src/video/SDL_pixels.c
author Sam Lantinga <slouken@libsdl.org>
Sat, 18 Aug 2007 05:39:09 +0000
changeset 2267 c785543d1843
parent 2260 202ddfd1cfb1
child 2275 12ea0fdc0df2
permissions -rw-r--r--
Okay, still some bugs, but everything builds again...
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/*
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    SDL - Simple DirectMedia Layer
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    Copyright (C) 1997-2006 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_BITSPERPIXEL(format) == 24) {
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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_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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    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 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 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 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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    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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    if (colors != (palette->colors + firstcolor)) {
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        SDL_memcpy(palette->colors + firstcolor, colors,
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                   ncolors * sizeof(*colors));
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    }
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    for (watch = palette->watch; watch; watch = watch->next) {
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        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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    return status;
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}
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void
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SDL_FreePalette(SDL_Palette * palette)
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{
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    if (!palette) {
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        return;
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    }
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    if (--palette->refcount > 0) {
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        return;
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    }
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    if (palette->colors) {
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        SDL_free(palette->colors);
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    }
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    SDL_free(palette);
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}
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   337
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/*
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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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{
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   345
    SDL_PixelFormat *format;
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   346
    Uint32 mask;
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   347
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   348
    /* Allocate an empty pixel format structure */
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    format = SDL_calloc(1, sizeof(*format));
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   350
    if (format == NULL) {
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   351
        SDL_OutOfMemory();
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   352
        return (NULL);
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   353
    }
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   354
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   355
    /* Set up the format */
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    format->BitsPerPixel = bpp;
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    format->BytesPerPixel = (bpp + 7) / 8;
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   358
    if (Rmask || Bmask || Gmask) {      /* Packed pixels with custom mask */
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   359
        format->Rshift = 0;
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   360
        format->Rloss = 8;
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   361
        if (Rmask) {
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   362
            for (mask = Rmask; !(mask & 0x01); mask >>= 1)
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   363
                ++format->Rshift;
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   364
            for (; (mask & 0x01); mask >>= 1)
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   365
                --format->Rloss;
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   366
        }
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   367
        format->Gshift = 0;
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   368
        format->Gloss = 8;
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   369
        if (Gmask) {
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   370
            for (mask = Gmask; !(mask & 0x01); mask >>= 1)
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   371
                ++format->Gshift;
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   372
            for (; (mask & 0x01); mask >>= 1)
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   373
                --format->Gloss;
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   374
        }
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   375
        format->Bshift = 0;
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   376
        format->Bloss = 8;
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   377
        if (Bmask) {
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   378
            for (mask = Bmask; !(mask & 0x01); mask >>= 1)
slouken@1895
   379
                ++format->Bshift;
slouken@1895
   380
            for (; (mask & 0x01); mask >>= 1)
slouken@1895
   381
                --format->Bloss;
slouken@1895
   382
        }
slouken@1895
   383
        format->Ashift = 0;
slouken@1895
   384
        format->Aloss = 8;
slouken@1895
   385
        if (Amask) {
slouken@1895
   386
            for (mask = Amask; !(mask & 0x01); mask >>= 1)
slouken@1895
   387
                ++format->Ashift;
slouken@1895
   388
            for (; (mask & 0x01); mask >>= 1)
slouken@1895
   389
                --format->Aloss;
slouken@1895
   390
        }
slouken@1895
   391
        format->Rmask = Rmask;
slouken@1895
   392
        format->Gmask = Gmask;
slouken@1895
   393
        format->Bmask = Bmask;
slouken@1895
   394
        format->Amask = Amask;
slouken@1895
   395
    } else if (bpp > 8) {       /* Packed pixels with standard mask */
slouken@1895
   396
        /* R-G-B */
slouken@1895
   397
        if (bpp > 24)
slouken@1895
   398
            bpp = 24;
slouken@1895
   399
        format->Rloss = 8 - (bpp / 3);
slouken@1895
   400
        format->Gloss = 8 - (bpp / 3) - (bpp % 3);
slouken@1895
   401
        format->Bloss = 8 - (bpp / 3);
slouken@1895
   402
        format->Rshift = ((bpp / 3) + (bpp % 3)) + (bpp / 3);
slouken@1895
   403
        format->Gshift = (bpp / 3);
slouken@1895
   404
        format->Bshift = 0;
slouken@1895
   405
        format->Rmask = ((0xFF >> format->Rloss) << format->Rshift);
slouken@1895
   406
        format->Gmask = ((0xFF >> format->Gloss) << format->Gshift);
slouken@1895
   407
        format->Bmask = ((0xFF >> format->Bloss) << format->Bshift);
slouken@1895
   408
    } else {
slouken@1895
   409
        /* Palettized formats have no mask info */
slouken@1895
   410
        format->Rloss = 8;
slouken@1895
   411
        format->Gloss = 8;
slouken@1895
   412
        format->Bloss = 8;
slouken@1895
   413
        format->Aloss = 8;
slouken@1895
   414
        format->Rshift = 0;
slouken@1895
   415
        format->Gshift = 0;
slouken@1895
   416
        format->Bshift = 0;
slouken@1895
   417
        format->Ashift = 0;
slouken@1895
   418
        format->Rmask = 0;
slouken@1895
   419
        format->Gmask = 0;
slouken@1895
   420
        format->Bmask = 0;
slouken@1895
   421
        format->Amask = 0;
slouken@1895
   422
    }
slouken@1895
   423
    format->palette = NULL;
slouken@1057
   424
slouken@1895
   425
    return (format);
slouken@0
   426
}
slouken@0
   427
slouken@0
   428
/*
slouken@0
   429
 * Change any previous mappings from/to the new surface format
slouken@0
   430
 */
slouken@1895
   431
void
slouken@1895
   432
SDL_FormatChanged(SDL_Surface * surface)
slouken@0
   433
{
slouken@1895
   434
    static int format_version = 0;
slouken@1895
   435
    ++format_version;
slouken@1895
   436
    if (format_version < 0) {   /* It wrapped... */
slouken@1895
   437
        format_version = 1;
slouken@1895
   438
    }
slouken@1895
   439
    surface->format_version = format_version;
slouken@1895
   440
    SDL_InvalidateMap(surface->map);
slouken@0
   441
}
slouken@1895
   442
slouken@0
   443
/*
slouken@0
   444
 * Free a previously allocated format structure
slouken@0
   445
 */
slouken@1895
   446
void
slouken@1895
   447
SDL_FreeFormat(SDL_PixelFormat * format)
slouken@0
   448
{
slouken@1895
   449
    if (!format) {
slouken@1895
   450
        return;
slouken@1895
   451
    }
slouken@1895
   452
    SDL_free(format);
slouken@0
   453
}
slouken@1895
   454
slouken@0
   455
/*
slouken@0
   456
 * Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
slouken@0
   457
 */
slouken@1895
   458
void
slouken@1895
   459
SDL_DitherColors(SDL_Color * colors, int bpp)
slouken@0
   460
{
slouken@1895
   461
    int i;
slouken@1895
   462
    if (bpp != 8)
slouken@1895
   463
        return;                 /* only 8bpp supported right now */
slouken@0
   464
slouken@1895
   465
    for (i = 0; i < 256; i++) {
slouken@1895
   466
        int r, g, b;
slouken@1895
   467
        /* map each bit field to the full [0, 255] interval,
slouken@1895
   468
           so 0 is mapped to (0, 0, 0) and 255 to (255, 255, 255) */
slouken@1895
   469
        r = i & 0xe0;
slouken@1895
   470
        r |= r >> 3 | r >> 6;
slouken@1895
   471
        colors[i].r = r;
slouken@1895
   472
        g = (i << 3) & 0xe0;
slouken@1895
   473
        g |= g >> 3 | g >> 6;
slouken@1895
   474
        colors[i].g = g;
slouken@1895
   475
        b = i & 0x3;
slouken@1895
   476
        b |= b << 2;
slouken@1895
   477
        b |= b << 4;
slouken@1895
   478
        colors[i].b = b;
slouken@1895
   479
        colors[i].unused = SDL_ALPHA_OPAQUE;
slouken@1895
   480
    }
slouken@0
   481
}
slouken@1895
   482
slouken@0
   483
/* 
slouken@0
   484
 * Calculate the pad-aligned scanline width of a surface
slouken@0
   485
 */
slouken@1895
   486
int
slouken@1895
   487
SDL_CalculatePitch(SDL_Surface * surface)
slouken@0
   488
{
slouken@1895
   489
    int pitch;
slouken@0
   490
slouken@1895
   491
    /* Surface should be 4-byte aligned for speed */
slouken@1895
   492
    pitch = surface->w * surface->format->BytesPerPixel;
slouken@1895
   493
    switch (surface->format->BitsPerPixel) {
slouken@1895
   494
    case 1:
slouken@1895
   495
        pitch = (pitch + 7) / 8;
slouken@1895
   496
        break;
slouken@1895
   497
    case 4:
slouken@1895
   498
        pitch = (pitch + 1) / 2;
slouken@1895
   499
        break;
slouken@1895
   500
    default:
slouken@1895
   501
        break;
slouken@1895
   502
    }
slouken@1895
   503
    pitch = (pitch + 3) & ~3;   /* 4-byte aligning */
slouken@1895
   504
    return (pitch);
slouken@0
   505
}
slouken@1895
   506
slouken@0
   507
/*
slouken@0
   508
 * Match an RGB value to a particular palette index
slouken@0
   509
 */
slouken@1895
   510
Uint8
slouken@1895
   511
SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
slouken@0
   512
{
slouken@1895
   513
    /* Do colorspace distance matching */
slouken@1895
   514
    unsigned int smallest;
slouken@1895
   515
    unsigned int distance;
slouken@1895
   516
    int rd, gd, bd;
slouken@1895
   517
    int i;
slouken@1895
   518
    Uint8 pixel = 0;
slouken@1895
   519
slouken@1895
   520
    smallest = ~0;
slouken@1895
   521
    for (i = 0; i < pal->ncolors; ++i) {
slouken@1895
   522
        rd = pal->colors[i].r - r;
slouken@1895
   523
        gd = pal->colors[i].g - g;
slouken@1895
   524
        bd = pal->colors[i].b - b;
slouken@1895
   525
        distance = (rd * rd) + (gd * gd) + (bd * bd);
slouken@1895
   526
        if (distance < smallest) {
slouken@1895
   527
            pixel = i;
slouken@1895
   528
            if (distance == 0) {        /* Perfect match! */
slouken@1895
   529
                break;
slouken@1895
   530
            }
slouken@1895
   531
            smallest = distance;
slouken@1895
   532
        }
slouken@1895
   533
    }
slouken@1895
   534
    return (pixel);
slouken@0
   535
}
slouken@0
   536
slouken@0
   537
/* Find the opaque pixel value corresponding to an RGB triple */
slouken@1895
   538
Uint32
icculus@2102
   539
SDL_MapRGB(const SDL_PixelFormat * const format, const Uint8 r, const Uint8 g,
icculus@2102
   540
           const Uint8 b)
slouken@0
   541
{
slouken@1895
   542
    if (format->palette == NULL) {
slouken@1895
   543
        return (r >> format->Rloss) << format->Rshift
slouken@1895
   544
            | (g >> format->Gloss) << format->Gshift
slouken@1895
   545
            | (b >> format->Bloss) << format->Bshift | format->Amask;
slouken@1895
   546
    } else {
slouken@1895
   547
        return SDL_FindColor(format->palette, r, g, b);
slouken@1895
   548
    }
slouken@0
   549
}
slouken@0
   550
slouken@0
   551
/* Find the pixel value corresponding to an RGBA quadruple */
slouken@1895
   552
Uint32
slouken@2120
   553
SDL_MapRGBA(const SDL_PixelFormat * const format, const Uint8 r,
slouken@2120
   554
            const Uint8 g, const Uint8 b, const Uint8 a)
slouken@0
   555
{
slouken@1895
   556
    if (format->palette == NULL) {
slouken@1895
   557
        return (r >> format->Rloss) << format->Rshift
slouken@1895
   558
            | (g >> format->Gloss) << format->Gshift
slouken@1895
   559
            | (b >> format->Bloss) << format->Bshift
slouken@1895
   560
            | ((a >> format->Aloss) << format->Ashift & format->Amask);
slouken@1895
   561
    } else {
slouken@1895
   562
        return SDL_FindColor(format->palette, r, g, b);
slouken@1895
   563
    }
slouken@0
   564
}
slouken@0
   565
slouken@1895
   566
void
slouken@1895
   567
SDL_GetRGBA(Uint32 pixel, SDL_PixelFormat * fmt,
slouken@1895
   568
            Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
slouken@0
   569
{
slouken@1895
   570
    if (fmt->palette == NULL) {
slouken@1895
   571
        /*
slouken@1895
   572
         * This makes sure that the result is mapped to the
slouken@1895
   573
         * interval [0..255], and the maximum value for each
slouken@1895
   574
         * component is 255. This is important to make sure
slouken@1895
   575
         * that white is indeed reported as (255, 255, 255),
slouken@1895
   576
         * and that opaque alpha is 255.
slouken@1895
   577
         * This only works for RGB bit fields at least 4 bit
slouken@1895
   578
         * wide, which is almost always the case.
slouken@1895
   579
         */
slouken@1895
   580
        unsigned v;
slouken@1895
   581
        v = (pixel & fmt->Rmask) >> fmt->Rshift;
slouken@1895
   582
        *r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1)));
slouken@1895
   583
        v = (pixel & fmt->Gmask) >> fmt->Gshift;
slouken@1895
   584
        *g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1)));
slouken@1895
   585
        v = (pixel & fmt->Bmask) >> fmt->Bshift;
slouken@1895
   586
        *b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1)));
slouken@1895
   587
        if (fmt->Amask) {
slouken@1895
   588
            v = (pixel & fmt->Amask) >> fmt->Ashift;
slouken@1895
   589
            *a = (v << fmt->Aloss) + (v >> (8 - (fmt->Aloss << 1)));
slouken@1895
   590
        } else {
slouken@1895
   591
            *a = SDL_ALPHA_OPAQUE;
slouken@1895
   592
        }
slouken@1895
   593
    } else {
slouken@1895
   594
        *r = fmt->palette->colors[pixel].r;
slouken@1895
   595
        *g = fmt->palette->colors[pixel].g;
slouken@1895
   596
        *b = fmt->palette->colors[pixel].b;
slouken@1895
   597
        *a = SDL_ALPHA_OPAQUE;
slouken@1895
   598
    }
slouken@0
   599
}
slouken@0
   600
slouken@1895
   601
void
slouken@1895
   602
SDL_GetRGB(Uint32 pixel, SDL_PixelFormat * fmt, Uint8 * r, Uint8 * g,
slouken@1895
   603
           Uint8 * b)
slouken@0
   604
{
slouken@1895
   605
    if (fmt->palette == NULL) {
slouken@1895
   606
        /* the note for SDL_GetRGBA above applies here too */
slouken@1895
   607
        unsigned v;
slouken@1895
   608
        v = (pixel & fmt->Rmask) >> fmt->Rshift;
slouken@1895
   609
        *r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1)));
slouken@1895
   610
        v = (pixel & fmt->Gmask) >> fmt->Gshift;
slouken@1895
   611
        *g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1)));
slouken@1895
   612
        v = (pixel & fmt->Bmask) >> fmt->Bshift;
slouken@1895
   613
        *b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1)));
slouken@1895
   614
    } else {
slouken@1895
   615
        *r = fmt->palette->colors[pixel].r;
slouken@1895
   616
        *g = fmt->palette->colors[pixel].g;
slouken@1895
   617
        *b = fmt->palette->colors[pixel].b;
slouken@1895
   618
    }
slouken@0
   619
}
slouken@0
   620
slouken@0
   621
/* Apply gamma to a set of colors - this is easy. :) */
slouken@1895
   622
void
slouken@1895
   623
SDL_ApplyGamma(Uint16 * gamma, SDL_Color * colors, SDL_Color * output,
slouken@1895
   624
               int ncolors)
slouken@0
   625
{
slouken@1895
   626
    int i;
slouken@0
   627
slouken@1895
   628
    for (i = 0; i < ncolors; ++i) {
slouken@1895
   629
        output[i].r = gamma[0 * 256 + colors[i].r] >> 8;
slouken@1895
   630
        output[i].g = gamma[1 * 256 + colors[i].g] >> 8;
slouken@1895
   631
        output[i].b = gamma[2 * 256 + colors[i].b] >> 8;
slouken@1895
   632
    }
slouken@0
   633
}
slouken@0
   634
slouken@0
   635
/* Map from Palette to Palette */
slouken@1895
   636
static Uint8 *
slouken@1895
   637
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
slouken@0
   638
{
slouken@1895
   639
    Uint8 *map;
slouken@1895
   640
    int i;
slouken@0
   641
slouken@1895
   642
    if (identical) {
slouken@1895
   643
        if (src->ncolors <= dst->ncolors) {
slouken@1895
   644
            /* If an identical palette, no need to map */
slouken@1895
   645
            if (src == dst
slouken@1895
   646
                ||
slouken@1895
   647
                (SDL_memcmp
slouken@1895
   648
                 (src->colors, dst->colors,
slouken@1895
   649
                  src->ncolors * sizeof(SDL_Color)) == 0)) {
slouken@1895
   650
                *identical = 1;
slouken@1895
   651
                return (NULL);
slouken@1895
   652
            }
slouken@1895
   653
        }
slouken@1895
   654
        *identical = 0;
slouken@1895
   655
    }
slouken@1895
   656
    map = (Uint8 *) SDL_malloc(src->ncolors);
slouken@1895
   657
    if (map == NULL) {
slouken@1895
   658
        SDL_OutOfMemory();
slouken@1895
   659
        return (NULL);
slouken@1895
   660
    }
slouken@1895
   661
    for (i = 0; i < src->ncolors; ++i) {
slouken@1895
   662
        map[i] = SDL_FindColor(dst,
slouken@1895
   663
                               src->colors[i].r, src->colors[i].g,
slouken@1895
   664
                               src->colors[i].b);
slouken@1895
   665
    }
slouken@1895
   666
    return (map);
slouken@0
   667
}
slouken@1895
   668
slouken@0
   669
/* Map from Palette to BitField */
slouken@1895
   670
static Uint8 *
slouken@2267
   671
Map1toN(SDL_PixelFormat * src, Uint8 Rmod, Uint8 Gmod, Uint8 Bmod, Uint8 Amod,
slouken@2267
   672
        SDL_PixelFormat * dst)
slouken@0
   673
{
slouken@1895
   674
    Uint8 *map;
slouken@1895
   675
    int i;
slouken@1895
   676
    int bpp;
slouken@1895
   677
    SDL_Palette *pal = src->palette;
slouken@0
   678
slouken@1895
   679
    bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel);
slouken@1895
   680
    map = (Uint8 *) SDL_malloc(pal->ncolors * bpp);
slouken@1895
   681
    if (map == NULL) {
slouken@1895
   682
        SDL_OutOfMemory();
slouken@1895
   683
        return (NULL);
slouken@1895
   684
    }
slouken@0
   685
slouken@1895
   686
    /* We memory copy to the pixel map so the endianness is preserved */
slouken@1895
   687
    for (i = 0; i < pal->ncolors; ++i) {
slouken@2257
   688
        Uint8 A = Amod;
slouken@2267
   689
        Uint8 R = (Uint8) ((pal->colors[i].r * Rmod) / 255);
slouken@2267
   690
        Uint8 G = (Uint8) ((pal->colors[i].g * Gmod) / 255);
slouken@2267
   691
        Uint8 B = (Uint8) ((pal->colors[i].b * Bmod) / 255);
slouken@2257
   692
        ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst, R, G, B, A);
slouken@1895
   693
    }
slouken@1895
   694
    return (map);
slouken@0
   695
}
slouken@1895
   696
slouken@0
   697
/* Map from BitField to Dithered-Palette to Palette */
slouken@1895
   698
static Uint8 *
slouken@1895
   699
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
slouken@0
   700
{
slouken@1895
   701
    /* Generate a 256 color dither palette */
slouken@1895
   702
    SDL_Palette dithered;
slouken@1895
   703
    SDL_Color colors[256];
slouken@1895
   704
    SDL_Palette *pal = dst->palette;
slouken@0
   705
slouken@1895
   706
    dithered.ncolors = 256;
slouken@1895
   707
    SDL_DitherColors(colors, 8);
slouken@1895
   708
    dithered.colors = colors;
slouken@1895
   709
    return (Map1to1(&dithered, pal, identical));
slouken@0
   710
}
slouken@0
   711
slouken@1895
   712
SDL_BlitMap *
slouken@1895
   713
SDL_AllocBlitMap(void)
slouken@0
   714
{
slouken@1895
   715
    SDL_BlitMap *map;
slouken@0
   716
slouken@1895
   717
    /* Allocate the empty map */
slouken@1920
   718
    map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
slouken@1895
   719
    if (map == NULL) {
slouken@1895
   720
        SDL_OutOfMemory();
slouken@1895
   721
        return (NULL);
slouken@1895
   722
    }
slouken@2267
   723
    map->info.r = 0xFF;
slouken@2267
   724
    map->info.g = 0xFF;
slouken@2267
   725
    map->info.b = 0xFF;
slouken@2267
   726
    map->info.a = 0xFF;
slouken@0
   727
slouken@1895
   728
    /* It's ready to go */
slouken@1895
   729
    return (map);
slouken@0
   730
}
slouken@1895
   731
slouken@1895
   732
void
slouken@1895
   733
SDL_InvalidateMap(SDL_BlitMap * map)
slouken@0
   734
{
slouken@1895
   735
    if (!map) {
slouken@1895
   736
        return;
slouken@1895
   737
    }
slouken@1895
   738
    map->dst = NULL;
slouken@1895
   739
    map->format_version = (unsigned int) -1;
slouken@2267
   740
    if (map->info.table) {
slouken@2267
   741
        SDL_free(map->info.table);
slouken@2267
   742
        map->info.table = NULL;
slouken@1895
   743
    }
slouken@0
   744
}
slouken@1895
   745
int
slouken@1895
   746
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
slouken@0
   747
{
slouken@1895
   748
    SDL_PixelFormat *srcfmt;
slouken@1895
   749
    SDL_PixelFormat *dstfmt;
slouken@1895
   750
    SDL_BlitMap *map;
slouken@0
   751
slouken@1895
   752
    /* Clear out any previous mapping */
slouken@1895
   753
    map = src->map;
slouken@1895
   754
    if ((src->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
slouken@1895
   755
        SDL_UnRLESurface(src, 1);
slouken@1895
   756
    }
slouken@1895
   757
    SDL_InvalidateMap(map);
slouken@0
   758
slouken@1895
   759
    /* Figure out what kind of mapping we're doing */
slouken@1895
   760
    map->identity = 0;
slouken@1895
   761
    srcfmt = src->format;
slouken@1895
   762
    dstfmt = dst->format;
slouken@1895
   763
    switch (srcfmt->BytesPerPixel) {
slouken@1895
   764
    case 1:
slouken@1895
   765
        switch (dstfmt->BytesPerPixel) {
slouken@1895
   766
        case 1:
slouken@1895
   767
            /* Palette --> Palette */
slouken@2267
   768
            map->info.table =
slouken@1895
   769
                Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
slouken@1895
   770
            if (!map->identity) {
slouken@2267
   771
                if (map->info.table == NULL) {
slouken@1895
   772
                    return (-1);
slouken@1895
   773
                }
slouken@1895
   774
            }
slouken@1895
   775
            if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
slouken@1895
   776
                map->identity = 0;
slouken@1895
   777
            break;
slouken@0
   778
slouken@1895
   779
        default:
slouken@1895
   780
            /* Palette --> BitField */
slouken@2267
   781
            map->info.table =
slouken@2267
   782
                Map1toN(srcfmt, src->map->info.r, src->map->info.g,
slouken@2267
   783
                        src->map->info.b, src->map->info.a, dstfmt);
slouken@2267
   784
            if (map->info.table == NULL) {
slouken@1895
   785
                return (-1);
slouken@1895
   786
            }
slouken@1895
   787
            break;
slouken@1895
   788
        }
slouken@1895
   789
        break;
slouken@1895
   790
    default:
slouken@1895
   791
        switch (dstfmt->BytesPerPixel) {
slouken@1895
   792
        case 1:
slouken@1895
   793
            /* BitField --> Palette */
slouken@2267
   794
            map->info.table = MapNto1(srcfmt, dstfmt, &map->identity);
slouken@1895
   795
            if (!map->identity) {
slouken@2267
   796
                if (map->info.table == NULL) {
slouken@1895
   797
                    return (-1);
slouken@1895
   798
                }
slouken@1895
   799
            }
slouken@1895
   800
            map->identity = 0;  /* Don't optimize to copy */
slouken@1895
   801
            break;
slouken@1895
   802
        default:
slouken@1895
   803
            /* BitField --> BitField */
slouken@1895
   804
            if (FORMAT_EQUAL(srcfmt, dstfmt))
slouken@1895
   805
                map->identity = 1;
slouken@1895
   806
            break;
slouken@1895
   807
        }
slouken@1895
   808
        break;
slouken@1895
   809
    }
slouken@0
   810
slouken@1895
   811
    map->dst = dst;
slouken@1895
   812
    map->format_version = dst->format_version;
slouken@0
   813
slouken@1895
   814
    /* Choose your blitters wisely */
slouken@1895
   815
    return (SDL_CalculateBlit(src));
slouken@0
   816
}
slouken@1895
   817
slouken@1895
   818
void
slouken@1895
   819
SDL_FreeBlitMap(SDL_BlitMap * map)
slouken@0
   820
{
slouken@1895
   821
    if (map) {
slouken@1895
   822
        SDL_InvalidateMap(map);
slouken@1895
   823
        SDL_free(map);
slouken@1895
   824
    }
slouken@0
   825
}
slouken@1895
   826
slouken@1895
   827
/* vi: set ts=4 sw=4 expandtab: */