From: Ian Jackson <ian@liberator.relativity.greenend.org.uk>
Date: Sun, 5 Jul 2009 19:39:29 +0000 (+0100)
Subject: cope with subpixel antialiasing (urgh)
X-Git-Tag: 1.9.3
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~yarrgweb/git?p=ypp-sc-tools.db-test.git;a=commitdiff_plain;h=refs%2Ftags%2F1.9.3

cope with subpixel antialiasing (urgh)
---

diff --git a/pctb/structure.c b/pctb/structure.c
index 967de1e..d777d57 100644
--- a/pctb/structure.c
+++ b/pctb/structure.c
@@ -525,39 +525,52 @@ static void find_table_entry(Rect commod, int colno, Rect *cell) {
 
   const RgbImage *ri= cim->rgb;
   
-  Rgb background= ri_rgb(ri, cell->br.x, cell->br.y);
+  Rgb background;
+  unsigned char chanbg[3];
   long bg_count=0, light_count=0, dark_count=0;
   Point p;
+
+  background= ri_rgb(ri, cell->br.x, cell->br.y);
+  memcpy(chanbg, RI_PIXEL(ri, cell->br.x, cell->br.y), 3);
+
   FOR_P_RECT(p,*cell) {
-    Rgb here= ri_rgb(ri, p.x, p.y);
-    if (here == background) bg_count++;
-    else if (here < background) dark_count++;
-    else if (here > background) light_count++;
+    const unsigned char *here_pixel= RI_PIXEL(ri, p.x, p.y);
+    int i;
+    for (i=0; i<3; i++) {
+      unsigned here= here_pixel[i];
+      if (here == chanbg[i]) bg_count++;
+      else if (here < chanbg[i]) dark_count  += (chanbg[i] - here)/4 + 1;
+      else if (here > chanbg[i]) light_count += (here - chanbg[i])/4 + 1;
+    }
   }
-  long total_count= RECT_W(*cell) * RECT_H(*cell);
+  long total_count= RECT_W(*cell) * RECT_H(*cell) * 3;
+
   MUST( bg_count > total_count / 2,
 	MR(*cell);MIL(total_count);MIL(bg_count);
 	MIL(light_count);MIL(dark_count) );
+
   if (bg_count == total_count)
     return;
 
-  MUST( !!dark_count != !!light_count,
-	MR(*cell);MIL(total_count);MIL(bg_count);
-	MIL(light_count);MIL(dark_count);MRGB(background); );
-
-  debugf("TABLEENTRY col=%d %d,%d..%d,%d bg=%ld light=%ld dark=%ld\n",
-	 colno, cell->tl.x,cell->tl.y, cell->br.x,cell->br.y,
-	 bg_count, light_count, dark_count);
-  
   Rgb foreground;
   double fg_extra;
-  if (light_count) {
+
+  if (light_count/16 > dark_count) {
     foreground= 0xffffffU;
     fg_extra= +1;
-  } else {
+  } else if (dark_count/16 > light_count) {
     foreground= 0;
     fg_extra= -1;
+  } else {
+    MUST( !"tell light from dark",
+	  MR(*cell);MIL(total_count);MIL(bg_count);
+	  MIL(light_count);MIL(dark_count);MRGB(background); );
   }
+
+  debugf("TABLEENTRY col=%d %d,%d..%d,%d bg=%ld light=%ld dark=%ld\n",
+	 colno, cell->tl.x,cell->tl.y, cell->br.x,cell->br.y,
+	 bg_count, light_count, dark_count);
+  
   int monochrome= 1;
 
   FOR_P_RECT(p,*cell) {
diff --git a/pctb/x.gdb b/pctb/x.gdb
index 9c71346..0f6bf86 100644
--- a/pctb/x.gdb
+++ b/pctb/x.gdb
@@ -1,4 +1,4 @@
 file ypp-commodities
-set args --screenshot-only --test-servers --single-page
-break pages.c:277
+set args -Drect 2>u --edit-charset --raw-tsv --same --screenshot-file t.ppm >raw.tsv 
+break mustfail2
 run