Include zero in orientation checks

manimlib/shaders/quadratic_bezier_fill/frag.glsl

@@ -43,7 +43,7 @@ float sdf(){
     // Sign takes care of whether we should be filling the inside or outside of curve.
     float sgn = orientation * sign(v2);
     float Fp = (p.x * p.x - p.y);
-    if(sgn * Fp < 0){
+    if(sgn * Fp <= 0){
         return 0.0;
     }else{
         return min_dist_to_curve(uv_coords, uv_b2, bezier_degree);

manimlib/shaders/quadratic_bezier_fill/geom.glsl

@@ -78,7 +78,7 @@ void emit_pentagon(vec3[3] points, vec3 normal){
     vec3 p0_perp = cross(t01, normal);
     vec3 p2_perp = cross(t12, normal);
 
-    bool fill_inside = orientation > 0;
+    bool fill_inside = orientation >= 0.0;
     float aaw = anti_alias_width;
     vec3 corners[5];
     if(fill_inside){