I have a spaceship. I want the spaceship to move to the area that the player has touched. So far I have this code:
- (void) ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
// initialize touch
UITouch *touch = [touches anyObject];
// point out location of touch
CGPoint location = [touch locationInView:[touch view]];
// move to location
[player runAction:[CCMoveTo actionWithDuration:0.5 position:location]];
// log action
CCLOG(#"player moved");
}
However, this has a quirk: When I touch in certain places the shuttle will move slow, up instead of down, and other weird movements. Is there any way to correct this code?
After the line :
CGPoint location = [touch locationInView:[touch view]];
Add this line:
location = [[CCDirector sharedDirector] convertToGL: location];
Then try. :)
Related
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event touchesForView:self.view] anyObject];
CGPoint point = [touch locationInView:self.view];
basketView.center = CGPointMake(point.x, point.y);
}
I currently have this code that works to allow the user to move an image around with their finger. However, if I wanted to add multiple moveable images to the screen (say I also wanted to be able to move UIImages basketView2 and basketView3), how would I alter the code to allow for this?
you just need to modify your code as below
UITouch *touch = [[event touchesForView:self.view] anyObject];
CGPoint point = [touch locationInView:self.view];
UIImageView *currentView=(UIImageView *)touch.view;
currentView.center = CGPointMake(point.x, point.y);
I'm working on an image editing app. Right now I have the app built so a user can choose a photo from their library or take a photo with the camera. I also have another view (a picker view) that has other images a user can choose from. By selecting one of the images the app takes the user back to the main photo.
I want the user to be able to touch anywhere on screen and add the image they selected.
What is the best way to approach this?
touchesBegan? touchesMoved? UITapGestureRecognizer?
If anyone knows of any sample code or can give me a general idea of how to approach this that would be great!
EDIT:
Now I am able to see the coordinates and that my UIImage is getting the image I select from my Picker. But the image is not being displayed on the screen when I tap. Can someone help me troubleshoot my code please:
-(void)drawRect:(CGRect)rect
{
CGRect currentRect = CGRectMake(touchPoint.x, touchPoint.y, 30.0, 30.0);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextFillRect(context, currentRect);
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch * touch = [touches anyObject];
touchPoint = [touch locationInView:imageView];
NSLog(#"%f", touchPoint.x);
NSLog(#"%f", touchPoint.y);
if (touchPoint.x > -1 && touchPoint.y > -1)
{
stampedImage = _imagePicker.selectedImage;
//[stampedImage drawAtPoint:touchPoint];
[_stampedImageView setFrame:CGRectMake(touchPoint.x, touchPoint.y, 30.0, 30.0)];
[_stampedImageView setImage:stampedImage];
[imageView addSubview:_stampedImageView];
NSLog(#"Stamped Image = %#", stampedImage);
//[self.view setNeedsDisplay];
}
}
For an example of my NSLogs I am seeing:
162.500000
236.000000
Stamped Image = <UIImage: 0xe68a7d0>
Thanks!
In your ViewController, user the method "-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event" to get the X and Y coordinate of where a touch happened. Here is some sample code that shows how to get the x and y of the touch
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
/* Detect touch anywhere */
UITouch *touch = [touches anyObject];
CGPoint touchPoint = [touch locationInView:self.view];
NSLog(#"%f", touchPoint.x); // The x coordinate of the touch
NSLog(#"%f", touchPoint.y); // The y coordinate of the touch
}
Once you have this x and y data, you can set the image that the user selected or shot with the built in camera to appear at those coordinates.
EDIT:
I think the issue MIGHT lie in how you create you UIImage view. Instead of this:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch * touch = [touches anyObject];
touchPoint = [touch locationInView:imageView];
CGRect myImageRect = CGRectMake(touchPoint.x, touchPoint.y, 20.0f, 20.0f);
UIImageView * myImage = [[UIImageView alloc] initWithFrame:myImageRect];
[myImage setImage:_stampedImageView.image];
myImage.opaque = YES;
[imageView addSubview:myImage];
[myImage release];
}
Try this:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch * touch = [touches anyObject];
touchPoint = [touch locationInView:imageView];
myImage = [[UIImageView alloc] initWithImage:_stampedImageView.image];
[imageView addSubview:myImage];
[myImage release];
}
If this does not work, try checking if "_stampedImageView.image == nil". If this is true, Your UIImage may not have been created properly.
In cocos2d game development, CGRectContainsPoint method often used to detect if touch on a CCSprite.
I use code fllow to get a sprite's (which in a CCNode) rect property
- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event {
CCLOG(#"ccTouchEnded");
CGPoint location = [touch locationInView:[touch view]];
location = [[CCDirector sharedDirector] convertToGL:location];
CCLOG(#"location.x:%f, y:%f", location.x, location.y);
CGRect rect;
rect = CGRectMake(self.firstCard.face.position.x-(self.firstCard.face.contentSize.width/2), self.firstCard.face.position.y-(self.firstCard.face.contentSize.height/2),
self.firstCard.face.contentSize.width, self.firstCard.face.contentSize.height);
if (CGRectContainsPoint(rect, location)) {
CCLOG(#"first card touched");
[firstCard open];
}
rect = CGRectMake(self.secondCard.face.position.x-(self.secondCard.face.contentSize.width/2), self.secondCard.face.position.y-(self.secondCard.face.contentSize.height/2),
self.secondCard.face.contentSize.width, self.secondCard.face.contentSize.height);
if (CGRectContainsPoint(rect, location)) {
CCLOG(#"second card touched");
[secondCard open];
}
}
I want to know if there is a convenient way to get a CCSprite 's rect straightforward?
Please use boundingBox i think it will be a great option to use.
Like this:
- ( void ) ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
locationTouchBegan = [touch locationInView: [touch view]];
//location is The Point Where The User Touched
locationTouchBegan = [[CCDirector sharedDirector] convertToGL:locationTouchBegan];
//Detect the Touch On sprite
if(CGRectContainsPoint([sprite boundingBox], locationTouchBegan))
{
isSpriteTouched=YES;
}
}
Kobold2D has a convenience method containsPoint as a CCNode extension (Objective-C category) which you can replicate in your project:
-(BOOL) containsPoint:(CGPoint)point
{
CGRect bbox = CGRectMake(0, 0, contentSize_.width, contentSize_.height);
CGPoint locationInNodeSpace = [self convertToNodeSpace:point];
return CGRectContainsPoint(bbox, locationInNodeSpace);
}
Your code then be simplified to this and it will work with rotated and/or scaled sprites as well (the boundingBox method fails to test rotated and scaled sprites correctly).
if ([firstCard.face containsPoint:location]) {
CCLOG(#"first card touched");
}
I've created a 200x200 circle in a custom UIView. I am using the following script to move the view object around the screen on the iPad.
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
if([touch view] == newShape)
{
newShape.center = currentPoint;
}
[self.view setNeedsDisplay];
}
Everything works fine, I can move the circle anywhere on the screen. However, if I don't touch dead center on the circle object, it jumps slightly. By reading the code, this is quite obvious because newShape.center is being set to wherever the touch happens and ultimately snapping quickly to that position.
I'm looking for a way to move an object without snapping to the touch position. I'm thinking I would use xy coordinates to achieve this, but I'm not sure how to implement it.
Thanks!
Declare CGPoint prevPos; in .h file.
Here my view is _rectView.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
prevPos = currentPoint;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
if([touch view] == _rectView)
{
float delX = currentPoint.x - prevPos.x;
float delY = currentPoint.y - prevPos.y;
CGPoint np = CGPointMake(_rectView.frame.origin.x+delX, _rectView.frame.origin.y+delY);
//_rect.center = np;
CGRect fr = _rectView.frame;
fr.origin = np;
_rectView.frame = fr;
}
//[self.view setNeedsDisplay];
prevPos = currentPoint;
}
Use the above code. You will not get that 'jump' effect.
An obvious way to do it is to store the offset of the touch from the shape's center in -touchesBegan:withEvent: and apply the offset in -touchesMoved:withEvent:.
I'm working with cocos2d. How to get last touch in ccTouchesMoved?
Add a global Variable in your ccTouchesBegan,
CGPoint touchPoint = [touch locationInView:[touch view]];
startPosition = [[CCDirector sharedDirector] convertToGL:touchPoint];
in your ccTouchesMoved just use startPosition to check whether your hand moved
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[touches allObjects] objectAtIndex: 0];
// The last location you touch
CGPoint lastLocation = [touch previousLocationInView:self.view];
// Current location
CGPoint currentLocation = [touch locationInView:self.view];
}
You can do like that :)