/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#include "SDL_video.h"
#include "SDL_blit.h"

/* Functions to blit from bitmaps to other surfaces */

static void
BlitBto1(SDL_BlitInfo * info)
{
    int c;
    int width, height;
    Uint8 *src, *map, *dst;
    int srcskip, dstskip;

    /* Set up some basic variables */
    width = info->d_width;
    height = info->d_height;
    src = info->s_pixels;
    srcskip = info->s_skip;
    dst = info->d_pixels;
    dstskip = info->d_skip;
    map = info->table;
    srcskip += width - (width + 7) / 8;

    if (map) {
        while (height--) {
            Uint8 byte = 0, bit;
            for (c = 0; c < width; ++c) {
                if ((c & 7) == 0) {
                    byte = *src++;
                }
                bit = (byte & 0x80) >> 7;
                if (1) {
                    *dst = map[bit];
                }
                dst++;
                byte <<= 1;
            }
            src += srcskip;
            dst += dstskip;
        }
    } else {
        while (height--) {
            Uint8 byte = 0, bit;
            for (c = 0; c < width; ++c) {
                if ((c & 7) == 0) {
                    byte = *src++;
                }
                bit = (byte & 0x80) >> 7;
                if (1) {
                    *dst = bit;
                }
                dst++;
                byte <<= 1;
            }
            src += srcskip;
            dst += dstskip;
        }
    }
}
static void
BlitBto2(SDL_BlitInfo * info)
{
    int c;
    int width, height;
    Uint8 *src;
    Uint16 *map, *dst;
    int srcskip, dstskip;

    /* Set up some basic variables */
    width = info->d_width;
    height = info->d_height;
    src = info->s_pixels;
    srcskip = info->s_skip;
    dst = (Uint16 *) info->d_pixels;
    dstskip = info->d_skip / 2;
    map = (Uint16 *) info->table;
    srcskip += width - (width + 7) / 8;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (1) {
                *dst = map[bit];
            }
            byte <<= 1;
            dst++;
        }
        src += srcskip;
        dst += dstskip;
    }
}
static void
BlitBto3(SDL_BlitInfo * info)
{
    int c, o;
    int width, height;
    Uint8 *src, *map, *dst;
    int srcskip, dstskip;

    /* Set up some basic variables */
    width = info->d_width;
    height = info->d_height;
    src = info->s_pixels;
    srcskip = info->s_skip;
    dst = info->d_pixels;
    dstskip = info->d_skip;
    map = info->table;
    srcskip += width - (width + 7) / 8;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (1) {
                o = bit * 4;
                dst[0] = map[o++];
                dst[1] = map[o++];
                dst[2] = map[o++];
            }
            byte <<= 1;
            dst += 3;
        }
        src += srcskip;
        dst += dstskip;
    }
}
static void
BlitBto4(SDL_BlitInfo * info)
{
    int width, height;
    Uint8 *src;
    Uint32 *map, *dst;
    int srcskip, dstskip;
    int c;

    /* Set up some basic variables */
    width = info->d_width;
    height = info->d_height;
    src = info->s_pixels;
    srcskip = info->s_skip;
    dst = (Uint32 *) info->d_pixels;
    dstskip = info->d_skip / 4;
    map = (Uint32 *) info->table;
    srcskip += width - (width + 7) / 8;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (1) {
                *dst = map[bit];
            }
            byte <<= 1;
            dst++;
        }
        src += srcskip;
        dst += dstskip;
    }
}

static void
BlitBto1Key(SDL_BlitInfo * info)
{
    int width = info->d_width;
    int height = info->d_height;
    Uint8 *src = info->s_pixels;
    Uint8 *dst = info->d_pixels;
    int srcskip = info->s_skip;
    int dstskip = info->d_skip;
    Uint32 ckey = info->src->colorkey;
    Uint8 *palmap = info->table;
    int c;

    /* Set up some basic variables */
    srcskip += width - (width + 7) / 8;

    if (palmap) {
        while (height--) {
            Uint8 byte = 0, bit;
            for (c = 0; c < width; ++c) {
                if ((c & 7) == 0) {
                    byte = *src++;
                }
                bit = (byte & 0x80) >> 7;
                if (bit != ckey) {
                    *dst = palmap[bit];
                }
                dst++;
                byte <<= 1;
            }
            src += srcskip;
            dst += dstskip;
        }
    } else {
        while (height--) {
            Uint8 byte = 0, bit;
            for (c = 0; c < width; ++c) {
                if ((c & 7) == 0) {
                    byte = *src++;
                }
                bit = (byte & 0x80) >> 7;
                if (bit != ckey) {
                    *dst = bit;
                }
                dst++;
                byte <<= 1;
            }
            src += srcskip;
            dst += dstskip;
        }
    }
}

static void
BlitBto2Key(SDL_BlitInfo * info)
{
    int width = info->d_width;
    int height = info->d_height;
    Uint8 *src = info->s_pixels;
    Uint16 *dstp = (Uint16 *) info->d_pixels;
    int srcskip = info->s_skip;
    int dstskip = info->d_skip;
    Uint32 ckey = info->src->colorkey;
    Uint8 *palmap = info->table;
    int c;

    /* Set up some basic variables */
    srcskip += width - (width + 7) / 8;
    dstskip /= 2;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (bit != ckey) {
                *dstp = ((Uint16 *) palmap)[bit];
            }
            byte <<= 1;
            dstp++;
        }
        src += srcskip;
        dstp += dstskip;
    }
}

static void
BlitBto3Key(SDL_BlitInfo * info)
{
    int width = info->d_width;
    int height = info->d_height;
    Uint8 *src = info->s_pixels;
    Uint8 *dst = info->d_pixels;
    int srcskip = info->s_skip;
    int dstskip = info->d_skip;
    Uint32 ckey = info->src->colorkey;
    Uint8 *palmap = info->table;
    int c;

    /* Set up some basic variables */
    srcskip += width - (width + 7) / 8;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (bit != ckey) {
                SDL_memcpy(dst, &palmap[bit * 4], 3);
            }
            byte <<= 1;
            dst += 3;
        }
        src += srcskip;
        dst += dstskip;
    }
}

static void
BlitBto4Key(SDL_BlitInfo * info)
{
    int width = info->d_width;
    int height = info->d_height;
    Uint8 *src = info->s_pixels;
    Uint32 *dstp = (Uint32 *) info->d_pixels;
    int srcskip = info->s_skip;
    int dstskip = info->d_skip;
    Uint32 ckey = info->src->colorkey;
    Uint8 *palmap = info->table;
    int c;

    /* Set up some basic variables */
    srcskip += width - (width + 7) / 8;
    dstskip /= 4;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (bit != ckey) {
                *dstp = ((Uint32 *) palmap)[bit];
            }
            byte <<= 1;
            dstp++;
        }
        src += srcskip;
        dstp += dstskip;
    }
}

static void
BlitBtoNAlpha(SDL_BlitInfo * info)
{
    int width = info->d_width;
    int height = info->d_height;
    Uint8 *src = info->s_pixels;
    Uint8 *dst = info->d_pixels;
    int srcskip = info->s_skip;
    int dstskip = info->d_skip;
    const SDL_Color *srcpal = info->src->palette->colors;
    SDL_PixelFormat *dstfmt = info->dst;
    int dstbpp;
    int c;
    const int A = info->src->alpha;

    /* Set up some basic variables */
    dstbpp = dstfmt->BytesPerPixel;
    srcskip += width - (width + 7) / 8;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (1) {
                Uint32 pixel;
                unsigned sR, sG, sB;
                unsigned dR, dG, dB;
                sR = srcpal[bit].r;
                sG = srcpal[bit].g;
                sB = srcpal[bit].b;
                DISEMBLE_RGB(dst, dstbpp, dstfmt, pixel, dR, dG, dB);
                ALPHA_BLEND(sR, sG, sB, A, dR, dG, dB);
                ASSEMBLE_RGB(dst, dstbpp, dstfmt, dR, dG, dB);
            }
            byte <<= 1;
            dst += dstbpp;
        }
        src += srcskip;
        dst += dstskip;
    }
}

static void
BlitBtoNAlphaKey(SDL_BlitInfo * info)
{
    int width = info->d_width;
    int height = info->d_height;
    Uint8 *src = info->s_pixels;
    Uint8 *dst = info->d_pixels;
    int srcskip = info->s_skip;
    int dstskip = info->d_skip;
    SDL_PixelFormat *srcfmt = info->src;
    SDL_PixelFormat *dstfmt = info->dst;
    const SDL_Color *srcpal = srcfmt->palette->colors;
    int dstbpp;
    int c;
    const int A = srcfmt->alpha;
    Uint32 ckey = srcfmt->colorkey;

    /* Set up some basic variables */
    dstbpp = dstfmt->BytesPerPixel;
    srcskip += width - (width + 7) / 8;

    while (height--) {
        Uint8 byte = 0, bit;
        for (c = 0; c < width; ++c) {
            if ((c & 7) == 0) {
                byte = *src++;
            }
            bit = (byte & 0x80) >> 7;
            if (bit != ckey) {
                int sR, sG, sB;
                int dR, dG, dB;
                Uint32 pixel;
                sR = srcpal[bit].r;
                sG = srcpal[bit].g;
                sB = srcpal[bit].b;
                DISEMBLE_RGB(dst, dstbpp, dstfmt, pixel, dR, dG, dB);
                ALPHA_BLEND(sR, sG, sB, A, dR, dG, dB);
                ASSEMBLE_RGB(dst, dstbpp, dstfmt, dR, dG, dB);
            }
            byte <<= 1;
            dst += dstbpp;
        }
        src += srcskip;
        dst += dstskip;
    }
}

static SDL_loblit bitmap_blit[] = {
    NULL, BlitBto1, BlitBto2, BlitBto3, BlitBto4
};

static SDL_loblit colorkey_blit[] = {
    NULL, BlitBto1Key, BlitBto2Key, BlitBto3Key, BlitBto4Key
};

SDL_loblit
SDL_CalculateBlit0(SDL_Surface * surface, int blit_index)
{
    int which;

    if (surface->format->BitsPerPixel != 1) {
        /* We don't support sub 8-bit packed pixel modes */
        return NULL;
    }
    if (surface->map->dst->format->BitsPerPixel < 8) {
        which = 0;
    } else {
        which = surface->map->dst->format->BytesPerPixel;
    }
    switch (blit_index) {
    case 0:                    /* copy */
        return bitmap_blit[which];

    case 1:                    /* colorkey */
        return colorkey_blit[which];

    case 2:                    /* alpha */
        return which >= 2 ? BlitBtoNAlpha : NULL;

    case 4:                    /* alpha + colorkey */
        return which >= 2 ? BlitBtoNAlphaKey : NULL;
    }
    return NULL;
}

/* vi: set ts=4 sw=4 expandtab: */