[PATCH 1/1] opengl: Avoid inifinite recursion in bezier_approximate() in case of degraded curve.

[Paul Gofman]

From: Paul Gofman

---
 dlls/opengl32/wgl.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/dlls/opengl32/wgl.c b/dlls/opengl32/wgl.c
index c6414054ff5..eac22011e08 100644
--- a/dlls/opengl32/wgl.c
+++ b/dlls/opengl32/wgl.c
@@ -1176,7 +1176,7 @@ typedef struct _bezier_vector {
     GLdouble y;
 } bezier_vector;

-static double bezier_deviation_squared(const bezier_vector *p)
+static BOOL bezier_fits_deviation(const bezier_vector *p, FLOAT max_deviation)
 {
     bezier_vector deviation;
     bezier_vector vertex;
@@ -1184,6 +1184,8 @@ static double bezier_deviation_squared(const bezier_vector *p)
     double base_length;
     double dot;

+    max_deviation *= max_deviation;
+
     vertex.x = (p[0].x + p[1].x*2 + p[2].x)/4 - p[0].x;
     vertex.y = (p[0].y + p[1].y*2 + p[2].y)/4 - p[0].y;

@@ -1191,6 +1193,7 @@ static double bezier_deviation_squared(const bezier_vector *p)
     base.y = p[2].y - p[0].y;

base_length = sqrt(base.x*base.x + base.y*base.y);
+    if (base_length <= max_deviation) return TRUE;
     base.x /= base_length;
     base.y /= base_length;

@@ -1202,7 +1205,7 @@ static double bezier_deviation_squared(const bezier_vector *p)
     deviation.x = vertex.x-base.x;
     deviation.y = vertex.y-base.y;

-    return deviation.x*deviation.x + deviation.y*deviation.y;
+    return deviation.x*deviation.x + deviation.y*deviation.y <= max_deviation;
 }

static int bezier_approximate(const bezier_vector *p, bezier_vector *points, FLOAT deviation)
@@ -1212,7 +1215,7 @@ static int bezier_approximate(const bezier_vector *p, bezier_vector *points, FLO
     bezier_vector vertex;
     int total_vertices;

-    if(bezier_deviation_squared(p) <= deviation*deviation)
+    if (bezier_fits_deviation(p, deviation))
     {
         if(points)
             *points = p[2];