Dogcows Code - chaz/openbox/blob - render/gradient.c

   1 #include "render.h"
   2 #include "gradient.h"
   3 #include "color.h"
   4 #include <glib.h>
   5
   6 static void highlight(RrPixel32 *x, RrPixel32 *y, gboolean raised);
   7 static void gradient_solid(RrAppearance *l, int w, int h);
   8 static void gradient_vertical(RrSurface *sf, int w, int h);
   9 static void gradient_horizontal(RrSurface *sf, int w, int h);
  10 static void gradient_diagonal(RrSurface *sf, int w, int h);
  11 static void gradient_crossdiagonal(RrSurface *sf, int w, int h);
  12 static void gradient_pyramid(RrSurface *sf, int inw, int inh);
  13 static void gradient_rectangle(RrSurface *sf, int inw, int inh);
  14 static void gradient_pipecross(RrSurface *sf, int inw, int inh);
  15
  16 void RrRender(RrAppearance *a, int w, int h)
  17 {
  18     RrPixel32 *data = a->surface.RrPixel_data;
  19     RrPixel32 current;
  20     unsigned int r,g,b;
  21     int off, x;
  22
  23     switch (a->surface.grad) {
  24     case RR_SURFACE_SOLID:
  25         gradient_solid(a, w, h);
  26         return;
  27     case RR_SURFACE_VERTICAL:
  28         gradient_vertical(&a->surface, w, h);
  29         break;
  30     case RR_SURFACE_HORIZONTAL:
  31         gradient_horizontal(&a->surface, w, h);
  32         break;
  33     case RR_SURFACE_DIAGONAL:
  34         gradient_diagonal(&a->surface, w, h);
  35         break;
  36     case RR_SURFACE_CROSS_DIAGONAL:
  37         gradient_crossdiagonal(&a->surface, w, h);
  38         break;
  39     case RR_SURFACE_PYRAMID:
  40         gradient_pyramid(&a->surface, w, h);
  41         break;
  42     case RR_SURFACE_PIPECROSS:
  43         gradient_pipecross(&a->surface, w, h);
  44         break;
  45     case RR_SURFACE_RECTANGLE:
  46         gradient_rectangle(&a->surface, w, h);
  47         break;
  48     default:
  49         g_message("unhandled gradient");
  50         return;
  51     }
  52
  53     if (a->surface.relief == RR_RELIEF_FLAT && a->surface.border) {
  54         r = a->surface.border_color->r;
  55         g = a->surface.border_color->g;
  56         b = a->surface.border_color->b;
  57         current = (r << RrDefaultRedOffset)
  58             + (g << RrDefaultGreenOffset)
  59             + (b << RrDefaultBlueOffset);
  60         for (off = 0, x = 0; x < w; ++x, off++) {
  61             *(data + off) = current;
  62             *(data + off + ((h-1) * w)) = current;
  63         }
  64         for (off = 0, x = 0; x < h; ++x, off++) {
  65             *(data + (off * w)) = current;
  66             *(data + (off * w) + w - 1) = current;
  67         }
  68     }
  69
  70     if (a->surface.relief != RR_RELIEF_FLAT) {
  71         if (a->surface.bevel == RR_BEVEL_1) {
  72             for (off = 1, x = 1; x < w - 1; ++x, off++)
  73                 highlight(data + off,
  74                           data + off + (h-1) * w,
  75                           a->surface.relief==RR_RELIEF_RAISED);
  76             for (off = 0, x = 0; x < h; ++x, off++)
  77                 highlight(data + off * w,
  78                           data + off * w + w - 1,
  79                           a->surface.relief==RR_RELIEF_RAISED);
  80         }
  81
  82         if (a->surface.bevel == RR_BEVEL_2) {
  83             for (off = 2, x = 2; x < w - 2; ++x, off++)
  84                 highlight(data + off + w,
  85                           data + off + (h-2) * w,
  86                           a->surface.relief==RR_RELIEF_RAISED);
  87             for (off = 1, x = 1; x < h-1; ++x, off++)
  88                 highlight(data + off * w + 1,
  89                           data + off * w + w - 2,
  90                           a->surface.relief==RR_RELIEF_RAISED);
  91         }
  92     }
  93 }
  94
  95 static void highlight(RrPixel32 *x, RrPixel32 *y, gboolean raised)
  96 {
  97     int r, g, b;
  98
  99     RrPixel32 *up, *down;
 100     if (raised) {
 101         up = x;
 102         down = y;
 103     } else {
 104         up = y;
 105         down = x;
 106     }
 107     r = (*up >> RrDefaultRedOffset) & 0xFF;
 108     r += r >> 1;
 109     g = (*up >> RrDefaultGreenOffset) & 0xFF;
 110     g += g >> 1;
 111     b = (*up >> RrDefaultBlueOffset) & 0xFF;
 112     b += b >> 1;
 113     if (r > 0xFF) r = 0xFF;
 114     if (g > 0xFF) g = 0xFF;
 115     if (b > 0xFF) b = 0xFF;
 116     *up = (r << RrDefaultRedOffset) + (g << RrDefaultGreenOffset)
 117         + (b << RrDefaultBlueOffset);
 118
 119     r = (*down >> RrDefaultRedOffset) & 0xFF;
 120     r = (r >> 1) + (r >> 2);
 121     g = (*down >> RrDefaultGreenOffset) & 0xFF;
 122     g = (g >> 1) + (g >> 2);
 123     b = (*down >> RrDefaultBlueOffset) & 0xFF;
 124     b = (b >> 1) + (b >> 2);
 125     *down = (r << RrDefaultRedOffset) + (g << RrDefaultGreenOffset)
 126         + (b << RrDefaultBlueOffset);
 127 }
 128
 129 static void create_bevel_colors(RrAppearance *l)
 130 {
 131     int r, g, b;
 132
 133     /* light color */
 134     r = l->surface.primary->r;
 135     r += r >> 1;
 136     g = l->surface.primary->g;
 137     g += g >> 1;
 138     b = l->surface.primary->b;
 139     b += b >> 1;
 140     if (r > 0xFF) r = 0xFF;
 141     if (g > 0xFF) g = 0xFF;
 142     if (b > 0xFF) b = 0xFF;
 143     g_assert(!l->surface.bevel_light);
 144     l->surface.bevel_light = RrColorNew(l->inst, r, g, b);
 145     RrColorAllocateGC(l->surface.bevel_light);
 146
 147     /* dark color */
 148     r = l->surface.primary->r;
 149     r = (r >> 1) + (r >> 2);
 150     g = l->surface.primary->g;
 151     g = (g >> 1) + (g >> 2);
 152     b = l->surface.primary->b;
 153     b = (b >> 1) + (b >> 2);
 154     g_assert(!l->surface.bevel_dark);
 155     l->surface.bevel_dark = RrColorNew(l->inst, r, g, b);
 156     RrColorAllocateGC(l->surface.bevel_dark);
 157 }
 158
 159 static void gradient_solid(RrAppearance *l, int w, int h)
 160 {
 161     RrPixel32 pix;
 162     int i, a, b;
 163     RrSurface *sp = &l->surface;
 164     int left = 0, top = 0, right = w - 1, bottom = h - 1;
 165
 166     if (sp->primary->gc == None)
 167         RrColorAllocateGC(sp->primary);
 168     pix = (sp->primary->r << RrDefaultRedOffset)
 169         + (sp->primary->g << RrDefaultGreenOffset)
 170         + (sp->primary->b << RrDefaultBlueOffset);
 171
 172     for (a = 0; a < w; a++)
 173         for (b = 0; b < h; b++)
 174             sp->RrPixel_data[a + b * w] = pix;
 175
 176     XFillRectangle(RrDisplay(l->inst), l->pixmap, sp->primary->gc,
 177                    0, 0, w, h);
 178
 179     if (sp->interlaced) {
 180         if (sp->secondary->gc == None)
 181             RrColorAllocateGC(sp->secondary);
 182         for (i = 0; i < h; i += 2)
 183             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->secondary->gc,
 184                       0, i, w, i);
 185     }
 186
 187     switch (sp->relief) {
 188     case RR_RELIEF_RAISED:
 189         if (!sp->bevel_dark)
 190             create_bevel_colors(l);
 191
 192         switch (sp->bevel) {
 193         case RR_BEVEL_1:
 194             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_dark->gc,
 195                       left, bottom, right, bottom);
 196             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_dark->gc,
 197                       right, bottom, right, top);
 198
 199             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_light->gc,
 200                       left, top, right, top);
 201             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_light->gc,
 202                       left, bottom, left, top);
 203             break;
 204         case RR_BEVEL_2:
 205             XDrawLine(RrDisplay(l->inst), l->pixmap,
 206                       sp->bevel_dark->gc,
 207                       left + 1, bottom - 2, right - 2, bottom - 2);
 208             XDrawLine(RrDisplay(l->inst), l->pixmap,
 209                       sp->bevel_dark->gc,
 210                       right - 2, bottom - 2, right - 2, top + 1);
 211
 212             XDrawLine(RrDisplay(l->inst), l->pixmap,
 213                       sp->bevel_light->gc,
 214                       left + 1, top + 1, right - 2, top + 1);
 215             XDrawLine(RrDisplay(l->inst), l->pixmap,
 216                       sp->bevel_light->gc,
 217                       left + 1, bottom - 2, left + 1, top + 1);
 218             break;
 219         default:
 220             g_assert_not_reached(); /* unhandled BevelType */
 221         }
 222         break;
 223     case RR_RELIEF_SUNKEN:
 224         if (!sp->bevel_dark)
 225             create_bevel_colors(l);
 226
 227         switch (sp->bevel) {
 228         case RR_BEVEL_1:
 229             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_light->gc,
 230                       left, bottom, right, bottom);
 231             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_light->gc,
 232                       right, bottom, right, top);
 233
 234             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_dark->gc,
 235                       left, top, right, top);
 236             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_dark->gc,
 237                       left, bottom, left, top);
 238             break;
 239         case RR_BEVEL_2:
 240             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_light->gc,
 241                       left + 1, bottom - 2, right - 2, bottom - 2);
 242             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_light->gc,
 243                       right - 2, bottom - 2, right - 2, top + 1);
 244
 245             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_dark->gc,
 246                       left + 1, top + 1, right - 2, top + 1);
 247             XDrawLine(RrDisplay(l->inst), l->pixmap, sp->bevel_dark->gc,
 248                       left + 1, bottom - 2, left + 1, top + 1);
 249
 250             break;
 251         default:
 252             g_assert_not_reached(); /* unhandled BevelType */
 253         }
 254         break;
 255     case RR_RELIEF_FLAT:
 256         if (sp->border) {
 257             if (sp->border_color->gc == None)
 258                 RrColorAllocateGC(sp->border_color);
 259             XDrawRectangle(RrDisplay(l->inst), l->pixmap, sp->border_color->gc,
 260                            left, top, right, bottom);
 261         }
 262         break;
 263     default:
 264         g_assert_not_reached(); /* unhandled ReliefType */
 265     }
 266 }
 267
 268 /* * * * * * * * * * * * * * GRADIENT MAGIC WOOT * * * * * * * * * * * * * * */
 269
 270 #define VARS(x)                                                     \
 271     unsigned int color##x[3];                                       \
 272     int len##x, cdelta##x[3], error##x[3] = { 0, 0, 0 }, inc##x[3]; \
 273     gboolean bigslope##x[3] /* color slope > 1 */
 274
 275 #define SETUP(x, from, to, w)         \
 276     len##x = w;                       \
 277                                       \
 278     color##x[0] = from->r;            \
 279     color##x[1] = from->g;            \
 280     color##x[2] = from->b;            \
 281                                       \
 282     cdelta##x[0] = to->r - from->r;   \
 283     cdelta##x[1] = to->g - from->g;   \
 284     cdelta##x[2] = to->b - from->b;   \
 285                                       \
 286     if (cdelta##x[0] < 0) {           \
 287         cdelta##x[0] = -cdelta##x[0]; \
 288         inc##x[0] = -1;               \
 289     } else                            \
 290         inc##x[0] = 1;                \
 291     if (cdelta##x[1] < 0) {           \
 292         cdelta##x[1] = -cdelta##x[1]; \
 293         inc##x[1] = -1;               \
 294     } else                            \
 295         inc##x[1] = 1;                \
 296     if (cdelta##x[2] < 0) {           \
 297         cdelta##x[2] = -cdelta##x[2]; \
 298         inc##x[2] = -1;               \
 299     } else                            \
 300         inc##x[2] = 1;                \
 301     bigslope##x[0] = cdelta##x[0] > w;\
 302     bigslope##x[1] = cdelta##x[1] > w;\
 303     bigslope##x[2] = cdelta##x[2] > w
 304
 305 #define COLOR_RR(x, c)                       \
 306     c->r = color##x[0];                      \
 307     c->g = color##x[1];                      \
 308     c->b = color##x[2]
 309
 310 #define COLOR(x)                             \
 311     ((color##x[0] << RrDefaultRedOffset) +   \
 312      (color##x[1] << RrDefaultGreenOffset) + \
 313      (color##x[2] << RrDefaultBlueOffset))
 314
 315 #define NEXT(x)                                           \
 316 {                                                         \
 317     int i;                                                \
 318     for (i = 2; i >= 0; --i) {                            \
 319         if (!cdelta##x[i]) continue;                      \
 320                                                           \
 321         if (!bigslope##x[i]) {                            \
 322             /* Y (color) is dependant on X */             \
 323             error##x[i] += cdelta##x[i];                  \
 324             if ((error##x[i] << 1) >= len##x) {           \
 325                 color##x[i] += inc##x[i];                 \
 326                 error##x[i] -= len##x;                    \
 327             }                                             \
 328         } else {                                          \
 329             /* X is dependant on Y (color) */             \
 330             while (1) {                                   \
 331                 color##x[i] += inc##x[i];                 \
 332                 error##x[i] += len##x;                    \
 333                 if ((error##x[i] << 1) >= cdelta##x[i]) { \
 334                     error##x[i] -= cdelta##x[i];          \
 335                     break;                                \
 336                 }                                         \
 337             }                                             \
 338         }                                                 \
 339     }                                                     \
 340 }
 341
 342 static void gradient_horizontal(RrSurface *sf, int w, int h)
 343 {
 344     int x, y;
 345     RrPixel32 *data = sf->RrPixel_data;
 346     RrPixel32 current;
 347
 348     VARS(x);
 349     SETUP(x, sf->primary, sf->secondary, w);
 350
 351     for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 352         current = COLOR(x);
 353         for (y = h - 1; y >= 0; --y)  /* 0 -> h */
 354             *(data + y * w) = current;
 355         ++data;
 356
 357         NEXT(x);
 358     }
 359     current = COLOR(x);
 360     for (y = h - 1; y >= 0; --y)  /* 0 -> h */
 361         *(data + y * w) = current;
 362 }
 363
 364 static void gradient_vertical(RrSurface *sf, int w, int h)
 365 {
 366     int x, y;
 367     RrPixel32 *data = sf->RrPixel_data;
 368     RrPixel32 current;
 369
 370     VARS(y);
 371     SETUP(y, sf->primary, sf->secondary, h);
 372
 373     for (y = h - 1; y > 0; --y) {  /* 0 -> h-1 */
 374         current = COLOR(y);
 375         for (x = w - 1; x >= 0; --x)  /* 0 -> w */
 376             *(data++) = current;
 377
 378         NEXT(y);
 379     }
 380     current = COLOR(y);
 381     for (x = w - 1; x >= 0; --x)  /* 0 -> w */
 382         *(data++) = current;
 383 }
 384
 385
 386 static void gradient_diagonal(RrSurface *sf, int w, int h)
 387 {
 388     int x, y;
 389     RrPixel32 *data = sf->RrPixel_data;
 390     RrColor left, right;
 391     RrColor extracorner;
 392
 393     VARS(lefty);
 394     VARS(righty);
 395     VARS(x);
 396
 397     extracorner.r = (sf->primary->r + sf->secondary->r) / 2;
 398     extracorner.g = (sf->primary->g + sf->secondary->g) / 2;
 399     extracorner.b = (sf->primary->b + sf->secondary->b) / 2;
 400
 401     SETUP(lefty, sf->primary, (&extracorner), h);
 402     SETUP(righty, (&extracorner), sf->secondary, h);
 403
 404     for (y = h - 1; y > 0; --y) {  /* 0 -> h-1 */
 405         COLOR_RR(lefty, (&left));
 406         COLOR_RR(righty, (&right));
 407
 408         SETUP(x, (&left), (&right), w);
 409
 410         for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 411             *(data++) = COLOR(x);
 412
 413             NEXT(x);
 414         }
 415         *(data++) = COLOR(x);
 416
 417         NEXT(lefty);
 418         NEXT(righty);
 419     }
 420     COLOR_RR(lefty, (&left));
 421     COLOR_RR(righty, (&right));
 422
 423     SETUP(x, (&left), (&right), w);
 424
 425     for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 426         *(data++) = COLOR(x);
 427
 428         NEXT(x);
 429     }
 430     *data = COLOR(x);
 431 }
 432
 433 static void gradient_crossdiagonal(RrSurface *sf, int w, int h)
 434 {
 435     int x, y;
 436     RrPixel32 *data = sf->RrPixel_data;
 437     RrColor left, right;
 438     RrColor extracorner;
 439
 440     VARS(lefty);
 441     VARS(righty);
 442     VARS(x);
 443
 444     extracorner.r = (sf->primary->r + sf->secondary->r) / 2;
 445     extracorner.g = (sf->primary->g + sf->secondary->g) / 2;
 446     extracorner.b = (sf->primary->b + sf->secondary->b) / 2;
 447
 448     SETUP(lefty, (&extracorner), sf->secondary, h);
 449     SETUP(righty, sf->primary, (&extracorner), h);
 450
 451     for (y = h - 1; y > 0; --y) {  /* 0 -> h-1 */
 452         COLOR_RR(lefty, (&left));
 453         COLOR_RR(righty, (&right));
 454
 455         SETUP(x, (&left), (&right), w);
 456
 457         for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 458             *(data++) = COLOR(x);
 459
 460             NEXT(x);
 461         }
 462         *(data++) = COLOR(x);
 463
 464         NEXT(lefty);
 465         NEXT(righty);
 466     }
 467     COLOR_RR(lefty, (&left));
 468     COLOR_RR(righty, (&right));
 469
 470     SETUP(x, (&left), (&right), w);
 471
 472     for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 473         *(data++) = COLOR(x);
 474
 475         NEXT(x);
 476     }
 477     *data = COLOR(x);
 478 }
 479
 480 static void gradient_pyramid(RrSurface *sf, int inw, int inh)
 481 {
 482     int x, y, w = (inw >> 1) + 1, h = (inh >> 1) + 1;
 483     RrPixel32 *data = sf->RrPixel_data;
 484     RrPixel32 *end = data + inw*inh - 1;
 485     RrPixel32 current;
 486     RrColor left, right;
 487     RrColor extracorner;
 488
 489     VARS(lefty);
 490     VARS(righty);
 491     VARS(x);
 492
 493     extracorner.r = (sf->primary->r + sf->secondary->r) / 2;
 494     extracorner.g = (sf->primary->g + sf->secondary->g) / 2;
 495     extracorner.b = (sf->primary->b + sf->secondary->b) / 2;
 496
 497     SETUP(lefty, (&extracorner), sf->secondary, h);
 498     SETUP(righty, sf->primary, (&extracorner), h);
 499
 500     for (y = h - 1; y > 0; --y) {  /* 0 -> h-1 */
 501         COLOR_RR(lefty, (&left));
 502         COLOR_RR(righty, (&right));
 503
 504         SETUP(x, (&left), (&right), w);
 505
 506         for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 507             current = COLOR(x);
 508             *(data+x) = current;
 509             *(data+inw-x) = current;
 510             *(end-x) = current;
 511             *(end-(inw-x)) = current;
 512
 513             NEXT(x);
 514         }
 515         current = COLOR(x);
 516         *(data+x) = current;
 517         *(data+inw-x) = current;
 518         *(end-x) = current;
 519         *(end-(inw-x)) = current;
 520
 521         data+=inw;
 522         end-=inw;
 523
 524         NEXT(lefty);
 525         NEXT(righty);
 526     }
 527     COLOR_RR(lefty, (&left));
 528     COLOR_RR(righty, (&right));
 529
 530     SETUP(x, (&left), (&right), w);
 531
 532     for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 533         current = COLOR(x);
 534         *(data+x) = current;
 535         *(data+inw-x) = current;
 536         *(end-x) = current;
 537         *(end-(inw-x)) = current;
 538
 539         NEXT(x);
 540     }
 541     *(data+x) = current;
 542     *(data+inw-x) = current;
 543     *(end-x) = current;
 544     *(end-(inw-x)) = current;
 545 }
 546
 547 static void gradient_rectangle(RrSurface *sf, int inw, int inh)
 548 {
 549     int x, y, w = (inw >> 1) + 1, h = (inh >> 1) + 1;
 550     RrPixel32 *data = sf->RrPixel_data;
 551     RrPixel32 *end = data + inw*inh - 1;
 552     RrPixel32 current;
 553     RrColor left, right;
 554     RrColor extracorner;
 555
 556     VARS(lefty);
 557     VARS(righty);
 558     VARS(x);
 559
 560     extracorner.r = (sf->primary->r + sf->secondary->r) / 2;
 561     extracorner.g = (sf->primary->g + sf->secondary->g) / 2;
 562     extracorner.b = (sf->primary->b + sf->secondary->b) / 2;
 563
 564     SETUP(lefty, (&extracorner), sf->secondary, h);
 565     SETUP(righty, sf->primary, (&extracorner), h);
 566
 567     for (y = h - 1; y > 0; --y) {  /* 0 -> h-1 */
 568         COLOR_RR(lefty, (&left));
 569         COLOR_RR(righty, (&right));
 570
 571         SETUP(x, (&left), (&right), w);
 572
 573         for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 574             current = COLOR(x);
 575             *(data+x) = current;
 576             *(data+inw-x) = current;
 577             *(end-x) = current;
 578             *(end-(inw-x)) = current;
 579
 580             NEXT(x);
 581         }
 582         current = COLOR(x);
 583         *(data+x) = current;
 584         *(data+inw-x) = current;
 585         *(end-x) = current;
 586         *(end-(inw-x)) = current;
 587
 588         data+=inw;
 589         end-=inw;
 590
 591         NEXT(lefty);
 592         NEXT(righty);
 593     }
 594     COLOR_RR(lefty, (&left));
 595     COLOR_RR(righty, (&right));
 596
 597     SETUP(x, (&left), (&right), w);
 598
 599     for (x = w - 1; x > 0; --x) {  /* 0 -> w-1 */
 600         current = COLOR(x);
 601         *(data+x) = current;
 602         *(data+inw-x) = current;
 603         *(end-x) = current;
 604         *(end-(inw-x)) = current;
 605
 606         NEXT(x);
 607     }
 608     *(data+x) = current;
 609     *(data+inw-x) = current;
 610     *(end-x) = current;
 611     *(end-(inw-x)) = current;
 612 }
 613
 614 static void gradient_pipecross(RrSurface *sf, int inw, int inh)
 615 {
 616     RrPixel32 *data = sf->RrPixel_data;
 617     RrPixel32 *end = data + inw*inh - 1;
 618     RrPixel32 current;
 619     float drx, dgx, dbx, dry, dgy, dby;
 620     unsigned int r,g,b;
 621     int x, y, h=(inh/2) + 1, w=(inw/2) + 1;
 622
 623     drx = (float)(sf->secondary->r -
 624                   sf->primary->r);
 625     dry = drx/(float)h;
 626     drx/= (float)w;
 627
 628     dgx = (float)(sf->secondary->g -
 629                   sf->primary->g);
 630     dgy = dgx/(float)h;
 631     dgx/= (float)w;
 632
 633     dbx = (float)(sf->secondary->b -
 634                   sf->primary->b);
 635     dby = dbx/(float)h;
 636     dbx/= (float)w;
 637
 638     for (y = 0; y < h; ++y) {
 639         for (x = 0; x < w; ++x, data) {
 640             if ((float)x/(float)w > (float)y/(float)h) {
 641                 r = sf->primary->r + (drx * x);
 642                 g = sf->primary->g + (dgx * x);
 643                 b = sf->primary->b + (dbx * x);
 644             } else {
 645                 r = sf->primary->r + (dry * x);
 646                 g = sf->primary->g + (dgy * x);
 647                 b = sf->primary->b + (dby * x);
 648             }
 649             current = (r << RrDefaultRedOffset)
 650                 + (g << RrDefaultGreenOffset)
 651                 + (b << RrDefaultBlueOffset);
 652             *(data+x) = current;
 653             *(data+inw-x) = current;
 654             *(end-x) = current;
 655             *(end-(inw-x)) = current;
 656         }
 657         data+=inw;
 658         end-=inw;
 659     }
 660 }