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view src/video/SDL_blit_1.c @ 4085:51486c979189 SDL-1.2

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> Hi Ryan, > I checked the list you linked to, but did not see any reference to whether > the Win32 window centering bug was fixed... Has that been addressed at all? > I refer to the bug where, unless one has globally set the > SDL_WINDOW_CENTERED variable in the OS, only the 1st window that is created > will be centered. Subsequent calls to SetVideoMode will create a window tha t > shares the same upper-left corner location. I'm working on that now, thanks for reporting it. What I'm doing is if the width and height are the same, I'm leaving the window position alone, but if they're different they will respect the positioning environment variables.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 20 Jul 2007 03:25:40 +0000
parents d910939febfa
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
line wrap: on
line source

/*
    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"
#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->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;

	while ( height-- ) {
#ifdef USE_DUFFS_LOOP
		DUFFS_LOOP(
			{
			  *dst = map[*src];
			}
			dst++;
			src++;
		, width);
#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->d_width;
	height = info->d_height;
	src = info->s_pixels;
	srcskip = info->s_skip;
	dst = info->d_pixels;
	dstskip = info->d_skip;
	map = (Uint16 *)info->table;

#ifdef USE_DUFFS_LOOP
	while ( height-- ) {
		DUFFS_LOOP(
		{
			*(Uint16 *)dst = map[*src++];
			dst += 2;
		},
		width);
		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->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;

	while ( height-- ) {
#ifdef USE_DUFFS_LOOP
		DUFFS_LOOP(
			{
				o = *src * 4;
				dst[0] = map[o++];
				dst[1] = map[o++];
				dst[2] = map[o++];
			}
			src++;
			dst += 3;
		, width);
#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->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;

	while ( height-- ) {
#ifdef USE_DUFFS_LOOP
		DUFFS_LOOP(
			*dst++ = map[*src++];
		, width);
#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->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	int srcskip = info->s_skip;
	Uint8 *dst = info->d_pixels;
	int dstskip = info->d_skip;
	Uint8 *palmap = info->table;
	Uint32 ckey = info->src->colorkey;
        
	if ( palmap ) {
		while ( height-- ) {
			DUFFS_LOOP(
			{
				if ( *src != ckey ) {
				  *dst = palmap[*src];
				}
				dst++;
				src++;
			},
			width);
			src += srcskip;
			dst += dstskip;
		}
	} else {
		while ( height-- ) {
			DUFFS_LOOP(
			{
				if ( *src != ckey ) {
				  *dst = *src;
				}
				dst++;
				src++;
			},
			width);
			src += srcskip;
			dst += dstskip;
		}
	}
}

static void Blit1to2Key(SDL_BlitInfo *info)
{
	int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	int srcskip = info->s_skip;
	Uint16 *dstp = (Uint16 *)info->d_pixels;
	int dstskip = info->d_skip;
	Uint16 *palmap = (Uint16 *)info->table;
	Uint32 ckey = info->src->colorkey;

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

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

static void Blit1to3Key(SDL_BlitInfo *info)
{
	int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	int srcskip = info->s_skip;
	Uint8 *dst = info->d_pixels;
	int dstskip = info->d_skip;
	Uint8 *palmap = info->table;
	Uint32 ckey = info->src->colorkey;
	int o;

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

static void Blit1to4Key(SDL_BlitInfo *info)
{
	int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	int srcskip = info->s_skip;
	Uint32 *dstp = (Uint32 *)info->d_pixels;
	int dstskip = info->d_skip;
	Uint32 *palmap = (Uint32 *)info->table;
	Uint32 ckey = info->src->colorkey;

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

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

static void Blit1toNAlpha(SDL_BlitInfo *info)
{
	int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	int srcskip = info->s_skip;
	Uint8 *dst = info->d_pixels;
	int dstskip = info->d_skip;
	SDL_PixelFormat *dstfmt = info->dst;
	const SDL_Color *srcpal	= info->src->palette->colors;
	int dstbpp;
	const int A = info->src->alpha;

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

	while ( height-- ) {
	        int sR, sG, sB;
		int dR, dG, dB;
	    	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);
		src += srcskip;
		dst += dstskip;
	}
}

static void Blit1toNAlphaKey(SDL_BlitInfo *info)
{
	int width = info->d_width;
	int height = info->d_height;
	Uint8 *src = info->s_pixels;
	int srcskip = info->s_skip;
	Uint8 *dst = info->d_pixels;
	int dstskip = info->d_skip;
	SDL_PixelFormat *srcfmt = info->src;
	SDL_PixelFormat *dstfmt = info->dst;
	const SDL_Color *srcpal	= info->src->palette->colors;
	Uint32 ckey = srcfmt->colorkey;
	int dstbpp;
	const int A = srcfmt->alpha;

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

	while ( height-- ) {
	        int sR, sG, sB;
		int dR, dG, dB;
		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);
		src += srcskip;
		dst += dstskip;
	}
}

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

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

SDL_loblit SDL_CalculateBlit1(SDL_Surface *surface, int blit_index)
{
	int which;
	SDL_PixelFormat *dstfmt;

	dstfmt = surface->map->dst->format;
	if ( dstfmt->BitsPerPixel < 8 ) {
		which = 0;
	} else {
		which = dstfmt->BytesPerPixel;
	}
	switch(blit_index) {
	case 0:			/* copy */
	    return one_blit[which];

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

	case 2:			/* alpha */
	    /* 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 3:			/* alpha + colorkey */
	    return which >= 2 ? Blit1toNAlphaKey : NULL;

	}
	return NULL;
}