objective-c - Objective-C : How do i smoothen the brush like a real brush?

Question

我正在构建一个画笔应用程序，它快完成了，我所做的只是一个基本的画笔/绘图工具。我想给它一种更像画笔的感觉，因为在我当前的输出中它有角度并且看起来不像真正的画笔墨水。

这是我的代码:

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    touchSwiped = YES;
    UITouch *touch = [touches anyObject];   
    currentTouch = [touch locationInView:self.view];
    currentTouch.y -= 20;
    UIGraphicsBeginImageContext(self.view.frame.size);
    [touchDraw.image drawInRect:CGRectMake(0, 0, touchDraw.frame.size.width, touchDraw.frame.size.height)];
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 35.0);
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), redAmt, blueAmt, greenAmt, 1.0);
    CGContextBeginPath(UIGraphicsGetCurrentContext());
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), endingPoint.x, endingPoint.y);
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentTouch.x, currentTouch.y);
    CGContextStrokePath(UIGraphicsGetCurrentContext());
    touchDraw.image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    endingPoint = currentTouch;

    touchMoved++;

    if (touchMoved == 10) {
        touchMoved = 0;
    }
}

Answer 1

我不知道您是否能够在没有获得您描述的角度的情况下为此使用触摸事件。事件的解决不够离散。

OpenGL 似乎更合适。查看 Apple 的 GLPaint sample code举个例子。