I am working on a drawing App which have two UIImageViews. What I would like to do is erase the top UIImageView so that I can see the bottom UIImageView and vice versa. I have implemented all the functionality and its working perfect but the issue happens when I Pan/Zoom the UIImageView using UIGestureRecognizer and the I started to erase the Image so the LineWidth is also Zoomed e.g: initialy my eraser width set to 25.0f if I zoom my UIImageView 200% my eraser also zoomed out to 200% i.e from 25.0f to 50.0f which makes everything go crazy. So My question is How can I remain my eraser to its original width rather than zoomed out/in with Image Zooming?
Here is my Code:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if (selectedButton == self.Image1Btn)
currentPoint = [touch locationInView:self.ImageCaptureView];
if (selectedButton == self.Image2Btn)
currentPoint = [touch locationInView:self.ImageCaptureView];
if (bottomBarSelectedButton == 1)
{
if (selectedButton == self.Image1Btn)
{
UIGraphicsBeginImageContext(self.Image1.frame.size);
[self.Image1.image drawAtPoint:CGPointZero];
}
if (selectedButton == self.Image2Btn)
{
UIGraphicsBeginImageContext(self.Image2.image.size);
[self.Image2.image drawAtPoint:CGPointZero];
}
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, self.lineWidth);
CGContextSetStrokeColorWithColor(context, self.lineColor.CGColor);
CGContextSetBlendMode(context, kCGBlendModeClear);
CGContextBeginPath(context);
CGContextMoveToPoint(context, previousPoint1.x, previousPoint1.y-36);
CGContextAddLineToPoint(context, currentPoint.x, currentPoint.y-36);
CGContextStrokePath(context);
if (selectedButton == self.Image1Btn)
{
self.Image1.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
previousPoint1 = [touch locationInView:self.ImageCaptureView];
}
if (selectedButton == self.Image2Btn)
{
self.Image2.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
previousPoint1 = [touch locationInView:self.ImageCaptureView];
}
}
}
- (IBAction)handlePinch:(UIPinchGestureRecognizer *)recognizer {
CGAffineTransform t = CGAffineTransformScale(recognizer.view.transform, recognizer.scale, recognizer.scale);
recognizer.view.transform = t;
recognizer.scale = 1;
}
Related
I have planned to do simple drawing up, using that use can draw straight lines and free hand drawing, based on the selection it change. But the problem is straight line gets repeated from the starting point more than 10 or 15 lines when i try to draw 1 line, free hand drawing working fine.I have posted my code here. Please give your suggestions to fix this issue.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
mouseSwiped = NO;
UITouch *touch = [touches anyObject];
previousPoint1 = [touch previousLocationInView:self.view];
previousPoint2 = [touch previousLocationInView:self.view];
currentPoint = [touch locationInView:self.view];
lastPoint = [touch locationInView:self.view];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
// Work download Flag
_isWorkModified = YES;
mouseSwiped = YES;
UITouch *touch = [touches anyObject];
previousPoint2 = previousPoint1;
previousPoint1 = [touch previousLocationInView:self.view];
currentPoint = [touch locationInView:self.view];
UIGraphicsBeginImageContext(self.view.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[drawImage.image drawInRect:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
if(_selectedShape == 3)
{
// calculate mid point
CGPoint mid1 = [self midPoint:previousPoint1 :previousPoint2];
CGPoint mid2 = [self midPoint:currentPoint :previousPoint1];
CGContextMoveToPoint(context, mid1.x, mid1.y);
CGContextAddQuadCurveToPoint(context, previousPoint1.x, previousPoint1.y, mid2.x, mid2.y);
CGContextSetLineCap(context, kCGLineCapRound);
if(self.isEraseButtonSelected)
{
CGContextSetLineWidth(context, 40.0);
CGContextSetRGBStrokeColor(context, 0.823,0.886,0.898,1.0);
}
else
{
CGContextSetLineWidth(context, 3.0);
CGContextSetRGBStrokeColor(context, 0.0, 0.0, 0.0, 1.0);
}
CGContextStrokePath(context);
}
else if(_selectedShape == 0)
{
CGContextSetLineWidth(context, 3.0);
CGContextSetRGBStrokeColor(context, 0.0, 0.0, 0.0, 1.0);
CGContextBeginPath(context);
CGContextMoveToPoint(context, lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(context, currentPoint.x, currentPoint.y);
CGContextClosePath(context);
CGContextStrokePath(context);
}
drawImage.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"touch ended");
if(!mouseSwiped)
{
NSInteger index = [[[AnswerDataHandler getAnswerDataHandler]workAreaArray] indexOfObject:self];
[[ImageStoreHelper getImageStoreHelper] saveImageForQuestionNumber:index image:drawImage.image];
}
}
}
How can I clear a drawing in a subview? What should I put in my (void)clearLine below?
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Setup subview to draw a line
CGRect subviewRect = CGRectMake(0, 0, 250, 300);
Draw* _draw = [[Draw alloc] initWithFrame:subviewRect];
_draw.exclusiveTouch = NO;
_draw.backgroundColor = [UIColor clearColor];
[self addSubview:_draw];
}
return self;
}
- (void) clearLine
{
// how can I clear the drawing in Draw
}
And below is the Draw.m file, that will draw a straight line by getting the first touch as the starting point and the second touch as the ending point.
#implementation Draw
- (void)drawRect:(CGRect)rect {
CGPoint fromPoint;
CGPoint toPoint;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 2.0);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
CGFloat components[] = {0.0, 0.0, 1.0, 1.0};
CGColorRef color = CGColorCreate(colorspace, components);
CGContextSetStrokeColorWithColor(context, color);
CGContextSetLineCap(context, kCGLineCapRound);
CGContextMoveToPoint(context, fromPoint.x, fromPoint.y);
CGContextAddLineToPoint(context, toPoint.x, toPoint.y);
CGContextStrokePath(context);
CGColorSpaceRelease(colorspace);
CGColorRelease(color);
}
// Touch event
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch* touchPoint = [touches anyObject];
fromPoint = [touchPoint locationInView:self];
toPoint = [touchPoint locationInView:self];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch* touch = [touches anyObject];
toPoint = [touch locationInView:self];
[self setNeedsDisplay];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch* touch = [touches anyObject];
toPoint = [touch locationInView:self];
[self setNeedsDisplay];
}
In clear line you should remove Draw view and set it nil
Draw* _draw;
- (void) clearLine
{
[_draw removeFromSuperview];
_draw=nil;
}
and to again enable drawing use
-(void) initDrawView
{
CGRect subviewRect = CGRectMake(0, 0, 250, 300);
if(_draw!=nil)
{
[_draw removeFromSuperview];
_draw=nil;
}
_draw = [[Draw alloc] initWithFrame:subviewRect];
_draw.exclusiveTouch = NO;
_draw.backgroundColor = [UIColor clearColor];
[self addSubview:_draw];
}
Draw the background color on your view,
Like if you have white background then [UIColor whiteColor];
if you have black background then [UIColor blackColor];
Make a Bool variable in Draw class
And when you want to clear all like this
- (void) clearLine
{
// Here you can clearn lines
[_draw CleanAllLines]
}
And In Draw class make the method
-(void)CleanAllLines{
isNeedToClear = YES;
[self setNeedsLayout];
}
- (void)drawRect:(CGRect)rect {
if(isNeedToClear){
isNeedToClear = NO;
return;
}
CGPoint fromPoint;
CGPoint toPoint;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineWidth(context, 2.0);
CGColorSpaceRef colorspace = CGColorSpaceCreateDeviceRGB();
CGFloat components[] = {0.0, 0.0, 1.0, 1.0};
CGColorRef color = CGColorCreate(colorspace, components);
CGContextSetStrokeColorWithColor(context, color);
CGContextSetLineCap(context, kCGLineCapRound);
CGContextMoveToPoint(context, fromPoint.x, fromPoint.y);
CGContextAddLineToPoint(context, toPoint.x, toPoint.y);
CGContextStrokePath(context);
CGColorSpaceRelease(colorspace);
CGColorRelease(color);
}
I am trying an image erasing code in my PanGesture. I am using the code below:
UIImage * image = [UIImage imageNamed:#"326d4fb72362a2e44659141cadfc4977.jpg"];
holderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 235)];
imgForeground = [[UIImageView alloc] initWithFrame:[holderView frame]];
[imgForeground setImage:image];
[holderView addSubview:imgForeground];
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(move:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[holderView addGestureRecognizer:panRecognizer];
[self.view addSubview:holderView];
Then I am handling this here:
-(void)move:(id)sender {
CGPoint currentPoint;
if([(UIPanGestureRecognizer*)sender state] == UIGestureRecognizerStateBegan){
lastPoint = [sender locationInView:imgForeground];
lastPoint.y -=20;
}
else{
currentPoint = [sender locationInView:imgForeground];;
currentPoint.y -=20;
}
UIGraphicsBeginImageContext(imgForeground.frame.size);
[imgForeground.image drawInRect:CGRectMake(imgForeground.frame.origin.x, imgForeground.frame.origin.y, imgForeground.frame.size.width, imgForeground.frame.size.height)];
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineCap(context,kCGLineCapRound); //kCGImageAlphaPremultipliedLast);
CGContextSetLineWidth(context, 10);
CGContextSetRGBStrokeColor(context, 0, 0, 0, 1.0);
CGContextSetBlendMode(UIGraphicsGetCurrentContext(), kCGBlendModeClear);
CGContextBeginPath(context);
CGContextMoveToPoint(context, lastPoint.x, lastPoint.y);
CGContextAddLineToPoint(context, lastPoint.x, lastPoint.y);
CGContextStrokePath(context);
imgForeground.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
How to unerase the same image?
I have the same issue in my app after the long search i found the simple solution for this issue.
i just used touches methods of the UIViewController
The below is the my approach,
Code:-
#pragma mark touches stuff...
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
lastTouch = [touch locationInView:self.editedImageView];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
currentTouch = [touch locationInView:self.editedImageView];
CGFloat brushSize;
if (isEraser)
{
brushSize=eraser;
}
else
{
brushSize=mark;
}
CGColorRef strokeColor = [UIColor whiteColor].CGColor;
UIGraphicsBeginImageContext(self.editedImageView.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
[self.editedImageView.image drawInRect:CGRectMake(0, 0, self.editedImageView.frame.size.width, self.editedImageView.frame.size.height)];
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, brushSize);
if (isEraser) {
CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);
}
else
{
CGContextSetStrokeColorWithColor(context, strokeColor);
CGContextSetBlendMode(context, kCGBlendModeClear);
}
CGContextBeginPath(context);
CGContextMoveToPoint(context, lastTouch.x, lastTouch.y);
CGContextAddLineToPoint(context, currentTouch.x, currentTouch.y);
CGContextStrokePath(context);
self.editedImageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
lastTouch = [touch locationInView:self.editedImageView];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
}
The Inputs:
self.editedImageView.image = "Your Custom image";
self.im = "Your Custom image";
The simple solution of your problem will be :-
CGContextSetStrokeColorWithColor(UIGraphicsGetCurrentContext(), [UIColor colorWithPatternImage:self.im].CGColor);
Note:
This not unerase it again drawing the image over
Update:-
self.im = "Your Custom image";
this will be like this....
-(void)eraserConfigure
{
UIImageView *resizeImage=[[[UIImageView alloc]initWithImage:editedImage]autorelease];
/*UIImage */self.im=[UIImage imageFromView:resizeImage scaledToSize:CGSizeMake(self.editedImageView.frame.size.width, self.editedImageView.frame.size.height)];
}
Save a temporary image after every drawing operation.
You should save on temporary files and limit the number of undo operations.
Using core graphics , I am trying to draw a line, in that when I try to add shadow is creates lin and bubbles inside the line, see the image, I am not able to solve the issue. please find my code below
-(void)drawRect:(CGRect)rect
{
[curImage drawAtPoint:CGPointMake(0, 0)];
CGPoint mid1 = midPoint(previousPoint1, previousPoint2);
CGPoint mid2 = midPoint(currentPoint, previousPoint1);
CGContextRef context = UIGraphicsGetCurrentContext();
[self.layer renderInContext:context];
CGContextMoveToPoint(context, mid1.x, mid1.y);
CGContextAddQuadCurveToPoint(context, previousPoint1.x, previousPoint1.y, mid2.x, mid2.y);
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, self.lineWidth);
CGContextSetStrokeColorWithColor(context, self.lineColor.CGColor);
CGContextSetShadow(context, CGSizeMake(-16.00, -5.0f), 5.0f);
CGContextStrokePath(context);
[super drawRect:rect];
[curImage release];
}
Below is the touchesMoved method.
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
previousPoint2 = previousPoint1;
previousPoint1 = [touch previousLocationInView:self];
currentPoint = [touch locationInView:self];
// calculate mid point
CGPoint mid1 = midPoint(previousPoint1, previousPoint2);
CGPoint mid2 = midPoint(currentPoint, previousPoint1);
CGMutablePathRef path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, mid1.x, mid1.y);
CGPathAddQuadCurveToPoint(path, NULL, previousPoint1.x, previousPoint1.y, mid2.x, mid2.y);
CGRect bounds = CGPathGetBoundingBox(path);
CGPathRelease(path);
CGRect drawBox = bounds;
//Pad our values so the bounding box respects our line width
drawBox.origin.x -= self.lineWidth * 2;
drawBox.origin.y -= self.lineWidth * 2;
drawBox.size.width += self.lineWidth * 4;
drawBox.size.height += self.lineWidth * 4;
UIGraphicsBeginImageContext(drawBox.size);
[self.layer renderInContext:UIGraphicsGetCurrentContext()];
curImage = UIGraphicsGetImageFromCurrentImageContext();
[curImage retain];
UIGraphicsEndImageContext();
[self setNeedsDisplayInRect:drawBox];
}
CGPoint midPoint(CGPoint p1, CGPoint p2)
{
return CGPointMake((p1.x + p2.x) * 0.5, (p1.y + p2.y) * 0.5);
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
previousPoint1 = [touch previousLocationInView:self];
previousPoint2 = [touch previousLocationInView:self];
currentPoint = [touch locationInView:self];
[self touchesMoved:touches withEvent:event];
}
Here the issue arrives when I try to add the line
CGContextSetShadow(context, CGSizeMake(-16.00, -5.0f), 5.0f);
Please help me out from the issue, thanks in advance. please see editing question with methods .
It would appear you are drawing a series of segments as quad curves. The bubbles would be where the previous segment and the current segment overlap. Since your segment line is a solid red, you don't notice the overlap, but it shows up in the shadows as darker regions.
Try setting your stroke color to have and alpha of 0.5 (or some such translucency). I think (know) you will see the overlapping segments will also show a similar effect as the the shadow.
To solve it, you will want to draw the segment as a continuous path for each line. I'm guessing you are using touchesBegan:withEvent: / touchesMoved:withEvent / touchesEnded:withEvent: to obtain the points of the lines?
In that case, when touchesBegan:withEvent: is called, start your new path. During touchesMoved:withEvent render the new path over the current image. Commit the path to a UIImage in touchesEnded:withEvent:. At this point you may discard the path until touchesBegan:withEvent: is called again with the next stroke.
Update
In your code snippets you end up rendering the whole view three times every run loop. That's a lot of drawing overhead. I quickly put together some code that demonstrates what I am talking about above. It is not tested code, but it should be mostly right:
Update 2
I had a bit of time to write and test some code that will do what you are seeking based on my latest two comments. This code is from the view controller instead of the view itself, but with a little modification, you can move in the view if you like. As such, I added an UIImageView as a subview to the generic UIView to hold and display the image (and maintained a reference to in the view controller), and made the view controller the first responder in order to receive the touch events. Lots of hard coded values that you can clean up when integrating into your own project:
static
UIImage *CreateImage( CGRect rect, NSArray *paths )
{
UIGraphicsBeginImageContextWithOptions(rect.size, NO, 1.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGFloat colorComponents[4] = {0.0,0.0,0.0,0.0};
CGContextSetFillColor(context, colorComponents);
CGContextFillRect(context, rect);
for ( id obj in paths ) {
CGPathRef path = (CGPathRef)obj;
CGContextAddPath(context, path);
}
CGContextSetStrokeColorWithColor(context, [[UIColor redColor] CGColor]);
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, 5.0);
CGContextSetShadow(context, (CGSize){-8.0,40}, 5.0);
CGContextBeginTransparencyLayer(context, NULL);
CGContextDrawPath(context, kCGPathStroke);
CGContextEndTransparencyLayer(context);
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
static
CGPoint MidPoint( CGPoint pt1, CGPoint pt2 )
{
return (CGPoint){(pt1.x+pt2.x)/2.0,(pt1.y+pt2.y)/2.0};
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
CGPoint location = [[touches anyObject] locationInView:self.view];
myPath = CGPathCreateMutable();
CGPathMoveToPoint(myPath, NULL, location.x, location.y);
[self.paths addObject:(id)myPath];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesMoved:touches withEvent:event];
UITouch *touch = [touches anyObject];
CGPoint previousLocation = [touch previousLocationInView:self.view];
CGPoint location = [touch locationInView:self.view];
CGPoint midPoint = MidPoint(previousLocation, location);
CGPathAddQuadCurveToPoint(myPath, NULL, midPoint.x, midPoint.y, location.x, location.y);
self.imageView.image = CreateImage(self.view.bounds, self.paths);
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesEnded:touches withEvent:event];
UITouch *touch = [touches anyObject];
CGPoint previousLocation = [touch previousLocationInView:self.view];
CGPoint location = [touch locationInView:self.view];
CGPoint midPoint = MidPoint(previousLocation, location);
CGPathAddQuadCurveToPoint(myPath, NULL, midPoint.x, midPoint.y, location.x, location.y);
self.imageView.image = CreateImage(self.view.bounds, self.paths);
CGPathRelease(myPath);
myPath = nil;
}
the problem is you have multiple lines which lie above each other. So the shadows of both overlap and you get a darker color.
For something that easy like your line drawings you can simply copy the whole drawing code and redraw with a different color and a view pixel offset (instead of the shadow). E.g. you save the curves into an array and draw them separately later.
EDIT:
ok #gschandler describes the problem great too.
But you may also like to have a look at the Transparency Layer documentation. Group the elements together and apply a shadow for the group.
Another way round to this is to create an array of points on touch move events, and then draw them..
Create an array of points :
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[pointArray release]; pointArray = nil;
pointArray=[[NSMutableArray alloc] init];
UITouch *touch = [touches anyObject];
[bufferArray removeAllObjects];
previousPoint1 = [touch previousLocationInView:self];
previousPoint2 = [touch previousLocationInView:self];
currentPoint = [touch locationInView:self];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
previousPoint2 = previousPoint1;
previousPoint1 = [touch previousLocationInView:self];
currentPoint = [touch locationInView:self];
[pointArray addObject: [NSValue valueWithCGPoint:previousPoint2]];
[pointArray addObject:[NSValue valueWithCGPoint:previousPoint1]];
[pointArray addObject:[NSValue valueWithCGPoint:currentPoint]];
[self setNeedsDisplay];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
}
-(void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, self.lineWidth);
CGContextSetStrokeColorWithColor(context, self.lineColor.CGColor);
CGContextSetShadow(context, CGSizeMake(-16.00, -5.0f), 5.0f);
for(int i = 1 ; i < [pointArray count]-1;i++)
{
CGPoint mid1 = midPoint([pointArray objectAtIndex:i+1], [pointArray objectAtIndex:i]);
CGPoint mid2 = midPoint([pointArray objectAtIndex:i+2], [pointArray objectAtIndex:i+1]);
CGContextMoveToPoint(context, mid1.x, mid1.y);
CGContextAddQuadCurveToPoint(context, previousPoint1.x, previousPoint1.y, mid2.x, mid2.y);
i+=2;
}
CGContextStrokePath(context);
}
You can manage multiple lines with multiple dimensional array :)
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.
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();
}
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