This repository has been archived by the owner on Feb 11, 2021.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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/* Lookup tables to expand partial bytes to the full 0..255 range */
static Uint8 lookup_0[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255
};
static Uint8 lookup_1[] = {
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, 178, 180, 182, 184, 186, 188, 190, 192, 194, 196, 198, 200, 202, 204, 206, 208, 210, 212, 214, 216, 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 238, 240, 242, 244, 246, 248, 250, 252, 255
};
static Uint8 lookup_2[] = {
0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60, 64, 68, 72, 76, 80, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 170, 174, 178, 182, 186, 190, 194, 198, 202, 206, 210, 214, 218, 222, 226, 230, 234, 238, 242, 246, 250, 255
};
static Uint8 lookup_3[] = {
0, 8, 16, 24, 32, 41, 49, 57, 65, 74, 82, 90, 98, 106, 115, 123, 131, 139, 148, 156, 164, 172, 180, 189, 197, 205, 213, 222, 230, 238, 246, 255
};
static Uint8 lookup_4[] = {
0, 17, 34, 51, 68, 85, 102, 119, 136, 153, 170, 187, 204, 221, 238, 255
};
static Uint8 lookup_5[] = {
0, 36, 72, 109, 145, 182, 218, 255
};
static Uint8 lookup_6[] = {
0, 85, 170, 255
};
static Uint8 lookup_7[] = {
0, 255
};
static Uint8 lookup_8[] = {
255
};
Uint8* SDL_expand_byte[9] = {
lookup_0,
lookup_1,
lookup_2,
lookup_3,
lookup_4,
lookup_5,
lookup_6,
lookup_7,
lookup_8
};
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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];
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/* This function doesn't work with FourCC pixel formats */
if (SDL_ISPIXELFORMAT_FOURCC(format)) {
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SDL_SetError("FOURCC pixel formats are not supported");
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return SDL_FALSE;
}
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/* 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) {
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/* SDL defaults to MSB ordering */
return SDL_PIXELFORMAT_INDEX1MSB;
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/* SDL defaults to MSB ordering */
return SDL_PIXELFORMAT_INDEX4MSB;
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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) {
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return SDL_PIXELFORMAT_RGB332;
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}
break;
case 12:
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if (Rmask == 0) {
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return SDL_PIXELFORMAT_RGB444;
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}
if (Rmask == 0x0F00 &&
Gmask == 0x00F0 &&
Bmask == 0x000F &&
Amask == 0x0000) {
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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) {
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return SDL_PIXELFORMAT_RGB555;
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}
if (Rmask == 0x001F &&
Gmask == 0x03E0 &&
Bmask == 0x7C00 &&
Amask == 0x0000) {
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return SDL_PIXELFORMAT_BGR555;
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}
if (Rmask == 0x0F00 &&
Gmask == 0x00F0 &&
Bmask == 0x000F &&
Amask == 0xF000) {
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return SDL_PIXELFORMAT_ARGB4444;
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}
if (Rmask == 0xF000 &&
Gmask == 0x0F00 &&
Bmask == 0x00F0 &&
Amask == 0x000F) {
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return SDL_PIXELFORMAT_RGBA4444;
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}
if (Rmask == 0x000F &&
Gmask == 0x00F0 &&
Bmask == 0x0F00 &&
Amask == 0xF000) {
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return SDL_PIXELFORMAT_ABGR4444;
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}
if (Rmask == 0x00F0 &&
Gmask == 0x0F00 &&
Bmask == 0xF000 &&
Amask == 0x000F) {
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return SDL_PIXELFORMAT_BGRA4444;
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}
if (Rmask == 0x7C00 &&
Gmask == 0x03E0 &&
Bmask == 0x001F &&
Amask == 0x8000) {
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return SDL_PIXELFORMAT_ARGB1555;
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}
if (Rmask == 0xF800 &&
Gmask == 0x07C0 &&
Bmask == 0x003E &&
Amask == 0x0001) {
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return SDL_PIXELFORMAT_RGBA5551;
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}
if (Rmask == 0x001F &&
Gmask == 0x03E0 &&
Bmask == 0x7C00 &&
Amask == 0x8000) {
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return SDL_PIXELFORMAT_ABGR1555;
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}
if (Rmask == 0x003E &&
Gmask == 0x07C0 &&
Bmask == 0xF800 &&
Amask == 0x0001) {
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return SDL_PIXELFORMAT_BGRA5551;
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}
if (Rmask == 0xF800 &&
Gmask == 0x07E0 &&
Bmask == 0x001F &&
Amask == 0x0000) {
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return SDL_PIXELFORMAT_RGB565;
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}
if (Rmask == 0x001F &&
Gmask == 0x07E0 &&
Bmask == 0xF800 &&
Amask == 0x0000) {
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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) {
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return SDL_PIXELFORMAT_RGB888;
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}
if (Rmask == 0x000000FF &&
Gmask == 0x0000FF00 &&
Bmask == 0x00FF0000 &&
Amask == 0x00000000) {
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return SDL_PIXELFORMAT_BGR888;
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}
if (Rmask == 0x00FF0000 &&
Gmask == 0x0000FF00 &&
Bmask == 0x000000FF &&
Amask == 0xFF000000) {
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return SDL_PIXELFORMAT_ARGB8888;
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}
if (Rmask == 0xFF000000 &&
Gmask == 0x00FF0000 &&
Bmask == 0x0000FF00 &&
Amask == 0x000000FF) {
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return SDL_PIXELFORMAT_RGBA8888;
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}
if (Rmask == 0x000000FF &&
Gmask == 0x0000FF00 &&
Bmask == 0x00FF0000 &&
Amask == 0xFF000000) {
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return SDL_PIXELFORMAT_ABGR8888;
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}
if (Rmask == 0x0000FF00 &&
Gmask == 0x00FF0000 &&
Bmask == 0xFF000000 &&
Amask == 0x000000FF) {
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return SDL_PIXELFORMAT_BGRA8888;
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}
if (Rmask == 0x3FF00000 &&
Gmask == 0x000FFC00 &&
Bmask == 0x000003FF &&
Amask == 0xC0000000) {
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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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/* 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();
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return NULL;
}
if (SDL_InitFormat(format, pixel_format) < 0) {
SDL_free(format);
return NULL;
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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;
Uint32 mask;
if (!SDL_PixelFormatEnumToMasks(pixel_format, &bpp,
&Rmask, &Gmask, &Bmask, &Amask)) {
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;
format->Rmask = Rmask;
format->Rshift = 0;
format->Rloss = 8;
if (Rmask) {
for (mask = Rmask; !(mask & 0x01); mask >>= 1)
++format->Rshift;
for (; (mask & 0x01); mask >>= 1)
--format->Rloss;
}
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format->Gmask = Gmask;
format->Gshift = 0;
format->Gloss = 8;
if (Gmask) {
for (mask = Gmask; !(mask & 0x01); mask >>= 1)
++format->Gshift;
for (; (mask & 0x01); mask >>= 1)
--format->Gloss;
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format->Bmask = Bmask;
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->Amask = Amask;
format->Ashift = 0;
format->Aloss = 8;
if (Amask) {
for (mask = Amask; !(mask & 0x01); mask >>= 1)
++format->Ashift;
for (; (mask & 0x01); mask >>= 1)
--format->Aloss;
}
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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;
}
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}
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/*
* Calculate the pad-aligned scanline width of a surface
*/
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int
SDL_CalculatePitch(SDL_Surface * surface)
729
{
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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);
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}
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/*
* 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)
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{
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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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}
/* Find the opaque pixel value corresponding to an RGB triple */
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SDL_MapRGB(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
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{
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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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}
/* 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)
795
{
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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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}
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SDL_GetRGB(Uint32 pixel, const SDL_PixelFormat * format, Uint8 * r, Uint8 * g,
Uint8 * b)
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{
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if (format->palette == NULL) {
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v = (pixel & format->Rmask) >> format->Rshift;
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*r = SDL_expand_byte[format->Rloss][v];
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v = (pixel & format->Gmask) >> format->Gshift;
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*g = SDL_expand_byte[format->Gloss][v];
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v = (pixel & format->Bmask) >> format->Bshift;
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*b = SDL_expand_byte[format->Bloss][v];
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if (pixel < (unsigned)format->palette->ncolors) {
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*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
} else {
*r = *g = *b = 0;
}
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}
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SDL_GetRGBA(Uint32 pixel, const SDL_PixelFormat * format,
Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
832
{
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if (format->palette == NULL) {
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v = (pixel & format->Rmask) >> format->Rshift;
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*r = SDL_expand_byte[format->Rloss][v];
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v = (pixel & format->Gmask) >> format->Gshift;
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*g = SDL_expand_byte[format->Gloss][v];
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v = (pixel & format->Bmask) >> format->Bshift;
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*b = SDL_expand_byte[format->Bloss][v];
v = (pixel & format->Amask) >> format->Ashift;
*a = SDL_expand_byte[format->Aloss][v];
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if (pixel < (unsigned)format->palette->ncolors) {
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*r = format->palette->colors[pixel].r;
*g = format->palette->colors[pixel].g;
*b = format->palette->colors[pixel].b;
*a = SDL_ALPHA_OPAQUE;
} else {
*r = *g = *b = *a = 0;
}
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}
/* Map from Palette to Palette */
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static Uint8 *
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
858
{
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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);
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}
889
/* Map from Palette to BitField */
890
static Uint8 *
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Map1toN(SDL_PixelFormat * src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod,
SDL_PixelFormat * dst)
893
{
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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) {
908
Uint8 A = Amod;
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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);
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ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst, R, G, B, A);
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}
return (map);
915
}
917
/* Map from BitField to Dithered-Palette to Palette */
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919
static Uint8 *
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
920
{
921
922
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926
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929
/* 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));
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}
932
933
SDL_BlitMap *
SDL_AllocBlitMap(void)
934
{
935
936
937
SDL_BlitMap *map;
/* Allocate the empty map */
938
map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
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942
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
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map->info.r = 0xFF;
map->info.g = 0xFF;
map->info.b = 0xFF;
map->info.a = 0xFF;
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949
/* It's ready to go */
return (map);
950
}
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953
void
SDL_InvalidateMap(SDL_BlitMap * map)
954
{
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957
958
if (!map) {
return;
}
map->dst = NULL;
959
map->palette_version = 0;
960
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962
if (map->info.table) {
SDL_free(map->info.table);
map->info.table = NULL;
964
}
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967
int
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
968
{
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983
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;
984
985
if (SDL_ISPIXELFORMAT_INDEXED(srcfmt->format)) {
if (SDL_ISPIXELFORMAT_INDEXED(dstfmt->format)) {
986
/* Palette --> Palette */
987
map->info.table =
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989
Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
if (!map->identity) {
990
if (map->info.table == NULL) {
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995
return (-1);
}
}
if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
map->identity = 0;
996
} else {
997
/* Palette --> BitField */
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1000
map->info.table =
Map1toN(srcfmt, src->map->info.r, src->map->info.g,
src->map->info.b, src->map->info.a, dstfmt);