Fix up offseting degenerate splines

1 files changed, 54 insertions, 36 deletions

diff --git a/src/cairo-spline-offset.c b/src/cairo-spline-offset.c
index 23a89170..853da4c5 100644
--- a/src/cairo-spline-offset.c
+++ b/src/cairo-spline-offset.c
@@ -13,7 +13,7 @@
 #define ISFINITE(x) ((x) * (x) >= 0.) /* check for NaNs */
 #endif
 
-#define printf(a, ...)
+//#define printf(a, ...)
 #include "cairoint.h"
 #include "cairo-spline-offset.h"
 
@@ -919,6 +919,9 @@ miter_point_muiz(point_t a, point_t b, point_t c, double width)
 static knots_t
 knot_offset(knots_t self, double width, cairo_bool_t *is_parallel)
 {
+    printf("in: ");
+    print_knot(self);
+    printf("\n");
     knots_t result;
     double dx0 = self.b.x - self.a.x;
     double dy0 = self.b.y - self.a.y;
@@ -935,55 +938,59 @@ knot_offset(knots_t self, double width, cairo_bool_t *is_parallel)
     double last_x = 0;
     double last_y = 0;
 
+    double scale;
+
+    scale = 1. / ld0;
+    double dlx0 = -dy0 * scale;
+    double dly0 = dx0 * scale;
+
+    scale = 1. / ld1;
+    double dlx1 = -dy1 * scale;
+    double dly1 = dx1 * scale;
+
+    scale = 1. / ld2;
+    double dlx2 = -dy2 * scale;
+    double dly2 = dx2 * scale;
+
+
     if (ld0) {
-	last_x = dx0;
-	last_y = dy0;
+	last_x = dlx0;
+	last_y = dly0;
     }
     if (ld1) {
-	last_x = dx1;
-	last_y = dy1;
+	last_x = dlx1;
+	last_y = dly1;
     }
     if (ld2) {
-	last_x = dx2;
-	last_y = dy2;
+	last_x = dlx2;
+	last_y = dly2;
     }
 
     if (!ld2) {
-	dx2 = last_x;
-	dy2 = last_y;
+	printf("not 2\n");
+	dlx2 = last_x;
+	dly2 = last_y;
     } else {
-	last_x = dx2;
-	last_y = dy2;
+	last_x = dlx2;
+	last_y = dly2;
     }
     if (!ld1) {
-	dx1 = last_x;
-	dy1 = last_y;
+	printf("not 1\n");
+	dlx1 = last_x;
+	dly1 = last_y;
     } else {
-	last_x = dx1;
-	last_y = dy1;
+	last_x = dlx1;
+	last_y = dly1;
     }
     if (!ld0) {
-	dx0 = last_x;
-	dy0 = last_y;
+	printf("not 0\n");
+	dlx0 = last_x;
+	dly0 = last_y;
     } else {
-	last_x = dx0;
-	last_y = dy0;
+	last_x = dlx0;
+	last_y = dly0;
     }
 
-    double scale;
-
-    scale = 1. / ld0;
-    double dlx0 = -dy0 * scale;
-    double dly0 = dx0 * scale;
-
-    scale = 1. / ld1;
-    double dlx1 = -dy1 * scale;
-    double dly1 = dx1 * scale;
-
-    scale = 1. / ld2;
-    double dlx2 = -dy2 * scale;
-    double dly2 = dx2 * scale;
-
     /* mid-point vector sum */
     double dm1x = (dlx0 + dlx1);
     double dm1y = (dly0 + dly1);
@@ -1014,8 +1021,11 @@ knot_offset(knots_t self, double width, cairo_bool_t *is_parallel)
     result.b.y = self.b.y + dm1y;
     result.c.x = self.c.x + dm2x;
     result.c.y = self.c.y + dm2y;
-    result.d.x = self.d.x + dlx0 * width;
-    result.d.y = self.d.y + dly0 * width;
+    result.d.x = self.d.x + dlx2 * width;
+    result.d.y = self.d.y + dly2 * width;
+    printf("out: ");
+    print_knot(result);
+    printf("\n");
     return result;
 }
 
@@ -1048,6 +1058,7 @@ knot_offset(knots_t self, double width, cairo_bool_t *is_parallel)
 void
 curve_offset(knots_t self, double dist, double tolerance, void (*curve_fn)(void *, knots_t), void *closure)
 {
+#if 1
 	point_t n1, n2;
 #if 0
 	self.a.x  = 0;
@@ -1137,10 +1148,17 @@ curve_offset(knots_t self, double dist, double tolerance, void (*curve_fn)(void
 	}
 
 	knots_t offset = {{p0p1.x0, p0p1.y0}, n1, n2, {p2p3.x1, p2p3.y1}};
+#endif
+	cairo_bool_t recurse_n;
+	knots_t offset2 = knot_offset(self, dist, &recurse_n);
+	printf("new result: ");
+	print_knot(offset2);
+	recurse = recurse_n;
+	offset = offset2;
 
 	// we need to make sure we have a finite offset before checking the error
 	printf("curve result: ");
-	//print_knot(offset);
+	print_knot(offset);
 	double max_error = 0.01;//500;//0.01;//tolerance;
 	//double max_error = 0.01;//tolerance;
 	//bool recurse = !error_within_bounds(self, offset, dist, max_error);