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ユーザーがタッチでイメージビュー内の色を塗りつぶしたりストロークしたりできるアプリを作成しています。しかし、ユーザーがイメージビューの境界内で色を塗りつぶしているときに、誤ってイメージビューの外側に触れても、そのイメージビューから色をこぼしてはいけません。私は今までこれを実装しました。助言がありますか？

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {

    mouseSwiped = NO;
    UITouch *touch = [touches anyObject];
    lastPoint = [touch locationInView:self.view];
}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

//    mouseSwiped = YES;
//    UITouch *touch = [touches anyObject];
//    CGPoint currentPoint = [touch locationInView:self.view];
//    
//    UIGraphicsBeginImageContext(self.view.frame.size);
//    [self.tempDrawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
//    CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
//    CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
//    CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
//    CGContextSetLineWidth(UIGraphicsGetCurrentContext(), brush );
//    CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), red, green, blue, 1.0);
//    CGContextSetBlendMode(UIGraphicsGetCurrentContext(),kCGBlendModeNormal);
//    
//    CGContextStrokePath(UIGraphicsGetCurrentContext());
//    self.tempDrawImage.image = UIGraphicsGetImageFromCurrentImageContext();
//    [self.tempDrawImage setAlpha:opacity];
//    UIGraphicsEndImageContext();
//    
//    lastPoint = currentPoint;

    if(CGRectContainsPoint([testImage bounds], lastPoint))
    {
        mouseSwiped = YES;
        UITouch *touch = [touches anyObject];
        CGPoint currentPoint = [touch locationInView:self.view];

        UIGraphicsBeginImageContext(self.view.frame.size);
        [self.testImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
        CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
        CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), currentPoint.x, currentPoint.y);
        CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
        CGContextSetLineWidth(UIGraphicsGetCurrentContext(), brush );
        CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), red, green, blue, 1.0);
        CGContextSetBlendMode(UIGraphicsGetCurrentContext(),kCGBlendModeNormal);

        CGContextStrokePath(UIGraphicsGetCurrentContext());
        self.testImage.image = UIGraphicsGetImageFromCurrentImageContext();
        [self.testImage setAlpha:opacity];
        UIGraphicsEndImageContext();

        lastPoint = currentPoint;
   }
    else
    {
       // CGRectContainsPoint(testImage.frame, lastPoint) = ;
    }
}

- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {

    if(!mouseSwiped) {
        UIGraphicsBeginImageContext(self.view.frame.size);
        [self.testImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
        CGContextSetLineCap(UIGraphicsGetCurrentContext(), kCGLineCapRound);
        CGContextSetLineWidth(UIGraphicsGetCurrentContext(), brush);
        CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), red, green, blue, opacity);
        CGContextMoveToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
        CGContextAddLineToPoint(UIGraphicsGetCurrentContext(), lastPoint.x, lastPoint.y);
        CGContextStrokePath(UIGraphicsGetCurrentContext());
        CGContextFlush(UIGraphicsGetCurrentContext());
        self.tempDrawImage.image = UIGraphicsGetImageFromCurrentImageContext();
        UIGraphicsEndImageContext();
    }

    UIGraphicsBeginImageContext(self.mainImage.frame.size);
    [self.mainImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height) blendMode:kCGBlendModeNormal alpha:1.0];
    [self.tempDrawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height) blendMode:kCGBlendModeNormal alpha:opacity];
    self.mainImage.image = UIGraphicsGetImageFromCurrentImageContext();
    self.tempDrawImage.image = nil;
    UIGraphicsEndImageContext();
}
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1 に答える 1

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ビューの境界を越えてパスを作成し、これをビューの として設定するとどうなりますか?clipping path一度設定すると、その外側には何も描画されるべきではないと思います。

于 2012-10-01T08:14:21.780 に答える