- vRectSize = visualSize / 2.0 - vCornerRadius;
- vCornerRadius = max( vCornerRadius, 1.0 );
+ vRectSize = visualSize / 2.0;
+ // optimize fragment shader
+ mediump float maxRadius = max(max(vCornerRadius.x, vCornerRadius.y), max(vCornerRadius.z, vCornerRadius.w));
+ vOptRectSize = vRectSize - 0.2929 * maxRadius - 1.0;