src/video/SDL_blit.c
author Sam Lantinga <slouken@libsdl.org>
Thu, 16 Feb 2006 10:11:48 +0000
changeset 1361 19418e4422cb
parent 1358 c71e05b4dc2e
child 1402 d910939febfa
permissions -rw-r--r--
New configure-based build system. Still work in progress, but much improved
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 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 
    23 #include "SDL_video.h"
    24 #include "SDL_sysvideo.h"
    25 #include "SDL_blit.h"
    26 #include "SDL_RLEaccel_c.h"
    27 #include "SDL_pixels_c.h"
    28 
    29 #if (i386 || __x86_64__) && __GNUC__ && SDL_ASSEMBLY_BLITTERS
    30 #define MMX_ASMBLIT
    31 #endif
    32 
    33 #if defined(MMX_ASMBLIT)
    34 #include "SDL_cpuinfo.h"
    35 #include "mmx.h"
    36 #endif
    37 
    38 /* The general purpose software blit routine */
    39 static int SDL_SoftBlit(SDL_Surface *src, SDL_Rect *srcrect,
    40 			SDL_Surface *dst, SDL_Rect *dstrect)
    41 {
    42 	int okay;
    43 	int src_locked;
    44 	int dst_locked;
    45 
    46 	/* Everything is okay at the beginning...  */
    47 	okay = 1;
    48 
    49 	/* Lock the destination if it's in hardware */
    50 	dst_locked = 0;
    51 	if ( SDL_MUSTLOCK(dst) ) {
    52 		if ( SDL_LockSurface(dst) < 0 ) {
    53 			okay = 0;
    54 		} else {
    55 			dst_locked = 1;
    56 		}
    57 	}
    58 	/* Lock the source if it's in hardware */
    59 	src_locked = 0;
    60 	if ( SDL_MUSTLOCK(src) ) {
    61 		if ( SDL_LockSurface(src) < 0 ) {
    62 			okay = 0;
    63 		} else {
    64 			src_locked = 1;
    65 		}
    66 	}
    67 
    68 	/* Set up source and destination buffer pointers, and BLIT! */
    69 	if ( okay  && srcrect->w && srcrect->h ) {
    70 		SDL_BlitInfo info;
    71 		SDL_loblit RunBlit;
    72 
    73 		/* Set up the blit information */
    74 		info.s_pixels = (Uint8 *)src->pixels +
    75 				(Uint16)srcrect->y*src->pitch +
    76 				(Uint16)srcrect->x*src->format->BytesPerPixel;
    77 		info.s_width = srcrect->w;
    78 		info.s_height = srcrect->h;
    79 		info.s_skip=src->pitch-info.s_width*src->format->BytesPerPixel;
    80 		info.d_pixels = (Uint8 *)dst->pixels +
    81 				(Uint16)dstrect->y*dst->pitch +
    82 				(Uint16)dstrect->x*dst->format->BytesPerPixel;
    83 		info.d_width = dstrect->w;
    84 		info.d_height = dstrect->h;
    85 		info.d_skip=dst->pitch-info.d_width*dst->format->BytesPerPixel;
    86 		info.aux_data = src->map->sw_data->aux_data;
    87 		info.src = src->format;
    88 		info.table = src->map->table;
    89 		info.dst = dst->format;
    90 		RunBlit = src->map->sw_data->blit;
    91 
    92 		/* Run the actual software blit */
    93 		RunBlit(&info);
    94 	}
    95 
    96 	/* We need to unlock the surfaces if they're locked */
    97 	if ( dst_locked ) {
    98 		SDL_UnlockSurface(dst);
    99 	}
   100 	if ( src_locked ) {
   101 		SDL_UnlockSurface(src);
   102 	}
   103 	/* Blit is done! */
   104 	return(okay ? 0 : -1);
   105 }
   106 
   107 #ifdef MMX_ASMBLIT
   108 static __inline__ void SDL_memcpyMMX(Uint8 *to, const Uint8 *from, int len)
   109 {
   110 	int i;
   111 
   112 	for(i=0; i<len/8; i++) {
   113 		__asm__ __volatile__ (
   114 		"	movq (%0), %%mm0\n"
   115 		"	movq %%mm0, (%1)\n"
   116 		: : "r" (from), "r" (to) : "memory");
   117 		from+=8;
   118 		to+=8;
   119 	}
   120 	if (len&7)
   121 		SDL_memcpy(to, from, len&7);
   122 }
   123 
   124 static __inline__ void SDL_memcpySSE(Uint8 *to, const Uint8 *from, int len)
   125 {
   126 	int i;
   127 
   128 	__asm__ __volatile__ (
   129 	"	prefetchnta (%0)\n"
   130 	"	prefetchnta 64(%0)\n"
   131 	"	prefetchnta 128(%0)\n"
   132 	"	prefetchnta 192(%0)\n"
   133 	: : "r" (from) );
   134 
   135 	for(i=0; i<len/8; i++) {
   136 		__asm__ __volatile__ (
   137 		"	prefetchnta 256(%0)\n"
   138 		"	movq (%0), %%mm0\n"
   139 		"	movntq %%mm0, (%1)\n"
   140 		: : "r" (from), "r" (to) : "memory");
   141 		from+=8;
   142 		to+=8;
   143 	}
   144 	if (len&7)
   145 		SDL_memcpy(to, from, len&7);
   146 }
   147 #endif
   148 
   149 static void SDL_BlitCopy(SDL_BlitInfo *info)
   150 {
   151 	Uint8 *src, *dst;
   152 	int w, h;
   153 	int srcskip, dstskip;
   154 
   155 	w = info->d_width*info->dst->BytesPerPixel;
   156 	h = info->d_height;
   157 	src = info->s_pixels;
   158 	dst = info->d_pixels;
   159 	srcskip = w+info->s_skip;
   160 	dstskip = w+info->d_skip;
   161 #ifdef MMX_ASMBLIT
   162 	if(SDL_HasSSE())
   163 	{
   164 		while ( h-- ) {
   165 			SDL_memcpySSE(dst, src, w);
   166 			src += srcskip;
   167 			dst += dstskip;
   168 		}
   169 		__asm__ __volatile__ (
   170 		"	emms\n"
   171 		::);
   172 	}
   173 	else
   174 	if(SDL_HasMMX())
   175 	{
   176 		while ( h-- ) {
   177 			SDL_memcpyMMX(dst, src, w);
   178 			src += srcskip;
   179 			dst += dstskip;
   180 		}
   181 		__asm__ __volatile__ (
   182 		"	emms\n"
   183 		::);
   184 	}
   185 	else
   186 #endif
   187 	while ( h-- ) {
   188 		SDL_memcpy(dst, src, w);
   189 		src += srcskip;
   190 		dst += dstskip;
   191 	}
   192 }
   193 
   194 static void SDL_BlitCopyOverlap(SDL_BlitInfo *info)
   195 {
   196 	Uint8 *src, *dst;
   197 	int w, h;
   198 	int srcskip, dstskip;
   199 
   200 	w = info->d_width*info->dst->BytesPerPixel;
   201 	h = info->d_height;
   202 	src = info->s_pixels;
   203 	dst = info->d_pixels;
   204 	srcskip = w+info->s_skip;
   205 	dstskip = w+info->d_skip;
   206 	if ( dst < src ) {
   207 		while ( h-- ) {
   208 			SDL_memcpy(dst, src, w);
   209 			src += srcskip;
   210 			dst += dstskip;
   211 		}
   212 	} else {
   213 		src += ((h-1) * srcskip);
   214 		dst += ((h-1) * dstskip);
   215 		while ( h-- ) {
   216 			SDL_revcpy(dst, src, w);
   217 			src -= srcskip;
   218 			dst -= dstskip;
   219 		}
   220 	}
   221 }
   222 
   223 /* Figure out which of many blit routines to set up on a surface */
   224 int SDL_CalculateBlit(SDL_Surface *surface)
   225 {
   226 	int blit_index;
   227 
   228 	/* Clean everything out to start */
   229 	if ( (surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL ) {
   230 		SDL_UnRLESurface(surface, 1);
   231 	}
   232 	surface->map->sw_blit = NULL;
   233 
   234 	/* Figure out if an accelerated hardware blit is possible */
   235 	surface->flags &= ~SDL_HWACCEL;
   236 	if ( surface->map->identity ) {
   237 		int hw_blit_ok;
   238 
   239 		if ( (surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE ) {
   240 			/* We only support accelerated blitting to hardware */
   241 			if ( surface->map->dst->flags & SDL_HWSURFACE ) {
   242 				hw_blit_ok = current_video->info.blit_hw;
   243 			} else {
   244 				hw_blit_ok = 0;
   245 			}
   246 			if (hw_blit_ok && (surface->flags & SDL_SRCCOLORKEY)) {
   247 				hw_blit_ok = current_video->info.blit_hw_CC;
   248 			}
   249 			if ( hw_blit_ok && (surface->flags & SDL_SRCALPHA) ) {
   250 				hw_blit_ok = current_video->info.blit_hw_A;
   251 			}
   252 		} else {
   253 			/* We only support accelerated blitting to hardware */
   254 			if ( surface->map->dst->flags & SDL_HWSURFACE ) {
   255 				hw_blit_ok = current_video->info.blit_sw;
   256 			} else {
   257 				hw_blit_ok = 0;
   258 			}
   259 			if (hw_blit_ok && (surface->flags & SDL_SRCCOLORKEY)) {
   260 				hw_blit_ok = current_video->info.blit_sw_CC;
   261 			}
   262 			if ( hw_blit_ok && (surface->flags & SDL_SRCALPHA) ) {
   263 				hw_blit_ok = current_video->info.blit_sw_A;
   264 			}
   265 		}
   266 		if ( hw_blit_ok ) {
   267 			SDL_VideoDevice *video = current_video;
   268 			SDL_VideoDevice *this  = current_video;
   269 			video->CheckHWBlit(this, surface, surface->map->dst);
   270 		}
   271 	}
   272 	
   273 	/* if an alpha pixel format is specified, we can accelerate alpha blits */
   274 	if (((surface->flags & SDL_HWSURFACE) == SDL_HWSURFACE )&&(current_video->displayformatalphapixel)) 
   275 	{
   276 		if ( (surface->flags & SDL_SRCALPHA) ) 
   277 			if ( current_video->info.blit_hw_A ) {
   278 				SDL_VideoDevice *video = current_video;
   279 				SDL_VideoDevice *this  = current_video;
   280 				video->CheckHWBlit(this, surface, surface->map->dst);
   281 			}
   282 	}
   283 
   284 	/* Get the blit function index, based on surface mode */
   285 	/* { 0 = nothing, 1 = colorkey, 2 = alpha, 3 = colorkey+alpha } */
   286 	blit_index = 0;
   287 	blit_index |= (!!(surface->flags & SDL_SRCCOLORKEY))      << 0;
   288 	if ( surface->flags & SDL_SRCALPHA
   289 	     && (surface->format->alpha != SDL_ALPHA_OPAQUE
   290 		 || surface->format->Amask) ) {
   291 	        blit_index |= 2;
   292 	}
   293 
   294 	/* Check for special "identity" case -- copy blit */
   295 	if ( surface->map->identity && blit_index == 0 ) {
   296 	        surface->map->sw_data->blit = SDL_BlitCopy;
   297 
   298 		/* Handle overlapping blits on the same surface */
   299 		if ( surface == surface->map->dst ) {
   300 		        surface->map->sw_data->blit = SDL_BlitCopyOverlap;
   301 		}
   302 	} else {
   303 		if ( surface->format->BitsPerPixel < 8 ) {
   304 			surface->map->sw_data->blit =
   305 			    SDL_CalculateBlit0(surface, blit_index);
   306 		} else {
   307 			switch ( surface->format->BytesPerPixel ) {
   308 			    case 1:
   309 				surface->map->sw_data->blit =
   310 				    SDL_CalculateBlit1(surface, blit_index);
   311 				break;
   312 			    case 2:
   313 			    case 3:
   314 			    case 4:
   315 				surface->map->sw_data->blit =
   316 				    SDL_CalculateBlitN(surface, blit_index);
   317 				break;
   318 			    default:
   319 				surface->map->sw_data->blit = NULL;
   320 				break;
   321 			}
   322 		}
   323 	}
   324 	/* Make sure we have a blit function */
   325 	if ( surface->map->sw_data->blit == NULL ) {
   326 		SDL_InvalidateMap(surface->map);
   327 		SDL_SetError("Blit combination not supported");
   328 		return(-1);
   329 	}
   330 
   331 	/* Choose software blitting function */
   332 	if(surface->flags & SDL_RLEACCELOK
   333 	   && (surface->flags & SDL_HWACCEL) != SDL_HWACCEL) {
   334 
   335 	        if(surface->map->identity
   336 		   && (blit_index == 1
   337 		       || (blit_index == 3 && !surface->format->Amask))) {
   338 		        if ( SDL_RLESurface(surface) == 0 )
   339 			        surface->map->sw_blit = SDL_RLEBlit;
   340 		} else if(blit_index == 2 && surface->format->Amask) {
   341 		        if ( SDL_RLESurface(surface) == 0 )
   342 			        surface->map->sw_blit = SDL_RLEAlphaBlit;
   343 		}
   344 	}
   345 	
   346 	if ( surface->map->sw_blit == NULL ) {
   347 		surface->map->sw_blit = SDL_SoftBlit;
   348 	}
   349 	return(0);
   350 }
   351