绘制图片代码

-(UIImage*)composeStereogramLeft:(UIImage *)leftImage right:(UIImage *)rightImage
{
    float w = leftImage.size.width;
    float h = leftImage.size.height;
    UIGraphicsBeginImageContext(CGSizeMake(w * 2.0, h + 32.0));
    [leftImage drawAtPoint:CGPointMake(0.0, 32.0)];
    [rightImage drawAtPoint:CGPointMake(w, 32.0)];
    float leftCircleX = (w / 2.0) - 8.0;
    float rightCircleX = leftCircleX + w;
    float circleY = 8.0;
    [[UIColor blackColor] setFill];
    UIRectFill(CGRectMake(0.0, 0.0, w * 2.0, 32.0));

    [[UIColor whiteColor] setFill];
    CGRect leftRect = CGRectMake(leftCircleX, circleY, 16.0, 16.0);
    CGRect rightRect = CGRectMake(rightCircleX, circleY, 16.0, 16.0);
    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:leftRect];
    [path appendPath:[UIBezierPath bezierPathWithOvalInRect:rightRect]];
    [path fill];
    UIImage *savedImg = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return savedImg;
}