src/video/SDL_blit.c
author Sam Lantinga <slouken@libsdl.org>
Mon, 08 Dec 2008 00:25:42 +0000
branchSDL-1.2
changeset 4159 a1b03ba2fcd0
parent 3909 6832b00d3594
child 5334 d898ee5431f5
permissions -rw-r--r--
Updated copyright date
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2009 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 #include "SDL_config.h"
    23 
    24 #include "SDL_video.h"
    25 #include "SDL_sysvideo.h"
    26 #include "SDL_blit.h"
    27 #include "SDL_RLEaccel_c.h"
    28 #include "SDL_pixels_c.h"
    29 
    30 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) && SDL_ASSEMBLY_ROUTINES
    31 #define MMX_ASMBLIT
    32 #if (__GNUC__ > 2)  /* SSE instructions aren't in GCC 2. */
    33 #define SSE_ASMBLIT
    34 #endif
    35 #endif
    36 
    37 #if defined(MMX_ASMBLIT)
    38 #include "SDL_cpuinfo.h"
    39 #include "mmx.h"
    40 #endif
    41 
    42 /* The general purpose software blit routine */
    43 static int SDL_SoftBlit(SDL_Surface *src, SDL_Rect *srcrect,
    44 			SDL_Surface *dst, SDL_Rect *dstrect)
    45 {
    46 	int okay;
    47 	int src_locked;
    48 	int dst_locked;
    49 
    50 	/* Everything is okay at the beginning...  */
    51 	okay = 1;
    52 
    53 	/* Lock the destination if it's in hardware */
    54 	dst_locked = 0;
    55 	if ( SDL_MUSTLOCK(dst) ) {
    56 		if ( SDL_LockSurface(dst) < 0 ) {
    57 			okay = 0;
    58 		} else {
    59 			dst_locked = 1;
    60 		}
    61 	}
    62 	/* Lock the source if it's in hardware */
    63 	src_locked = 0;
    64 	if ( SDL_MUSTLOCK(src) ) {
    65 		if ( SDL_LockSurface(src) < 0 ) {
    66 			okay = 0;
    67 		} else {
    68 			src_locked = 1;
    69 		}
    70 	}
    71 
    72 	/* Set up source and destination buffer pointers, and BLIT! */
    73 	if ( okay  && srcrect->w && srcrect->h ) {
    74 		SDL_BlitInfo info;
    75 		SDL_loblit RunBlit;
    76 
    77 		/* Set up the blit information */
    78 		info.s_pixels = (Uint8 *)src->pixels +
    79 				(Uint16)srcrect->y*src->pitch +
    80 				(Uint16)srcrect->x*src->format->BytesPerPixel;
    81 		info.s_width = srcrect->w;
    82 		info.s_height = srcrect->h;
    83 		info.s_skip=src->pitch-info.s_width*src->format->BytesPerPixel;
    84 		info.d_pixels = (Uint8 *)dst->pixels +
    85 				(Uint16)dstrect->y*dst->pitch +
    86 				(Uint16)dstrect->x*dst->format->BytesPerPixel;
    87 		info.d_width = dstrect->w;
    88 		info.d_height = dstrect->h;
    89 		info.d_skip=dst->pitch-info.d_width*dst->format->BytesPerPixel;
    90 		info.aux_data = src->map->sw_data->aux_data;
    91 		info.src = src->format;
    92 		info.table = src->map->table;
    93 		info.dst = dst->format;
    94 		RunBlit = src->map->sw_data->blit;
    95 
    96 		/* Run the actual software blit */
    97 		RunBlit(&info);
    98 	}
    99 
   100 	/* We need to unlock the surfaces if they're locked */
   101 	if ( dst_locked ) {
   102 		SDL_UnlockSurface(dst);
   103 	}
   104 	if ( src_locked ) {
   105 		SDL_UnlockSurface(src);
   106 	}
   107 	/* Blit is done! */
   108 	return(okay ? 0 : -1);
   109 }
   110 
   111 #ifdef MMX_ASMBLIT
   112 static __inline__ void SDL_memcpyMMX(Uint8 *to, const Uint8 *from, int len)
   113 {
   114 	int i;
   115 
   116 	for(i=0; i<len/8; i++) {
   117 		__asm__ __volatile__ (
   118 		"	movq (%0), %%mm0\n"
   119 		"	movq %%mm0, (%1)\n"
   120 		: : "r" (from), "r" (to) : "memory");
   121 		from+=8;
   122 		to+=8;
   123 	}
   124 	if (len&7)
   125 		SDL_memcpy(to, from, len&7);
   126 }
   127 
   128 #ifdef SSE_ASMBLIT
   129 static __inline__ void SDL_memcpySSE(Uint8 *to, const Uint8 *from, int len)
   130 {
   131 	int i;
   132 
   133 	__asm__ __volatile__ (
   134 	"	prefetchnta (%0)\n"
   135 	"	prefetchnta 64(%0)\n"
   136 	"	prefetchnta 128(%0)\n"
   137 	"	prefetchnta 192(%0)\n"
   138 	: : "r" (from) );
   139 
   140 	for(i=0; i<len/8; i++) {
   141 		__asm__ __volatile__ (
   142 		"	prefetchnta 256(%0)\n"
   143 		"	movq (%0), %%mm0\n"
   144 		"	movntq %%mm0, (%1)\n"
   145 		: : "r" (from), "r" (to) : "memory");
   146 		from+=8;
   147 		to+=8;
   148 	}
   149 	if (len&7)
   150 		SDL_memcpy(to, from, len&7);
   151 }
   152 #endif
   153 #endif
   154 
   155 static void SDL_BlitCopy(SDL_BlitInfo *info)
   156 {
   157 	Uint8 *src, *dst;
   158 	int w, h;
   159 	int srcskip, dstskip;
   160 
   161 	w = info->d_width*info->dst->BytesPerPixel;
   162 	h = info->d_height;
   163 	src = info->s_pixels;
   164 	dst = info->d_pixels;
   165 	srcskip = w+info->s_skip;
   166 	dstskip = w+info->d_skip;
   167 
   168 #ifdef SSE_ASMBLIT
   169 	if(SDL_HasSSE())
   170 	{
   171 		while ( h-- ) {
   172 			SDL_memcpySSE(dst, src, w);
   173 			src += srcskip;
   174 			dst += dstskip;
   175 		}
   176 		__asm__ __volatile__ (
   177 		"	emms\n"
   178 		::);
   179 	}
   180 	else
   181 #endif
   182 #ifdef MMX_ASMBLIT
   183 	if(SDL_HasMMX())
   184 	{
   185 		while ( h-- ) {
   186 			SDL_memcpyMMX(dst, src, w);
   187 			src += srcskip;
   188 			dst += dstskip;
   189 		}
   190 		__asm__ __volatile__ (
   191 		"	emms\n"
   192 		::);
   193 	}
   194 	else
   195 #endif
   196 	while ( h-- ) {
   197 		SDL_memcpy(dst, src, w);
   198 		src += srcskip;
   199 		dst += dstskip;
   200 	}
   201 }
   202 
   203 static void SDL_BlitCopyOverlap(SDL_BlitInfo *info)
   204 {
   205 	Uint8 *src, *dst;
   206 	int w, h;
   207 	int srcskip, dstskip;
   208 
   209 	w = info->d_width*info->dst->BytesPerPixel;
   210 	h = info->d_height;
   211 	src = info->s_pixels;
   212 	dst = info->d_pixels;
   213 	srcskip = w+info->s_skip;
   214 	dstskip = w+info->d_skip;
   215 	if ( dst < src ) {
   216 		while ( h-- ) {
   217 			SDL_memcpy(dst, src, w);
   218 			src += srcskip;
   219 			dst += dstskip;
   220 		}
   221 	} else {
   222 		src += ((h-1) * srcskip);
   223 		dst += ((h-1) * dstskip);
   224 		while ( h-- ) {
   225 			SDL_revcpy(dst, src, w);
   226 			src -= srcskip;
   227 			dst -= dstskip;
   228 		}
   229 	}
   230 }
   231 
   232 /* Figure out which of many blit routines to set up on a surface */
   233 int SDL_CalculateBlit(SDL_Surface *surface)
   234 {
   235 	int blit_index;
   236 
   237 	/* Clean everything out to start */
   238 	if ( (surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL ) {
   239 		SDL_UnRLESurface(surface, 1);
   240 	}
   241 	surface->map->sw_blit = NULL;
   242 
   243 	/* Figure out if an accelerated hardware blit is possible */
   244 	surface->flags &= ~SDL_HWACCEL;
   245 	if ( surface->map->identity ) {
   246 		int hw_blit_ok;
   247 
   248 		if ( (surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
   249 			/* We only support accelerated blitting to hardware */
   250 			if ( surface->map->dst->flags & SDL_HWSURFACE ) {
   251 				hw_blit_ok = current_video->info.blit_hw;
   252 			} else {
   253 				hw_blit_ok = 0;
   254 			}
   255 			if (hw_blit_ok && (surface->flags & SDL_SRCCOLORKEY)) {
   256 				hw_blit_ok = current_video->info.blit_hw_CC;
   257 			}
   258 			if ( hw_blit_ok && (surface->flags & SDL_SRCALPHA) ) {
   259 				hw_blit_ok = current_video->info.blit_hw_A;
   260 			}
   261 		} else {
   262 			/* We only support accelerated blitting to hardware */
   263 			if ( surface->map->dst->flags & SDL_HWSURFACE ) {
   264 				hw_blit_ok = current_video->info.blit_sw;
   265 			} else {
   266 				hw_blit_ok = 0;
   267 			}
   268 			if (hw_blit_ok && (surface->flags & SDL_SRCCOLORKEY)) {
   269 				hw_blit_ok = current_video->info.blit_sw_CC;
   270 			}
   271 			if ( hw_blit_ok && (surface->flags & SDL_SRCALPHA) ) {
   272 				hw_blit_ok = current_video->info.blit_sw_A;
   273 			}
   274 		}
   275 		if ( hw_blit_ok ) {
   276 			SDL_VideoDevice *video = current_video;
   277 			SDL_VideoDevice *this  = current_video;
   278 			video->CheckHWBlit(this, surface, surface->map->dst);
   279 		}
   280 	}
   281 	
   282 	/* if an alpha pixel format is specified, we can accelerate alpha blits */
   283 	if (((surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE )&&(current_video->displayformatalphapixel)) 
   284 	{
   285 		if ( (surface->flags & SDL_SRCALPHA) ) 
   286 			if ( current_video->info.blit_hw_A ) {
   287 				SDL_VideoDevice *video = current_video;
   288 				SDL_VideoDevice *this  = current_video;
   289 				video->CheckHWBlit(this, surface, surface->map->dst);
   290 			}
   291 	}
   292 
   293 	/* Get the blit function index, based on surface mode */
   294 	/* { 0 = nothing, 1 = colorkey, 2 = alpha, 3 = colorkey+alpha } */
   295 	blit_index = 0;
   296 	blit_index |= (!!(surface->flags & SDL_SRCCOLORKEY))      << 0;
   297 	if ( surface->flags & SDL_SRCALPHA
   298 	     && (surface->format->alpha != SDL_ALPHA_OPAQUE
   299 		 || surface->format->Amask) ) {
   300 	        blit_index |= 2;
   301 	}
   302 
   303 	/* Check for special "identity" case -- copy blit */
   304 	if ( surface->map->identity && blit_index == 0 ) {
   305 	        surface->map->sw_data->blit = SDL_BlitCopy;
   306 
   307 		/* Handle overlapping blits on the same surface */
   308 		if ( surface == surface->map->dst ) {
   309 		        surface->map->sw_data->blit = SDL_BlitCopyOverlap;
   310 		}
   311 	} else {
   312 		if ( surface->format->BitsPerPixel < 8 ) {
   313 			surface->map->sw_data->blit =
   314 			    SDL_CalculateBlit0(surface, blit_index);
   315 		} else {
   316 			switch ( surface->format->BytesPerPixel ) {
   317 			    case 1:
   318 				surface->map->sw_data->blit =
   319 				    SDL_CalculateBlit1(surface, blit_index);
   320 				break;
   321 			    case 2:
   322 			    case 3:
   323 			    case 4:
   324 				surface->map->sw_data->blit =
   325 				    SDL_CalculateBlitN(surface, blit_index);
   326 				break;
   327 			    default:
   328 				surface->map->sw_data->blit = NULL;
   329 				break;
   330 			}
   331 		}
   332 	}
   333 	/* Make sure we have a blit function */
   334 	if ( surface->map->sw_data->blit == NULL ) {
   335 		SDL_InvalidateMap(surface->map);
   336 		SDL_SetError("Blit combination not supported");
   337 		return(-1);
   338 	}
   339 
   340 	/* Choose software blitting function */
   341 	if(surface->flags & SDL_RLEACCELOK
   342 	   && (surface->flags & SDL_HWACCEL) != SDL_HWACCEL) {
   343 
   344 	        if(surface->map->identity
   345 		   && (blit_index == 1
   346 		       || (blit_index == 3 && !surface->format->Amask))) {
   347 		        if ( SDL_RLESurface(surface) == 0 )
   348 			        surface->map->sw_blit = SDL_RLEBlit;
   349 		} else if(blit_index == 2 && surface->format->Amask) {
   350 		        if ( SDL_RLESurface(surface) == 0 )
   351 			        surface->map->sw_blit = SDL_RLEAlphaBlit;
   352 		}
   353 	}
   354 	
   355 	if ( surface->map->sw_blit == NULL ) {
   356 		surface->map->sw_blit = SDL_SoftBlit;
   357 	}
   358 	return(0);
   359 }
   360