_per_pixel == 1) {
return BlitNto1Key;
} else {
#ifdef SDL_ALTIVEC_BLITTERS
if ((srcfmt->bytes_per_pixel == 4) && (dstfmt->bytes_per_pixel == 4) && SDL_HasAltiVec()) {
return Blit32to32KeyAltivec;
} else
#endif
if (srcfmt->Amask && dstfmt->Amask) {
if (srcfmt->Amask && dstfmt->Amask) {
return BlitNtoNKeyCopyAlpha;
} else {
return BlitNtoNKey;

16
src/video/SDL_blit_slow.c
View File

@ -69,15 +69,21 @@ void SDL_Blit_Slow(SDL_BlitInfo *info)
const SDL_Palette *src_pal = info->src_pal;
const SDL_PixelFormatDetails *dst_fmt = info->dst_fmt;
const SDL_Palette *dst_pal = info->dst_pal;
SDL_HashTable *palette_map = info->palette_map;
int srcbpp = src_fmt->bytes_per_pixel;
int dstbpp = dst_fmt->bytes_per_pixel;
SlowBlitPixelAccess src_access;
SlowBlitPixelAccess dst_access;
Uint32 rgbmask = ~src_fmt->Amask;
Uint32 ckey = info->colorkey & rgbmask;
Uint32 last_pixel = 0;
Uint8 last_index = 0;
src_access = GetPixelAccessMethod(src_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;
incx = ((Uint64)info->src_w << 16) / info->dst_w;
@ -275,12 +281,12 @@ void SDL_Blit_Slow(SDL_BlitInfo *info)
switch (dst_access) {
case SlowBlitPixelAccess_Index8:
RGB332_FROM_RGB(dstpixel, dstR, dstG, dstB);
if (info->table) {
*dst = info->table[dstpixel];
} else {
*dst = dstpixel;
dstpixel = (dstR << 24 | dstG << 16 | dstB << 8 | dstA);
if (dstpixel != last_pixel) {
last_pixel = dstpixel;
last_index = SDL_LookupRGBAColor(palette_map, dstpixel, dst_pal);
}
*dst = last_index;
break;
case SlowBlitPixelAccess_RGB:
ASSEMBLE_RGB(dst, dstbpp, dst_fmt, dstR, dstG, dstB);

53
src/video/SDL_pixels.c
View File

@ -1131,6 +1131,23 @@ Uint8 SDL_FindColor(const SDL_Palette *pal, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
return pixel;
}
Uint8 SDL_LookupRGBAColor(SDL_HashTable *palette_map, Uint32 pixel, const SDL_Palette *pal)
{
Uint8 color_index = 0;
const void *value;
if (SDL_FindInHashTable(palette_map, (const void *)(uintptr_t)pixel, &value)) {
color_index = (Uint8)(uintptr_t)value;
} else {
Uint8 r = (Uint8)((pixel >> 24) & 0xFF);
Uint8 g = (Uint8)((pixel >> 16) & 0xFF);
Uint8 b = (Uint8)((pixel >> 8) & 0xFF);
Uint8 a = (Uint8)((pixel >> 0) & 0xFF);
color_index = SDL_FindColor(pal, r, g, b, a);
SDL_InsertIntoHashTable(palette_map, (const void *)(uintptr_t)pixel, (const void *)(uintptr_t)color_index);
}
return color_index;
}
/* Tell whether palette is opaque, and if it has an alpha_channel */
void SDL_DetectPalette(const SDL_Palette *pal, SDL_bool *is_opaque, SDL_bool *has_alpha_channel)
{
@ -1401,24 +1418,6 @@ static Uint8 *Map1toN(const SDL_Palette *pal, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod
return map;
}
/* Map from BitField to Dithered-Palette to Palette */
static Uint8 *MapNto1(const SDL_PixelFormatDetails *src, const SDL_Palette *pal, int *identical)
{
/* Generate a 256 color dither palette */
SDL_Palette dithered;
SDL_Color colors[256];
if (!pal) {
SDL_SetError("dst does not have a palette set");
return NULL;
}
dithered.colors = colors;
dithered.ncolors = SDL_arraysize(colors);
SDL_DitherPalette(&dithered);
return Map1to1(&dithered, pal, identical);
}
int SDL_ValidateMap(SDL_Surface *src, SDL_Surface *dst)
{
SDL_BlitMap *map = &src->internal->map;
@ -1449,8 +1448,14 @@ void SDL_InvalidateMap(SDL_BlitMap *map)
map->info.dst_pal = NULL;
map->src_palette_version = 0;
map->dst_palette_version = 0;
SDL_free(map->info.table);
map->info.table = NULL;
if (map->info.table) {
SDL_free(map->info.table);
map->info.table = NULL;
}
if (map->info.palette_map) {
SDL_DestroyHashTable(map->info.palette_map);
map->info.palette_map = NULL;
}
}
int SDL_MapSurface(SDL_Surface *src, SDL_Surface *dst)
@ -1504,13 +1509,7 @@ int SDL_MapSurface(SDL_Surface *src, SDL_Surface *dst)
} else {
if (SDL_ISPIXELFORMAT_INDEXED(dstfmt->format)) {
/* BitField --> Palette */
map->info.table = MapNto1(srcfmt, dstpal, &map->identity);
if (!map->identity) {
if (!map->info.table) {
return -1;
}
}
map->identity = 0; /* Don't optimize to copy */
map->info.palette_map = SDL_CreateHashTable(NULL, 32, SDL_HashID, SDL_KeyMatchID, NULL, SDL_FALSE);
} else {
/* BitField --> BitField */
if (srcfmt == dstfmt) {

1
src/video/SDL_pixels_c.h
View File

@ -50,6 +50,7 @@ extern int SDL_MapSurface(SDL_Surface *src, SDL_Surface *dst);
/* Miscellaneous functions */
extern void SDL_DitherPalette(SDL_Palette *palette);
extern Uint8 SDL_FindColor(const SDL_Palette *pal, Uint8 r, Uint8 g, Uint8 b, Uint8 a);
extern Uint8 SDL_LookupRGBAColor(SDL_HashTable *palette_map, Uint32 pixel, const SDL_Palette *pal);
extern void SDL_DetectPalette(const SDL_Palette *pal, SDL_bool *is_opaque, SDL_bool *has_alpha_channel);
extern SDL_Surface *SDL_DuplicatePixels(int width, int height, SDL_PixelFormat format, SDL_Colorspace colorspace, void *pixels, int pitch);