iPhone:使用Core Graphics重写GLPaint

问题描述

我想重写Apple源代码GLPaint应用程序，但不像示例一样使用OpenGL，而是要使用Core Graphics库.但是我坚持显示GLPaint这样的纹理.

这是我在Core Graphics中的代码:

---但我收到以下结果:

---我想得到这个结果:

我的代码错误吗?有人可以帮助我吗?非常感谢.

解决方案

如果您不想要图案，请不要将带有图案图像的颜色设置为笔触颜色.

代替

UIImage * image = [UIImage imageNamed:@"Particle.png"];
UIColor * color = [UIColor colorWithPatternImage:image];

就做

UIColor *color = [UIColor blackColor];

I would like to rewrite the Apple source code, GLPaint application, but not using OpenGL like the example, I would like to use Core Graphics library. But I stuck in displaying the texture like GLPaint.

This is my code in Core Graphics:

- (void) drawLineFromPoint: (CGPoint) fromPoint toPoint: (CGPoint) toPoint {
    UIGraphicsBeginImageContext(self.frame.size);
    CGContextRef context = UIGraphicsGetCurrentContext();
    [drawImage.image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
    UIImage * image = [UIImage imageNamed:@"Particle.png"];
    UIColor * color = [UIColor colorWithPatternImage:image];
    CGContextSetStrokeColorWithColor(context, color.CGColor);

    CGContextSetLineCap(context, kCGLineCapRound);
    CGContextSetLineWidth(context, 5.0);
    CGContextBeginPath(context);
    CGContextMoveToPoint(context, fromPoint.x, fromPoint.y);
    CGContextAddLineToPoint(context, toPoint.x, toPoint.y);
    CGContextStrokePath(context);
    drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
}

--- But I receive this result:

--- I would like to have this result:

Does my code wrong? Any one can help me on this? Thank you very much.

解决方案

If you don't want the pattern, don't set a colour with a pattern image as your stroke colour.

Instead of

UIImage * image = [UIImage imageNamed:@"Particle.png"];
UIColor * color = [UIColor colorWithPatternImage:image];

Just do

UIColor *color = [UIColor blackColor];

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