Question

我正在做一个需要像Sketchpad一样快速绘制的应用程序，但它需要在某些边界内。这些边界不是几何形状，但我将它们放在二维矩阵上。例如：

00000000000000000000
00000000111001111000
00000001111111001000
00000111110001001000
00001111110000000000
00001111110000001100
00000111111000111000
00000011111111110000
00000000111111100000
00000000001111100000
00000000000000000000

不完全是那个，而是作为一个例子。

使用CoreGraphics进行绘制时，它并不尊重边界并从图中抽出。

这是我正在使用的代码

BOOL containsPoint = [self.currentFilledImageGraphics isTransparentAt:(int)imagePoint.x y:(int)imagePoint.y];

if (containsPoint) {
    _mouseSwiped = YES;

    UIGraphicsBeginImageContext(self.frame.size);
    [self.tempPaintImageView.image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), _lastPoint.x, _lastPoint.y);
    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), UIPoint.x, UIPoint.y);
    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), _brush );
    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), _red, _green, _blue, _opacity);
    CGContextSetBlendMode(UIGraphicsGetCurrentContext(),self.blendMode);

    CGContextStrokePath(UIGraphicsGetCurrentContext());
    self.tempPaintImageView.image = UIGraphicsGetImageFromCurrentImageContext();
    [self.tempPaintImageView setAlpha:_opacity];
    UIGraphicsEndImageContext();


}
_lastPoint = UIPoint;

请帮帮我!!!!!

iOS绘图使用CoreGraphics和边界性能

0 个答案: