src/bilinear.c

   1 // VisualBoyAdvance - Nintendo Gameboy/GameboyAdvance (TM) emulator.
   2 // Copyright (C) 1999-2003 Forgotten
   3 // Copyright (C) 2004 Forgotten and the VBA development team
   4
   5 // This program is free software; you can redistribute it and/or modify
   6 // it under the terms of the GNU General Public License as published by
   7 // the Free Software Foundation; either version 2, or(at your option)
   8 // any later version.
   9 //
  10 // This program 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
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with this program; if not, write to the Free Software Foundation,
  17 // Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  18
  19 /**     Code adapted from Exult source code by Forgotten
  20  **     Scale.cc - Trying to scale with bilinear interpolation.
  21  **
  22  **     Written: 6/14/00 - JSF
  23  **/
  24
  25 #include "System.h"
  26
  27 static u8 row_cur[3*322];
  28 static u8 row_next[3*322];
  29
  30 static u8 *rgb_row_cur = row_cur;
  31 static u8 *rgb_row_next = row_next;
  32
  33 #define RGB(r,g,b) ((r)>>3) << systemRedShift |\
  34   ((g) >> 3) << systemGreenShift |\
  35   ((b) >> 3) << systemBlueShift\
  36
  37 static void fill_rgb_row_16(u16 *from, int src_width, u8 *row, int width)
  38 {
  39   u8 *copy_start = row + src_width*3;
  40   u8 *all_stop = row + width*3;
  41   while (row < copy_start) {
  42     u16 color = *from++;
  43     *row++ = ((color >> systemRedShift) & 0x1f) << 3;
  44     *row++ = ((color >> systemGreenShift) & 0x1f) << 3;
  45     *row++ = ((color >> systemBlueShift) & 0x1f) << 3;
  46   }
  47   // any remaining elements to be written to 'row' are a replica of the
  48   // preceding pixel
  49   u8 *p = row-3;
  50   while (row < all_stop) {
  51     // we're guaranteed three elements per pixel; could unroll the loop
  52     // further, especially with a Duff's Device, but the gains would be
  53     // probably limited (judging by profiler output)
  54     *row++ = *p++;
  55     *row++ = *p++;
  56     *row++ = *p++;
  57   }
  58 }
  59
  60 static void fill_rgb_row_32(u32 *from, int src_width, u8 *row, int width)
  61 {
  62   u8 *copy_start = row + src_width*3;
  63   u8 *all_stop = row + width*3;
  64   while (row < copy_start) {
  65     u32 color = *from++;
  66     *row++ = ((color >> systemRedShift) & 0x1f) << 3;
  67     *row++ = ((color >> systemGreenShift) & 0x1f) << 3;
  68     *row++ = ((color >> systemBlueShift) & 0x1f) << 3;
  69   }
  70   // any remaining elements to be written to 'row' are a replica of the
  71   // preceding pixel
  72   u8 *p = row-3;
  73   while (row < all_stop) {
  74     // we're guaranteed three elements per pixel; could unroll the loop
  75     // further, especially with a Duff's Device, but the gains would be
  76     // probably limited (judging by profiler output)
  77     *row++ = *p++;
  78     *row++ = *p++;
  79     *row++ = *p++;
  80   }
  81 }
  82
  83 void Bilinear(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
  84               u8 *dstPtr, u32 dstPitch, int width, int height)
  85 {
  86   u16 *to = (u16 *)dstPtr;
  87   u16 *to_odd = (u16 *)(dstPtr + dstPitch);
  88
  89   int from_width = width;
  90   u16 *from = (u16 *)srcPtr;
  91   fill_rgb_row_16(from, from_width, rgb_row_cur, width+1);
  92
  93   for(int y = 0; y < height; y++) {
  94     u16 *from_orig = from;
  95     u16 *to_orig = to;
  96
  97     if (y+1 < height)
  98       fill_rgb_row_16(from+width+2, from_width, rgb_row_next,
  99                    width+1);
 100     else
 101       fill_rgb_row_16(from, from_width, rgb_row_next, width+1);
 102
 103     // every pixel in the src region, is extended to 4 pixels in the
 104     // destination, arranged in a square 'quad'; if the current src
 105     // pixel is 'a', then in what follows 'b' is the src pixel to the
 106     // right, 'c' is the src pixel below, and 'd' is the src pixel to
 107     // the right and down
 108     u8 *cur_row  = rgb_row_cur;
 109     u8 *next_row = rgb_row_next;
 110     u8 *ar = cur_row++;
 111     u8 *ag = cur_row++;
 112     u8 *ab = cur_row++;
 113     u8 *cr = next_row++;
 114     u8 *cg = next_row++;
 115     u8 *cb = next_row++;
 116     for(int x=0; x < width; x++) {
 117       u8 *br = cur_row++;
 118       u8 *bg = cur_row++;
 119       u8 *bb = cur_row++;
 120       u8 *dr = next_row++;
 121       u8 *dg = next_row++;
 122       u8 *db = next_row++;
 123
 124       // upper left pixel in quad: just copy it in
 125       *to++ = RGB(*ar, *ag, *ab);
 126
 127       // upper right
 128       *to++ = RGB((*ar+*br)>>1, (*ag+*bg)>>1, (*ab+*bb)>>1);
 129
 130       // lower left
 131       *to_odd++ = RGB((*ar+*cr)>>1, (*ag+*cg)>>1, (*ab+*cb)>>1);
 132
 133       // lower right
 134       *to_odd++ = RGB((*ar+*br+*cr+*dr)>>2,
 135                       (*ag+*bg+*cg+*dg)>>2,
 136                       (*ab+*bb+*cb+*db)>>2);
 137
 138       // 'b' becomes 'a', 'd' becomes 'c'
 139       ar = br;
 140       ag = bg;
 141       ab = bb;
 142       cr = dr;
 143       cg = dg;
 144       cb = db;
 145     }
 146
 147     // the "next" rgb row becomes the current; the old current rgb row is
 148     // recycled and serves as the new "next" row
 149     u8 *temp;
 150     temp = rgb_row_cur;
 151     rgb_row_cur = rgb_row_next;
 152     rgb_row_next = temp;
 153
 154     // update the pointers for start of next pair of lines
 155     from = (u16 *)((u8 *)from_orig + srcPitch);
 156     to = (u16 *)((u8 *)to_orig + (dstPitch << 1));
 157     to_odd = (u16 *)((u8 *)to + dstPitch);
 158   }
 159 }
 160
 161 void BilinearPlus(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
 162                   u8 *dstPtr, u32 dstPitch, int width, int height)
 163 {
 164   u16 *to = (u16 *)dstPtr;
 165   u16 *to_odd = (u16 *)(dstPtr + dstPitch);
 166
 167   int from_width = width;
 168   u16 *from = (u16 *)srcPtr;
 169   fill_rgb_row_16(from, from_width, rgb_row_cur, width+1);
 170
 171   for(int y = 0; y < height; y++) {
 172     u16 *from_orig = from;
 173     u16 *to_orig = to;
 174
 175     if (y+1 < height)
 176       fill_rgb_row_16(from+width+2, from_width, rgb_row_next,
 177                    width+1);
 178     else
 179       fill_rgb_row_16(from, from_width, rgb_row_next, width+1);
 180
 181     // every pixel in the src region, is extended to 4 pixels in the
 182     // destination, arranged in a square 'quad'; if the current src
 183     // pixel is 'a', then in what follows 'b' is the src pixel to the
 184     // right, 'c' is the src pixel below, and 'd' is the src pixel to
 185     // the right and down
 186     u8 *cur_row  = rgb_row_cur;
 187     u8 *next_row = rgb_row_next;
 188     u8 *ar = cur_row++;
 189     u8 *ag = cur_row++;
 190     u8 *ab = cur_row++;
 191     u8 *cr = next_row++;
 192     u8 *cg = next_row++;
 193     u8 *cb = next_row++;
 194     for(int x=0; x < width; x++) {
 195       u8 *br = cur_row++;
 196       u8 *bg = cur_row++;
 197       u8 *bb = cur_row++;
 198       u8 *dr = next_row++;
 199       u8 *dg = next_row++;
 200       u8 *db = next_row++;
 201
 202       // upper left pixel in quad: just copy it in
 203       //*to++ = manip.rgb(*ar, *ag, *ab);
 204 #ifdef USE_ORIGINAL_BILINEAR_PLUS
 205       *to++ = RGB(
 206                   (((*ar)<<2) +((*ar)) + (*cr+*br+*br) )>> 3,
 207                   (((*ag)<<2) +((*ag)) + (*cg+*bg+*bg) )>> 3,
 208                   (((*ab)<<2) +((*ab)) + (*cb+*bb+*bb) )>> 3);
 209 #else
 210       *to++ = RGB(
 211                   (((*ar)<<3) +((*ar)<<1) + (*cr+*br+*br+*cr) )>> 4,
 212                   (((*ag)<<3) +((*ag)<<1) + (*cg+*bg+*bg+*cg) )>> 4,
 213                   (((*ab)<<3) +((*ab)<<1) + (*cb+*bb+*bb+*cb) )>> 4);
 214 #endif
 215
 216       // upper right
 217       *to++ = RGB((*ar+*br)>>1, (*ag+*bg)>>1, (*ab+*bb)>>1);
 218
 219       // lower left
 220       *to_odd++ = RGB((*ar+*cr)>>1, (*ag+*cg)>>1, (*ab+*cb)>>1);
 221
 222       // lower right
 223       *to_odd++ = RGB((*ar+*br+*cr+*dr)>>2,
 224                       (*ag+*bg+*cg+*dg)>>2,
 225                       (*ab+*bb+*cb+*db)>>2);
 226
 227       // 'b' becomes 'a', 'd' becomes 'c'
 228       ar = br;
 229       ag = bg;
 230       ab = bb;
 231       cr = dr;
 232       cg = dg;
 233       cb = db;
 234     }
 235
 236     // the "next" rgb row becomes the current; the old current rgb row is
 237     // recycled and serves as the new "next" row
 238     u8 *temp;
 239     temp = rgb_row_cur;
 240     rgb_row_cur = rgb_row_next;
 241     rgb_row_next = temp;
 242
 243     // update the pointers for start of next pair of lines
 244     from = (u16 *)((u8 *)from_orig + srcPitch);
 245     to = (u16 *)((u8 *)to_orig + (dstPitch << 1));
 246     to_odd = (u16 *)((u8 *)to + dstPitch);
 247   }
 248 }
 249
 250 void Bilinear32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
 251                 u8 *dstPtr, u32 dstPitch, int width, int height)
 252 {
 253   u32 *to = (u32 *)dstPtr;
 254   u32 *to_odd = (u32 *)(dstPtr + dstPitch);
 255
 256   int from_width = width;
 257   if(width+1 < from_width)
 258     from_width = width+1;
 259   u32 *from = (u32 *)srcPtr;
 260   fill_rgb_row_32(from, from_width, rgb_row_cur, width+1);
 261
 262   for(int y = 0; y < height; y++) {
 263     u32 *from_orig = from;
 264     u32 *to_orig = to;
 265
 266     if (y+1 < height)
 267       fill_rgb_row_32(from+width+1, from_width, rgb_row_next,
 268                    width+1);
 269     else
 270       fill_rgb_row_32(from, from_width, rgb_row_next, width+1);
 271
 272     // every pixel in the src region, is extended to 4 pixels in the
 273     // destination, arranged in a square 'quad'; if the current src
 274     // pixel is 'a', then in what follows 'b' is the src pixel to the
 275     // right, 'c' is the src pixel below, and 'd' is the src pixel to
 276     // the right and down
 277     u8 *cur_row  = rgb_row_cur;
 278     u8 *next_row = rgb_row_next;
 279     u8 *ar = cur_row++;
 280     u8 *ag = cur_row++;
 281     u8 *ab = cur_row++;
 282     u8 *cr = next_row++;
 283     u8 *cg = next_row++;
 284     u8 *cb = next_row++;
 285     for(int x=0; x < width; x++) {
 286       u8 *br = cur_row++;
 287       u8 *bg = cur_row++;
 288       u8 *bb = cur_row++;
 289       u8 *dr = next_row++;
 290       u8 *dg = next_row++;
 291       u8 *db = next_row++;
 292
 293       // upper left pixel in quad: just copy it in
 294       *to++ = RGB(*ar, *ag, *ab);
 295
 296       // upper right
 297       *to++ = RGB((*ar+*br)>>1, (*ag+*bg)>>1, (*ab+*bb)>>1);
 298
 299       // lower left
 300       *to_odd++ = RGB((*ar+*cr)>>1, (*ag+*cg)>>1, (*ab+*cb)>>1);
 301
 302       // lower right
 303       *to_odd++ = RGB((*ar+*br+*cr+*dr)>>2,
 304                       (*ag+*bg+*cg+*dg)>>2,
 305                       (*ab+*bb+*cb+*db)>>2);
 306
 307       // 'b' becomes 'a', 'd' becomes 'c'
 308       ar = br;
 309       ag = bg;
 310       ab = bb;
 311       cr = dr;
 312       cg = dg;
 313       cb = db;
 314     }
 315
 316     // the "next" rgb row becomes the current; the old current rgb row is
 317     // recycled and serves as the new "next" row
 318     u8 *temp;
 319     temp = rgb_row_cur;
 320     rgb_row_cur = rgb_row_next;
 321     rgb_row_next = temp;
 322
 323     // update the pointers for start of next pair of lines
 324     from = (u32 *)((u8 *)from_orig + srcPitch);
 325     to = (u32 *)((u8 *)to_orig + (dstPitch << 1));
 326     to_odd = (u32 *)((u8 *)to + dstPitch);
 327   }
 328 }
 329
 330 void BilinearPlus32(u8 *srcPtr, u32 srcPitch, u8 * /* deltaPtr */,
 331                     u8 *dstPtr, u32 dstPitch, int width, int height)
 332 {
 333   u32 *to = (u32 *)dstPtr;
 334   u32 *to_odd = (u32 *)(dstPtr + dstPitch);
 335
 336   int from_width = width;
 337   if(width+1 < from_width)
 338     from_width = width+1;
 339   u32 *from = (u32 *)srcPtr;
 340   fill_rgb_row_32(from, from_width, rgb_row_cur, width+1);
 341
 342   for(int y = 0; y < height; y++) {
 343     u32 *from_orig = from;
 344     u32 *to_orig = to;
 345
 346     if (y+1 < height)
 347       fill_rgb_row_32(from+width+1, from_width, rgb_row_next,
 348                    width+1);
 349     else
 350       fill_rgb_row_32(from, from_width, rgb_row_next, width+1);
 351
 352     // every pixel in the src region, is extended to 4 pixels in the
 353     // destination, arranged in a square 'quad'; if the current src
 354     // pixel is 'a', then in what follows 'b' is the src pixel to the
 355     // right, 'c' is the src pixel below, and 'd' is the src pixel to
 356     // the right and down
 357     u8 *cur_row  = rgb_row_cur;
 358     u8 *next_row = rgb_row_next;
 359     u8 *ar = cur_row++;
 360     u8 *ag = cur_row++;
 361     u8 *ab = cur_row++;
 362     u8 *cr = next_row++;
 363     u8 *cg = next_row++;
 364     u8 *cb = next_row++;
 365     for(int x=0; x < width; x++) {
 366       u8 *br = cur_row++;
 367       u8 *bg = cur_row++;
 368       u8 *bb = cur_row++;
 369       u8 *dr = next_row++;
 370       u8 *dg = next_row++;
 371       u8 *db = next_row++;
 372
 373       // upper left pixel in quad: just copy it in
 374       //*to++ = manip.rgb(*ar, *ag, *ab);
 375 #ifdef USE_ORIGINAL_BILINEAR_PLUS
 376       *to++ = RGB(
 377                   (((*ar)<<2) +((*ar)) + (*cr+*br+*br) )>> 3,
 378                   (((*ag)<<2) +((*ag)) + (*cg+*bg+*bg) )>> 3,
 379                   (((*ab)<<2) +((*ab)) + (*cb+*bb+*bb) )>> 3);
 380 #else
 381       *to++ = RGB(
 382                   (((*ar)<<3) +((*ar)<<1) + (*cr+*br+*br+*cr) )>> 4,
 383                   (((*ag)<<3) +((*ag)<<1) + (*cg+*bg+*bg+*cg) )>> 4,
 384                   (((*ab)<<3) +((*ab)<<1) + (*cb+*bb+*bb+*cb) )>> 4);
 385 #endif
 386
 387       // upper right
 388       *to++ = RGB((*ar+*br)>>1, (*ag+*bg)>>1, (*ab+*bb)>>1);
 389
 390       // lower left
 391       *to_odd++ = RGB((*ar+*cr)>>1, (*ag+*cg)>>1, (*ab+*cb)>>1);
 392
 393       // lower right
 394       *to_odd++ = RGB((*ar+*br+*cr+*dr)>>2,
 395                       (*ag+*bg+*cg+*dg)>>2,
 396                       (*ab+*bb+*cb+*db)>>2);
 397
 398       // 'b' becomes 'a', 'd' becomes 'c'
 399       ar = br;
 400       ag = bg;
 401       ab = bb;
 402       cr = dr;
 403       cg = dg;
 404       cb = db;
 405     }
 406
 407     // the "next" rgb row becomes the current; the old current rgb row is
 408     // recycled and serves as the new "next" row
 409     u8 *temp;
 410     temp = rgb_row_cur;
 411     rgb_row_cur = rgb_row_next;
 412     rgb_row_next = temp;
 413
 414     // update the pointers for start of next pair of lines
 415     from = (u32 *)((u8 *)from_orig + srcPitch);
 416     to = (u32 *)((u8 *)to_orig + (dstPitch << 1));
 417     to_odd = (u32 *)((u8 *)to + dstPitch);
 418   }
 419 }
 420