Another tweak to the solver to make it handle blank tiles correctly.

The previous checkin stopped it choking on them, but it didn't
actually manage to _deduce_ that all the edges bordering them had to
be closed. Now it does better.

[originally from svn r5829]

diff --git a/net.c b/net.c
index 5037c9b2ec83df3e41af839123d52f4d22ee25c7..76323ca99616289491aa5924fec081606064e6c0 100644 (file)
--- a/net.c
+++ b/net.c
@@ -694,7 +694,6 @@ static int net_solver(int w, int h, unsigned char *tiles,
            assert(j > 0);             /* we can't lose _all_ possibilities! */
 
            if (j < i) {
-               int a, o;
                done_something = TRUE;
 
                /*
@@ -703,12 +702,16 @@ static int net_solver(int w, int h, unsigned char *tiles,
                 */
                while (j < 4)
                    tilestate[(y*w+x) * 4 + j++] = 255;
+           }
 
-               /*
-                * Now go through them again and see if we've
-                * deduced anything new about any edges.
-                */
+           /*
+            * Now go through the tile orientations again and see
+            * if we've deduced anything new about any edges.
+            */
+           {
+               int a, o;
                a = 0xF; o = 0;
+
                for (i = 0; i < 4 && tilestate[(y*w+x) * 4 + i] != 255; i++) {
                    a &= tilestate[(y*w+x) * 4 + i];
                    o |= tilestate[(y*w+x) * 4 + i];