how to draw airbrush on UIImageView? - iphone

Question

I am a beginner working on paint application on iphone.
adding new tool for my iphone App called airbrush...
which will spray on UIImageView. can any one help me out how to work with it.

Answer 1

Logic for air brush.........
- (UIBezierPath *)pathFromPoint:(CGPoint)start toPoint:(CGPoint)end {
CGFloat lineWidth=10;
redrawRect = CGRectMake(end.x-lineWidth,end.y-lineWidth,lineWidth*2,lineWidth*2);
UIBezierPath *bezierPath = [UIBezierPath bezierPath];
UIBezierPath *circle = [UIBezierPath bezierPathWithOvalInRect:redrawRect];
NSInteger i, x, y;
NSInteger modNumber =4*(int)lineWidth;
for (i = 0; i < (lineWidth*lineWidth)/2; i++) {
do {
x = (random() % modNumber)+end.x - 2*lineWidth;
y = (random() % modNumber)+end.y - 2*lineWidth;
} while (![circle containsPoint:CGPointMake(x,y)]);
[bezierPath appendPath:[UIBezierPath bezierPathWithRect:CGRectMake(x,y,0.5,0.5)]];
}
return bezierPath;
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
currentPoint = [touch locationInView:self.view];
currentPoint.y -=20;
[self drawCircle];
}
-(void)drawCircle{
UIGraphicsBeginImageContext(self.drawImage.frame.size);
[drawImage.image drawInRect:CGRectMake(0,0, drawImage.frame.size.width, drawImage.frame.size.height)]; //originally self.frame.size.width, self.frame.size.height)];
CGContextSetLineWidth(UIGraphicsGetCurrentContext(),10);
CGContextSetRGBStrokeColor(UIGraphicsGetCurrentContext(), 0.0, 0.0, 0.0, 1.0);
UIBezierPath *path=[self pathFromPoint:currentPoint
toPoint:currentPoint];
[path stroke];
lastPoint = currentPoint;
CGContextStrokePath(UIGraphicsGetCurrentContext());
CGContextFlush(UIGraphicsGetCurrentContext());
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}

Answer 2

I think you might be looking for CGContextBeginPath and its related functions. I am not quite sure how to define a new stroke but I imagine it can be handled with something like [UIColor colorFromImage:myImage]. You should look into Quartz 2D, try looking here.
/Thomas