objective-c - 使用图案颜色的描边路径来模拟画笔纹理

Question

我正在制作一个手指绘画应用程序，但我很难让我的画笔具有漂亮的画笔般的手感和质感。

我有这个代码:

    UIColor * brushTexture = [UIColor colorWithPatternImage:[UIImage imageNamed:@"Brush_Black.png"]]; 
    CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), brushTexture.CGColor); 

但我的输出是这样的:

我画笔的纹理是平铺的。如何使其适合笔画大小并停止图像的平铺？

Answer 1

在这里我找到了解决方案!

    UIImage *texture = [UIImage imageNamed:"brush.png"]    
    CGPoint vector = CGPointMake(currentPoint.x - endPoint.x, currentTPoint.y - endPoint.y);
    CGFloat distance = hypotf(vector.x, vector.y);
    vector.x /= distance;
    vector.y /= distance;
    for (CGFloat i = 0; i < distance; i += 1.0f) {
        CGPoint p = CGPointMake(endPoint.x + i * vector.x, endPoint.y + i * vector.y);
        [texture drawAtPoint:p blendMode:blendMode alpha:0.5f];
    }