Mercurial > sdl-ios-xcode
annotate src/video/SDL_stretch.c @ 252:e8157fcb3114
Updated the source with the correct e-mail address
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Fri, 14 Dec 2001 12:38:15 +0000 |
| parents | 74212992fb08 |
| children | 051b991765ba |
| rev | line source |
|---|---|
| 0 | 1 /* |
| 2 SDL - Simple DirectMedia Layer | |
| 3 Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga | |
| 4 | |
| 5 This library is free software; you can redistribute it and/or | |
| 6 modify it under the terms of the GNU Library General Public | |
| 7 License as published by the Free Software Foundation; either | |
| 8 version 2 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 Library General Public License for more details. | |
| 14 | |
| 15 You should have received a copy of the GNU Library General Public | |
| 16 License along with this library; if not, write to the Free | |
| 17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
| 18 | |
| 19 Sam Lantinga | |
|
252
e8157fcb3114
Updated the source with the correct e-mail address
Sam Lantinga <slouken@libsdl.org>
parents:
0
diff
changeset
|
20 slouken@libsdl.org |
| 0 | 21 */ |
| 22 | |
| 23 #ifdef SAVE_RCSID | |
| 24 static char rcsid = | |
| 25 "@(#) $Id$"; | |
| 26 #endif | |
| 27 | |
| 28 /* This a stretch blit implementation based on ideas given to me by | |
| 29 Tomasz Cejner - thanks! :) | |
| 30 | |
| 31 April 27, 2000 - Sam Lantinga | |
| 32 */ | |
| 33 | |
| 34 #include "SDL_error.h" | |
| 35 #include "SDL_video.h" | |
| 36 #include "SDL_blit.h" | |
| 37 | |
| 38 /* This isn't ready for general consumption yet - it should be folded | |
| 39 into the general blitting mechanism. | |
| 40 */ | |
| 41 | |
| 42 #if (defined(WIN32) && !defined(_M_ALPHA) && !defined(_WIN32_WCE)) || \ | |
| 43 defined(i386) && defined(__GNUC__) && defined(USE_ASMBLIT) | |
| 44 #define USE_ASM_STRETCH | |
| 45 #endif | |
| 46 | |
| 47 #ifdef USE_ASM_STRETCH | |
| 48 | |
| 49 #if defined(WIN32) || defined(i386) | |
| 50 #define PREFIX16 0x66 | |
| 51 #define STORE_BYTE 0xAA | |
| 52 #define STORE_WORD 0xAB | |
| 53 #define LOAD_BYTE 0xAC | |
| 54 #define LOAD_WORD 0xAD | |
| 55 #define RETURN 0xC3 | |
| 56 #else | |
| 57 #error Need assembly opcodes for this architecture | |
| 58 #endif | |
| 59 | |
| 60 #if defined(__ELF__) && defined(__GNUC__) | |
| 61 extern unsigned char _copy_row[4096] __attribute__ ((alias ("copy_row"))); | |
| 62 #endif | |
| 63 static unsigned char copy_row[4096]; | |
| 64 | |
| 65 static int generate_rowbytes(int src_w, int dst_w, int bpp) | |
| 66 { | |
| 67 static struct { | |
| 68 int bpp; | |
| 69 int src_w; | |
| 70 int dst_w; | |
| 71 } last; | |
| 72 | |
| 73 int i; | |
| 74 int pos, inc; | |
| 75 unsigned char *eip; | |
| 76 unsigned char load, store; | |
| 77 | |
| 78 /* See if we need to regenerate the copy buffer */ | |
| 79 if ( (src_w == last.src_w) && | |
| 80 (dst_w == last.src_w) && (bpp == last.bpp) ) { | |
| 81 return(0); | |
| 82 } | |
| 83 last.bpp = bpp; | |
| 84 last.src_w = src_w; | |
| 85 last.dst_w = dst_w; | |
| 86 | |
| 87 switch (bpp) { | |
| 88 case 1: | |
| 89 load = LOAD_BYTE; | |
| 90 store = STORE_BYTE; | |
| 91 break; | |
| 92 case 2: | |
| 93 case 4: | |
| 94 load = LOAD_WORD; | |
| 95 store = STORE_WORD; | |
| 96 break; | |
| 97 default: | |
| 98 SDL_SetError("ASM stretch of %d bytes isn't supported\n", bpp); | |
| 99 return(-1); | |
| 100 } | |
| 101 pos = 0x10000; | |
| 102 inc = (src_w << 16) / dst_w; | |
| 103 eip = copy_row; | |
| 104 for ( i=0; i<dst_w; ++i ) { | |
| 105 while ( pos >= 0x10000L ) { | |
| 106 if ( bpp == 2 ) { | |
| 107 *eip++ = PREFIX16; | |
| 108 } | |
| 109 *eip++ = load; | |
| 110 pos -= 0x10000L; | |
| 111 } | |
| 112 if ( bpp == 2 ) { | |
| 113 *eip++ = PREFIX16; | |
| 114 } | |
| 115 *eip++ = store; | |
| 116 pos += inc; | |
| 117 } | |
| 118 *eip++ = RETURN; | |
| 119 | |
| 120 /* Verify that we didn't overflow (too late) */ | |
| 121 if ( eip > (copy_row+sizeof(copy_row)) ) { | |
| 122 SDL_SetError("Copy buffer overflow"); | |
| 123 return(-1); | |
| 124 } | |
| 125 return(0); | |
| 126 } | |
| 127 | |
| 128 #else | |
| 129 | |
| 130 #define DEFINE_COPY_ROW(name, type) \ | |
| 131 void name(type *src, int src_w, type *dst, int dst_w) \ | |
| 132 { \ | |
| 133 int i; \ | |
| 134 int pos, inc; \ | |
| 135 type pixel = 0; \ | |
| 136 \ | |
| 137 pos = 0x10000; \ | |
| 138 inc = (src_w << 16) / dst_w; \ | |
| 139 for ( i=dst_w; i>0; --i ) { \ | |
| 140 while ( pos >= 0x10000L ) { \ | |
| 141 pixel = *src++; \ | |
| 142 pos -= 0x10000L; \ | |
| 143 } \ | |
| 144 *dst++ = pixel; \ | |
| 145 pos += inc; \ | |
| 146 } \ | |
| 147 } | |
| 148 DEFINE_COPY_ROW(copy_row1, Uint8) | |
| 149 DEFINE_COPY_ROW(copy_row2, Uint16) | |
| 150 DEFINE_COPY_ROW(copy_row4, Uint32) | |
| 151 | |
| 152 #endif /* USE_ASM_STRETCH */ | |
| 153 | |
| 154 /* The ASM code doesn't handle 24-bpp stretch blits */ | |
| 155 void copy_row3(Uint8 *src, int src_w, Uint8 *dst, int dst_w) | |
| 156 { | |
| 157 int i; | |
| 158 int pos, inc; | |
| 159 Uint8 pixel[3]; | |
| 160 | |
| 161 pos = 0x10000; | |
| 162 inc = (src_w << 16) / dst_w; | |
| 163 for ( i=dst_w; i>0; --i ) { | |
| 164 while ( pos >= 0x10000L ) { | |
| 165 pixel[0] = *src++; | |
| 166 pixel[1] = *src++; | |
| 167 pixel[2] = *src++; | |
| 168 pos -= 0x10000L; | |
| 169 } | |
| 170 *dst++ = pixel[0]; | |
| 171 *dst++ = pixel[1]; | |
| 172 *dst++ = pixel[2]; | |
| 173 pos += inc; | |
| 174 } | |
| 175 } | |
| 176 | |
| 177 /* Perform a stretch blit between two surfaces of the same format. | |
| 178 NOTE: This function is not safe to call from multiple threads! | |
| 179 */ | |
| 180 int SDL_SoftStretch(SDL_Surface *src, SDL_Rect *srcrect, | |
| 181 SDL_Surface *dst, SDL_Rect *dstrect) | |
| 182 { | |
| 183 int pos, inc; | |
| 184 int dst_width; | |
| 185 int dst_maxrow; | |
| 186 int src_row, dst_row; | |
| 187 Uint8 *srcp = NULL; | |
| 188 Uint8 *dstp; | |
| 189 SDL_Rect full_src; | |
| 190 SDL_Rect full_dst; | |
| 191 #if defined(USE_ASM_STRETCH) && defined(__GNUC__) | |
| 192 int u1, u2; | |
| 193 #endif | |
| 194 const int bpp = dst->format->BytesPerPixel; | |
| 195 | |
| 196 if ( src->format->BitsPerPixel != dst->format->BitsPerPixel ) { | |
| 197 SDL_SetError("Only works with same format surfaces"); | |
| 198 return(-1); | |
| 199 } | |
| 200 | |
| 201 /* Verify the blit rectangles */ | |
| 202 if ( srcrect ) { | |
| 203 if ( (srcrect->x < 0) || (srcrect->y < 0) || | |
| 204 ((srcrect->x+srcrect->w) > src->w) || | |
| 205 ((srcrect->y+srcrect->h) > src->h) ) { | |
| 206 SDL_SetError("Invalid source blit rectangle"); | |
| 207 return(-1); | |
| 208 } | |
| 209 } else { | |
| 210 full_src.x = 0; | |
| 211 full_src.y = 0; | |
| 212 full_src.w = src->w; | |
| 213 full_src.h = src->h; | |
| 214 srcrect = &full_src; | |
| 215 } | |
| 216 if ( dstrect ) { | |
| 217 if ( (dstrect->x < 0) || (dstrect->y < 0) || | |
| 218 ((dstrect->x+dstrect->w) > dst->w) || | |
| 219 ((dstrect->y+dstrect->h) > dst->h) ) { | |
| 220 SDL_SetError("Invalid destination blit rectangle"); | |
| 221 return(-1); | |
| 222 } | |
| 223 } else { | |
| 224 full_dst.x = 0; | |
| 225 full_dst.y = 0; | |
| 226 full_dst.w = dst->w; | |
| 227 full_dst.h = dst->h; | |
| 228 dstrect = &full_dst; | |
| 229 } | |
| 230 | |
| 231 /* Set up the data... */ | |
| 232 pos = 0x10000; | |
| 233 inc = (srcrect->h << 16) / dstrect->h; | |
| 234 src_row = srcrect->y; | |
| 235 dst_row = dstrect->y; | |
| 236 dst_width = dstrect->w*bpp; | |
| 237 | |
| 238 #ifdef USE_ASM_STRETCH | |
| 239 /* Write the opcodes for this stretch */ | |
| 240 if ( (bpp != 3) && | |
| 241 (generate_rowbytes(srcrect->w, dstrect->w, bpp) < 0) ) { | |
| 242 return(-1); | |
| 243 } | |
| 244 #endif | |
| 245 | |
| 246 /* Perform the stretch blit */ | |
| 247 for ( dst_maxrow = dst_row+dstrect->h; dst_row<dst_maxrow; ++dst_row ) { | |
| 248 dstp = (Uint8 *)dst->pixels + (dst_row*dst->pitch) | |
| 249 + (dstrect->x*bpp); | |
| 250 while ( pos >= 0x10000L ) { | |
| 251 srcp = (Uint8 *)src->pixels + (src_row*src->pitch) | |
| 252 + (srcrect->x*bpp); | |
| 253 ++src_row; | |
| 254 pos -= 0x10000L; | |
| 255 } | |
| 256 #ifdef USE_ASM_STRETCH | |
| 257 switch (bpp) { | |
| 258 case 3: | |
| 259 copy_row3(srcp, srcrect->w, dstp, dstrect->w); | |
| 260 break; | |
| 261 default: | |
| 262 #ifdef __GNUC__ | |
| 263 __asm__ __volatile__ (" | |
| 264 call _copy_row | |
| 265 " | |
| 266 : "=&D" (u1), "=&S" (u2) | |
| 267 : "0" (dstp), "1" (srcp) | |
| 268 : "memory" ); | |
| 269 #else | |
| 270 #ifdef WIN32 | |
| 271 { void *code = ©_row; | |
| 272 __asm { | |
| 273 push edi | |
| 274 push esi | |
| 275 | |
| 276 mov edi, dstp | |
| 277 mov esi, srcp | |
| 278 call dword ptr code | |
| 279 | |
| 280 pop esi | |
| 281 pop edi | |
| 282 } | |
| 283 } | |
| 284 #else | |
| 285 #error Need inline assembly for this compiler | |
| 286 #endif | |
| 287 #endif /* __GNUC__ */ | |
| 288 break; | |
| 289 } | |
| 290 #else | |
| 291 switch (bpp) { | |
| 292 case 1: | |
| 293 copy_row1(srcp, srcrect->w, dstp, dstrect->w); | |
| 294 break; | |
| 295 case 2: | |
| 296 copy_row2((Uint16 *)srcp, srcrect->w, | |
| 297 (Uint16 *)dstp, dstrect->w); | |
| 298 break; | |
| 299 case 3: | |
| 300 copy_row3(srcp, srcrect->w, dstp, dstrect->w); | |
| 301 break; | |
| 302 case 4: | |
| 303 copy_row4((Uint32 *)srcp, srcrect->w, | |
| 304 (Uint32 *)dstp, dstrect->w); | |
| 305 break; | |
| 306 } | |
| 307 #endif | |
| 308 pos += inc; | |
| 309 } | |
| 310 return(0); | |
| 311 } | |
| 312 |