-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch=[touches anyObject];
currentPoint=[touch locationInView:self.view];
rootLayer = [CALayer layer];
rootLayer.frame = self.view.bounds;
[self.view.layer addSublayer:rootLayer];
starPath = CGPathCreateMutable();
CGPathMoveToPoint(starPath, NULL, currentPoint.x, currentPoint.y + 15.0);
for(int i = 1; i < 5; ++i)
{
CGFloat x = 15.0 * sinf(i * 4.0 * M_PI / 5.0);
CGFloat y = 15.0 * cosf(i * 4.0 * M_PI / 5.0);
CGPathAddLineToPoint(starPath, NULL, currentPoint.x + x, currentPoint.y + y);
}
CGPathCloseSubpath(starPath);
shapeLayer = [CAShapeLayer layer];
shapeLayer.path = starPath;
UIColor *fillColor = [UIColor colorWithWhite:0.9 alpha:1.0];
shapeLayer.fillColor = fillColor.CGColor;
[rootLayer addSublayer:shapeLayer];
}
- (void)dealloc {
[imageView release];
CGPathRelease(starPath);
[super dealloc];
}
When i am running with performance tool leaks it occupying more memory
when iam moving ....
what to do....
i need to draw this star shape on touches movies on the layer so i can perform animations later ....
You're releasing the path in dealloc, but creating it (potentially) many times inside your touchesMoved:. You can safely release this resource at the end of your touchesMoved:, please consider doing that.
Also, after you've made that change, you can remove the release from dealloc, since you will never have to release it there any longer. Your path doesn't exist outside your method.
Related
I am trying to clear graphics context. It clears perfectly using these 2 ways.
1. clearContextBeforeDrawing
2. CGContextClearRect(context, rect);
CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
CGContextFillRect(context, rect);
CGContextFlush(context);
But when I draw lines again. The previous lines are mixed up with the new lines with dots appearing. Can anyone please help ?
This is how I am clearing lines
-(IBAction)eraseButton:(id)sender
{
self.viewmainHandwriting.isErase = TRUE;
[self.viewmainHandwriting setBackgroundColor:[UIColor clearColor]];
[self.viewmainHandwriting setNeedsDisplay]; //It calls my drawRect Function
}
- (void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
if (!self.isErase)
{
CGContextAddPath(context, path);
CGContextSetLineCap(context, kCGLineCapRound);
CGContextSetLineWidth(context, self.lineWidth);
CGContextSetStrokeColorWithColor(context, self.lineColor.CGColor);
CGContextStrokePath(context);
self.empty = NO;
}
else
{
CGContextClearRect(context, self.bounds);
path
self.isErase = FALSE;
}
}
The is how I am drawing lines
- (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];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView:self];
/* check if the point is farther than min dist from previous */
CGFloat dx = point.x - currentPoint.x;
CGFloat dy = point.y - currentPoint.y;
if ((dx * dx + dy * dy) < kPointMinDistanceSquared) {
return;
}
previousPoint2 = previousPoint1;
previousPoint1 = [touch previousLocationInView:self];
currentPoint = [touch locationInView:self];
CGPoint mid1 = midPoint(previousPoint1, previousPoint2);
CGPoint mid2 = midPoint(currentPoint, previousPoint1);
CGMutablePathRef subpath = CGPathCreateMutable();
CGPathMoveToPoint(subpath, NULL, mid1.x, mid1.y);
CGPathAddQuadCurveToPoint(subpath, NULL, previousPoint1.x, previousPoint1.y, mid2.x, mid2.y);
CGRect bounds = CGPathGetBoundingBox(subpath);
CGPathAddPath(path, NULL, subpath);
CGPathRelease(subpath);
CGRect drawBox = bounds;
drawBox.origin.x -= self.lineWidth * 2.0;
drawBox.origin.y -= self.lineWidth * 2.0;
drawBox.size.width += self.lineWidth * 4.0;
drawBox.size.height += self.lineWidth * 4.0;
[self setNeedsDisplayInRect:drawBox];
}
It looks like you don't clear path in the method that clears the whole view (eraseButton ?).
So the path would still contain the whole old drawing. Only those parts would show on which you call setNeedsDisplayInRect: (from within touchesMoved:). You can reveal the old drawing by drawing over it again.
You should clear path (probably an ivar) by just creating a new one in eraseButton:
CGPathRelease(path);
path = CGPathCreateMutable();
I currently have the following code to try and allow the user to draw a dotted path and make a custom shape. Once they have made this shape, I wanted it to automatically be filled with colour. That isn't happening.
At the moment I am getting this error for the code below:
<Error>: CGContextClosePath: no current point.
Here's the code I'm using:
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint previous = [touch previousLocationInView:self];
CGPoint current = [touch locationInView:self];
#define SQR(x) ((x)*(x))
//Check for a minimal distance to avoid silly data
if ((SQR(current.x - self.previousPoint2.x) + SQR(current.y - self.previousPoint2.y)) > SQR(10))
{
float dashPhase = 5.0;
float dashLengths[] = {10, 10};
CGContextSetLineDash(context,
dashPhase, dashLengths, 2);
CGContextSetFillColorWithColor(context, [[UIColor lightGrayColor] CGColor]);
CGContextFillPath(context);
CGContextSetLineWidth(context, 2);
CGFloat gray[4] = {0.5f, 0.5f, 0.5f, 1.0f};
CGContextSetStrokeColor(context, gray);
self.brushSize = 5;
self.brushColor = [UIColor lightGrayColor];
self.previousPoint2 = self.previousPoint1;
self.previousPoint1 = previous;
self.currentPoint = current;
// calculate mid point
self.mid1 = [self pointBetween:self.previousPoint1 andPoint:self.previousPoint2];
self.mid2 = [self pointBetween:self.currentPoint andPoint:self.previousPoint1];
if(self.paths.count == 0)
{
UIBezierPath* newPath = [UIBezierPath bezierPath];
CGContextBeginPath(context);
[newPath moveToPoint:self.mid1];
[newPath addLineToPoint:self.mid2];
[self.paths addObject:newPath];
CGContextClosePath(context);
}
else
{
UIBezierPath* lastPath = [self.paths lastObject];
CGContextBeginPath(context);
[lastPath addLineToPoint:self.mid2];
[self.paths replaceObjectAtIndex:[self.paths indexOfObject:[self.paths lastObject]] withObject:lastPath];
CGContextClosePath(context);
}
//Save
[self.pathColors addObject:self.brushColor];
self.needsToRedraw = YES;
[self setNeedsDisplayInRect:[self dirtyRect]];
//[self setNeedsDisplay];
}
}
Why is this happening and why is the inside of the path not being filled with colour?
Your code has a few issues:
You should be doing your drawing in your view's drawRect: method, not the touch handler.
You never set the variable context with a value for the current context. Do that with the UIGraphicsGetCurrentContext() method. Again, within your drawRect: method.
You go through the trouble of creating a UIBezierPath object, but you never use it. Do that by calling CGContextAddPath( context, newPath.CGPath ), changing the variable name as needed in the two places you appear to the using a UIBezierPath.
Keep the call to setNeedsDisplayInRect: in your touch handler method. That tells the system to do the work to update your view using the drawing that your (yet to be implemented) drawRect: method draws.
I'm trying to develop a chess game on the iPhone, and have become stuck on an otherwise insignificant detail but can not seem to get past it. Can anybody see the piece that's missing?
Here's the problem. When a user clicks on a square, it should highlight in some faded color. What actually is happening though, is it just draws black, totally regardless of what color I set it to.
Here's an image of what I get. The black circle should be red, or any color.
Here, notice the UIView I'm drawing to is behind the pieces view. Doubt it matters, but I want to be complete.
Finally, the code for the layer:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
self.backgroundColor = [UIColor clearColor];
rowSelected = 0;
colSelected = 0;
}
return self;
}
-(void)drawRect:(CGRect)rect
{
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextClearRect(context, rect);
CGContextSetRGBStrokeColor(context, 255.0, 0.0, 0.0, 1.0);
if (rowSelected && colSelected)
{
int gridsize = (self.frame.size.width / 8);
int sx = (colSelected-1) * gridsize;
int sy = (rowSelected-1) * gridsize;
int ex = gridsize;
int ey = gridsize;
CGContextFillEllipseInRect(context, CGRectMake(sx,sy,ex,ey));
}
}
// Handles the start of a touch
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
int gridsize = (self.frame.size.width / 8);
// Position of touch in view
UITouch *touch = [[event allTouches] anyObject];
CGPoint loc = [touch locationInView:self.superview];
int x = loc.x / gridsize;
int y = loc.y / gridsize;
rowSelected = y + 1;
colSelected = x + 1;
[self setNeedsDisplay];
}
I have tried a number of things, using a value of 1 rather than 255, playing with the alpha, etc, but I can't get anything other than a solid black.
EDIT:
Also, here's the code of this view's superview:
#implementation ChessBoard
-(id)initWithFrame:(CGRect)frame
{
if (self != [super initWithFrame:frame])
return self;
int SQUARE_SIZE = frame.size.width / 8;
currentSet = BW;
UIImage *img = [UIImage imageNamed:#"board.png"];
background = [[UIImageView alloc] initWithImage:img];
[background setFrame:frame];
[self addSubview:background];
overlay = [[ChessBoardOverlay alloc] initWithFrame:frame];
[self addSubview:overlay];
In the function CGContextSetRGBStrokeColor color compontent values (red, green,blue, alpha) need to be between 0 and 1. Since you are assuming that 255 is the maximum for a color you need to divide all of your color component values by 255.0f.
CGContextSetRGBStrokeColor(context, 255.0f/255.0f, 0.0/255.0f, 0.0/255.0f, 1.0);
You say you're drawing to a layer... but a CALayer doesn't have a drawRect: method, it has drawInContext:
I would guess by trying to call drawRect: in your instance of a CALayer that the true context hasn't been built correctly, or it has but you're not tying in to it.
Maybe you should state your color this way:
CGContextSetRGBStrokeColor(context, 255.0/255.0f, 0.0/255.0f, 0.0/255.0f, 1.0f);
This happened to me once using:
[UIColor colorWithRed:12.0/255.0f green:78.0/255.0f blue:149.0/255.0f alpha:1.0f];
until I added the /255.0f so that may work.
Hi everyone I'm french so scuse me for my english.So I want to make a game like flight control. When I draw line from an image like a plane I want that the plane follow that line .How can I do this please?
To draw the line, implement touchesBegan:, touchedMove:, touchedEnded, touchesCancelled: in your view or view controller and build a path (CGPathRef) using the touch points.
To make an an object move along the line, create a CAKeyframeAnimation, set the path and assign it to the object's layer.
Edit: sample code
When you have a CGPathRef path, creating the animation is as easy as:
CAKeyframeAnimation* animation = [CAKeyframeAnimation animation];
animation.path = thePath;
animation.duration = 2;
animation.rotationMode = kCAAnimationRotateAuto; // object auto rotates to follow the path
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
Finally, assign the animation to a layer:
[layer1 addAnimation:animation forKey:#"position"];
Edit 2: sample application:
I built an entire project called PathAnimation for you.
Edit 3: this is the code I used in the PathAnimation project:
//
// CustomView.m
// PathAnimation
//
// Created by Dominique d'Argent on 19.04.11.
// Copyright 2011 Nicky Nubbel. All rights reserved.
//
#import "CustomView.h"
#implementation CustomView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
object = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"arrow"]];
object.frame = CGRectMake(10.0, 30.0, 20.0, 20.0);
[self addSubview:object];
[self createPath];
}
return self;
}
- (void)dealloc
{
[object release];
[super dealloc];
}
#pragma mark - Custom drawing
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
CGContextRef g = UIGraphicsGetCurrentContext();
CGFloat bgColor[4] = {1.0f, 1.0f, 1.0f, 1.0f};
CGContextSetFillColor(g, bgColor);
CGContextFillRect(g, self.frame);
CGFloat color[4] = {1.0f, 0.0f, 0.0f, 1.0f};
CGContextAddPath(g,path);
CGContextSetStrokeColor(g, color);
CGContextDrawPath(g, kCGPathStroke);
CGPoint position = CGPathGetCurrentPoint(path);
CGContextAddArc(g, position.x, position.y, 5.0f, 0.0f, 2 * M_PI, 0);
CGContextSetFillColor(g, color);
CGContextDrawPath(g, kCGPathFill);
}
#pragma mark - Path creation
- (void)createPath {
path = CGPathCreateMutable();
CGPathMoveToPoint(path, NULL, object.center.x, object.center.y);
}
#pragma mark - Touch handling
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint position = [touch locationInView:self];
if (CGRectContainsPoint(object.frame, position)) {
// start animation
[self go];
}
else {
CGPoint lastPosition = CGPathGetCurrentPoint(path);
if (CGPointEqualToPoint(lastPosition, object.center)) {
CGFloat angle = -atan2f(position.x - lastPosition.x, position.y - lastPosition.y);
angle += M_PI_2;
object.layer.transform = CATransform3DMakeRotation(angle, 0.0, 0.0, 1.0);
}
CGPathAddLineToPoint(path, NULL, position.x, position.y);
[self setNeedsDisplay];
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
}
#pragma mark - Animations
- (void) go {
NSLog(#"go");
object.layer.transform = CATransform3DIdentity;
CAKeyframeAnimation* animation = [CAKeyframeAnimation animation];
animation.path = path;
animation.duration = 5.0;
animation.rotationMode = kCAAnimationRotateAuto; // object auto rotates to follow the path
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[object.layer addAnimation:animation forKey:#"position"];
object.center = CGPathGetCurrentPoint(path);
[self createPath];
}
#end
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