diff options
Diffstat (limited to 'distrib/sdl-1.2.15/src/video/SDL_pixels.c')
| -rw-r--r-- | distrib/sdl-1.2.15/src/video/SDL_pixels.c | 626 |
1 files changed, 626 insertions, 0 deletions
diff --git a/distrib/sdl-1.2.15/src/video/SDL_pixels.c b/distrib/sdl-1.2.15/src/video/SDL_pixels.c new file mode 100644 index 0000000..1a7fd51 --- /dev/null +++ b/distrib/sdl-1.2.15/src/video/SDL_pixels.c @@ -0,0 +1,626 @@ +/* + SDL - Simple DirectMedia Layer + Copyright (C) 1997-2012 Sam Lantinga + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + + Sam Lantinga + slouken@libsdl.org +*/ +#include "SDL_config.h" + +/* General (mostly internal) pixel/color manipulation routines for SDL */ + +#include "SDL_endian.h" +#include "SDL_video.h" +#include "SDL_sysvideo.h" +#include "SDL_blit.h" +#include "SDL_pixels_c.h" +#include "SDL_RLEaccel_c.h" + +/* Helper functions */ +/* + * Allocate a pixel format structure and fill it according to the given info. + */ +SDL_PixelFormat *SDL_AllocFormat(int bpp, + Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask) +{ + SDL_PixelFormat *format; + Uint32 mask; + + /* Allocate an empty pixel format structure */ + format = SDL_malloc(sizeof(*format)); + if ( format == NULL ) { + SDL_OutOfMemory(); + return(NULL); + } + SDL_memset(format, 0, sizeof(*format)); + format->alpha = SDL_ALPHA_OPAQUE; + + /* Set up the format */ + format->BitsPerPixel = bpp; + format->BytesPerPixel = (bpp+7)/8; + if ( Rmask || Bmask || Gmask ) { /* Packed pixels with custom mask */ + format->palette = NULL; + format->Rshift = 0; + format->Rloss = 8; + if ( Rmask ) { + for ( mask = Rmask; !(mask&0x01); mask >>= 1 ) + ++format->Rshift; + for ( ; (mask&0x01); mask >>= 1 ) + --format->Rloss; + } + format->Gshift = 0; + format->Gloss = 8; + if ( Gmask ) { + for ( mask = Gmask; !(mask&0x01); mask >>= 1 ) + ++format->Gshift; + for ( ; (mask&0x01); mask >>= 1 ) + --format->Gloss; + } + format->Bshift = 0; + format->Bloss = 8; + if ( Bmask ) { + for ( mask = Bmask; !(mask&0x01); mask >>= 1 ) + ++format->Bshift; + for ( ; (mask&0x01); mask >>= 1 ) + --format->Bloss; + } + format->Ashift = 0; + format->Aloss = 8; + if ( Amask ) { + for ( mask = Amask; !(mask&0x01); mask >>= 1 ) + ++format->Ashift; + for ( ; (mask&0x01); mask >>= 1 ) + --format->Aloss; + } + format->Rmask = Rmask; + format->Gmask = Gmask; + format->Bmask = Bmask; + format->Amask = Amask; + } else if ( bpp > 8 ) { /* Packed pixels with standard mask */ + /* R-G-B */ + if ( bpp > 24 ) + bpp = 24; + format->Rloss = 8-(bpp/3); + format->Gloss = 8-(bpp/3)-(bpp%3); + format->Bloss = 8-(bpp/3); + format->Rshift = ((bpp/3)+(bpp%3))+(bpp/3); + format->Gshift = (bpp/3); + format->Bshift = 0; + format->Rmask = ((0xFF>>format->Rloss)<<format->Rshift); + format->Gmask = ((0xFF>>format->Gloss)<<format->Gshift); + format->Bmask = ((0xFF>>format->Bloss)<<format->Bshift); + } else { + /* Palettized formats have no mask info */ + format->Rloss = 8; + format->Gloss = 8; + format->Bloss = 8; + format->Aloss = 8; + format->Rshift = 0; + format->Gshift = 0; + format->Bshift = 0; + format->Ashift = 0; + format->Rmask = 0; + format->Gmask = 0; + format->Bmask = 0; + format->Amask = 0; + } + if ( bpp <= 8 ) { /* Palettized mode */ + int ncolors = 1<<bpp; +#ifdef DEBUG_PALETTE + fprintf(stderr,"bpp=%d ncolors=%d\n",bpp,ncolors); +#endif + format->palette = (SDL_Palette *)SDL_malloc(sizeof(SDL_Palette)); + if ( format->palette == NULL ) { + SDL_FreeFormat(format); + SDL_OutOfMemory(); + return(NULL); + } + (format->palette)->ncolors = ncolors; + (format->palette)->colors = (SDL_Color *)SDL_malloc( + (format->palette)->ncolors*sizeof(SDL_Color)); + if ( (format->palette)->colors == NULL ) { + SDL_FreeFormat(format); + SDL_OutOfMemory(); + return(NULL); + } + if ( Rmask || Bmask || Gmask ) { + /* create palette according to masks */ + int i; + int Rm=0,Gm=0,Bm=0; + int Rw=0,Gw=0,Bw=0; +#ifdef ENABLE_PALETTE_ALPHA + int Am=0,Aw=0; +#endif + if(Rmask) + { + Rw=8-format->Rloss; + for(i=format->Rloss;i>0;i-=Rw) + Rm|=1<<i; + } +#ifdef DEBUG_PALETTE + fprintf(stderr,"Rw=%d Rm=0x%02X\n",Rw,Rm); +#endif + if(Gmask) + { + Gw=8-format->Gloss; + for(i=format->Gloss;i>0;i-=Gw) + Gm|=1<<i; + } +#ifdef DEBUG_PALETTE + fprintf(stderr,"Gw=%d Gm=0x%02X\n",Gw,Gm); +#endif + if(Bmask) + { + Bw=8-format->Bloss; + for(i=format->Bloss;i>0;i-=Bw) + Bm|=1<<i; + } +#ifdef DEBUG_PALETTE + fprintf(stderr,"Bw=%d Bm=0x%02X\n",Bw,Bm); +#endif +#ifdef ENABLE_PALETTE_ALPHA + if(Amask) + { + Aw=8-format->Aloss; + for(i=format->Aloss;i>0;i-=Aw) + Am|=1<<i; + } +# ifdef DEBUG_PALETTE + fprintf(stderr,"Aw=%d Am=0x%02X\n",Aw,Am); +# endif +#endif + for(i=0; i < ncolors; ++i) { + int r,g,b; + r=(i&Rmask)>>format->Rshift; + r=(r<<format->Rloss)|((r*Rm)>>Rw); + format->palette->colors[i].r=r; + + g=(i&Gmask)>>format->Gshift; + g=(g<<format->Gloss)|((g*Gm)>>Gw); + format->palette->colors[i].g=g; + + b=(i&Bmask)>>format->Bshift; + b=(b<<format->Bloss)|((b*Bm)>>Bw); + format->palette->colors[i].b=b; + +#ifdef ENABLE_PALETTE_ALPHA + a=(i&Amask)>>format->Ashift; + a=(a<<format->Aloss)|((a*Am)>>Aw); + format->palette->colors[i].unused=a; +#else + format->palette->colors[i].unused=0; +#endif + } + } else if ( ncolors == 2 ) { + /* Create a black and white bitmap palette */ + format->palette->colors[0].r = 0xFF; + format->palette->colors[0].g = 0xFF; + format->palette->colors[0].b = 0xFF; + format->palette->colors[1].r = 0x00; + format->palette->colors[1].g = 0x00; + format->palette->colors[1].b = 0x00; + } else { + /* Create an empty palette */ + SDL_memset((format->palette)->colors, 0, + (format->palette)->ncolors*sizeof(SDL_Color)); + } + } + return(format); +} +SDL_PixelFormat *SDL_ReallocFormat(SDL_Surface *surface, int bpp, + Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask) +{ + if ( surface->format ) { + SDL_FreeFormat(surface->format); + SDL_FormatChanged(surface); + } + surface->format = SDL_AllocFormat(bpp, Rmask, Gmask, Bmask, Amask); + return surface->format; +} + +/* + * Change any previous mappings from/to the new surface format + */ +void SDL_FormatChanged(SDL_Surface *surface) +{ + static int format_version = 0; + ++format_version; + if ( format_version < 0 ) { /* It wrapped... */ + format_version = 1; + } + surface->format_version = format_version; + SDL_InvalidateMap(surface->map); +} +/* + * Free a previously allocated format structure + */ +void SDL_FreeFormat(SDL_PixelFormat *format) +{ + if ( format ) { + if ( format->palette ) { + if ( format->palette->colors ) { + SDL_free(format->palette->colors); + } + SDL_free(format->palette); + } + SDL_free(format); + } +} +/* + * Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors + */ +void SDL_DitherColors(SDL_Color *colors, int bpp) +{ + int i; + if(bpp != 8) + return; /* only 8bpp supported right now */ + + for(i = 0; i < 256; i++) { + int r, g, b; + /* map each bit field to the full [0, 255] interval, + so 0 is mapped to (0, 0, 0) and 255 to (255, 255, 255) */ + r = i & 0xe0; + r |= r >> 3 | r >> 6; + colors[i].r = r; + g = (i << 3) & 0xe0; + g |= g >> 3 | g >> 6; + colors[i].g = g; + b = i & 0x3; + b |= b << 2; + b |= b << 4; + colors[i].b = b; + } +} +/* + * Calculate the pad-aligned scanline width of a surface + */ +Uint16 SDL_CalculatePitch(SDL_Surface *surface) +{ + Uint16 pitch; + + /* Surface should be 4-byte aligned for speed */ + pitch = surface->w*surface->format->BytesPerPixel; + switch (surface->format->BitsPerPixel) { + case 1: + pitch = (pitch+7)/8; + break; + case 4: + pitch = (pitch+1)/2; + break; + default: + break; + } + pitch = (pitch + 3) & ~3; /* 4-byte aligning */ + return(pitch); +} +/* + * Match an RGB value to a particular palette index + */ +Uint8 SDL_FindColor(SDL_Palette *pal, Uint8 r, Uint8 g, Uint8 b) +{ + /* Do colorspace distance matching */ + unsigned int smallest; + unsigned int distance; + int rd, gd, bd; + int i; + Uint8 pixel=0; + + smallest = ~0; + for ( i=0; i<pal->ncolors; ++i ) { + rd = pal->colors[i].r - r; + gd = pal->colors[i].g - g; + bd = pal->colors[i].b - b; + distance = (rd*rd)+(gd*gd)+(bd*bd); + if ( distance < smallest ) { + pixel = i; + if ( distance == 0 ) { /* Perfect match! */ + break; + } + smallest = distance; + } + } + return(pixel); +} + +/* Find the opaque pixel value corresponding to an RGB triple */ +Uint32 SDL_MapRGB +(const SDL_PixelFormat * const format, + const Uint8 r, const Uint8 g, const Uint8 b) +{ + if ( format->palette == NULL ) { + return (r >> format->Rloss) << format->Rshift + | (g >> format->Gloss) << format->Gshift + | (b >> format->Bloss) << format->Bshift + | format->Amask; + } else { + return SDL_FindColor(format->palette, r, g, b); + } +} + +/* Find the pixel value corresponding to an RGBA quadruple */ +Uint32 SDL_MapRGBA +(const SDL_PixelFormat * const format, + const Uint8 r, const Uint8 g, const Uint8 b, const Uint8 a) +{ + if ( format->palette == NULL ) { + return (r >> format->Rloss) << format->Rshift + | (g >> format->Gloss) << format->Gshift + | (b >> format->Bloss) << format->Bshift + | ((a >> format->Aloss) << format->Ashift & format->Amask); + } else { + return SDL_FindColor(format->palette, r, g, b); + } +} + +void SDL_GetRGBA(Uint32 pixel, const SDL_PixelFormat * const fmt, + Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a) +{ + if ( fmt->palette == NULL ) { + /* + * This makes sure that the result is mapped to the + * interval [0..255], and the maximum value for each + * component is 255. This is important to make sure + * that white is indeed reported as (255, 255, 255), + * and that opaque alpha is 255. + * This only works for RGB bit fields at least 4 bit + * wide, which is almost always the case. + */ + unsigned v; + v = (pixel & fmt->Rmask) >> fmt->Rshift; + *r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1))); + v = (pixel & fmt->Gmask) >> fmt->Gshift; + *g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1))); + v = (pixel & fmt->Bmask) >> fmt->Bshift; + *b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1))); + if(fmt->Amask) { + v = (pixel & fmt->Amask) >> fmt->Ashift; + *a = (v << fmt->Aloss) + (v >> (8 - (fmt->Aloss << 1))); + } else { + *a = SDL_ALPHA_OPAQUE; + } + } else { + *r = fmt->palette->colors[pixel].r; + *g = fmt->palette->colors[pixel].g; + *b = fmt->palette->colors[pixel].b; + *a = SDL_ALPHA_OPAQUE; + } +} + +void SDL_GetRGB(Uint32 pixel, const SDL_PixelFormat * const fmt, + Uint8 *r,Uint8 *g,Uint8 *b) +{ + if ( fmt->palette == NULL ) { + /* the note for SDL_GetRGBA above applies here too */ + unsigned v; + v = (pixel & fmt->Rmask) >> fmt->Rshift; + *r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1))); + v = (pixel & fmt->Gmask) >> fmt->Gshift; + *g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1))); + v = (pixel & fmt->Bmask) >> fmt->Bshift; + *b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1))); + } else { + *r = fmt->palette->colors[pixel].r; + *g = fmt->palette->colors[pixel].g; + *b = fmt->palette->colors[pixel].b; + } +} + +/* Apply gamma to a set of colors - this is easy. :) */ +void SDL_ApplyGamma(Uint16 *gamma, SDL_Color *colors, SDL_Color *output, + int ncolors) +{ + int i; + + for ( i=0; i<ncolors; ++i ) { + output[i].r = gamma[0*256 + colors[i].r] >> 8; + output[i].g = gamma[1*256 + colors[i].g] >> 8; + output[i].b = gamma[2*256 + colors[i].b] >> 8; + } +} + +/* Map from Palette to Palette */ +static Uint8 *Map1to1(SDL_Palette *src, SDL_Palette *dst, int *identical) +{ + Uint8 *map; + int i; + + if ( identical ) { + if ( src->ncolors <= dst->ncolors ) { + /* If an identical palette, no need to map */ + if ( SDL_memcmp(src->colors, dst->colors, src->ncolors* + sizeof(SDL_Color)) == 0 ) { + *identical = 1; + return(NULL); + } + } + *identical = 0; + } + map = (Uint8 *)SDL_malloc(src->ncolors); + if ( map == NULL ) { + SDL_OutOfMemory(); + return(NULL); + } + for ( i=0; i<src->ncolors; ++i ) { + map[i] = SDL_FindColor(dst, + src->colors[i].r, src->colors[i].g, src->colors[i].b); + } + return(map); +} +/* Map from Palette to BitField */ +static Uint8 *Map1toN(SDL_PixelFormat *src, SDL_PixelFormat *dst) +{ + Uint8 *map; + int i; + int bpp; + unsigned alpha; + SDL_Palette *pal = src->palette; + + bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel); + map = (Uint8 *)SDL_malloc(pal->ncolors*bpp); + if ( map == NULL ) { + SDL_OutOfMemory(); + return(NULL); + } + + alpha = dst->Amask ? src->alpha : 0; + /* We memory copy to the pixel map so the endianness is preserved */ + for ( i=0; i<pal->ncolors; ++i ) { + ASSEMBLE_RGBA(&map[i*bpp], dst->BytesPerPixel, dst, + pal->colors[i].r, pal->colors[i].g, + pal->colors[i].b, alpha); + } + return(map); +} +/* Map from BitField to Dithered-Palette to Palette */ +static Uint8 *MapNto1(SDL_PixelFormat *src, SDL_PixelFormat *dst, int *identical) +{ + /* Generate a 256 color dither palette */ + SDL_Palette dithered; + SDL_Color colors[256]; + SDL_Palette *pal = dst->palette; + + /* SDL_DitherColors does not initialize the 'unused' component of colors, + but Map1to1 compares it against pal, so we should initialize it. */ + SDL_memset(colors, 0, sizeof(colors)); + + dithered.ncolors = 256; + SDL_DitherColors(colors, 8); + dithered.colors = colors; + return(Map1to1(&dithered, pal, identical)); +} + +SDL_BlitMap *SDL_AllocBlitMap(void) +{ + SDL_BlitMap *map; + + /* Allocate the empty map */ + map = (SDL_BlitMap *)SDL_malloc(sizeof(*map)); + if ( map == NULL ) { + SDL_OutOfMemory(); + return(NULL); + } + SDL_memset(map, 0, sizeof(*map)); + + /* Allocate the software blit data */ + map->sw_data = (struct private_swaccel *)SDL_malloc(sizeof(*map->sw_data)); + if ( map->sw_data == NULL ) { + SDL_FreeBlitMap(map); + SDL_OutOfMemory(); + return(NULL); + } + SDL_memset(map->sw_data, 0, sizeof(*map->sw_data)); + + /* It's ready to go */ + return(map); +} +void SDL_InvalidateMap(SDL_BlitMap *map) +{ + if ( ! map ) { + return; + } + map->dst = NULL; + map->format_version = (unsigned int)-1; + if ( map->table ) { + SDL_free(map->table); + map->table = NULL; + } +} +int SDL_MapSurface (SDL_Surface *src, SDL_Surface *dst) +{ + SDL_PixelFormat *srcfmt; + SDL_PixelFormat *dstfmt; + SDL_BlitMap *map; + + /* Clear out any previous mapping */ + map = src->map; + if ( (src->flags & SDL_RLEACCEL) == SDL_RLEACCEL ) { + SDL_UnRLESurface(src, 1); + } + SDL_InvalidateMap(map); + + /* Figure out what kind of mapping we're doing */ + map->identity = 0; + srcfmt = src->format; + dstfmt = dst->format; + switch (srcfmt->BytesPerPixel) { + case 1: + switch (dstfmt->BytesPerPixel) { + case 1: + /* Palette --> Palette */ + /* If both SDL_HWSURFACE, assume have same palette */ + if ( ((src->flags & SDL_HWSURFACE) == SDL_HWSURFACE) && + ((dst->flags & SDL_HWSURFACE) == SDL_HWSURFACE) ) { + map->identity = 1; + } else { + map->table = Map1to1(srcfmt->palette, + dstfmt->palette, &map->identity); + } + if ( ! map->identity ) { + if ( map->table == NULL ) { + return(-1); + } + } + if (srcfmt->BitsPerPixel!=dstfmt->BitsPerPixel) + map->identity = 0; + break; + + default: + /* Palette --> BitField */ + map->table = Map1toN(srcfmt, dstfmt); + if ( map->table == NULL ) { + return(-1); + } + break; + } + break; + default: + switch (dstfmt->BytesPerPixel) { + case 1: + /* BitField --> Palette */ + map->table = MapNto1(srcfmt, dstfmt, &map->identity); + if ( ! map->identity ) { + if ( map->table == NULL ) { + return(-1); + } + } + map->identity = 0; /* Don't optimize to copy */ + break; + default: + /* BitField --> BitField */ + if ( FORMAT_EQUAL(srcfmt, dstfmt) ) + map->identity = 1; + break; + } + break; + } + + map->dst = dst; + map->format_version = dst->format_version; + + /* Choose your blitters wisely */ + return(SDL_CalculateBlit(src)); +} +void SDL_FreeBlitMap(SDL_BlitMap *map) +{ + if ( map ) { + SDL_InvalidateMap(map); + if ( map->sw_data != NULL ) { + SDL_free(map->sw_data); + } + SDL_free(map); + } +} |