Catch and break out of excessive bezier recursion

diff --git a/libol/libol.c b/libol/libol.c
index 75f72a7783204911c9216adc90bc5485607b88b0..f95e3be05ced5a9602bb57ecb87cb2feb7de2277 100644 (file)
--- a/libol/libol.c
+++ b/libol/libol.c
@@ -418,12 +418,17 @@ static void line_to(float x, float y, uint32_t color)
        dstate.points++;
 }
 
-static void recurse_bezier(float x1, float y1, float x2, float y2, float x3, float y3, uint32_t color)
+static void recurse_bezier(float x1, float y1, float x2, float y2, float x3, float y3, uint32_t color, int depth)
 {
        float x0 = dstate.last_point.x;
        float y0 = dstate.last_point.y;
        int subdivide = 0;
 
+       if (depth > 100) {
+               olLog("Bezier recurse error: %f,%f %f,%f %f,%f %f,%f\n", x0, y0, x1, y1, x2, y2, x3, y3);
+               return;
+       }
+       
        float dx = x3-x0;
        float dy = y3-y0;
        float distance = fmaxf(fabsf(dx),fabsf(dy));
@@ -456,8 +461,8 @@ static void recurse_bezier(float x1, float y1, float x2, float y2, float x3, flo
                float by1 = (by2 + mcy) * 0.5;
                float xm = (ax2 + bx1) * 0.5;
                float ym = (ay2 + by1) * 0.5;
-               recurse_bezier(ax1, ay1, ax2, ay2, xm, ym, color);
-               recurse_bezier(bx1, by1, bx2, by2, x3, y3, color);
+               recurse_bezier(ax1, ay1, ax2, ay2, xm, ym, color, depth+1);
+               recurse_bezier(bx1, by1, bx2, by2, x3, y3, color, depth+1);
        } else {
                addpoint(x3, y3, color);
                dstate.last_point = POINT(x3,y3,color);
@@ -497,7 +502,7 @@ static void bezier_to(float x, float y, uint32_t color)
        for (i=0; i<dwell; i++)
                addpoint(last.x,last.y,last.color);
 
-       recurse_bezier(dstate.c1.x, dstate.c1.y, dstate.c2.x, dstate.c2.y, x, y, color);
+       recurse_bezier(dstate.c1.x, dstate.c1.y, dstate.c2.x, dstate.c2.y, x, y, color, 0);
 
        dstate.last_point = POINT(x,y,color);
        if (near(dstate.c2, dstate.last_point))