This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_pixels.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2011 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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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
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Lesser General Public License for more details.
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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
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Sam Lantinga
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slouken@libsdl.org
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*/
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#include "SDL_config.h"
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/* 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"
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/* Helper functions */
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const char*
SDL_GetPixelFormatName(Uint32 format)
{
switch (format) {
#define CASE(X) case X: return #X;
CASE(SDL_PIXELFORMAT_INDEX1LSB)
CASE(SDL_PIXELFORMAT_INDEX1MSB)
CASE(SDL_PIXELFORMAT_INDEX4LSB)
CASE(SDL_PIXELFORMAT_INDEX4MSB)
CASE(SDL_PIXELFORMAT_INDEX8)
CASE(SDL_PIXELFORMAT_RGB332)
CASE(SDL_PIXELFORMAT_RGB444)
CASE(SDL_PIXELFORMAT_RGB555)
CASE(SDL_PIXELFORMAT_BGR555)
CASE(SDL_PIXELFORMAT_ARGB4444)
CASE(SDL_PIXELFORMAT_RGBA4444)
CASE(SDL_PIXELFORMAT_ABGR4444)
CASE(SDL_PIXELFORMAT_BGRA4444)
CASE(SDL_PIXELFORMAT_ARGB1555)
CASE(SDL_PIXELFORMAT_RGBA5551)
CASE(SDL_PIXELFORMAT_ABGR1555)
CASE(SDL_PIXELFORMAT_BGRA5551)
CASE(SDL_PIXELFORMAT_RGB565)
CASE(SDL_PIXELFORMAT_BGR565)
CASE(SDL_PIXELFORMAT_RGB24)
CASE(SDL_PIXELFORMAT_BGR24)
CASE(SDL_PIXELFORMAT_RGB888)
CASE(SDL_PIXELFORMAT_BGR888)
CASE(SDL_PIXELFORMAT_ARGB8888)
CASE(SDL_PIXELFORMAT_RGBA8888)
CASE(SDL_PIXELFORMAT_ABGR8888)
CASE(SDL_PIXELFORMAT_BGRA8888)
CASE(SDL_PIXELFORMAT_ARGB2101010)
CASE(SDL_PIXELFORMAT_YV12)
CASE(SDL_PIXELFORMAT_IYUV)
CASE(SDL_PIXELFORMAT_YUY2)
CASE(SDL_PIXELFORMAT_UYVY)
CASE(SDL_PIXELFORMAT_YVYU)
#undef CASE
default:
return "SDL_PIXELFORMAT_UNKNOWN";
}
}
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SDL_bool
SDL_PixelFormatEnumToMasks(Uint32 format, int *bpp, Uint32 * Rmask,
Uint32 * Gmask, Uint32 * Bmask, Uint32 * Amask)
{
Uint32 masks[4];
/* Initialize the values here */
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if (SDL_BYTESPERPIXEL(format) <= 2) {
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*bpp = SDL_BITSPERPIXEL(format);
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} else {
*bpp = SDL_BYTESPERPIXEL(format) * 8;
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}
*Rmask = *Gmask = *Bmask = *Amask = 0;
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if (format == SDL_PIXELFORMAT_RGB24) {
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
*Rmask = 0x00FF0000;
*Gmask = 0x0000FF00;
*Bmask = 0x000000FF;
#else
*Rmask = 0x000000FF;
*Gmask = 0x0000FF00;
*Bmask = 0x00FF0000;
#endif
return SDL_TRUE;
}
if (format == SDL_PIXELFORMAT_BGR24) {
#if SDL_BYTEORDER == SDL_BIG_ENDIAN
*Rmask = 0x000000FF;
*Gmask = 0x0000FF00;
*Bmask = 0x00FF0000;
#else
*Rmask = 0x00FF0000;
*Gmask = 0x0000FF00;
*Bmask = 0x000000FF;
#endif
return SDL_TRUE;
}
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if (SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED8 &&
SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED16 &&
SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED32) {
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/* Not a format that uses masks */
return SDL_TRUE;
}
switch (SDL_PIXELLAYOUT(format)) {
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case SDL_PACKEDLAYOUT_332:
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masks[0] = 0x00000000;
masks[1] = 0x000000E0;
masks[2] = 0x0000001C;
masks[3] = 0x00000003;
break;
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case SDL_PACKEDLAYOUT_4444:
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masks[0] = 0x0000F000;
masks[1] = 0x00000F00;
masks[2] = 0x000000F0;
masks[3] = 0x0000000F;
break;
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case SDL_PACKEDLAYOUT_1555:
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masks[0] = 0x00008000;
masks[1] = 0x00007C00;
masks[2] = 0x000003E0;
masks[3] = 0x0000001F;
break;
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case SDL_PACKEDLAYOUT_5551:
masks[0] = 0x0000F800;
masks[1] = 0x000007C0;
masks[2] = 0x0000003E;
masks[3] = 0x00000001;
break;
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case SDL_PACKEDLAYOUT_565:
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masks[0] = 0x00000000;
masks[1] = 0x0000F800;
masks[2] = 0x000007E0;
masks[3] = 0x0000001F;
break;
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case SDL_PACKEDLAYOUT_8888:
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masks[0] = 0xFF000000;
masks[1] = 0x00FF0000;
masks[2] = 0x0000FF00;
masks[3] = 0x000000FF;
break;
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case SDL_PACKEDLAYOUT_2101010:
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masks[0] = 0xC0000000;
masks[1] = 0x3FF00000;
masks[2] = 0x000FFC00;
masks[3] = 0x000003FF;
break;
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case SDL_PACKEDLAYOUT_1010102:
masks[0] = 0xFFC00000;
masks[1] = 0x003FF000;
masks[2] = 0x00000FFC;
masks[3] = 0x00000003;
break;
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SDL_SetError("Unknown pixel format");
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return SDL_FALSE;
}
switch (SDL_PIXELORDER(format)) {
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case SDL_PACKEDORDER_XRGB:
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*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
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case SDL_PACKEDORDER_RGBX:
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*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
break;
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case SDL_PACKEDORDER_ARGB:
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*Amask = masks[0];
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
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case SDL_PACKEDORDER_RGBA:
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*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
*Amask = masks[3];
break;
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case SDL_PACKEDORDER_XBGR:
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*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
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case SDL_PACKEDORDER_BGRX:
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*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
break;
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case SDL_PACKEDORDER_BGRA:
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*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
*Amask = masks[3];
break;
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case SDL_PACKEDORDER_ABGR:
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*Amask = masks[0];
*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
default:
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SDL_SetError("Unknown pixel format");
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return SDL_FALSE;
}
return SDL_TRUE;
}
Uint32
SDL_MasksToPixelFormatEnum(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask,
Uint32 Amask)
{
switch (bpp) {
case 8:
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if (Rmask == 0) {
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return SDL_PIXELFORMAT_INDEX8;
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}
if (Rmask == 0xE0 &&
Gmask == 0x1C &&
Bmask == 0x03 &&
Amask == 0x00) {
return SDL_PIXELFORMAT_RGB332
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}
break;
case 12:
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if (Rmask == 0) {
return SDL_PIXELFORMAT_RGB444
}
if (Rmask == 0x0F00 &&
Gmask == 0x00F0 &&
Bmask == 0x000F &&
Amask == 0x0000) {
return SDL_PIXELFORMAT_RGB444
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}
break;
case 15:
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if (Rmask == 0) {
return SDL_PIXELFORMAT_RGB555;
}
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/* Fall through to 16-bit checks */
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if (Rmask == 0) {
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return SDL_PIXELFORMAT_RGB565;
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}
if (Rmask == 0x7C00 &&
Gmask == 0x03E0 &&
Bmask == 0x001F &&
Amask == 0x0000) {
return SDL_PIXELFORMAT_RGB555
}
if (Rmask == 0x001F &&
Gmask == 0x03E0 &&
Bmask == 0x7C00 &&
Amask == 0x0000) {
return SDL_PIXELFORMAT_BGR555
}
if (Rmask == 0x0F00 &&
Gmask == 0x00F0 &&
Bmask == 0x000F &&
Amask == 0xF000) {
return SDL_PIXELFORMAT_ARGB4444
}
if (Rmask == 0xF000 &&
Gmask == 0x0F00 &&
Bmask == 0x00F0 &&
Amask == 0x000F) {
return SDL_PIXELFORMAT_RGBA4444
}
if (Rmask == 0x000F &&
Gmask == 0x00F0 &&
Bmask == 0x0F00 &&
Amask == 0xF000) {
return SDL_PIXELFORMAT_ABGR4444
}
if (Rmask == 0x00F0 &&
Gmask == 0x0F00 &&
Bmask == 0xF000 &&
Amask == 0x000F) {
return SDL_PIXELFORMAT_BGRA4444
}
if (Rmask == 0x7C00 &&
Gmask == 0x03E0 &&
Bmask == 0x001F &&
Amask == 0x8000) {
return SDL_PIXELFORMAT_ARGB1555
}
if (Rmask == 0xF800 &&
Gmask == 0x07C0 &&
Bmask == 0x003E &&
Amask == 0x0001) {
return SDL_PIXELFORMAT_RGBA5551
}
if (Rmask == 0x001F &&
Gmask == 0x03E0 &&
Bmask == 0x7C00 &&
Amask == 0x8000) {
return SDL_PIXELFORMAT_ABGR1555
}
if (Rmask == 0x003E &&
Gmask == 0x07C0 &&
Bmask == 0xF800 &&
Amask == 0x0001) {
return SDL_PIXELFORMAT_BGRA5551
}
if (Rmask == 0xF800 &&
Gmask == 0x07E0 &&
Bmask == 0x001F &&
Amask == 0x0000) {
return SDL_PIXELFORMAT_RGB565
}
if (Rmask == 0x001F &&
Gmask == 0x07E0 &&
Bmask == 0xF800 &&
Amask == 0x0000) {
return SDL_PIXELFORMAT_BGR565
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case 24:
switch (Rmask) {
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case 0:
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case 0x00FF0000:
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#if SDL_BYTEORDER == SDL_BIG_ENDIAN
return SDL_PIXELFORMAT_RGB24;
#else
return SDL_PIXELFORMAT_BGR24;
#endif
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case 0x000000FF:
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#if SDL_BYTEORDER == SDL_BIG_ENDIAN
return SDL_PIXELFORMAT_BGR24;
#else
return SDL_PIXELFORMAT_RGB24;
#endif
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if (Rmask == 0) {
return SDL_PIXELFORMAT_RGB888;
}
if (Rmask == 0x00FF0000 &&
Gmask == 0x0000FF00 &&
Bmask == 0x000000FF &&
Amask == 0x00000000) {
return SDL_PIXELFORMAT_RGB888
}
if (Rmask == 0x000000FF &&
Gmask == 0x0000FF00 &&
Bmask == 0x00FF0000 &&
Amask == 0x00000000) {
return SDL_PIXELFORMAT_BGR888
}
if (Rmask == 0x00FF0000 &&
Gmask == 0x0000FF00 &&
Bmask == 0x000000FF &&
Amask == 0xFF000000) {
return SDL_PIXELFORMAT_ARGB8888
}
if (Rmask == 0xFF000000 &&
Gmask == 0x00FF0000 &&
Bmask == 0x0000FF00 &&
Amask == 0x000000FF) {
return SDL_PIXELFORMAT_RGBA8888
}
if (Rmask == 0x000000FF &&
Gmask == 0x0000FF00 &&
Bmask == 0x00FF0000 &&
Amask == 0xFF000000) {
return SDL_PIXELFORMAT_ABGR8888
}
if (Rmask == 0x0000FF00 &&
Gmask == 0x00FF0000 &&
Bmask == 0xFF000000 &&
Amask == 0x000000FF) {
return SDL_PIXELFORMAT_BGRA8888
}
if (Rmask == 0x3FF00000 &&
Gmask == 0x000FFC00 &&
Bmask == 0x000003FF &&
Amask == 0xC0000000) {
return SDL_PIXELFORMAT_ARGB2101010
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return SDL_PIXELFORMAT_UNKNOWN;
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static SDL_PixelFormat *formats;
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SDL_PixelFormat *
SDL_AllocFormat(Uint32 pixel_format)
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SDL_PixelFormat *format;
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if (SDL_ISPIXELFORMAT_FOURCC(pixel_format)) {
SDL_SetError("FOURCC pixel formats are not supported");
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return NULL;
}
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/* Look it up in our list of previously allocated formats */
for (format = formats; format; format = format->next) {
if (pixel_format == format->format) {
++format->refcount;
return format;
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/* Allocate an empty pixel format structure, and initialize it */
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format = SDL_malloc(sizeof(*format));
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if (format == NULL) {
SDL_OutOfMemory();
return (NULL);
}
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SDL_InitFormat(format, pixel_format);
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if (!SDL_ISPIXELFORMAT_INDEXED(pixel_format)) {
/* Cache the RGB formats */
format->next = formats;
formats = format;
}
return format;
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int
SDL_InitFormat(SDL_PixelFormat * format, Uint32 pixel_format)
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int bpp;
Uint32 Rmask, Gmask, Bmask, Amask;
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Uint32 mask;
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if (!SDL_PixelFormatEnumToMasks(pixel_format, &bpp,
&Rmask, &Gmask, &Bmask, &Amask)) {
SDL_SetError("Unknown pixel format");
return -1;
}
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/* Set up the format */
SDL_zerop(format);
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format->format = pixel_format;
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format->BitsPerPixel = bpp;
format->BytesPerPixel = (bpp + 7) / 8;
if (Rmask || Bmask || Gmask) { /* Packed pixels with custom mask */
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;
}
format->palette = NULL;
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format->refcount = 1;
format->next = NULL;
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return 0;
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}
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SDL_FreeFormat(SDL_PixelFormat *format)
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{
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SDL_PixelFormat *prev;
if (!format) {
return;
}
if (--format->refcount > 0) {
return;
}
/* Remove this format from our list */
if (format == formats) {
formats = format->next;
} else if (formats) {
for (prev = formats; prev->next; prev = prev->next) {
if (prev->next == format) {
prev->next = format->next;
break;
}
}
}
if (format->palette) {
SDL_FreePalette(format->palette);
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SDL_free(format);
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}
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SDL_Palette *
SDL_AllocPalette(int ncolors)
{
SDL_Palette *palette;
palette = (SDL_Palette *) SDL_malloc(sizeof(*palette));
if (!palette) {
SDL_OutOfMemory();
return NULL;
}
palette->colors =
(SDL_Color *) SDL_malloc(ncolors * sizeof(*palette->colors));
if (!palette->colors) {
SDL_free(palette);
return NULL;
}
palette->ncolors = ncolors;
palette->version = 1;
palette->refcount = 1;
SDL_memset(palette->colors, 0xFF, ncolors * sizeof(*palette->colors));
return palette;
}
int
SDL_SetPixelFormatPalette(SDL_PixelFormat * format, SDL_Palette *palette)
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{
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if (!format) {
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SDL_SetError("SDL_SetPixelFormatPalette() passed NULL format");
return -1;
}
if (palette && palette->ncolors != (1 << format->BitsPerPixel)) {
SDL_SetError("SDL_SetPixelFormatPalette() passed a palette that doesn't match the format");
return -1;
}
if (format->palette == palette) {
return 0;
}
if (format->palette) {
SDL_FreePalette(format->palette);
}
format->palette = palette;
if (format->palette) {
++format->palette->refcount;
}
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return 0;
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}
int
SDL_SetPaletteColors(SDL_Palette * palette, const SDL_Color * colors,
int firstcolor, int ncolors)
{
int status = 0;
/* Verify the parameters */
if (!palette) {
return -1;
}
if (ncolors > (palette->ncolors - firstcolor)) {
ncolors = (palette->ncolors - firstcolor);
status = -1;
}
if (colors != (palette->colors + firstcolor)) {
SDL_memcpy(palette->colors + firstcolor, colors,
ncolors * sizeof(*colors));
}
++palette->version;
if (!palette->version) {
palette->version = 1;
}
return status;
}
void
SDL_FreePalette(SDL_Palette * palette)
{
if (!palette) {
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return;
}
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if (--palette->refcount > 0) {
return;
}
if (palette->colors) {
SDL_free(palette->colors);
}
SDL_free(palette);
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}
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/*
* Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
*/
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void
SDL_DitherColors(SDL_Color * colors, int bpp)
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{
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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;
colors[i].unused = SDL_ALPHA_OPAQUE;
}
687
}
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/*
* Calculate the pad-aligned scanline width of a surface
*/
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int
SDL_CalculatePitch(SDL_Surface * surface)
694
{
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int 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);
711
}
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715
/*
* Match an RGB value to a particular palette index
*/
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Uint8
SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
718
{
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/* 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);
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743
}
/* Find the opaque pixel value corresponding to an RGB triple */
745
SDL_MapRGB(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
746
{
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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);
}
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756
}
/* Find the pixel value corresponding to an RGBA quadruple */
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SDL_MapRGBA(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b,
Uint8 a)
760
{
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763
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768
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);
}
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770
}
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SDL_GetRGB(Uint32 pixel, const SDL_PixelFormat * format, Uint8 * r, Uint8 * g,
Uint8 * b)
774
{
775
if (format->palette == NULL) {
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779
/*
* 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
780
* that white is indeed reported as (255, 255, 255).
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* This only works for RGB bit fields at least 4 bit
* wide, which is almost always the case.
*/
unsigned v;
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v = (pixel & format->Rmask) >> format->Rshift;
*r = (v << format->Rloss) + (v >> (8 - (format->Rloss << 1)));
v = (pixel & format->Gmask) >> format->Gshift;
*g = (v << format->Gloss) + (v >> (8 - (format->Gloss << 1)));
v = (pixel & format->Bmask) >> format->Bshift;
*b = (v << format->Bloss) + (v >> (8 - (format->Bloss << 1)));
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*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
796
797
}
799
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SDL_GetRGBA(Uint32 pixel, const SDL_PixelFormat * format,
Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
801
{
802
803
804
805
806
807
808
809
810
811
if (format->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.
*/
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v = (pixel & format->Rmask) >> format->Rshift;
*r = (v << format->Rloss) + (v >> (8 - (format->Rloss << 1)));
v = (pixel & format->Gmask) >> format->Gshift;
*g = (v << format->Gloss) + (v >> (8 - (format->Gloss << 1)));
v = (pixel & format->Bmask) >> format->Bshift;
*b = (v << format->Bloss) + (v >> (8 - (format->Bloss << 1)));
if (format->Amask) {
v = (pixel & format->Amask) >> format->Ashift;
*a = (v << format->Aloss) + (v >> (8 - (format->Aloss << 1)));
} else {
*a = SDL_ALPHA_OPAQUE;
}
826
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828
829
*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
*a = SDL_ALPHA_OPAQUE;
831
832
833
}
/* Map from Palette to Palette */
834
835
static Uint8 *
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
836
{
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
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861
862
863
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Uint8 *map;
int i;
if (identical) {
if (src->ncolors <= dst->ncolors) {
/* If an identical palette, no need to map */
if (src == dst
||
(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);
865
}
867
/* Map from Palette to BitField */
868
static Uint8 *
869
870
Map1toN(SDL_PixelFormat * src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod,
SDL_PixelFormat * dst)
871
{
872
873
874
875
876
877
878
879
880
881
882
883
884
885
Uint8 *map;
int i;
int bpp;
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);
}
/* We memory copy to the pixel map so the endianness is preserved */
for (i = 0; i < pal->ncolors; ++i) {
886
Uint8 A = Amod;
887
888
889
Uint8 R = (Uint8) ((pal->colors[i].r * Rmod) / 255);
Uint8 G = (Uint8) ((pal->colors[i].g * Gmod) / 255);
Uint8 B = (Uint8) ((pal->colors[i].b * Bmod) / 255);
890
ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst, R, G, B, A);
891
892
}
return (map);
893
}
895
/* Map from BitField to Dithered-Palette to Palette */
896
897
static Uint8 *
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
898
{
899
900
901
902
903
904
905
906
907
/* Generate a 256 color dither palette */
SDL_Palette dithered;
SDL_Color colors[256];
SDL_Palette *pal = dst->palette;
dithered.ncolors = 256;
SDL_DitherColors(colors, 8);
dithered.colors = colors;
return (Map1to1(&dithered, pal, identical));
908
909
}
910
911
SDL_BlitMap *
SDL_AllocBlitMap(void)
912
{
913
914
915
SDL_BlitMap *map;
/* Allocate the empty map */
916
map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
917
918
919
920
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
921
922
923
924
map->info.r = 0xFF;
map->info.g = 0xFF;
map->info.b = 0xFF;
map->info.a = 0xFF;
925
926
927
/* It's ready to go */
return (map);
928
}
929
930
931
void
SDL_InvalidateMap(SDL_BlitMap * map)
932
{
933
934
935
936
if (!map) {
return;
}
map->dst = NULL;
937
map->palette_version = 0;
938
939
940
if (map->info.table) {
SDL_free(map->info.table);
map->info.table = NULL;
942
}
944
945
int
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
946
{
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
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;
962
963
if (SDL_ISPIXELFORMAT_INDEXED(srcfmt->format)) {
if (SDL_ISPIXELFORMAT_INDEXED(dstfmt->format)) {
964
/* Palette --> Palette */
965
map->info.table =
966
967
Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
if (!map->identity) {
968
if (map->info.table == NULL) {
969
970
971
972
973
return (-1);
}
}
if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
map->identity = 0;
974
} else {
975
/* Palette --> BitField */
976
977
978
979
map->info.table =
Map1toN(srcfmt, src->map->info.r, src->map->info.g,
src->map->info.b, src->map->info.a, dstfmt);
if (map->info.table == NULL) {
980
981
982
return (-1);
}
}
983
984
} else {
if (SDL_ISPIXELFORMAT_INDEXED(dstfmt->format)) {
985
/* BitField --> Palette */
986
map->info.table = MapNto1(srcfmt, dstfmt, &map->identity);
987
if (!map->identity) {
988
if (map->info.table == NULL) {
989
990
991
992
return (-1);
}
}
map->identity = 0; /* Don't optimize to copy */
993
} else {
994
/* BitField --> BitField */
995
if (srcfmt == dstfmt) {
996
map->identity = 1;
997
}