| 0,0 → 1,615 |
|---|
| /* |
| SDL - Simple DirectMedia Layer |
| Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga |
| |
| This library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Library General Public |
| License as published by the Free Software Foundation; either |
| version 2 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 |
| Library General Public License for more details. |
| |
| You should have received a copy of the GNU Library General Public |
| License along with this library; if not, write to the Free |
| Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| |
| Sam Lantinga |
| slouken@devolution.com |
| */ |
| |
| |
| /* General (mostly internal) pixel/color manipulation routines for SDL */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "SDL_error.h" |
| #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 = malloc(sizeof(*format)); |
| if ( format == NULL ) { |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| memset(format, 0, sizeof(*format)); |
| format->alpha = SDL_ALPHA_OPAQUE; |
| |
| /* Set up the format */ |
| format->BitsPerPixel = bpp; |
| format->BytesPerPixel = (bpp+7)/8; |
| switch (bpp) { |
| case 1: |
| /* Create the 2 color black-white palette */ |
| format->palette = (SDL_Palette *)malloc( |
| sizeof(SDL_Palette)); |
| if ( format->palette == NULL ) { |
| SDL_FreeFormat(format); |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| (format->palette)->ncolors = 2; |
| (format->palette)->colors = (SDL_Color *)malloc( |
| (format->palette)->ncolors*sizeof(SDL_Color)); |
| if ( (format->palette)->colors == NULL ) { |
| SDL_FreeFormat(format); |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| 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; |
| 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; |
| break; |
| |
| case 4: |
| /* Create the 16 color VGA palette */ |
| format->palette = (SDL_Palette *)malloc( |
| sizeof(SDL_Palette)); |
| if ( format->palette == NULL ) { |
| SDL_FreeFormat(format); |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| (format->palette)->ncolors = 16; |
| (format->palette)->colors = (SDL_Color *)malloc( |
| (format->palette)->ncolors*sizeof(SDL_Color)); |
| if ( (format->palette)->colors == NULL ) { |
| SDL_FreeFormat(format); |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| /* Punt for now, will this ever be used? */ |
| memset((format->palette)->colors, 0, |
| (format->palette)->ncolors*sizeof(SDL_Color)); |
| |
| /* 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; |
| break; |
| |
| case 8: |
| /* Create an empty 256 color palette */ |
| format->palette = (SDL_Palette *)malloc( |
| sizeof(SDL_Palette)); |
| if ( format->palette == NULL ) { |
| SDL_FreeFormat(format); |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| (format->palette)->ncolors = 256; |
| (format->palette)->colors = (SDL_Color *)malloc( |
| (format->palette)->ncolors*sizeof(SDL_Color)); |
| if ( (format->palette)->colors == NULL ) { |
| SDL_FreeFormat(format); |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| memset((format->palette)->colors, 0, |
| (format->palette)->ncolors*sizeof(SDL_Color)); |
| |
| /* 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; |
| break; |
| |
| default: |
| /* No palette, just packed pixel info */ |
| 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; |
| break; |
| } |
| /* Calculate some standard bitmasks, if necessary |
| * Note: This could conflict with an alpha mask, if given. |
| */ |
| if ( (bpp > 8) && !format->Rmask && !format->Gmask && !format->Bmask ) { |
| /* 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); |
| } |
| 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) |
| { |
| surface->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 ) { |
| free(format->palette->colors); |
| } |
| free(format->palette); |
| } |
| 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(SDL_PixelFormat *format, Uint8 r, Uint8 g, 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(SDL_PixelFormat *format, Uint8 r, Uint8 g, Uint8 b, 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, SDL_PixelFormat *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 rv, gv, bv, av; |
| rv = (pixel & fmt->Rmask) >> fmt->Rshift; |
| *r = (rv << fmt->Rloss) + (rv >> (8 - fmt->Rloss)); |
| gv = (pixel & fmt->Gmask) >> fmt->Gshift; |
| *g = (gv << fmt->Gloss) + (gv >> (8 - fmt->Gloss)); |
| bv = (pixel & fmt->Bmask) >> fmt->Bshift; |
| *b = (bv << fmt->Bloss) + (bv >> (8 - fmt->Bloss)); |
| if(fmt->Amask) { |
| av = (pixel & fmt->Amask) >> fmt->Ashift; |
| *a = (av << fmt->Aloss) + (av >> (8 - fmt->Aloss)); |
| } 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, SDL_PixelFormat *fmt, Uint8 *r,Uint8 *g,Uint8 *b) |
| { |
| if ( fmt->palette == NULL ) { |
| /* the note for SDL_GetRGBA above applies here too */ |
| unsigned rv, gv, bv; |
| rv = (pixel & fmt->Rmask) >> fmt->Rshift; |
| *r = (rv << fmt->Rloss) + (rv >> (8 - fmt->Rloss)); |
| gv = (pixel & fmt->Gmask) >> fmt->Gshift; |
| *g = (gv << fmt->Gloss) + (gv >> (8 - fmt->Gloss)); |
| bv = (pixel & fmt->Bmask) >> fmt->Bshift; |
| *b = (bv << fmt->Bloss) + (bv >> (8 - fmt->Bloss)); |
| } 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 ( memcmp(src->colors, dst->colors, src->ncolors* |
| sizeof(SDL_Color)) == 0 ) { |
| *identical = 1; |
| return(NULL); |
| } |
| } |
| *identical = 0; |
| } |
| map = (Uint8 *)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_Palette *src, SDL_PixelFormat *dst) |
| { |
| Uint8 *map; |
| int i; |
| int bpp; |
| unsigned alpha; |
| |
| bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel); |
| map = (Uint8 *)malloc(src->ncolors*bpp); |
| if ( map == NULL ) { |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| |
| alpha = dst->Amask ? SDL_ALPHA_OPAQUE : 0; |
| /* We memory copy to the pixel map so the endianness is preserved */ |
| for ( i=0; i<src->ncolors; ++i ) { |
| ASSEMBLE_RGBA(&map[i*bpp], dst->BytesPerPixel, dst, |
| src->colors[i].r, src->colors[i].g, |
| src->colors[i].b, alpha); |
| } |
| return(map); |
| } |
| /* Map from BitField to Dithered-Palette to Palette */ |
| static Uint8 *MapNto1(SDL_PixelFormat *src, SDL_Palette *dst, int *identical) |
| { |
| /* Generate a 256 color dither palette */ |
| SDL_Palette dithered; |
| SDL_Color colors[256]; |
| |
| dithered.ncolors = 256; |
| SDL_DitherColors(colors, 8); |
| dithered.colors = colors; |
| return(Map1to1(&dithered, dst, identical)); |
| } |
| |
| SDL_BlitMap *SDL_AllocBlitMap(void) |
| { |
| SDL_BlitMap *map; |
| |
| /* Allocate the empty map */ |
| map = (SDL_BlitMap *)malloc(sizeof(*map)); |
| if ( map == NULL ) { |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| memset(map, 0, sizeof(*map)); |
| |
| /* Allocate the software blit data */ |
| map->sw_data = (struct private_swaccel *)malloc(sizeof(*map->sw_data)); |
| if ( map->sw_data == NULL ) { |
| SDL_FreeBlitMap(map); |
| SDL_OutOfMemory(); |
| return(NULL); |
| } |
| 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 ) { |
| 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->palette, dstfmt); |
| if ( map->table == NULL ) { |
| return(-1); |
| } |
| break; |
| } |
| break; |
| default: |
| switch (dstfmt->BytesPerPixel) { |
| case 1: |
| /* BitField --> Palette */ |
| map->table = MapNto1(srcfmt, |
| dstfmt->palette, &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 ) { |
| free(map->sw_data); |
| } |
| free(map); |
| } |
| } |