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@nicholasjackson
Created May 9, 2011 21:26
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How to Draw with Touches
#pragma mark<Touch Methods>
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if ([touch tapCount] == 2) {
drawImage.image = nil;
return;
}
lastPoint = [touch locationInView:self.view];
lastPoint.y -= 20;
path = CGPathCreateMutable(); //create our fill path
CGPathMoveToPoint(path, NULL, lastPoint.x, lastPoint.y);
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
currentPoint.y -= 20;
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
CGContextSetLineWidth(UIGraphicsGetCurrentContext(), 5.0);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 0.8);
CGContextBeginPath(UIGraphicsGetCurrentContext());
CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
CGContextStrokePath(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
// add to our fill path
CGPathAddLineToPoint(path, NULL, currentPoint.x, currentPoint.y);
lastPoint = currentPoint;
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if ([touch tapCount] == 2) {
drawImage.image = nil;
return;
}
UIGraphicsBeginImageContext(self.view.frame.size);
[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
CGPathCloseSubpath(path);
CGContextSetRGBFillColor(UIGraphicsGetCurrentContext(), 1.0, 0.0, 0.0, 0.7);
CGContextAddPath(UIGraphicsGetCurrentContext(), path);
CGContextDrawPath(UIGraphicsGetCurrentContext(), kCGPathEOFill);
CGContextFillPath(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
CGPathRelease(path);
}
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