/*

    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->dst_w;

    height = info->dst_h;

    src = info->src;

    srcskip = info->src_skip;

    dst = info->dst;

    dstskip = info->dst_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->dst_w;

    height = info->dst_h;

    src = info->src;

    srcskip = info->src_skip;

    dst = (Uint16 *) info->dst;

    dstskip = info->dst_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->dst_w;

    height = info->dst_h;

    src = info->src;

    srcskip = info->src_skip;

    dst = info->dst;

    dstskip = info->dst_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->dst_w;

    height = info->dst_h;

    src = info->src;

    srcskip = info->src_skip;

    dst = (Uint32 *) info->dst;

    dstskip = info->dst_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->dst_w;

    int height = info->dst_h;

    Uint8 *src = info->src;

    Uint8 *dst = info->dst;

    int srcskip = info->src_skip;

    int dstskip = info->dst_skip;

    Uint32 ckey = info->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->dst_w;

    int height = info->dst_h;

    Uint8 *src = info->src;

    Uint16 *dstp = (Uint16 *) info->dst;

    int srcskip = info->src_skip;

    int dstskip = info->dst_skip;

    Uint32 ckey = info->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->dst_w;

    int height = info->dst_h;

    Uint8 *src = info->src;

    Uint8 *dst = info->dst;

    int srcskip = info->src_skip;

    int dstskip = info->dst_skip;

    Uint32 ckey = info->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->dst_w;

    int height = info->dst_h;

    Uint8 *src = info->src;

    Uint32 *dstp = (Uint32 *) info->dst;

    int srcskip = info->src_skip;

    int dstskip = info->dst_skip;

    Uint32 ckey = info->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->dst_w;

    int height = info->dst_h;

    Uint8 *src = info->src;

    Uint8 *dst = info->dst;

    int srcskip = info->src_skip;

    int dstskip = info->dst_skip;

    const SDL_Color *srcpal = info->src_fmt->palette->colors;

    SDL_PixelFormat *dstfmt = info->dst_fmt;

    int dstbpp;

    int c;

    const int A = info->a;

    /* 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->dst_w;

    int height = info->dst_h;

    Uint8 *src = info->src;

    Uint8 *dst = info->dst;

    int srcskip = info->src_skip;

    int dstskip = info->dst_skip;

    SDL_PixelFormat *srcfmt = info->src_fmt;

    SDL_PixelFormat *dstfmt = info->dst_fmt;

    const SDL_Color *srcpal = srcfmt->palette->colors;

    int dstbpp;

    int c;

    const int A = info->a;

    Uint32 ckey = info->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_BlitFunc bitmap_blit[] = {

    NULL, BlitBto1, BlitBto2, BlitBto3, BlitBto4

};

static SDL_BlitFunc colorkey_blit[] = {

    NULL, BlitBto1Key, BlitBto2Key, BlitBto3Key, BlitBto4Key

};

SDL_BlitFunc

SDL_CalculateBlit0(SDL_Surface * surface)

{

    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 (surface->map->info.flags) {

    case 0:

        return bitmap_blit[which];

    case SDL_COPY_COLORKEY:

        return colorkey_blit[which];

    case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:

        return which >= 2 ? BlitBtoNAlpha : NULL;

    case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:

        return which >= 2 ? BlitBtoNAlphaKey : NULL;

    }

    return NULL;

}

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