Hurrah. Seems to be working, finally.

diff --git a/ttxt.c b/ttxt.c
index b9356e04749465ef2800c8e25678ec5ca238e534..6287f8385a32bdbcf289613cf0b17f408eb63703 100644 (file)
--- a/ttxt.c
+++ b/ttxt.c
@@ -1,3 +1,4 @@
+#include <assert.h>
 #include <stdio.h>
 
 #define XSIZE 6
@@ -201,7 +202,7 @@ doprologue(void)
 */
 
 typedef struct vec {
-       unsigned char x, y;
+       signed char x, y;
 } vec;
 
 typedef struct point {
@@ -296,49 +297,83 @@ vec_bearing(vec v)
        if (v.x == v.y && v.x > 0) return 1;
        if (v.x > 0 && v.y == 0) return 2;
        if (v.x == -v.y && v.x > 0) return 3;
-       if (v.x == 0) return 4;
-       if (v.x == v.y) return 5;
-       if (v.y == 0) return 6;
-       if (v.x == -v.y) return 7;
+       if (v.x == 0 && v.y < 0) return 4;
+       if (v.x == v.y && v.x < 0) return 5;
+       if (v.x < 0 && v.y == 0) return 6;
+       if (v.x == -v.y && v.x < 0) return 7;
        return -1;
 }
 
 static void
 fix_identical(point *p)
 {
-       if (vec_eqp (p->next->v, p->v))
+       if (vec_eqp(p->next->v, p->v)) {
+               fprintf(stderr, "identical points at (%d,%d)\n",
+                   p->v.x, p->v.y);
                killpoint(p);
+       }
+}
+
+static int
+vec_inline3(vec a, vec b, vec c)
+{
+       return
+           vec_bearing(vec_sub(b, a)) == vec_bearing(vec_sub(c, b)) &&
+           vec_bearing(vec_sub(b, a)) != -1;
 }
 
 static int
-vec_inline(vec a, vec b, vec c)
+vec_inline4(vec a, vec b, vec c, vec d)
 {
-       return vec_eqp(a, b) || vec_eqp(b, c) ||
-           vec_bearing(vec_sub(b, a)) == vec_bearing(vec_sub(c, b));
+       return vec_inline3(a, b, c) && vec_inline3(b, c, d);
 }
 
 static void
 fix_collinear(point *p)
 {
-       if (vec_inline(p->prev->v, p->v, p->next->v))
+       if (vec_inline3(p->prev->v, p->v, p->next->v)) {
+               fprintf(stderr, "collinear point at (%d,%d)\n",
+                   p->v.x, p->v.y);
                killpoint(p);
+       }
 }
 
+static int done_anything;
+
 static void
 fix_edges(point *a0, point *b0)
 {
        point *a1 = a0->next, *b1 = b0->next;
 
-       if (vec_inline(a0->v, b0->v, a1->v) ||
-           vec_inline(a0->v, b1->v, a1->v) ||
-           vec_inline(b0->v, a0->v, b1->v) ||
-           vec_inline(b0->v, a1->v, b1->v)) {
-               a0->next = b1; b1->prev = a0;
-               fix_identical(a0);
-               fix_collinear(b1);
-               b0->next = a1; a1->prev = b0;
-               fix_identical(b0);
-               fix_collinear(a1);
+       assert(a1->prev == a0); assert(b1->prev == b0);
+       assert(a0 != a1); assert(a0 != b0);
+       assert(a1 != b1); assert(b0 != b1);
+       if (vec_bearing(vec_sub(a0->v, a1->v)) ==
+           vec_bearing(vec_sub(b1->v, b0->v)) &&
+           (vec_inline4(a0->v, b1->v, a1->v, b0->v) ||
+            vec_inline4(a0->v, b1->v, b0->v, a1->v) ||
+            vec_inline4(b1->v, a0->v, b0->v, a1->v) ||
+            vec_inline4(b1->v, a0->v, a1->v, b0->v) ||
+            vec_eqp(a0->v, b1->v) || vec_eqp(a1->v, b0->v))) {
+               fprintf(stderr,
+                   "linking (%d,%d)-(%d,%d)(%d) with (%d,%d)-(%d,%d)(%d)\n",
+                   a0->v.x, a0->v.y, a1->v.x, a1->v.y, vec_bearing(vec_sub(a0->v, a1->v)),
+                   b0->v.x, b0->v.y, b1->v.x, b1->v.y, vec_bearing(vec_sub(b1->v, b0->v)));
+               if (a0 == b1)
+                       killpoint(a0);
+               else {
+                       a0->next = b1; b1->prev = a0;
+                       fix_identical(a0);
+                       fix_collinear(b1);
+               }
+               if (b0 == a1)
+                       killpoint(b0);
+               else {
+                       b0->next = a1; a1->prev = b0;
+                       fix_identical(b0);
+                       fix_collinear(a1);
+               }
+               done_anything = 1;
        }
 }
 
@@ -347,11 +382,13 @@ clean_path()
 {
        int i, j;
 
-       for (i = 0; i < nextpoint; i++)
-               if (points[i].next)
-                       for (j = i; j < nextpoint; j++)
+       do {
+               done_anything = 0;
+               for (i = 0; i < nextpoint; i++)
+                       for (j = i+1; points[i].next && j < nextpoint; j++)
                                if (points[j].next)
                                        fix_edges(&points[i], &points[j]);
+       } while (done_anything);
 }
 
 static void 
@@ -534,6 +571,6 @@ dochar(char data[YSIZE])
 /*                     printf("grestore\n"); */
                }
        }
-/*     clean_path(); */
+       clean_path();
        emit_path();
 }