From: Ian Jackson <ian@liberator.(none)>
Date: Sun, 31 May 2009 23:23:46 +0000 (+0100)
Subject: Can find main rectangle
X-Git-Tag: 1.9.2~199
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?p=ypp-sc-tools.web-live.git;a=commitdiff_plain;h=f9c00eb882d1758e95422d8f40ef5606422cffa3

Can find main rectangle
---

diff --git a/pctb/convert.c b/pctb/convert.c
index 80bc894..95e75b3 100644
--- a/pctb/convert.c
+++ b/pctb/convert.c
@@ -5,14 +5,37 @@
 #include <string.h>
 
 #define eassert assert
+#define debug stdout
 
 typedef struct {
   unsigned long rgb; /* on screen */
   char c; /* canonical */
 } CanonColourInfo;
 
+static int height, width;
+static char *image;
+
+static void debug_flush(void) {
+  eassert(!fflush(debug));
+  eassert(!ferror(debug));
+}
+
+typedef struct {
+  int x, y;
+} Point;
+
+typedef struct { /* both inclusive */
+  Point tl;
+  Point br;
+} Rect;
+
+static inline char get(int x, int y) { return image[y * width + x]; }
+static inline char get_p(Point p) { return get(p.x,p.y); }
+
+
 static const CanonColourInfo canoncolourinfos[]= {
   { 0x475A5E, '*' }, /* edge */
+  { 0x2C5F7A, '*' }, /* edge just under box heading shadow */
   { 0x7D9094, '+' }, /* interbox */
   { 0xBDC5BF, ' ' }, /* background - pale */
   { 0xADB5AF, ' ' }, /* background - dark */
@@ -22,8 +45,78 @@ static const CanonColourInfo canoncolourinfos[]= {
   { 0,0 }
 };
 
-static int height, width;
-static char *image;
+#define START_MAIN {200,200}
+
+static void require_rectangle(int tlx, int tly, int brx, int bry, char c) {
+  int x,y;
+  for (x=tlx; x<=brx; x++)
+    for (y=tly; y<=bry; y++)
+      eassert(get(x,y) == c);
+}
+static void require_rectangle_r(Rect rr, char c) {
+  require_rectangle(rr.tl.x,rr.tl.y, rr.br.x,rr.br.y, c);
+}
+
+static void debug_rect(const char *what, int whati, Rect rr) {
+  int y,r,w;
+  fprintf(debug, "%s %d: %d,%d..%d,%d:\n", what, whati,
+	  rr.tl.x,rr.tl.y, rr.br.x,rr.br.y);
+  w= rr.br.x - rr.tl.x + 1;
+  for (y=rr.tl.y; y<=rr.br.y; y++) {
+    fprintf(debug, "%4d %4d ",y,y-rr.tl.y);
+    r= fwrite(image + y*width + rr.tl.x, 1, w, debug);
+    eassert(r==w);
+    fputc('|',debug);
+    fputc('\n',debug);
+  }
+  debug_flush();
+}
+
+static void find_main_rectangle(void) {
+  Rect whole = { {0,0}, {width-1,height-1} };
+  Rect mainr = { START_MAIN,START_MAIN };
+
+#define WALK_UNTIL(point,coord,increm,stop,edge)			\
+  for (;;) {								\
+    if (get_p((point)) == (edge)) { (point).coord -= (increm); break; }	\
+    eassert((point).coord != (stop));				\
+    (point).coord += (increm);						\
+  }
+
+  WALK_UNTIL(mainr.tl, x,-1, whole.tl.x, '*');
+  WALK_UNTIL(mainr.tl, y,-1, whole.tl.y, '*');
+  WALK_UNTIL(mainr.br, x,+1, whole.br.x, '*');
+  WALK_UNTIL(mainr.br, y,+1, whole.br.y, '*');
+
+  require_rectangle(mainr.tl.x-1, mainr.tl.y, mainr.tl.x-1, mainr.br.y, '*');
+  require_rectangle(mainr.br.x+1, mainr.tl.y, mainr.br.x+1, mainr.br.y, '*');
+  require_rectangle(mainr.tl.x, mainr.tl.y-1, mainr.br.x, mainr.tl.y-1, '*');
+  require_rectangle(mainr.tl.x, mainr.br.y+1, mainr.br.x, mainr.br.y+1, '*');
+
+#define CHECK_STRIP_BORDER(tlbr,xy,increm)	\
+  do {						\
+    Point csb_p;				\
+    Rect csb_r;					\
+    csb_p= mainr.tl;				\
+    csb_p.xy= mainr.tlbr.xy;			\
+    if (get_p(csb_p)=='+') {			\
+      csb_r= mainr;				\
+      csb_r.tl.xy= csb_p.xy;			\
+      csb_r.br.xy= csb_p.xy;			\
+      require_rectangle_r(csb_r, '+');		\
+      mainr.tlbr.xy += increm;			\
+    }						\
+  } while(0)
+
+  debug_rect("mainr",0, mainr);
+
+  CHECK_STRIP_BORDER(tl,x,+1);
+  CHECK_STRIP_BORDER(tl,y,+1);
+  CHECK_STRIP_BORDER(br,x,-1);
+  CHECK_STRIP_BORDER(br,y,-1);
+
+  debug_rect("mainr",1, mainr);
+}		    
 
 static void load_image_and_canonify(void) {
   struct pam inpam;
@@ -53,22 +146,18 @@ static void load_image_and_canonify(void) {
 	  image[y*width + x]= cci->c;
 	  break;
 	}
-      if (y==234 && x==82) {
-	printf("y=%d/%d x=%d/%d rgb=%d,%d,%d rgb_l=%lx c=%c\n",
-	       y,height,x,width, rgb[0],rgb[1],rgb[2], rgb_l, image[y*width+x]);
-      }
     }
-    r= fwrite(image + y*width, 1,width, stdout);  eassert(r==width);
-    putchar('\n');
+    fprintf(debug, "%4d ",y);
+    r= fwrite(image + y*width, 1,width, debug);  eassert(r==width);
+    fputc('\n',debug);
   }
-  eassert(!fflush(stdout));
-  eassert(!ferror(stdout));
+  debug_flush();
 }
- 
+
 int main(void) {
   load_image_and_canonify();
-  /*
   find_main_rectangle();
+  /*
   repeatedly_find_top_thing();
   */
   return 0;