* img2rubik.c: fix convex hull build, some points were not properly

excluded.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@2733 92316355-f0b4-4df1-b90c-862c8a59935f

examples/img2rubik.c

@@ -21,7 +21,7 @@
 #define BRIGHT(x) (0.299*(x)[0] + 0.587*(x)[1] + 0.114*(x)[2])
 
 #define MAXCOLORS 16
-#define STEPS 25
+#define STEPS 256
 #define EPSILON (0.000001)
 
 typedef struct
@@ -213,9 +213,9 @@ static hull_t *compute_hull(int ncolors, double const *palette)
                               * (pts[j + 1][Y] - pts[0][Y]);
                 double k2 = (pts[j + 1][X] - pts[0][X])
                               * (pts[j][Y] - pts[0][Y]);
-                if(k1 < k2)
+                if(k1 < k2 - EPSILON)
                     SWAP(pts[j], pts[j + 1]);
-                else if(k1 == k2)
+                else if(k1 < k2 + EPSILON)
                 {
                     /* Aligned! keep the farthest point */
                     double ax = pts[j][X] - pts[0][X];
@@ -250,6 +250,7 @@ static hull_t *compute_hull(int ncolors, double const *palette)
             else
                 i++;
         }
+        /* FIXME: check the last point */
 
         for(i = 0; i < npts; i++)
             debug("    2D pt[%i] (%g,%g)\n", i, pts[i][X], pts[i][Y]);