Question

I’m trying to create code for drawing what the user draws with his finger. I used the following code for this:

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    if ([touch tapCount] == 2) {
    [myImage setHidden:YES];
}
CGPoint currentTouch = [touch locationInView:self.view];
if (currentTouch.x >10 && currentTouch.x < 300 && currentTouch.y >245 && currentTouch.y < 440) {
CGRect myImageRect = CGRectMake(currentTouch.x, currentTouch.y, 5.0f, 5.0f); 
myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:@"dot.png"]];
[self.view addSubview:myImage];
}

But the problem is that the touchesMoved doesn’t get called every single pixel, so there is a big gap between every point and the next. So I need to somehow fill those gaps. Can someone help me do that with some code?

Thanks in advance.

Answer 1

No need for an answer anymore, I answered my own question :p

For anyone who wants the answer, though, here’s the code:

UITouch *touch = [touches anyObject];
currentTouch = [touch locationInView:self.view];

if (currentTouch.x >10 && currentTouch.x < 300 && currentTouch.y >245 && currentTouch.y < 440) {
CGRect myImageRect = CGRectMake(currentTouch.x, currentTouch.y, 5.0f, 5.0f); 
myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:[UIImage imageNamed:@"dot.png"]];
    myImage.tag = tag;
[self.view addSubview:myImage];
[myImage release];
    if (!CGPointEqualToPoint(lastTouch, CGPointMake(0, 0))) { 
        CGPoint nextPoint;
            for (double h = 0.0; h<25.0; h++) {
            double blend = h/25;
            nextPoint.x = currentTouch.x + (blend * (lastTouch.x - currentTouch.x));
            nextPoint.y = currentTouch.y + (blend * (lastTouch.y - currentTouch.y));
            myImageRect = CGRectMake(nextPoint.x, nextPoint.y, 5.0f, 5.0f);
            myImage = [[UIImageView alloc] initWithFrame:myImageRect];
            [myImage setImage:[UIImage imageNamed:@"dot.png"]];
                myImage.tag = tag;
            [self.view addSubview:myImage];
            [myImage release];
    }

    }
lastTouch = currentTouch;
}
}

I added a point called last touch to record the last point, and then a (for) loop to fill the spaces between the current point and the last one.