Check for d and use kmScalars

Cloudef · Mar 2, 2014 · b03c1f5 · b03c1f5
1 parent d6af627
commit b03c1f5
Showing 1 changed file with 13 additions and 6 deletions.
diff --git a/kazmath/ray3.c b/kazmath/ray3.c
@@ -21,12 +21,19 @@ kmRay3* kmRay3FromPointAndDirection(kmRay3* ray, const kmVec3* point, const kmVe
 
 kmBool kmRay3IntersectPlane(kmVec3* pOut, const kmRay3* ray, const kmPlane* plane) {
     //t = - (A*org.x + B*org.y + C*org.z + D) / (A*dir.x + B*dir.y + C*dir.z )
-    double t = -(plane->a * ray->start.x +
-                 plane->b * ray->start.y +
-                 plane->c * ray->start.z + plane->d) / (
-                 plane->a * ray->dir.x +
-                 plane->b * ray->dir.y +
-                 plane->c * ray->dir.z);
+
+    kmScalar d = (plane->a * ray->dir.x +
+                  plane->b * ray->dir.y +
+                  plane->c * ray->dir.z);
+
+    if(d == 0)
+    {
+      return KM_FALSE;
+    }
+
+    kmScalar t = -(plane->a * ray->start.x +
+                   plane->b * ray->start.y +
+                   plane->c * ray->start.z + plane->d) / d;
 
     if(t < 0)
     {