Improve full screen Core Graphics image blending performance?

Question

I'm working on a game in which the game elements look like they are made of construction paper. To achieve the texture effect I blend a fullscreen image at the end of each draw cycle:

- (void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();

    // ... draw things ... //

    CGContextSetBlendMode(context, kCGBlendModeHardLight);
    CGContextSetAlpha(context, 0.4);
    CGContextDrawImage(context, [self frame], [paperTexture CGImage]);
}

Unfortunately this makes the frame rate drop from 60 to what feels like ~10. Is there a better way to do this without moving into OpenGL?

Answer 1

查看我听说过的GPUImage确实具有出色的性能。