Mercurial > sdl-ios-xcode

view src/video/SDL_blit_1.c @ 3473:7bdc10624cba

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
This is terrible, but the OpenGL standard says that lines are half open, which means that one endpoint is not covered so adjoining lines don't overlap. It also doesn't define which end is open, and indeed Mac OS X and Linux differ. Mac OS X seems to leave the second endpoint open, but Linux uses the right-most endpoint for x major lines and the bottom-most endpoint for y major lines.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 21 Nov 2009 07:14:21 +0000
parents dc1eb82ffdaa
children f7b03b6838cb
line wrap: on
line source

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 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"
#include "SDL_sysvideo.h"
#include "SDL_endian.h"

/* Functions to blit from 8-bit surfaces to other surfaces */

static void
Blit1to1(SDL_BlitInfo * info)
{
#ifndef USE_DUFFS_LOOP
    int c;
#endif
    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;

    while (height--) {
#ifdef USE_DUFFS_LOOP
        /* *INDENT-OFF* */
		DUFFS_LOOP(
			{
			  *dst = map[*src];
			}
			dst++;
			src++;
		, width);
        /* *INDENT-ON* */
#else
        for (c = width; c; --c) {
            *dst = map[*src];
            dst++;
            src++;
        }
#endif
        src += srcskip;
        dst += dstskip;
    }
}

/* This is now endian dependent */
#if ( SDL_BYTEORDER == SDL_LIL_ENDIAN )
#define HI	1
#define LO	0
#else /* ( SDL_BYTEORDER == SDL_BIG_ENDIAN ) */
#define HI	0
#define LO	1
#endif
static void
Blit1to2(SDL_BlitInfo * info)
{
#ifndef USE_DUFFS_LOOP
    int c;
#endif
    int width, height;
    Uint8 *src, *dst;
    Uint16 *map;
    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 = (Uint16 *) info->table;

#ifdef USE_DUFFS_LOOP
    while (height--) {
		/* *INDENT-OFF* */
		DUFFS_LOOP(
		{
			*(Uint16 *)dst = map[*src++];
			dst += 2;
		},
		width);
		/* *INDENT-ON* */
        src += srcskip;
        dst += dstskip;
    }
#else
    /* Memory align at 4-byte boundary, if necessary */
    if ((long) dst & 0x03) {
        /* Don't do anything if width is 0 */
        if (width == 0) {
            return;
        }
        --width;

        while (height--) {
            /* Perform copy alignment */
            *(Uint16 *) dst = map[*src++];
            dst += 2;

            /* Copy in 4 pixel chunks */
            for (c = width / 4; c; --c) {
                *(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
                src += 2;
                dst += 4;
                *(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
                src += 2;
                dst += 4;
            }
            /* Get any leftovers */
            switch (width & 3) {
            case 3:
                *(Uint16 *) dst = map[*src++];
                dst += 2;
            case 2:
                *(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
                src += 2;
                dst += 4;
                break;
            case 1:
                *(Uint16 *) dst = map[*src++];
                dst += 2;
                break;
            }
            src += srcskip;
            dst += dstskip;
        }
    } else {
        while (height--) {
            /* Copy in 4 pixel chunks */
            for (c = width / 4; c; --c) {
                *(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
                src += 2;
                dst += 4;
                *(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
                src += 2;
                dst += 4;
            }
            /* Get any leftovers */
            switch (width & 3) {
            case 3:
                *(Uint16 *) dst = map[*src++];
                dst += 2;
            case 2:
                *(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);
                src += 2;
                dst += 4;
                break;
            case 1:
                *(Uint16 *) dst = map[*src++];
                dst += 2;
                break;
            }
            src += srcskip;
            dst += dstskip;
        }
    }
#endif /* USE_DUFFS_LOOP */
}

static void
Blit1to3(SDL_BlitInfo * info)
{
#ifndef USE_DUFFS_LOOP
    int c;
#endif
    int 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;

    while (height--) {
#ifdef USE_DUFFS_LOOP
		/* *INDENT-OFF* */
		DUFFS_LOOP(
			{
				o = *src * 4;
				dst[0] = map[o++];
				dst[1] = map[o++];
				dst[2] = map[o++];
			}
			src++;
			dst += 3;
		, width);
		/* *INDENT-ON* */
#else
        for (c = width; c; --c) {
            o = *src * 4;
            dst[0] = map[o++];
            dst[1] = map[o++];
            dst[2] = map[o++];
            src++;
            dst += 3;
        }
#endif /* USE_DUFFS_LOOP */
        src += srcskip;
        dst += dstskip;
    }
}

static void
Blit1to4(SDL_BlitInfo * info)
{
#ifndef USE_DUFFS_LOOP
    int c;
#endif
    int width, height;
    Uint8 *src;
    Uint32 *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 = (Uint32 *) info->dst;
    dstskip = info->dst_skip / 4;
    map = (Uint32 *) info->table;

    while (height--) {
#ifdef USE_DUFFS_LOOP
		/* *INDENT-OFF* */
		DUFFS_LOOP(
			*dst++ = map[*src++];
		, width);
		/* *INDENT-ON* */
#else
        for (c = width / 4; c; --c) {
            *dst++ = map[*src++];
            *dst++ = map[*src++];
            *dst++ = map[*src++];
            *dst++ = map[*src++];
        }
        switch (width & 3) {
        case 3:
            *dst++ = map[*src++];
        case 2:
            *dst++ = map[*src++];
        case 1:
            *dst++ = map[*src++];
        }
#endif /* USE_DUFFS_LOOP */
        src += srcskip;
        dst += dstskip;
    }
}

static void
Blit1to1Key(SDL_BlitInfo * info)
{
    int width = info->dst_w;
    int height = info->dst_h;
    Uint8 *src = info->src;
    int srcskip = info->src_skip;
    Uint8 *dst = info->dst;
    int dstskip = info->dst_skip;
    Uint8 *palmap = info->table;
    Uint32 ckey = info->colorkey;

    if (palmap) {
        while (height--) {
			/* *INDENT-OFF* */
			DUFFS_LOOP(
			{
				if ( *src != ckey ) {
				  *dst = palmap[*src];
				}
				dst++;
				src++;
			},
			width);
			/* *INDENT-ON* */
            src += srcskip;
            dst += dstskip;
        }
    } else {
        while (height--) {
			/* *INDENT-OFF* */
			DUFFS_LOOP(
			{
				if ( *src != ckey ) {
				  *dst = *src;
				}
				dst++;
				src++;
			},
			width);
			/* *INDENT-ON* */
            src += srcskip;
            dst += dstskip;
        }
    }
}

static void
Blit1to2Key(SDL_BlitInfo * info)
{
    int width = info->dst_w;
    int height = info->dst_h;
    Uint8 *src = info->src;
    int srcskip = info->src_skip;
    Uint16 *dstp = (Uint16 *) info->dst;
    int dstskip = info->dst_skip;
    Uint16 *palmap = (Uint16 *) info->table;
    Uint32 ckey = info->colorkey;

    /* Set up some basic variables */
    dstskip /= 2;

    while (height--) {
		/* *INDENT-OFF* */
		DUFFS_LOOP(
		{
			if ( *src != ckey ) {
				*dstp=palmap[*src];
			}
			src++;
			dstp++;
		},
		width);
		/* *INDENT-ON* */
        src += srcskip;
        dstp += dstskip;
    }
}

static void
Blit1to3Key(SDL_BlitInfo * info)
{
    int width = info->dst_w;
    int height = info->dst_h;
    Uint8 *src = info->src;
    int srcskip = info->src_skip;
    Uint8 *dst = info->dst;
    int dstskip = info->dst_skip;
    Uint8 *palmap = info->table;
    Uint32 ckey = info->colorkey;
    int o;

    while (height--) {
		/* *INDENT-OFF* */
		DUFFS_LOOP(
		{
			if ( *src != ckey ) {
				o = *src * 4;
				dst[0] = palmap[o++];
				dst[1] = palmap[o++];
				dst[2] = palmap[o++];
			}
			src++;
			dst += 3;
		},
		width);
		/* *INDENT-ON* */
        src += srcskip;
        dst += dstskip;
    }
}

static void
Blit1to4Key(SDL_BlitInfo * info)
{
    int width = info->dst_w;
    int height = info->dst_h;
    Uint8 *src = info->src;
    int srcskip = info->src_skip;
    Uint32 *dstp = (Uint32 *) info->dst;
    int dstskip = info->dst_skip;
    Uint32 *palmap = (Uint32 *) info->table;
    Uint32 ckey = info->colorkey;

    /* Set up some basic variables */
    dstskip /= 4;

    while (height--) {
		/* *INDENT-OFF* */
		DUFFS_LOOP(
		{
			if ( *src != ckey ) {
				*dstp = palmap[*src];
			}
			src++;
			dstp++;
		},
		width);
		/* *INDENT-ON* */
        src += srcskip;
        dstp += dstskip;
    }
}

static void
Blit1toNAlpha(SDL_BlitInfo * info)
{
    int width = info->dst_w;
    int height = info->dst_h;
    Uint8 *src = info->src;
    int srcskip = info->src_skip;
    Uint8 *dst = info->dst;
    int dstskip = info->dst_skip;
    SDL_PixelFormat *dstfmt = info->dst_fmt;
    const SDL_Color *srcpal = info->src_fmt->palette->colors;
    int dstbpp;
    const int A = info->a;

    /* Set up some basic variables */
    dstbpp = dstfmt->BytesPerPixel;

    while (height--) {
        int sR, sG, sB;
        int dR, dG, dB;
	    	/* *INDENT-OFF* */
	    	DUFFS_LOOP4(
			{
			        Uint32 pixel;
				sR = srcpal[*src].r;
				sG = srcpal[*src].g;
				sB = srcpal[*src].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);
				src++;
				dst += dstbpp;
			},
			width);
	    	/* *INDENT-ON* */
        src += srcskip;
        dst += dstskip;
    }
}

static void
Blit1toNAlphaKey(SDL_BlitInfo * info)
{
    int width = info->dst_w;
    int height = info->dst_h;
    Uint8 *src = info->src;
    int srcskip = info->src_skip;
    Uint8 *dst = info->dst;
    int dstskip = info->dst_skip;
    SDL_PixelFormat *srcfmt = info->src_fmt;
    SDL_PixelFormat *dstfmt = info->dst_fmt;
    const SDL_Color *srcpal = info->src_fmt->palette->colors;
    Uint32 ckey = info->colorkey;
    int dstbpp;
    const int A = info->a;

    /* Set up some basic variables */
    dstbpp = dstfmt->BytesPerPixel;

    while (height--) {
        int sR, sG, sB;
        int dR, dG, dB;
		/* *INDENT-OFF* */
		DUFFS_LOOP(
		{
			if ( *src != ckey ) {
			        Uint32 pixel;
				sR = srcpal[*src].r;
				sG = srcpal[*src].g;
				sB = srcpal[*src].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);
			}
			src++;
			dst += dstbpp;
		},
		width);
		/* *INDENT-ON* */
        src += srcskip;
        dst += dstskip;
    }
}

static const SDL_BlitFunc one_blit[] = {
    NULL, Blit1to1, Blit1to2, Blit1to3, Blit1to4
};

static const SDL_BlitFunc one_blitkey[] = {
    NULL, Blit1to1Key, Blit1to2Key, Blit1to3Key, Blit1to4Key
};

SDL_BlitFunc
SDL_CalculateBlit1(SDL_Surface * surface)
{
    int which;
    SDL_PixelFormat *dstfmt;

    dstfmt = surface->map->dst->format;
    if (dstfmt->BitsPerPixel < 8) {
        which = 0;
    } else {
        which = dstfmt->BytesPerPixel;
    }
    switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
    case 0:
        return one_blit[which];

    case SDL_COPY_COLORKEY:
        return one_blitkey[which];

    case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
        /* Supporting 8bpp->8bpp alpha is doable but requires lots of
           tables which consume space and takes time to precompute,
           so is better left to the user */
        return which >= 2 ? Blit1toNAlpha : NULL;

    case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
        return which >= 2 ? Blit1toNAlphaKey : NULL;
    }
    return NULL;
}

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