src/video/SDL_pixels.c
author Sam Lantinga
Sat, 19 Sep 2009 13:29:40 +0000
changeset 3280 00cace2d9080
parent 3182 9f82979eaaf0
child 3284 2b95b2c0b6d4
permissions -rw-r--r--
Merged a cleaned up version of Jiang's code changes from Google Summer of Code 2009
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/*
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    SDL - Simple DirectMedia Layer
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    Copyright (C) 1997-2009 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,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    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
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    License along with this library; if not, write to the Free Software
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    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 */
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#include "SDL_endian.h"
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#include "SDL_video.h"
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#include "SDL_sysvideo.h"
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#include "SDL_blit.h"
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#include "SDL_pixels_c.h"
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#include "SDL_RLEaccel_c.h"
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/* Helper functions */
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SDL_bool
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SDL_PixelFormatEnumToMasks(Uint32 format, int *bpp, Uint32 * Rmask,
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                           Uint32 * Gmask, Uint32 * Bmask, Uint32 * Amask)
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{
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    Uint32 masks[4];
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    /* Initialize the values here */
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    if (SDL_BYTESPERPIXEL(format) == 3) {
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        *bpp = SDL_BYTESPERPIXEL(format) * 8;
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    } else {
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        *bpp = SDL_BITSPERPIXEL(format);
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    }
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    *Rmask = *Gmask = *Bmask = *Amask = 0;
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    if (SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED8 &&
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        SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED16 &&
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        SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED32) {
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        /* Not a format that uses masks */
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        return SDL_TRUE;
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    }
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    switch (SDL_PIXELLAYOUT(format)) {
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    case SDL_PACKEDLAYOUT_332:
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        masks[0] = 0x00000000;
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        masks[1] = 0x000000E0;
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        masks[2] = 0x0000001C;
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        masks[3] = 0x00000003;
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        break;
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    case SDL_PACKEDLAYOUT_4444:
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        masks[0] = 0x0000F000;
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        masks[1] = 0x00000F00;
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        masks[2] = 0x000000F0;
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        masks[3] = 0x0000000F;
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        break;
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    case SDL_PACKEDLAYOUT_1555:
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        masks[0] = 0x00008000;
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        masks[1] = 0x00007C00;
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        masks[2] = 0x000003E0;
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        masks[3] = 0x0000001F;
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        break;
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    case SDL_PACKEDLAYOUT_5551:
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        masks[0] = 0x0000F800;
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        masks[1] = 0x000007C0;
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        masks[2] = 0x0000003E;
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        masks[3] = 0x00000001;
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        break;
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    case SDL_PACKEDLAYOUT_565:
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        masks[0] = 0x00000000;
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        masks[1] = 0x0000F800;
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        masks[2] = 0x000007E0;
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        masks[3] = 0x0000001F;
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        break;
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    case SDL_PACKEDLAYOUT_8888:
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        masks[0] = 0xFF000000;
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        masks[1] = 0x00FF0000;
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        masks[2] = 0x0000FF00;
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        masks[3] = 0x000000FF;
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        break;
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    case SDL_PACKEDLAYOUT_2101010:
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        masks[0] = 0xC0000000;
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        masks[1] = 0x3FF00000;
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        masks[2] = 0x000FFC00;
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        masks[3] = 0x000003FF;
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        break;
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    case SDL_PACKEDLAYOUT_1010102:
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        masks[0] = 0xFFC00000;
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        masks[1] = 0x003FF000;
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        masks[2] = 0x00000FFC;
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        masks[3] = 0x00000003;
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        break;
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    default:
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        /* Unknown layout */
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        return SDL_FALSE;
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    }
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    switch (SDL_PIXELORDER(format)) {
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    case SDL_PACKEDORDER_XRGB:
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        *Rmask = masks[1];
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        *Gmask = masks[2];
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        *Bmask = masks[3];
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        break;
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    case SDL_PACKEDORDER_RGBX:
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        *Rmask = masks[0];
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        *Gmask = masks[1];
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        *Bmask = masks[2];
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        break;
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    case SDL_PACKEDORDER_ARGB:
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        *Amask = masks[0];
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        *Rmask = masks[1];
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        *Gmask = masks[2];
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        *Bmask = masks[3];
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        break;
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    case SDL_PACKEDORDER_RGBA:
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        *Rmask = masks[0];
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        *Gmask = masks[1];
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        *Bmask = masks[2];
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        *Amask = masks[3];
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        break;
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    case SDL_PACKEDORDER_XBGR:
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        *Bmask = masks[1];
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        *Gmask = masks[2];
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        *Rmask = masks[3];
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        break;
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    case SDL_PACKEDORDER_BGRX:
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        *Bmask = masks[0];
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        *Gmask = masks[1];
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        *Rmask = masks[2];
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        break;
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    case SDL_PACKEDORDER_BGRA:
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        *Bmask = masks[0];
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        *Gmask = masks[1];
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        *Rmask = masks[2];
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        *Amask = masks[3];
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        break;
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    case SDL_PACKEDORDER_ABGR:
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        *Amask = masks[0];
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        *Bmask = masks[1];
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        *Gmask = masks[2];
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        *Rmask = masks[3];
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        break;
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    default:
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        /* Unknown order */
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        return SDL_FALSE;
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    }
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    return SDL_TRUE;
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}
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Uint32
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SDL_MasksToPixelFormatEnum(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask,
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                           Uint32 Amask)
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{
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    switch (bpp) {
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    case 8:
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        switch (Rmask) {
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        case 0:
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            return SDL_PIXELFORMAT_INDEX8;
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        case 0xE0:
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            return SDL_PIXELFORMAT_RGB332;
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        }
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        break;
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    case 12:
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        switch (Rmask) {
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        case 0x0F00:
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            return SDL_PIXELFORMAT_RGB444;
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        }
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        break;
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    case 15:
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        switch (Rmask) {
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        case 0x001F:
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            return SDL_PIXELFORMAT_BGR555;
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        case 0x7C00:
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            return SDL_PIXELFORMAT_RGB555;
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        }
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        break;
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    case 16:
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        switch (Rmask) {
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        case 0x000F:
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            return SDL_PIXELFORMAT_ABGR4444;
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        case 0x001F:
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            if (Gmask == 0x07E0) {
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                return SDL_PIXELFORMAT_BGR565;
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            }
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            return SDL_PIXELFORMAT_ABGR1555;
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        case 0x0F00:
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            return SDL_PIXELFORMAT_ARGB4444;
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        case 0x7C00:
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            return SDL_PIXELFORMAT_ARGB1555;
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        case 0xF800:
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            return SDL_PIXELFORMAT_RGB565;
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        }
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        break;
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    case 24:
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        switch (Rmask) {
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        case 0x00FF0000:
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            return SDL_PIXELFORMAT_RGB888;
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        case 0x000000FF:
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            return SDL_PIXELFORMAT_BGR888;
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        case 0x00000000:
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            /* FIXME: At this point we can't distinguish */
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            /* if this format is RGB24 or BGR24          */
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            return SDL_PIXELFORMAT_RGB24;
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        }
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    case 32:
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        switch (Rmask) {
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        case 0xFF000000:
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            if (Amask == 0x000000FF) {
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                return SDL_PIXELFORMAT_RGBA8888;
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            }
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            break;
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        case 0x00FF0000:
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            if (Amask == 0xFF000000) {
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                return SDL_PIXELFORMAT_ARGB8888;
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            } else {
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                return SDL_PIXELFORMAT_RGB888;
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            }
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            break;
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        case 0x0000FF00:
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            if (Amask == 0x000000FF) {
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                return SDL_PIXELFORMAT_BGRA8888;
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            }
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            break;
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        case 0x000000FF:
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            if (Amask == 0xFF000000) {
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                return SDL_PIXELFORMAT_ABGR8888;
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            } else {
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                return SDL_PIXELFORMAT_BGR888;
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            }
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            break;
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        case 0x3FF00000:
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            return SDL_PIXELFORMAT_ARGB2101010;
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        }
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    }
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    return SDL_PIXELFORMAT_UNKNOWN;
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}
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SDL_Palette *
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SDL_AllocPalette(int ncolors)
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{
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    SDL_Palette *palette;
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    palette = (SDL_Palette *) SDL_malloc(sizeof(*palette));
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    if (!palette) {
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        SDL_OutOfMemory();
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        return NULL;
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    }
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    palette->colors =
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        (SDL_Color *) SDL_malloc(ncolors * sizeof(*palette->colors));
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    if (!palette->colors) {
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        SDL_free(palette);
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        return NULL;
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    }
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    palette->ncolors = ncolors;
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    palette->watch = NULL;
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    palette->refcount = 1;
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    SDL_memset(palette->colors, 0xFF, ncolors * sizeof(*palette->colors));
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    return palette;
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}
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int
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SDL_AddPaletteWatch(SDL_Palette * palette, SDL_PaletteChangedFunc callback,
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                    void *userdata)
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{
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    SDL_PaletteWatch *watch;
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    if (!palette) {
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        return -1;
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    }
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    watch = (SDL_PaletteWatch *) SDL_malloc(sizeof(*watch));
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    if (!watch) {
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        SDL_OutOfMemory();
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        return -1;
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    }
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    watch->callback = callback;
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    watch->userdata = userdata;
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    watch->next = palette->watch;
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    palette->watch = watch;
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    ++palette->refcount;
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    return 0;
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}
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void
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SDL_DelPaletteWatch(SDL_Palette * palette, SDL_PaletteChangedFunc callback,
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                    void *userdata)
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{
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    SDL_PaletteWatch *prev, *watch;
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    if (!palette) {
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        return;
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    }
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    for (prev = NULL, watch = palette->watch; watch;
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         prev = watch, watch = watch->next) {
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        if (watch->callback == callback && watch->userdata == userdata) {
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            if (prev) {
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                prev->next = watch->next;
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            } else {
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                palette->watch = watch->next;
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            }
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            SDL_free(watch);
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            SDL_FreePalette(palette);
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            return;
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        }
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    }
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}
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int
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SDL_SetPaletteColors(SDL_Palette * palette, const SDL_Color * colors,
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                     int firstcolor, int ncolors)
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{
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    SDL_PaletteWatch *watch;
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    int status = 0;
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    /* Verify the parameters */
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    if (!palette) {
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        return -1;
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    }
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   336
    if (ncolors > (palette->ncolors - firstcolor)) {
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        ncolors = (palette->ncolors - firstcolor);
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        status = -1;
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    }
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   340
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   341
    if (colors != (palette->colors + firstcolor)) {
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        SDL_memcpy(palette->colors + firstcolor, colors,
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   343
                   ncolors * sizeof(*colors));
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    }
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   345
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   346
    for (watch = palette->watch; watch; watch = watch->next) {
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   347
        if (watch->callback(watch->userdata, palette) < 0) {
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            status = -1;
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        }
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    }
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   352
    return status;
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}
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   355
void
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SDL_FreePalette(SDL_Palette * palette)
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   357
{
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   358
    if (!palette) {
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   359
        return;
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   360
    }
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   361
    if (--palette->refcount > 0) {
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   362
        return;
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   363
    }
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   364
    if (palette->colors) {
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   365
        SDL_free(palette->colors);
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   366
    }
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   367
    SDL_free(palette);
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}
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   369
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   370
/*
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 * Allocate a pixel format structure and fill it according to the given info.
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 */
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SDL_PixelFormat *
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SDL_AllocFormat(int bpp,
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                Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
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   376
{
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   377
    SDL_PixelFormat *format;
slouken@0
   378
slouken@1895
   379
    /* Allocate an empty pixel format structure */
slouken@2967
   380
    format = SDL_malloc(sizeof(*format));
slouken@1895
   381
    if (format == NULL) {
slouken@1895
   382
        SDL_OutOfMemory();
slouken@1895
   383
        return (NULL);
slouken@1895
   384
    }
slouken@0
   385
slouken@1895
   386
    /* Set up the format */
slouken@2967
   387
    return SDL_InitFormat(format, bpp, Rmask, Gmask, Bmask, Amask);
slouken@2967
   388
}
slouken@2967
   389
slouken@2967
   390
SDL_PixelFormat *
slouken@2990
   391
SDL_InitFormat(SDL_PixelFormat * format, int bpp, Uint32 Rmask, Uint32 Gmask,
slouken@2990
   392
               Uint32 Bmask, Uint32 Amask)
slouken@2967
   393
{
slouken@2967
   394
    Uint32 mask;
slouken@2967
   395
slouken@2967
   396
    /* Set up the format */
slouken@2967
   397
    SDL_zerop(format);
slouken@1895
   398
    format->BitsPerPixel = bpp;
slouken@1895
   399
    format->BytesPerPixel = (bpp + 7) / 8;
slouken@1895
   400
    if (Rmask || Bmask || Gmask) {      /* Packed pixels with custom mask */
slouken@1895
   401
        format->Rshift = 0;
slouken@1895
   402
        format->Rloss = 8;
slouken@1895
   403
        if (Rmask) {
slouken@1895
   404
            for (mask = Rmask; !(mask & 0x01); mask >>= 1)
slouken@1895
   405
                ++format->Rshift;
slouken@1895
   406
            for (; (mask & 0x01); mask >>= 1)
slouken@1895
   407
                --format->Rloss;
slouken@1895
   408
        }
slouken@1895
   409
        format->Gshift = 0;
slouken@1895
   410
        format->Gloss = 8;
slouken@1895
   411
        if (Gmask) {
slouken@1895
   412
            for (mask = Gmask; !(mask & 0x01); mask >>= 1)
slouken@1895
   413
                ++format->Gshift;
slouken@1895
   414
            for (; (mask & 0x01); mask >>= 1)
slouken@1895
   415
                --format->Gloss;
slouken@1895
   416
        }
slouken@1895
   417
        format->Bshift = 0;
slouken@1895
   418
        format->Bloss = 8;
slouken@1895
   419
        if (Bmask) {
slouken@1895
   420
            for (mask = Bmask; !(mask & 0x01); mask >>= 1)
slouken@1895
   421
                ++format->Bshift;
slouken@1895
   422
            for (; (mask & 0x01); mask >>= 1)
slouken@1895
   423
                --format->Bloss;
slouken@1895
   424
        }
slouken@1895
   425
        format->Ashift = 0;
slouken@1895
   426
        format->Aloss = 8;
slouken@1895
   427
        if (Amask) {
slouken@1895
   428
            for (mask = Amask; !(mask & 0x01); mask >>= 1)
slouken@1895
   429
                ++format->Ashift;
slouken@1895
   430
            for (; (mask & 0x01); mask >>= 1)
slouken@1895
   431
                --format->Aloss;
slouken@1895
   432
        }
slouken@1895
   433
        format->Rmask = Rmask;
slouken@1895
   434
        format->Gmask = Gmask;
slouken@1895
   435
        format->Bmask = Bmask;
slouken@1895
   436
        format->Amask = Amask;
slouken@1895
   437
    } else if (bpp > 8) {       /* Packed pixels with standard mask */
slouken@1895
   438
        /* R-G-B */
slouken@1895
   439
        if (bpp > 24)
slouken@1895
   440
            bpp = 24;
slouken@1895
   441
        format->Rloss = 8 - (bpp / 3);
slouken@1895
   442
        format->Gloss = 8 - (bpp / 3) - (bpp % 3);
slouken@1895
   443
        format->Bloss = 8 - (bpp / 3);
slouken@1895
   444
        format->Rshift = ((bpp / 3) + (bpp % 3)) + (bpp / 3);
slouken@1895
   445
        format->Gshift = (bpp / 3);
slouken@1895
   446
        format->Bshift = 0;
slouken@1895
   447
        format->Rmask = ((0xFF >> format->Rloss) << format->Rshift);
slouken@1895
   448
        format->Gmask = ((0xFF >> format->Gloss) << format->Gshift);
slouken@1895
   449
        format->Bmask = ((0xFF >> format->Bloss) << format->Bshift);
slouken@1895
   450
    } else {
slouken@1895
   451
        /* Palettized formats have no mask info */
slouken@1895
   452
        format->Rloss = 8;
slouken@1895
   453
        format->Gloss = 8;
slouken@1895
   454
        format->Bloss = 8;
slouken@1895
   455
        format->Aloss = 8;
slouken@1895
   456
        format->Rshift = 0;
slouken@1895
   457
        format->Gshift = 0;
slouken@1895
   458
        format->Bshift = 0;
slouken@1895
   459
        format->Ashift = 0;
slouken@1895
   460
        format->Rmask = 0;
slouken@1895
   461
        format->Gmask = 0;
slouken@1895
   462
        format->Bmask = 0;
slouken@1895
   463
        format->Amask = 0;
slouken@1895
   464
    }
slouken@1895
   465
    format->palette = NULL;
slouken@1057
   466
slouken@2967
   467
    return format;
slouken@0
   468
}
slouken@0
   469
slouken@0
   470
/*
slouken@0
   471
 * Change any previous mappings from/to the new surface format
slouken@0
   472
 */
slouken@1895
   473
void
slouken@1895
   474
SDL_FormatChanged(SDL_Surface * surface)
slouken@0
   475
{
slouken@1895
   476
    static int format_version = 0;
slouken@1895
   477
    ++format_version;
slouken@1895
   478
    if (format_version < 0) {   /* It wrapped... */
slouken@1895
   479
        format_version = 1;
slouken@1895
   480
    }
slouken@1895
   481
    surface->format_version = format_version;
slouken@1895
   482
    SDL_InvalidateMap(surface->map);
slouken@0
   483
}
slouken@1895
   484
slouken@0
   485
/*
slouken@0
   486
 * Free a previously allocated format structure
slouken@0
   487
 */
slouken@1895
   488
void
slouken@1895
   489
SDL_FreeFormat(SDL_PixelFormat * format)
slouken@0
   490
{
slouken@1895
   491
    if (!format) {
slouken@1895
   492
        return;
slouken@1895
   493
    }
slouken@1895
   494
    SDL_free(format);
slouken@0
   495
}
slouken@1895
   496
slouken@0
   497
/*
slouken@0
   498
 * Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
slouken@0
   499
 */
slouken@1895
   500
void
slouken@1895
   501
SDL_DitherColors(SDL_Color * colors, int bpp)
slouken@0
   502
{
slouken@1895
   503
    int i;
slouken@1895
   504
    if (bpp != 8)
slouken@1895
   505
        return;                 /* only 8bpp supported right now */
slouken@0
   506
slouken@1895
   507
    for (i = 0; i < 256; i++) {
slouken@1895
   508
        int r, g, b;
slouken@1895
   509
        /* map each bit field to the full [0, 255] interval,
slouken@1895
   510
           so 0 is mapped to (0, 0, 0) and 255 to (255, 255, 255) */
slouken@1895
   511
        r = i & 0xe0;
slouken@1895
   512
        r |= r >> 3 | r >> 6;
slouken@1895
   513
        colors[i].r = r;
slouken@1895
   514
        g = (i << 3) & 0xe0;
slouken@1895
   515
        g |= g >> 3 | g >> 6;
slouken@1895
   516
        colors[i].g = g;
slouken@1895
   517
        b = i & 0x3;
slouken@1895
   518
        b |= b << 2;
slouken@1895
   519
        b |= b << 4;
slouken@1895
   520
        colors[i].b = b;
slouken@1895
   521
        colors[i].unused = SDL_ALPHA_OPAQUE;
slouken@1895
   522
    }
slouken@0
   523
}
slouken@1895
   524
slouken@0
   525
/* 
slouken@0
   526
 * Calculate the pad-aligned scanline width of a surface
slouken@0
   527
 */
slouken@1895
   528
int
slouken@1895
   529
SDL_CalculatePitch(SDL_Surface * surface)
slouken@0
   530
{
slouken@1895
   531
    int pitch;
slouken@0
   532
slouken@1895
   533
    /* Surface should be 4-byte aligned for speed */
slouken@1895
   534
    pitch = surface->w * surface->format->BytesPerPixel;
slouken@1895
   535
    switch (surface->format->BitsPerPixel) {
slouken@1895
   536
    case 1:
slouken@1895
   537
        pitch = (pitch + 7) / 8;
slouken@1895
   538
        break;
slouken@1895
   539
    case 4:
slouken@1895
   540
        pitch = (pitch + 1) / 2;
slouken@1895
   541
        break;
slouken@1895
   542
    default:
slouken@1895
   543
        break;
slouken@1895
   544
    }
slouken@1895
   545
    pitch = (pitch + 3) & ~3;   /* 4-byte aligning */
slouken@1895
   546
    return (pitch);
slouken@0
   547
}
slouken@1895
   548
slouken@0
   549
/*
slouken@0
   550
 * Match an RGB value to a particular palette index
slouken@0
   551
 */
slouken@1895
   552
Uint8
slouken@1895
   553
SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
slouken@0
   554
{
slouken@1895
   555
    /* Do colorspace distance matching */
slouken@1895
   556
    unsigned int smallest;
slouken@1895
   557
    unsigned int distance;
slouken@1895
   558
    int rd, gd, bd;
slouken@1895
   559
    int i;
slouken@1895
   560
    Uint8 pixel = 0;
slouken@1895
   561
slouken@1895
   562
    smallest = ~0;
slouken@1895
   563
    for (i = 0; i < pal->ncolors; ++i) {
slouken@1895
   564
        rd = pal->colors[i].r - r;
slouken@1895
   565
        gd = pal->colors[i].g - g;
slouken@1895
   566
        bd = pal->colors[i].b - b;
slouken@1895
   567
        distance = (rd * rd) + (gd * gd) + (bd * bd);
slouken@1895
   568
        if (distance < smallest) {
slouken@1895
   569
            pixel = i;
slouken@1895
   570
            if (distance == 0) {        /* Perfect match! */
slouken@1895
   571
                break;
slouken@1895
   572
            }
slouken@1895
   573
            smallest = distance;
slouken@1895
   574
        }
slouken@1895
   575
    }
slouken@1895
   576
    return (pixel);
slouken@0
   577
}
slouken@0
   578
slouken@0
   579
/* Find the opaque pixel value corresponding to an RGB triple */
slouken@1895
   580
Uint32
slouken@2275
   581
SDL_MapRGB(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b)
slouken@0
   582
{
slouken@1895
   583
    if (format->palette == NULL) {
slouken@1895
   584
        return (r >> format->Rloss) << format->Rshift
slouken@1895
   585
            | (g >> format->Gloss) << format->Gshift
slouken@1895
   586
            | (b >> format->Bloss) << format->Bshift | format->Amask;
slouken@1895
   587
    } else {
slouken@1895
   588
        return SDL_FindColor(format->palette, r, g, b);
slouken@1895
   589
    }
slouken@0
   590
}
slouken@0
   591
slouken@0
   592
/* Find the pixel value corresponding to an RGBA quadruple */
slouken@1895
   593
Uint32
slouken@2275
   594
SDL_MapRGBA(const SDL_PixelFormat * format, Uint8 r, Uint8 g, Uint8 b,
slouken@2275
   595
            Uint8 a)
slouken@0
   596
{
slouken@1895
   597
    if (format->palette == NULL) {
slouken@1895
   598
        return (r >> format->Rloss) << format->Rshift
slouken@1895
   599
            | (g >> format->Gloss) << format->Gshift
slouken@1895
   600
            | (b >> format->Bloss) << format->Bshift
slouken@1895
   601
            | ((a >> format->Aloss) << format->Ashift & format->Amask);
slouken@1895
   602
    } else {
slouken@1895
   603
        return SDL_FindColor(format->palette, r, g, b);
slouken@1895
   604
    }
slouken@0
   605
}
slouken@0
   606
slouken@1895
   607
void
slouken@2275
   608
SDL_GetRGB(Uint32 pixel, const SDL_PixelFormat * format, Uint8 * r, Uint8 * g,
slouken@2275
   609
           Uint8 * b)
slouken@2275
   610
{
slouken@2275
   611
    if (format->palette == NULL) {
slouken@2275
   612
        /*
slouken@2275
   613
         * This makes sure that the result is mapped to the
slouken@2275
   614
         * interval [0..255], and the maximum value for each
slouken@2275
   615
         * component is 255. This is important to make sure
slouken@2275
   616
         * that white is indeed reported as (255, 255, 255).
slouken@2275
   617
         * This only works for RGB bit fields at least 4 bit
slouken@2275
   618
         * wide, which is almost always the case.
slouken@2275
   619
         */
slouken@2275
   620
        unsigned v;
slouken@2275
   621
        v = (pixel & format->Rmask) >> format->Rshift;
slouken@2275
   622
        *r = (v << format->Rloss) + (v >> (8 - (format->Rloss << 1)));
slouken@2275
   623
        v = (pixel & format->Gmask) >> format->Gshift;
slouken@2275
   624
        *g = (v << format->Gloss) + (v >> (8 - (format->Gloss << 1)));
slouken@2275
   625
        v = (pixel & format->Bmask) >> format->Bshift;
slouken@2275
   626
        *b = (v << format->Bloss) + (v >> (8 - (format->Bloss << 1)));
slouken@2275
   627
    } else {
slouken@2275
   628
        *r = format->palette->colors[pixel].r;
slouken@2275
   629
        *g = format->palette->colors[pixel].g;
slouken@2275
   630
        *b = format->palette->colors[pixel].b;
slouken@2275
   631
    }
slouken@2275
   632
}
slouken@2275
   633
slouken@2275
   634
void
slouken@2275
   635
SDL_GetRGBA(Uint32 pixel, const SDL_PixelFormat * format,
slouken@1895
   636
            Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
slouken@0
   637
{
slouken@2275
   638
    if (format->palette == NULL) {
slouken@1895
   639
        /*
slouken@1895
   640
         * This makes sure that the result is mapped to the
slouken@1895
   641
         * interval [0..255], and the maximum value for each
slouken@1895
   642
         * component is 255. This is important to make sure
slouken@1895
   643
         * that white is indeed reported as (255, 255, 255),
slouken@1895
   644
         * and that opaque alpha is 255.
slouken@1895
   645
         * This only works for RGB bit fields at least 4 bit
slouken@1895
   646
         * wide, which is almost always the case.
slouken@1895
   647
         */
slouken@1895
   648
        unsigned v;
slouken@2275
   649
        v = (pixel & format->Rmask) >> format->Rshift;
slouken@2275
   650
        *r = (v << format->Rloss) + (v >> (8 - (format->Rloss << 1)));
slouken@2275
   651
        v = (pixel & format->Gmask) >> format->Gshift;
slouken@2275
   652
        *g = (v << format->Gloss) + (v >> (8 - (format->Gloss << 1)));
slouken@2275
   653
        v = (pixel & format->Bmask) >> format->Bshift;
slouken@2275
   654
        *b = (v << format->Bloss) + (v >> (8 - (format->Bloss << 1)));
slouken@2275
   655
        if (format->Amask) {
slouken@2275
   656
            v = (pixel & format->Amask) >> format->Ashift;
slouken@2275
   657
            *a = (v << format->Aloss) + (v >> (8 - (format->Aloss << 1)));
slouken@1895
   658
        } else {
slouken@1895
   659
            *a = SDL_ALPHA_OPAQUE;
slouken@1895
   660
        }
slouken@1895
   661
    } else {
slouken@2275
   662
        *r = format->palette->colors[pixel].r;
slouken@2275
   663
        *g = format->palette->colors[pixel].g;
slouken@2275
   664
        *b = format->palette->colors[pixel].b;
slouken@1895
   665
        *a = SDL_ALPHA_OPAQUE;
slouken@1895
   666
    }
slouken@0
   667
}
slouken@0
   668
slouken@0
   669
/* Apply gamma to a set of colors - this is easy. :) */
slouken@1895
   670
void
slouken@1895
   671
SDL_ApplyGamma(Uint16 * gamma, SDL_Color * colors, SDL_Color * output,
slouken@1895
   672
               int ncolors)
slouken@0
   673
{
slouken@1895
   674
    int i;
slouken@0
   675
slouken@1895
   676
    for (i = 0; i < ncolors; ++i) {
slouken@1895
   677
        output[i].r = gamma[0 * 256 + colors[i].r] >> 8;
slouken@1895
   678
        output[i].g = gamma[1 * 256 + colors[i].g] >> 8;
slouken@1895
   679
        output[i].b = gamma[2 * 256 + colors[i].b] >> 8;
slouken@1895
   680
    }
slouken@0
   681
}
slouken@0
   682
slouken@0
   683
/* Map from Palette to Palette */
slouken@1895
   684
static Uint8 *
slouken@1895
   685
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
slouken@0
   686
{
slouken@1895
   687
    Uint8 *map;
slouken@1895
   688
    int i;
slouken@0
   689
slouken@1895
   690
    if (identical) {
slouken@1895
   691
        if (src->ncolors <= dst->ncolors) {
slouken@1895
   692
            /* If an identical palette, no need to map */
slouken@1895
   693
            if (src == dst
slouken@1895
   694
                ||
slouken@1895
   695
                (SDL_memcmp
slouken@1895
   696
                 (src->colors, dst->colors,
slouken@1895
   697
                  src->ncolors * sizeof(SDL_Color)) == 0)) {
slouken@1895
   698
                *identical = 1;
slouken@1895
   699
                return (NULL);
slouken@1895
   700
            }
slouken@1895
   701
        }
slouken@1895
   702
        *identical = 0;
slouken@1895
   703
    }
slouken@1895
   704
    map = (Uint8 *) SDL_malloc(src->ncolors);
slouken@1895
   705
    if (map == NULL) {
slouken@1895
   706
        SDL_OutOfMemory();
slouken@1895
   707
        return (NULL);
slouken@1895
   708
    }
slouken@1895
   709
    for (i = 0; i < src->ncolors; ++i) {
slouken@1895
   710
        map[i] = SDL_FindColor(dst,
slouken@1895
   711
                               src->colors[i].r, src->colors[i].g,
slouken@1895
   712
                               src->colors[i].b);
slouken@1895
   713
    }
slouken@1895
   714
    return (map);
slouken@0
   715
}
slouken@1895
   716
slouken@0
   717
/* Map from Palette to BitField */
slouken@1895
   718
static Uint8 *
slouken@2267
   719
Map1toN(SDL_PixelFormat * src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod,
slouken@2267
   720
        SDL_PixelFormat * dst)
slouken@0
   721
{
slouken@1895
   722
    Uint8 *map;
slouken@1895
   723
    int i;
slouken@1895
   724
    int bpp;
slouken@1895
   725
    SDL_Palette *pal = src->palette;
slouken@0
   726
slouken@1895
   727
    bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel);
slouken@1895
   728
    map = (Uint8 *) SDL_malloc(pal->ncolors * bpp);
slouken@1895
   729
    if (map == NULL) {
slouken@1895
   730
        SDL_OutOfMemory();
slouken@1895
   731
        return (NULL);
slouken@1895
   732
    }
slouken@0
   733
slouken@1895
   734
    /* We memory copy to the pixel map so the endianness is preserved */
slouken@1895
   735
    for (i = 0; i < pal->ncolors; ++i) {
slouken@2257
   736
        Uint8 A = Amod;
slouken@2267
   737
        Uint8 R = (Uint8) ((pal->colors[i].r * Rmod) / 255);
slouken@2267
   738
        Uint8 G = (Uint8) ((pal->colors[i].g * Gmod) / 255);
slouken@2267
   739
        Uint8 B = (Uint8) ((pal->colors[i].b * Bmod) / 255);
slouken@2257
   740
        ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst, R, G, B, A);
slouken@1895
   741
    }
slouken@1895
   742
    return (map);
slouken@0
   743
}
slouken@1895
   744
slouken@0
   745
/* Map from BitField to Dithered-Palette to Palette */
slouken@1895
   746
static Uint8 *
slouken@1895
   747
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
slouken@0
   748
{
slouken@1895
   749
    /* Generate a 256 color dither palette */
slouken@1895
   750
    SDL_Palette dithered;
slouken@1895
   751
    SDL_Color colors[256];
slouken@1895
   752
    SDL_Palette *pal = dst->palette;
slouken@0
   753
slouken@1895
   754
    dithered.ncolors = 256;
slouken@1895
   755
    SDL_DitherColors(colors, 8);
slouken@1895
   756
    dithered.colors = colors;
slouken@1895
   757
    return (Map1to1(&dithered, pal, identical));
slouken@0
   758
}
slouken@0
   759
slouken@1895
   760
SDL_BlitMap *
slouken@1895
   761
SDL_AllocBlitMap(void)
slouken@0
   762
{
slouken@1895
   763
    SDL_BlitMap *map;
slouken@0
   764
slouken@1895
   765
    /* Allocate the empty map */
slouken@1920
   766
    map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
slouken@1895
   767
    if (map == NULL) {
slouken@1895
   768
        SDL_OutOfMemory();
slouken@1895
   769
        return (NULL);
slouken@1895
   770
    }
slouken@2267
   771
    map->info.r = 0xFF;
slouken@2267
   772
    map->info.g = 0xFF;
slouken@2267
   773
    map->info.b = 0xFF;
slouken@2267
   774
    map->info.a = 0xFF;
slouken@0
   775
slouken@1895
   776
    /* It's ready to go */
slouken@1895
   777
    return (map);
slouken@0
   778
}
slouken@1895
   779
slouken@1895
   780
void
slouken@1895
   781
SDL_InvalidateMap(SDL_BlitMap * map)
slouken@0
   782
{
slouken@1895
   783
    if (!map) {
slouken@1895
   784
        return;
slouken@1895
   785
    }
slouken@1895
   786
    map->dst = NULL;
slouken@1895
   787
    map->format_version = (unsigned int) -1;
slouken@2267
   788
    if (map->info.table) {
slouken@2267
   789
        SDL_free(map->info.table);
slouken@2267
   790
        map->info.table = NULL;
slouken@1895
   791
    }
slouken@0
   792
}
slouken@2735
   793
slouken@1895
   794
int
slouken@1895
   795
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
slouken@0
   796
{
slouken@1895
   797
    SDL_PixelFormat *srcfmt;
slouken@1895
   798
    SDL_PixelFormat *dstfmt;
slouken@1895
   799
    SDL_BlitMap *map;
slouken@0
   800
slouken@1895
   801
    /* Clear out any previous mapping */
slouken@1895
   802
    map = src->map;
slouken@1895
   803
    if ((src->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
slouken@1895
   804
        SDL_UnRLESurface(src, 1);
slouken@1895
   805
    }
slouken@1895
   806
    SDL_InvalidateMap(map);
slouken@0
   807
slouken@1895
   808
    /* Figure out what kind of mapping we're doing */
slouken@1895
   809
    map->identity = 0;
slouken@1895
   810
    srcfmt = src->format;
slouken@1895
   811
    dstfmt = dst->format;
slouken@1895
   812
    switch (srcfmt->BytesPerPixel) {
slouken@1895
   813
    case 1:
slouken@1895
   814
        switch (dstfmt->BytesPerPixel) {
slouken@1895
   815
        case 1:
slouken@1895
   816
            /* Palette --> Palette */
slouken@2267
   817
            map->info.table =
slouken@1895
   818
                Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
slouken@1895
   819
            if (!map->identity) {
slouken@2267
   820
                if (map->info.table == NULL) {
slouken@1895
   821
                    return (-1);
slouken@1895
   822
                }
slouken@1895
   823
            }
slouken@1895
   824
            if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
slouken@1895
   825
                map->identity = 0;
slouken@1895
   826
            break;
slouken@0
   827
slouken@1895
   828
        default:
slouken@1895
   829
            /* Palette --> BitField */
slouken@2267
   830
            map->info.table =
slouken@2267
   831
                Map1toN(srcfmt, src->map->info.r, src->map->info.g,
slouken@2267
   832
                        src->map->info.b, src->map->info.a, dstfmt);
slouken@2267
   833
            if (map->info.table == NULL) {
slouken@1895
   834
                return (-1);
slouken@1895
   835
            }
slouken@1895
   836
            break;
slouken@1895
   837
        }
slouken@1895
   838
        break;
slouken@1895
   839
    default:
slouken@1895
   840
        switch (dstfmt->BytesPerPixel) {
slouken@1895
   841
        case 1:
slouken@1895
   842
            /* BitField --> Palette */
slouken@2267
   843
            map->info.table = MapNto1(srcfmt, dstfmt, &map->identity);
slouken@1895
   844
            if (!map->identity) {
slouken@2267
   845
                if (map->info.table == NULL) {
slouken@1895
   846
                    return (-1);
slouken@1895
   847
                }
slouken@1895
   848
            }
slouken@1895
   849
            map->identity = 0;  /* Don't optimize to copy */
slouken@1895
   850
            break;
slouken@1895
   851
        default:
slouken@1895
   852
            /* BitField --> BitField */
slouken@1895
   853
            if (FORMAT_EQUAL(srcfmt, dstfmt))
slouken@1895
   854
                map->identity = 1;
slouken@1895
   855
            break;
slouken@1895
   856
        }
slouken@1895
   857
        break;
slouken@1895
   858
    }
slouken@0
   859
slouken@1895
   860
    map->dst = dst;
slouken@1895
   861
    map->format_version = dst->format_version;
slouken@0
   862
slouken@1895
   863
    /* Choose your blitters wisely */
slouken@1895
   864
    return (SDL_CalculateBlit(src));
slouken@0
   865
}
slouken@1895
   866
slouken@1895
   867
void
slouken@1895
   868
SDL_FreeBlitMap(SDL_BlitMap * map)
slouken@0
   869
{
slouken@1895
   870
    if (map) {
slouken@1895
   871
        SDL_InvalidateMap(map);
slouken@1895
   872
        SDL_free(map);
slouken@1895
   873
    }
slouken@0
   874
}
slouken@1895
   875
slouken@1895
   876
/* vi: set ts=4 sw=4 expandtab: */