work/gpstroke/erode.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <math.h>
   4 #include <string.h>
   5 #include <time.h>
   6 #include "c24lib/image/image.h"
   7 #include "c24lib/image/draw.h"
   8 #include "c24lib/image/pnm.h"
   9
  10 #include "pcb_draw.h"
  11
  12 int stat[100];
  13
  14 static inline void ray(image_t *i, double x, double y, double dx, double dy, int *out)
  15 {
  16         pixel_t *p;
  17         int h = 0, xx, yy;
  18         do {
  19                 x += dx;
  20                 y += dy;
  21                 xx = round(x);
  22                 yy = round(y);
  23                 p = &image_pix(i, xx, yy);
  24                 h++;
  25
  26         } while(p->r == 0);
  27
  28         if (h < *out)
  29                 *out = h;
  30 }
  31
  32 static inline int height(image_t *i, int cx, int cy)
  33 {
  34         pixel_t *p;
  35         double dx, dy;
  36         int h = i->sx + i->sy;
  37         p = &image_pix(i, cx, cy);
  38         if (p->r != 0)
  39                 return 0;
  40         for(dy = -1.0; dy <= 1.0; dy+=0.27)
  41                 for(dx = -1.0; dx <= 1.0; dx+=0.27)
  42                         ray(i, (double)cx, (double)cy, dx, dy, &h);
  43         return h;
  44 }
  45
  46 static int near(int *hg, int my, double cx, double cy, int width, int clear)
  47 {
  48         int x1 = round(cx - 1), x2 = round(cx + 1);
  49         int y1 = round(cy - 1), y2 = round(cy + 1);
  50         int x, y;
  51         for(y = y1; y <= y2; y++) {
  52                 for(x = x1; x <= x2; x++) {
  53                         if (hg[x + y*width] == my) {
  54                                 if (clear)
  55                                         hg[x + y*width] = 0;
  56                                 return 1;
  57                         }
  58                 }
  59         }
  60         return 0;
  61 }
  62
  63 static int find_line(image_t *trace, int *hg, int my, int cx, int cy, double ang, int width)
  64 {
  65         double dx, dy, x, y, ex, ey;
  66         int len = -2;
  67
  68         dx = cos(ang);
  69         dy = sin(ang);
  70         x = cx;
  71         y = cy;
  72         do {
  73                 len++;
  74                 x += dx;
  75                 y += dy;
  76                 if (trace != NULL) {
  77                         image_pix(trace, (int)round(x), (int)round(y)) = pixel_blue;
  78                         hg[(int)round(x) + (int)round(y) * width] = 0;
  79                 }
  80         } while(near(hg, my, x, y, width, trace != NULL));
  81         ex = x;
  82         ey = y;
  83         x = cx;
  84         y = cy;
  85         do {
  86                 len++;
  87                 x -= dx;
  88                 y -= dy;
  89                 if (trace != NULL) {
  90                         image_pix(trace, (int)round(x), (int)round(y)) = pixel_blue;
  91                         hg[(int)round(x) + (int)round(y) * width] = 0;
  92                 }
  93         } while(near(hg, my, x, y, width, trace != NULL));
  94         if (trace != NULL) {
  95                 printf("stroke %d %d %d %d\n", (int)round(ex), (int)round(ey), (int)round(x), (int)round(y));
  96         }
  97         return len;
  98 }
  99
 100 int main(int arc, char *argv[])
 101 {
 102         image_t *ref;
 103         int *hg;
 104         int maxh = 0;
 105         int x, y, n, cutoff, end;
 106         char *ref_fn = "l.pnm";
 107
 108         if (argv[1] != NULL)
 109                 ref_fn = argv[1];
 110
 111         ref = pnm_load(ref_fn);
 112
 113         /* height map */
 114         hg = calloc(sizeof(int), ref->sx * ref->sy);
 115         for(y = 1; y < ref->sy-1; y++) {
 116                 for(x = 1; x < ref->sy-1; x++) {
 117                         int h = height(ref, x, y);
 118                         if (h > maxh)
 119                                 maxh = h;
 120                         stat[h]++;
 121                         printf("%d", h);
 122                         hg[x + y*ref->sx] = h;
 123                 }
 124                 printf("\n");
 125         }
 126
 127         cutoff = 0;
 128         for(n = 1; n <= maxh; n++) {
 129                 printf("h=%d %d\n", n, stat[n]);
 130                 if ((n > 1) && (stat[n] < stat[n-1]/2) && (cutoff == 0)) {
 131                         cutoff = n-1;
 132                 }
 133         }
 134
 135         printf("-- cutoff=%d\n", cutoff);
 136         end = ref->sx * ref->sy;
 137         for(n = 0; n < end; n++) {
 138                 if (hg[n] == cutoff) {
 139                         ref->pixmap[n] = pixel_red;
 140                 }
 141                 else if (ref->pixmap[n].r != 255) {
 142                         ref->pixmap[n].r = 200;
 143                         ref->pixmap[n].g = 200;
 144                         ref->pixmap[n].b = 200;
 145                 }
 146         }
 147
 148
 149         /* brute force lines */
 150         for(;;) {
 151                 int best_len = 0, bestx, besty;
 152                 double besta;
 153                 for(n = 0; n < end; n++) {
 154                         if (hg[n] == cutoff) {
 155                                 double a;
 156                                 int x, y;
 157                                 x = image_x(ref, ref->pixmap+n);
 158                                 y = image_y(ref, ref->pixmap+n);
 159                                 for(a = 0; a < M_PI; a+=0.1) {
 160                                         int len = find_line(NULL, hg, cutoff, x, y, a, ref->sx);
 161                                         if (len > best_len) {
 162                                                 best_len = len;
 163                                                 bestx = x;
 164                                                 besty = y;
 165                                                 besta = a;
 166                                         }
 167                                 }
 168                         }
 169                 }
 170                 if (best_len <= cutoff*3)
 171                         break;
 172                 printf("len=%d\n", best_len);
 173                 find_line(ref, hg, cutoff, bestx, besty, besta, ref->sx);
 174         }
 175
 176         pnm_save(ref, "OUT.pnm");
 177 }
 178