lib/gfxpoly/convert.c

   1 #include <stdlib.h>
   2 #include <math.h>
   3 #include <string.h>
   4 #include "../gfxdevice.h"
   5 #include "../mem.h"
   6 #include "poly.h"
   7 #include "convert.h"
   8 #include "wind.h"
   9
  10 /* factor that determines into how many line fragments a spline is converted */
  11 #define SUBFRACTION (2.4)
  12
  13 static inline int32_t convert_coord(double x, double z)
  14 {
  15     /* we clamp to 26 bit because:
  16        a) we use a (x1-x2) shortcut when comparing coordinates
  17        b) we need to be able to multiply two coordinates and store them in a double w/o loss of precision
  18     */
  19     x *= z;
  20     if(x < -0x2000000) x = -0x2000000;
  21     if(x >  0x1ffffff) x =  0x1ffffff;
  22     return ceil(x);
  23 }
  24
  25 static void convert_gfxline(gfxline_t*line, polywriter_t*w, double gridsize)
  26 {
  27     assert(!line || line[0].type == gfx_moveTo);
  28     double lastx=0,lasty=0;
  29     double z = 1.0 / gridsize;
  30     while(line) {
  31         if(line->type == gfx_moveTo) {
  32             if(line->next && line->next->type != gfx_moveTo && (line->x!=lastx || line->y!=lasty)) {
  33                 w->moveto(w, convert_coord(line->x,z), convert_coord(line->y,z));
  34             }
  35         } else if(line->type == gfx_lineTo) {
  36             w->lineto(w, convert_coord(line->x,z), convert_coord(line->y,z));
  37         } else if(line->type == gfx_splineTo) {
  38             int parts = (int)(sqrt(fabs(line->x-2*line->sx+lastx) +
  39                                    fabs(line->y-2*line->sy+lasty))*SUBFRACTION);
  40             if(!parts) parts = 1;
  41             double stepsize = 1.0/parts;
  42             int i;
  43             for(i=0;i<parts;i++) {
  44                 double t = (double)i*stepsize;
  45                 double sx = (line->x*t*t + 2*line->sx*t*(1-t) + lastx*(1-t)*(1-t));
  46                 double sy = (line->y*t*t + 2*line->sy*t*(1-t) + lasty*(1-t)*(1-t));
  47                 w->lineto(w, convert_coord(sx,z), convert_coord(sy,z));
  48             }
  49             w->lineto(w, convert_coord(line->x,z), convert_coord(line->y,z));
  50         }
  51         lastx = line->x;
  52         lasty = line->y;
  53         line = line->next;
  54     }
  55 }
  56
  57 static char* readline(FILE*fi)
  58 {
  59     char c;
  60     while(1) {
  61         int l = fread(&c, 1, 1, fi);
  62         if(!l)
  63             return 0;
  64         if(c!=10 || c!=13)
  65             break;
  66     }
  67     char line[256];
  68     int pos = 0;
  69     while(1) {
  70         line[pos++] = c;
  71         line[pos] = 0;
  72         int l = fread(&c, 1, 1, fi);
  73         if(!l || c==10 || c==13) {
  74             return strdup(line);
  75         }
  76     }
  77 }
  78
  79 static void convert_file(const char*filename, polywriter_t*w, double gridsize)
  80 {
  81     FILE*fi = fopen(filename, "rb");
  82     if(!fi) {
  83         perror(filename);
  84     }
  85     double z = 1.0 / gridsize;
  86     int count = 0;
  87     double g = 0;
  88     double lastx=0,lasty=0;
  89     while(1) {
  90         char*line = readline(fi);
  91         if(!line)
  92             break;
  93         double x,y;
  94         char s[256];
  95         if(sscanf(line, "%lf %lf %s", &x, &y, (char*)&s) == 3) {
  96             if(s && !strcmp(s,"moveto")) {
  97                 w->moveto(w, convert_coord(x,z), convert_coord(y,z));
  98                 count++;
  99             } else if(s && !strcmp(s,"lineto")) {
 100                 w->lineto(w, convert_coord(x,z), convert_coord(y,z));
 101                 count++;
 102             } else {
 103                 fprintf(stderr, "invalid command: %s\n", s);
 104             }
 105         } else if(sscanf(line, "%% gridsize %lf", &g) == 1) {
 106             gridsize = g;
 107             z = 1.0 / gridsize;
 108             w->setgridsize(w, g);
 109         }
 110         free(line);
 111     }
 112     fclose(fi);
 113     if(g) {
 114         fprintf(stderr, "loaded %d points from %s (gridsize %f)\n", count, filename, g);
 115     } else {
 116         fprintf(stderr, "loaded %d points from %s\n", count, filename);
 117     }
 118 }
 119
 120 typedef struct _compactpoly {
 121     gfxpoly_t*poly;
 122     point_t last;
 123     point_t*points;
 124     int num_points;
 125     int points_size;
 126     segment_dir_t dir;
 127     char new;
 128 } compactpoly_t;
 129
 130 void finish_segment(compactpoly_t*data)
 131 {
 132     if(data->num_points <= 1)
 133         return;
 134     point_t*p = malloc(sizeof(point_t)*data->num_points);
 135     gfxpolystroke_t*s = rfx_calloc(sizeof(gfxpolystroke_t));
 136     s->fs = &edgestyle_default;
 137     s->next = data->poly->strokes;
 138     data->poly->strokes = s;
 139     s->num_points = s->points_size = data->num_points;
 140     s->dir = data->dir;
 141     s->points = p;
 142     assert(data->dir != DIR_UNKNOWN);
 143     if(data->dir == DIR_UP) {
 144         int t;
 145         int s = data->num_points;
 146         for(t=0;t<data->num_points;t++) {
 147             p[--s] = data->points[t];
 148         }
 149     } else {
 150         memcpy(p, data->points, sizeof(point_t)*data->num_points);
 151     }
 152 #ifdef CHECKS
 153     int t;
 154     for(t=0;t<data->num_points-1;t++) {
 155         assert(p[t].y<=p[t+1].y);
 156     }
 157 #endif
 158 }
 159 static void compactmoveto(polywriter_t*w, int32_t x, int32_t y)
 160 {
 161     compactpoly_t*data = (compactpoly_t*)w->internal;
 162     point_t p;
 163     p.x = x;
 164     p.y = y;
 165     if(p.x != data->last.x || p.y != data->last.y) {
 166         data->new = 1;
 167     }
 168     data->last = p;
 169 }
 170 static void compactlineto(polywriter_t*w, int32_t x, int32_t y)
 171 {
 172     compactpoly_t*data = (compactpoly_t*)w->internal;
 173     point_t p;
 174     p.x = x;
 175     p.y = y;
 176     if(p.x == data->last.x && p.y == data->last.y)
 177         return;
 178
 179     if((p.y < data->last.y && data->dir != DIR_UP) ||
 180        (p.y > data->last.y && data->dir != DIR_DOWN) || data->new) {
 181         finish_segment(data);
 182         data->dir = p.y > data->last.y ? DIR_DOWN : DIR_UP;
 183         data->points[0] = data->last;
 184         data->num_points = 1;
 185     }
 186     data->new = 0;
 187
 188     if(data->points_size == data->num_points) {
 189         data->points_size <<= 1;
 190         assert(data->points_size > data->num_points);
 191         data->points = rfx_realloc(data->points, sizeof(point_t)*data->points_size);
 192     }
 193     data->points[data->num_points++] = p;
 194     data->last = p;
 195 }
 196 static void compactsetgridsize(polywriter_t*w, double gridsize)
 197 {
 198     compactpoly_t*d = (compactpoly_t*)w->internal;
 199     d->poly->gridsize = gridsize;
 200 }
 201 /*static int compare_stroke(const void*_s1, const void*_s2)
 202 {
 203     gfxpolystroke_t*s1 = (gfxpolystroke_t*)_s1;
 204     gfxpolystroke_t*s2 = (gfxpolystroke_t*)_s2;
 205     return s1->points[0].y - s2->points[0].y;
 206 }*/
 207 static void*compactfinish(polywriter_t*w)
 208 {
 209     compactpoly_t*data = (compactpoly_t*)w->internal;
 210     finish_segment(data);
 211     //qsort(data->poly->strokes, data->poly->num_strokes, sizeof(gfxpolystroke_t), compare_stroke);
 212     free(data->points);
 213     gfxpoly_t*poly = data->poly;
 214     free(w->internal);w->internal = 0;
 215     return (void*)poly;
 216 }
 217 void gfxpolywriter_init(polywriter_t*w)
 218 {
 219     w->moveto = compactmoveto;
 220     w->lineto = compactlineto;
 221     w->setgridsize = compactsetgridsize;
 222     w->finish = compactfinish;
 223     compactpoly_t*data = w->internal = rfx_calloc(sizeof(compactpoly_t));
 224     data->poly = rfx_calloc(sizeof(gfxpoly_t));
 225     data->poly->gridsize = 1.0;
 226     data->last.x = data->last.y = 0;
 227     data->num_points = 0;
 228     data->points_size = 16;
 229     data->new = 1;
 230     data->dir = DIR_UNKNOWN;
 231     data->points = (point_t*)rfx_alloc(sizeof(point_t)*data->points_size);
 232     data->poly->strokes = 0;
 233 }
 234
 235 gfxpoly_t* gfxpoly_from_fill(gfxline_t*line, double gridsize)
 236 {
 237     polywriter_t writer;
 238     gfxpolywriter_init(&writer);
 239     writer.setgridsize(&writer, gridsize);
 240     convert_gfxline(line, &writer, gridsize);
 241     return (gfxpoly_t*)writer.finish(&writer);
 242 }
 243 gfxpoly_t* gfxpoly_from_file(const char*filename, double gridsize)
 244 {
 245     polywriter_t writer;
 246     gfxpolywriter_init(&writer);
 247     writer.setgridsize(&writer, gridsize);
 248     convert_file(filename, &writer, gridsize);
 249     return (gfxpoly_t*)writer.finish(&writer);
 250 }
 251 void gfxpoly_destroy(gfxpoly_t*poly)
 252 {
 253     int t;
 254     gfxpolystroke_t*stroke = poly->strokes;
 255     while(stroke) {
 256         gfxpolystroke_t*next = stroke->next;
 257         free(stroke->points);
 258         free(stroke);
 259         stroke = next;
 260     }
 261     free(poly);
 262 }
 263
 264 typedef struct _polydraw_internal
 265 {
 266     double lx, ly;
 267     int32_t lastx, lasty;
 268     int32_t x0, y0;
 269     double z;
 270     char last;
 271     polywriter_t writer;
 272 } polydraw_internal_t;
 273
 274 static void polydraw_moveTo(gfxdrawer_t*d, gfxcoord_t _x, gfxcoord_t _y)
 275 {
 276     polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
 277     int32_t x = convert_coord(_x, i->z);
 278     int32_t y = convert_coord(_y, i->z);
 279     if(i->lastx != x || i->lasty != y) {
 280         i->writer.moveto(&i->writer, x, y);
 281     }
 282     i->lx = _x;
 283     i->ly = _y;
 284     i->x0 = x;
 285     i->y0 = y;
 286     i->lastx = x;
 287     i->lasty = y;
 288     i->last = 1;
 289 }
 290 static void polydraw_lineTo(gfxdrawer_t*d, gfxcoord_t _x, gfxcoord_t _y)
 291 {
 292     polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
 293     if(!i->last) {
 294         polydraw_moveTo(d, _x, _y);
 295         return;
 296     }
 297     int32_t x = convert_coord(_x, i->z);
 298     int32_t y = convert_coord(_y, i->z);
 299     if(i->lastx != x || i->lasty != y) {
 300         i->writer.lineto(&i->writer, x, y);
 301     }
 302     i->lx = _x;
 303     i->ly = _y;
 304     i->lastx = x;
 305     i->lasty = y;
 306     i->last = 1;
 307 }
 308 static void polydraw_splineTo(gfxdrawer_t*d, gfxcoord_t sx, gfxcoord_t sy, gfxcoord_t x, gfxcoord_t y)
 309 {
 310     polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
 311     if(!i->last) {
 312         polydraw_moveTo(d, x, y);
 313         return;
 314     }
 315     double c = fabs(x-2*sx+i->lx) + fabs(y-2*sy+i->ly);
 316     int parts = (int)(sqrt(c)*SUBFRACTION);
 317     if(!parts) parts = 1;
 318     int t;
 319     int32_t nx,ny;
 320     for(t=0;t<parts;t++) {
 321         nx = convert_coord((double)(t*t*x + 2*t*(parts-t)*sx + (parts-t)*(parts-t)*i->lx)/(double)(parts*parts), i->z);
 322         ny = convert_coord((double)(t*t*y + 2*t*(parts-t)*sy + (parts-t)*(parts-t)*i->ly)/(double)(parts*parts), i->z);
 323         if(nx != i->lastx || ny != i->lasty) {
 324             i->writer.lineto(&i->writer, nx, ny);
 325             i->lastx = nx; i->lasty = ny;
 326         }
 327     }
 328     nx = convert_coord(x,i->z);
 329     ny = convert_coord(y,i->z);
 330     if(nx != i->lastx || ny != i->lasty) {
 331         i->writer.lineto(&i->writer, nx, ny);
 332     }
 333     i->lx = x;
 334     i->ly = y;
 335     i->lastx = nx;
 336     i->lasty = ny;
 337     i->last = 1;
 338 }
 339 static void polydraw_close(gfxdrawer_t*d)
 340 {
 341     polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
 342     assert(!(i->last && (i->x0 == INVALID_COORD || i->y0 == INVALID_COORD)));
 343     if(!i->last)
 344         return;
 345     if(i->lastx != i->x0 || i->lasty != i->y0) {
 346         i->writer.lineto(&i->writer, i->x0, i->y0);
 347         i->lastx = i->x0;
 348         i->lasty = i->y0;
 349     }
 350     i->last = 0;
 351     i->x0 = INVALID_COORD;
 352     i->y0 = INVALID_COORD;
 353 }
 354 static void* polydraw_result(gfxdrawer_t*d)
 355 {
 356     polydraw_internal_t*i = (polydraw_internal_t*)d->internal;
 357     void*result = i->writer.finish(&i->writer);
 358     rfx_free(i);
 359     memset(d, 0, sizeof(gfxdrawer_t));
 360     return result;
 361 }
 362
 363 void gfxdrawer_target_poly(gfxdrawer_t*d, double gridsize)
 364 {
 365     polydraw_internal_t*i = (polydraw_internal_t*)rfx_calloc(sizeof(polydraw_internal_t));
 366     d->internal = i;
 367     i->lastx = INVALID_COORD; // convert_coord can never return this value
 368     i->lasty = INVALID_COORD;
 369     i->x0 = INVALID_COORD;
 370     i->y0 = INVALID_COORD;
 371     d->moveTo = polydraw_moveTo;
 372     d->lineTo = polydraw_lineTo;
 373     d->splineTo = polydraw_splineTo;
 374     d->close = polydraw_close;
 375     d->result = polydraw_result;
 376     gfxpolywriter_init(&i->writer);
 377     i->writer.setgridsize(&i->writer, gridsize);
 378     i->z = 1.0 / gridsize;
 379 }
 380
 381 #if 0
 382 gfxline_t*gfxline_from_gfxpoly(gfxpoly_t*poly)
 383 {
 384     gfxpolystroke_t*stroke;
 385     int count = 0;
 386     for(stroke=poly->strokes;stroke;stroke=stroke->next) {
 387         assert(stroke->num_points);
 388         count += stroke->num_points;
 389     }
 390     if(!count) return 0;
 391     gfxline_t*l = malloc(sizeof(gfxline_t)*count);
 392     count = 0;
 393     /* TODO: it might make sense to concatenate strokes */
 394     for(stroke=poly->strokes;stroke;stroke=stroke->next) {
 395         int t;
 396         for(t=0;t<stroke->num_points;t++) {
 397             l[count+t].x = stroke->points[t].x * poly->gridsize;
 398             l[count+t].y = stroke->points[t].y * poly->gridsize;
 399             l[count+t].type = gfx_lineTo;
 400             l[count+t].next = &l[count+t+1];
 401         }
 402         l[count].type = gfx_moveTo;
 403         count+=stroke->num_points;
 404     }
 405     l[count-1].next = 0;
 406     return l;
 407 }
 408 #endif
 409
 410 static gfxline_t*mkgfxline(gfxpoly_t*poly, char preserve_direction)
 411 {
 412     gfxpolystroke_t*stroke;
 413     int count = 0;
 414     if(!poly->strokes)
 415         return 0;
 416     dict_t*d = dict_new2(&point_type);
 417     dict_t*todo = dict_new2(&ptr_type);
 418     gfxpolystroke_t*stroke_min= poly->strokes;
 419     int32_t x_min=stroke_min->points[0].x;
 420     int32_t y_min=stroke_min->points[0].y;
 421     for(stroke=poly->strokes;stroke;stroke=stroke->next) {
 422         dict_put(todo, stroke, stroke);
 423         assert(stroke->num_points>1);
 424         count += stroke->num_points;
 425         if(stroke->dir == DIR_UP) {
 426             dict_put(d, &stroke->points[stroke->num_points-1], stroke);
 427             if(!preserve_direction)
 428                 dict_put(d, &stroke->points[0], stroke);
 429         } else {
 430             dict_put(d, &stroke->points[0], stroke);
 431             if(!preserve_direction)
 432                 dict_put(d, &stroke->points[stroke->num_points-1], stroke);
 433         }
 434         if(stroke->points[0].y < y_min ||
 435            (stroke->points[0].y == y_min && stroke->points[0].x < x_min)) {
 436             y_min = stroke->points[0].y;
 437             stroke_min = stroke;
 438         }
 439     }
 440     gfxpolystroke_t*next_todo = poly->strokes;
 441     gfxline_t*l = malloc(sizeof(gfxline_t)*count);
 442     count = 0;
 443     stroke = stroke_min;
 444
 445     point_t last = {INVALID_COORD, INVALID_COORD};
 446     char should_connect = 0;
 447     while(stroke) {
 448         if(stroke && !preserve_direction) {
 449             char del1 = dict_del2(d, &stroke->points[0], stroke);
 450             char del2 = dict_del2(d, &stroke->points[stroke->num_points-1], stroke);
 451             assert(del1 && del2);
 452         }
 453         assert(dict_contains(todo, stroke));
 454         int t;
 455         int pos = 0;
 456         int incr = 1;
 457         if(preserve_direction) {
 458             if(stroke->dir == DIR_UP) {
 459                 pos = stroke->num_points-1;
 460                 incr = -1;
 461             }
 462         } else {
 463             // try to find matching point on either end.
 464             // Prefer downward.
 465             if(last.x == stroke->points[stroke->num_points-1].x &&
 466                last.y == stroke->points[stroke->num_points-1].y) {
 467                 pos = stroke->num_points-1;
 468                 incr = -1;
 469             }
 470         }
 471         if(last.x != stroke->points[pos].x || last.y != stroke->points[pos].y) {
 472             l[count].x = stroke->points[pos].x * poly->gridsize;
 473             l[count].y = stroke->points[pos].y * poly->gridsize;
 474             l[count].type = gfx_moveTo;
 475             l[count].next = &l[count+1];
 476             count++;
 477             assert(!should_connect);
 478         }
 479         pos += incr;
 480         for(t=1;t<stroke->num_points;t++) {
 481             l[count].x = stroke->points[pos].x * poly->gridsize;
 482             l[count].y = stroke->points[pos].y * poly->gridsize;
 483             l[count].type = gfx_lineTo;
 484             l[count].next = &l[count+1];
 485             count++;
 486             pos += incr;
 487         }
 488         last = stroke->points[pos-incr];
 489         char del = dict_del(todo, stroke);
 490         assert(del);
 491         assert(!dict_contains(todo, stroke));
 492
 493         /* try to find a poly which starts at the point we drew last */
 494         stroke = dict_lookup(d, &last);
 495         should_connect = 1;
 496         while(!dict_contains(todo, stroke)) {
 497             should_connect = 0;
 498             stroke = next_todo;
 499             if(!next_todo) {
 500                 stroke = 0;
 501                 break;
 502             }
 503             next_todo = next_todo->next;
 504         }
 505     }
 506     l[count-1].next = 0;
 507     dict_destroy(todo);
 508     dict_destroy(d);
 509     return l;
 510 }
 511
 512 gfxline_t*gfxline_from_gfxpoly(gfxpoly_t*poly)
 513 {
 514     return mkgfxline(poly, 0);
 515 }
 516
 517 gfxline_t*gfxline_from_gfxpoly_with_direction(gfxpoly_t*poly)
 518 {
 519     return mkgfxline(poly, 1);
 520 }
 521
 522 static windcontext_t onepolygon = {1};
 523 gfxline_t* gfxpoly_circular_to_evenodd(gfxline_t*line, double gridsize)
 524 {
 525     gfxpoly_t*poly = gfxpoly_from_fill(line, gridsize);
 526     gfxpoly_t*poly2 = gfxpoly_process(poly, 0, &windrule_circular, &onepolygon);
 527     gfxline_t*line2 = gfxline_from_gfxpoly(poly2);
 528     gfxpoly_destroy(poly);
 529     gfxpoly_destroy(poly2);
 530     return line2;
 531 }
 532
 533 gfxpoly_t* gfxpoly_createbox(double x1, double y1,double x2, double y2, double gridsize)
 534 {
 535     gfxline_t* line = gfxline_makerectangle(x1, y1, x2, y2);
 536     gfxpoly_t* poly = gfxpoly_from_fill(line, gridsize);
 537     gfxline_free(line);
 538     return poly;
 539 }
 540