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
   9 /* factor that determines into how many line fragments a spline is converted */
  10 #define SUBFRACTION (2.4)
  11
  12 static inline int32_t convert_coord(double x, double z)
  13 {
  14     /* we clamp to 31 bit instead of 32 bit because we use
  15        a (x1-x2) shortcut when comparing coordinates
  16     */
  17     x *= z;
  18     if(x < -0x40000000) x = -0x40000000;
  19     if(x >  0x3fffffff) x =  0x3fffffff;
  20     return ceil(x);
  21 }
  22
  23 static void convert_gfxline(gfxline_t*line, polywriter_t*w, double gridsize)
  24 {
  25     assert(!line || line[0].type == gfx_moveTo);
  26     double lastx=0,lasty=0;
  27     double z = 1.0 / gridsize;
  28     while(line) {
  29         if(line->type == gfx_moveTo) {
  30             if(line->next && line->next->type != gfx_moveTo && (line->x!=lastx || line->y!=lasty)) {
  31                 w->moveto(w, convert_coord(line->x,z), convert_coord(line->y,z));
  32             }
  33         } else if(line->type == gfx_lineTo) {
  34             w->lineto(w, convert_coord(line->x,z), convert_coord(line->y,z));
  35         } else if(line->type == gfx_splineTo) {
  36             int parts = (int)(sqrt(fabs(line->x-2*line->sx+lastx) +
  37                                    fabs(line->y-2*line->sy+lasty))*SUBFRACTION);
  38             if(!parts) parts = 1;
  39             double stepsize = 1.0/parts;
  40             int i;
  41             for(i=0;i<parts;i++) {
  42                 double t = (double)i*stepsize;
  43                 double sx = (line->x*t*t + 2*line->sx*t*(1-t) + lastx*(1-t)*(1-t));
  44                 double sy = (line->y*t*t + 2*line->sy*t*(1-t) + lasty*(1-t)*(1-t));
  45                 w->lineto(w, convert_coord(sx,z), convert_coord(sy,z));
  46             }
  47             w->lineto(w, convert_coord(line->x,z), convert_coord(line->y,z));
  48         }
  49         lastx = line->x;
  50         lasty = line->y;
  51         line = line->next;
  52     }
  53 }
  54
  55 static char* readline(FILE*fi)
  56 {
  57     char c;
  58     while(1) {
  59         int l = fread(&c, 1, 1, fi);
  60         if(!l)
  61             return 0;
  62         if(c!=10 || c!=13)
  63             break;
  64     }
  65     char line[256];
  66     int pos = 0;
  67     while(1) {
  68         line[pos++] = c;
  69         line[pos] = 0;
  70         int l = fread(&c, 1, 1, fi);
  71         if(!l || c==10 || c==13) {
  72             return strdup(line);
  73         }
  74     }
  75 }
  76
  77 static void convert_file(const char*filename, polywriter_t*w, double gridsize)
  78 {
  79     FILE*fi = fopen(filename, "rb");
  80     if(!fi) {
  81         perror(filename);
  82     }
  83     double z = 1.0 / gridsize;
  84     int count = 0;
  85     double g = 0;
  86     double lastx=0,lasty=0;
  87     while(1) {
  88         char*line = readline(fi);
  89         if(!line)
  90             break;
  91         double x,y;
  92         char s[256];
  93         if(sscanf(line, "%lf %lf %s", &x, &y, &s) == 3) {
  94             if(s && !strcmp(s,"moveto")) {
  95                 w->moveto(w, convert_coord(x,z), convert_coord(y,z));
  96                 count++;
  97             } else if(s && !strcmp(s,"lineto")) {
  98                 w->lineto(w, convert_coord(x,z), convert_coord(y,z));
  99                 count++;
 100             } else {
 101                 fprintf(stderr, "invalid command: %s\n", s);
 102             }
 103         } else if(sscanf(line, "%% gridsize %lf", &g) == 1) {
 104             gridsize = g;
 105             z = 1.0 / gridsize;
 106             w->setgridsize(w, g);
 107         }
 108         free(line);
 109     }
 110     fclose(fi);
 111     if(g) {
 112         fprintf(stderr, "loaded %d points from %s (gridsize %f)\n", count, filename, g);
 113     } else {
 114         fprintf(stderr, "loaded %d points from %s\n", count, filename);
 115     }
 116 }
 117
 118 typedef struct _compactpoly {
 119     gfxpoly_t*poly;
 120     point_t last;
 121     point_t*points;
 122     int num_points;
 123     int points_size;
 124     segment_dir_t dir;
 125     char new;
 126 } compactpoly_t;
 127
 128 void finish_segment(compactpoly_t*data)
 129 {
 130     if(data->num_points <= 1)
 131         return;
 132     point_t*p = malloc(sizeof(point_t)*data->num_points);
 133     gfxpolystroke_t*s = rfx_calloc(sizeof(gfxpolystroke_t));
 134     s->next = data->poly->strokes;
 135     data->poly->strokes = s;
 136     s->num_points = s->points_size = data->num_points;
 137     s->dir = data->dir;
 138     s->points = p;
 139     assert(data->dir != DIR_UNKNOWN);
 140     if(data->dir == DIR_UP) {
 141         int t;
 142         int s = data->num_points;
 143         for(t=0;t<data->num_points;t++) {
 144             p[--s] = data->points[t];
 145         }
 146     } else {
 147         memcpy(p, data->points, sizeof(point_t)*data->num_points);
 148     }
 149 #ifdef CHECKS
 150     int t;
 151     for(t=0;t<data->num_points-1;t++) {
 152         assert(p[t].y<=p[t+1].y);
 153     }
 154 #endif
 155 }
 156 static void compactmoveto(polywriter_t*w, int32_t x, int32_t y)
 157 {
 158     compactpoly_t*data = (compactpoly_t*)w->internal;
 159     point_t p;
 160     p.x = x;
 161     p.y = y;
 162     if(p.x != data->last.x || p.y != data->last.y) {
 163         data->new = 1;
 164     }
 165     data->last = p;
 166 }
 167 static void compactlineto(polywriter_t*w, int32_t x, int32_t y)
 168 {
 169     compactpoly_t*data = (compactpoly_t*)w->internal;
 170     point_t p;
 171     p.x = x;
 172     p.y = y;
 173     if(p.x == data->last.x && p.y == data->last.y)
 174         return;
 175
 176     if(p.y < data->last.y && data->dir != DIR_UP ||
 177        p.y > data->last.y && data->dir != DIR_DOWN ||
 178        data->new) {
 179         finish_segment(data);
 180         data->dir = p.y > data->last.y ? DIR_DOWN : DIR_UP;
 181         data->points[0] = data->last;
 182         data->num_points = 1;
 183     }
 184     data->new = 0;
 185
 186     if(data->points_size == data->num_points) {
 187         data->points_size <<= 1;
 188         assert(data->points_size > data->num_points);
 189         data->points = rfx_realloc(data->points, sizeof(point_t)*data->points_size);
 190     }
 191     data->points[data->num_points++] = p;
 192     data->last = p;
 193 }
 194 static void compactsetgridsize(polywriter_t*w, double gridsize)
 195 {
 196     compactpoly_t*d = (compactpoly_t*)w->internal;
 197     d->poly->gridsize = gridsize;
 198 }
 199 /*static int compare_stroke(const void*_s1, const void*_s2)
 200 {
 201     gfxpolystroke_t*s1 = (gfxpolystroke_t*)_s1;
 202     gfxpolystroke_t*s2 = (gfxpolystroke_t*)_s2;
 203     return s1->points[0].y - s2->points[0].y;
 204 }*/
 205 static void*compactfinish(polywriter_t*w)
 206 {
 207     compactpoly_t*data = (compactpoly_t*)w->internal;
 208     finish_segment(data);
 209     //qsort(data->poly->strokes, data->poly->num_strokes, sizeof(gfxpolystroke_t), compare_stroke);
 210     free(data->points);
 211     gfxpoly_t*poly = data->poly;
 212     free(w->internal);w->internal = 0;
 213     return (void*)poly;
 214 }
 215 void gfxpolywriter_init(polywriter_t*w)
 216 {
 217     w->moveto = compactmoveto;
 218     w->lineto = compactlineto;
 219     w->setgridsize = compactsetgridsize;
 220     w->finish = compactfinish;
 221     compactpoly_t*data = w->internal = rfx_calloc(sizeof(compactpoly_t));
 222     data->poly = rfx_calloc(sizeof(gfxpoly_t));
 223     data->poly->gridsize = 1.0;
 224     data->last.x = data->last.y = 0;
 225     data->num_points = 0;
 226     data->points_size = 16;
 227     data->new = 1;
 228     data->dir = DIR_UNKNOWN;
 229     data->points = (point_t*)rfx_alloc(sizeof(point_t)*data->points_size);
 230     data->poly->strokes = 0;
 231 }
 232
 233 gfxpoly_t* gfxpoly_from_gfxline(gfxline_t*line, double gridsize)
 234 {
 235     polywriter_t writer;
 236     gfxpolywriter_init(&writer);
 237     writer.setgridsize(&writer, gridsize);
 238     convert_gfxline(line, &writer, gridsize);
 239     return (gfxpoly_t*)writer.finish(&writer);
 240 }
 241 gfxpoly_t* gfxpoly_from_file(const char*filename, double gridsize)
 242 {
 243     polywriter_t writer;
 244     gfxpolywriter_init(&writer);
 245     writer.setgridsize(&writer, gridsize);
 246     convert_file(filename, &writer, gridsize);
 247     return (gfxpoly_t*)writer.finish(&writer);
 248 }
 249 void gfxpoly_destroy(gfxpoly_t*poly)
 250 {
 251     int t;
 252     gfxpolystroke_t*stroke = poly->strokes;
 253     while(stroke) {
 254         gfxpolystroke_t*next = stroke->next;
 255         free(stroke->points);
 256         free(stroke);
 257         stroke = next;
 258     }
 259     free(poly);
 260 }
 261