I have been trying to update two UIImageView elements almost simultaneously. Whilst one should have its position changed (image01), the other should have alter its image file (image02).
The problem here is that when I change image02's image file, image01's position data is reset to the center (which is the element's origin).
I am completely here. Do any of you have any ideas on what is causing this?
Here is the code:
- (void) touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event {
UITouch* touch = [touches anyObject];
CGPoint point = [touch locationInView:self.view];
// Setting crosshair new position
[self setCrossHairPosition:point];
// Getting camera preview, and discovering pixel color at touch location
// I also set colorName here
[self captureNow:touch];
// Getting file and inserting it in the UIImageView
fileName = [NSString stringWithFormat:#"%#.png", colorName];
_colorADDPreview.image = [UIImage imageNamed:fileName];
}
- (void) setCrossHairPosition:(CGPoint)point {
CGRect crossHairRect = _crossHair.frame;
crossHairRect.origin.x = point.x - (crossHairRect.size.width/2);
crossHairRect.origin.y = point.y - (crossHairRect.size.height/2);
_crossHair.frame = crossHairRect;
}
I realised that the problem was in the redrawing of the screen.
So instead of having the element inserted through the interface builder, I inserted it programatically and kept track of its position in a variable =]
Related
I'm trying to implement a scrollable background into my current GameScene. This is supposed to be done via Gesture Recognition, which I'm already using for Taps and moving other scene objects.
Unlike pretty much every other result returned by my Google searches, I don't want an infinitely scrolling background. It just needs to move with your finger, and stay where it's been moved.
The Problem:
I can move the background SKSpriteNode in my scene, but as soon as I try to move it again it snaps to the center and your scrolling effectively becomes useless. It keeps resetting itself.
Here's what I've got so far for moving my Sprites:
-(void)selectTouchedNode:(CGPoint)location
{
SKSpriteNode *node = (SKSpriteNode *)[self nodeAtPoint:location];
if ([self.selectedNode isEqual:node]){
if (![self.selectedNode isEqual:self.background]){
self.selectedNode = NULL;
}
}
if ([node isKindOfClass:[SKLabelNode class]]){
self.selectedNode = node.parent;
} else {
self.selectedNode = node;
}
NSLog(#"Node Selected: %# | Position: %f, %f",node.name,node.position.x,node.position.y);
}
- (void)respondToPan:(UIPanGestureRecognizer *)recognizer {
if (recognizer.state == UIGestureRecognizerStateBegan) {
// Get Touch Location in the View
CGPoint touchLocation = [recognizer locationInView:recognizer.view];
// Convert that Touch Location
touchLocation = [self convertPointFromView:touchLocation];
// Select Node at said Location.
[self selectTouchedNode:touchLocation];
} else if (recognizer.state == UIGestureRecognizerStateChanged) {
// Get the translation being performed on the sprite.
CGPoint translation = [recognizer translationInView:recognizer.view];
// Copy to another CGPoint
translation = CGPointMake(translation.x, -translation.y);
// Translate the currently selected object
[self translateMotion:recognizer Translation:translation];
// Reset translation to zero.
[recognizer setTranslation:CGPointZero inView:recognizer.view];
} else if (recognizer.state == UIGestureRecognizerStateEnded) {
// Fetch Current Location in View
CGPoint touchLocation = [recognizer locationInView:recognizer.view];
// Convert to location in game.
CGPoint correctLocation = [self convertPointFromView:touchLocation];
// If the selected node is the background node
if ([self.selectedNode isEqual:self.background]) {
NSLog(#"Scrolling the background: Node is: %#",self.selectedNode.name);
// Set up a scroll duration
float scrollDuration = 0.2;
// Get the new position based on what is allowed by the function
CGPoint newPos = [self backgroundPanPos:correctLocation];
NSLog(#"New Position: %f, %f",newPos.x,newPos.y);
// Remove all Actions from the background
[_selectedNode removeAllActions];
// Move the background to the new position with defined duration.
SKAction *moveTo = [SKAction moveTo:newPos duration:scrollDuration];
// SetTimingMode for a smoother transition
[moveTo setTimingMode:SKActionTimingEaseOut];
// Run the action
[_selectedNode runAction:moveTo];
} else {
// Otherwise, just put the damn node where the touch occured.
self.selectedNode.position = correctLocation;
}
}
}
// NEW PLAN: Kill myself
- (void)translateMotion:(UIGestureRecognizer *)recognizer Translation:(CGPoint)translation {
// Fetch Location being touched
CGPoint touchLocation = [recognizer locationInView:recognizer.view];
// Convert to place in View
CGPoint location = [self convertPointFromView:touchLocation];
// Set node to that location
self.selectedNode.position = location;
}
- (CGPoint)backgroundPanPos:(CGPoint)newPos {
// Create a new point based on the touched location
CGPoint correctedPos = newPos;
return correctedPos;
}
What do I know so far?
I've tried printing the positions before the scrolling, when it ends, and when it gets initiated again.
Results are that the background does move positions, and once you try to move it again it starts at those new Coordinates, the screen has just repositioned itself over the centre of the sprite.
Supporting Illustration:
I'm not sure I 100% understand the situation you are describing, but I believe that it might be related to the anchor point of your background sprite node.
in your method:
- (void)translateMotion:(UIGestureRecognizer *)recognizer Translation:(CGPoint)translation
you have the line:
self.selectedNode.position = location;
Since your background sprite's anchor point is set to its center by default, any time you move a new touch, it will snap the background sprite's center to the location of your finger.
In other words, background.sprite.position sets the coordinates for the background sprite's anchor point (which by default is the center of the sprite), and in this case any time you set a new position, it is moving the center to that position.
The solution in this case would be to shift the anchor point of the background sprite to be directly under the touch each time, so you are changing the position of the background relative to the point of the background the touch started on.
It's a little hard to explain, so here's some sample code to show you:
1) Create a new project in Xcode using the Sprite Kit Game template
2) Replace the contents of GameScene.m with the following:
#import "GameScene.h"
#interface GameScene ()
#property (nonatomic, strong) SKSpriteNode *sprite;
#end
#implementation GameScene
-(void)didMoveToView:(SKView *)view {
/* Setup your scene here */
self.sprite = [SKSpriteNode spriteNodeWithImageNamed:#"Spaceship"];
self.sprite.position = CGPointMake(CGRectGetMidX(self.frame),
CGRectGetMidY(self.frame));
[self addChild:self.sprite];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
/* Called when a touch begins */
UITouch *touch = [touches anyObject];
CGPoint nodelocation = [touch locationInNode:self.sprite];
//[self adjustAnchorPointForSprite:self.sprite toLocation:nodelocation];
CGPoint location = [touch locationInNode:self];
self.sprite.position = location;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInNode:self];
self.sprite.position = location;
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
}
-(void)adjustAnchorPointForSprite:(SKSpriteNode *)sprite toLocation:(CGPoint)location {
// Remember the sprite's current position
CGPoint originalPosition = sprite.position;
// Convert the coordinates of the passed-in location to be relative to the bottom left of the sprite (instead of its current anchor point)
CGPoint adjustedNodeLocation = CGPointMake(sprite.anchorPoint.x * sprite.size.width + location.x, sprite.anchorPoint.y * sprite.size.height + location.y);
// Move the anchor point of the sprite to match the passed-in location
sprite.anchorPoint = CGPointMake(adjustedNodeLocation.x / self.sprite.size.width, adjustedNodeLocation.y / self.sprite.size.height);
// Undo any change of position caused by moving the anchor point
self.sprite.position = CGPointMake(sprite.position.x - (sprite.position.x - originalPosition.x), sprite.position.y - (sprite.position.y - originalPosition.y));
}
-(void)update:(CFTimeInterval)currentTime {
/* Called before each frame is rendered */
}
#end
3) Run the project in the sim or on a device and click / touch the top tip of the space ship and start dragging.
4) Notice that the spaceship snaps its center point to where your touch is. If you drag and release it to a new location, and the touch the screen again, it snaps its center back to your finger.
5) Now uncomment the line:
[self adjustAnchorPointForSprite:self.sprite toLocation:nodelocation];
and run the project again.
6) See how you can now drag the ship where you want it, and when you touch it later, it stays in place and follows your finger from the point you touched it. This is because the anchor point is now being adjusted to the point under the touch each time a new touch begins.
Hopefully this gives you a solution you can use in your game as well.
I am developing a simple animation where an UIImageView moves along a UIBezierPath, now I want to provide user interation to the moving UIImageView so that user can guide the UIImageView by touching the UIImageView and drag the UIImageview around the screen.
Change the frame of the position of the image view in touchesMoved:withEvent:.
Edit: Some code
- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event {
UITouch *touch = [[event allTouches] anyObject];
if ([touch.view isEqual: self.view] || touch.view == nil) {
return;
}
lastLocation = [touch locationInView: self.view];
}
- (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event {
UITouch *touch = [[event allTouches] anyObject];
if ([touch.view isEqual: self.view]) {
return;
}
CGPoint location = [touch locationInView: self.view];
CGFloat xDisplacement = location.x - lastLocation.x;
CGFloat yDisplacement = location.y - lastLocation.y;
CGRect frame = touch.view.frame;
frame.origin.x += xDisplacement;
frame.origin.y += yDisplacement;
touch.view.frame = frame;
lastLocation=location;
}
You should also implement touchesEnded:withEvent: and touchesCanceled:withEvent:.
So you want the user to be able to touch an image in the middle of a keyframe animation along a curved path, and drag it to a different location? What do you want to happen to the animation at that point?
You have multiple challenges.
First is detecting the touch on the object while a keyframe animation is "in flight".
To do that, you want to use the parent view's layer's presentation layer's hitTest method.
A layer's presentation layer represents the state of the layer at any given instant, including animations.
Once you detect touches on your view, you will need to get the image's current location from the presentation layer, stop the animation, and take over with a touchesMoved/touchesDragged based animation.
I wrote a demo application that shows how to detect touches on an object that's being animated along a path. That would be a good starting point.
Take a look here:
Core Animation demo including detecting touches on a view while an animation is "in flight".
Easiest way would be subclassing UIImageView.
For simple dragging take a look at the code here (code borrowed from user MHC):
UIView drag (image and text)
Since you want to drag along Bezier path you'll have to modify touchesMoved:
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *aTouch = [touches anyObject];
//here you have location of user's finger
CGPoint location = [aTouch locationInView:self.superview];
[UIView beginAnimations:#"Dragging A DraggableView" context:nil];
//commented code would simply move the view to that point
//self.frame = CGRectMake(location.x-offset.x,location.y-offset.y,self.frame.size.width, self.frame.size.height);
//you need some kind of a function
CGPoint calculatedPosition = [self calculatePositonForPoint: location];
self.frame = CGRectMake(calculatedPosition.x,calculatedPosition.y,self.frame.size.width, self.frame.size.height);
[UIView commitAnimations];
}
What exactly you would like to do in -(CGPoint) calculatePositionForPoint:(CGPoint)location
is up to you. You could for example calculate point in Bezier path that is the closest to location. For simple test you can do:
-(CGPoint) calculatePositionForPoint:(CGPoint)location {
return location;
}
Along the way you're gonna have to decide what happens if user wonders off to far from your
precalculated Bezier path.
I have a few UIView subclasses that exist in a kind of inventory. When you tap one, another draggable version is placed over top of it. I want the inventory versions to stay put while you drag others around. The code to make a duplicate works but dragging your finger around doesn't move it.
If I release and then start dragging the newly created version it moves as expected. I think this is because the original touches (that made the dupe) didn't have the draggable version in the responder chain.
A little code...
in my stationary "icon"...
- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
[self.viewController placeDraggableItem:self.item WithPoint:self.frame.origin];
}
in my viewController...
- (void)placeDraggableItem:(Item *)item WithPoint:(CGPoint)point
{
DraggableItem *draggableItem = [[DraggableItem alloc] initWithImage:[UIImage imageNamed:item.graphic]];
draggableItem.frame = CGRectMake(point.x, scrollView.frame.origin.y + point.y, 64.0f, 64.0f);
[self.view addSubview:draggableItem];
[draggableItem release];
}
in my DraggableItem...
- (void)touchesBegan:(NSSet*)touches withEvent:(UIEvent*)event
{
currentPoint = [[touches anyObject] locationInView:self];
}
- (void) touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event
{
CGPoint activePoint = [[touches anyObject] locationInView:self];
CGPoint newPoint = CGPointMake(self.center.x + (activePoint.x - currentPoint.x), self.center.y + (activePoint.y - currentPoint.y));
float midPointX = CGRectGetMidX(self.bounds);
if (newPoint.x > self.superview.bounds.size.width - midPointX)
newPoint.x = self.superview.bounds.size.width - midPointX;
else if (newPoint.x < midPointX) // If too far left...
newPoint.x = midPointX;
float midPointY = CGRectGetMidY(self.bounds);
if (newPoint.y > self.superview.bounds.size.height - midPointY)
newPoint.y = self.superview.bounds.size.height - midPointY;
else if (newPoint.y < midPointY) // If too far up...
newPoint.y = midPointY;
self.center = newPoint;
}
Now again creating the draggable version works. And the draggable version is able to be moved after you first release your first touch. But I think I need to get the newly create UIView to respond to touches that were originally made for the "icon".
Any ideas?
I'm aware this question is kind of similar to this one: How to "transfer" first responder from one UIView to another? but in that case the view which should receive the touches is already there whereas I need to pass touches onto a newly created view.
I don't know of any way to hand touches off to a newly created view, though that doesn't mean there isn't a way to do it. It looks like you really only want your draggable view to handle the touches, I would probably create each draggable view with with an alpha of 0 at the same time you create the non draggable views, and in touchesBegan set it to 1. If your non-draggable views don't need to handle touches, then it doesn't make sense to make them handle touches just to pass them along.
i have this type of code....
// create a UIImageView
UIImageView *rollDiceImageMainTemp = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"rollDiceAnimationImage1.png"]];
// position and size the UIImageView
rollDiceImageMainTemp.frame = CGRectMake(0, 0, 100, 100);
// create an array of images that will represent your animation (in this case the array contains 2 images but you will want more)
NSArray *savingHighScoreAnimationImages = [NSArray arrayWithObjects:
[UIImage imageNamed:#"rollDiceAnimationImage1.png"],
[UIImage imageNamed:#"rollDiceAnimationImage2.png"],
nil];
// set the new UIImageView to a property in your view controller
self.viewController.rollDiceImage = rollDiceImageMainTemp;
// release the UIImageView that you created with alloc and init to avoid memory leak
[rollDiceImageMainTemp release];
// set the animation images and duration, and repeat count on your UIImageView
[self.viewController.rollDiceImageMain setAnimationImages:savingHighScoreAnimationImages];
[self.viewController.rollDiceImageMain setAnimationDuration:2.0];
[self.viewController.rollDiceImageMain.animationRepeatCount:3];
// start the animation
[self.viewController.rollDiceImageMain startAnimating];
// show the new UIImageView
[self.viewController.view addSubview:self.rollDiceImageMain];
Instead of startAnimation directly..there any way to control this code using touchesMoved??
Actually, what you want is the - (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event. Below is a sample of code that will allow a UIView to move on the x-axis only. Adapt to whatever you need your code to do.
- (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event
{
CGPoint original = self.center;
UITouch* touch = [touches anyObject];
CGPoint location = [touch locationInView:self.superview];
// Taking the delta will give us a nice, smooth movement that will
// track with the touch.
float delta = location.x - original.x;
// We need to substract half of the width of the view
// because we are using the view's center to reposition it.
float maxPos = self.superview.bounds.size.width
- (self.frame.size.width * 0.5f);
float minPos = self.frame.size.width * 0.5f;
float intendedPos = delta + original.x;
// Make sure they can't move the view off-screen
if (intendedPos > maxPos)
{
intendedPos = maxPos;
}
// Make sure they can't move the view off-screen
if (intendedPos < minPos)
{
intendedPos = minPos;
}
self.center = CGPointMake(intendedPos, original.y);
// We want to cancel all other touches for the view
// because we don't want the touchInside event firing.
[self touchesCancelled:touches withEvent:event];
// Pass on the touches to the super
[super touchesMoved:touches withEvent:event];
}
Notice here that I am taking the delta of the movement and not with the finger. If you track with the finger you will get very erratic behavior that is very undesirable. Applying the delta will give nice, fluid movement of the view that will track perfectly with the touch input.
Update: Also, for those wondering why I chose to multiply by 0.5f rather than divide by 2, the ARM processor doesn't support division in hardware, so there is a minuscule performance bump by going with multiplication. This performance optimization may only get called only a few times during the life of a program so it might not make a difference, but this particular message is called many, many times when dragging. Because it is in this case, it might be worth the multiplication, instead.
You can detect touches by using UIResponder methods like - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event in that you can call the [self.viewController.rollDiceImageMain startAnimating]; method.
And once it starts then you can stop after some time and restrict the touches.
I have two UIImageViews located about center of a horizontal screen and when the user clicks a button another UIImageView, located off screen, slides in from the right. I'm am just trying to detect when the view being brought onto the screen collides with the two static views. The problem is when I run my code and check the CGRect frames they are returned from where the views start, not end, regardless of where I place the frame calls in my method or even if I place them outside the method in a separate one. I'm a bit new to Obj-C and I understand that Core Animation runs on a separate thread and I am guessing that is why I am getting the starting values. (Correct me if I am wrong here).
So, I guess the question here is how do I detect collisions when one item is static and another is animated. Here's my code (feel free to clean it up):
- (IBAction)movegirl
{
//disabling button
self.movegirlbtn.enabled = NO;
//getting graphics center points
CGPoint pos = bushidogirl.center;
CGPoint box1 = topbox.center;
CGPoint box2 = bottombox.center;
//firing up animation
[UIView beginAnimations: nil context: NULL];
//setting animation speed
[UIView setAnimationDuration:2.0 ];
//setting final position of bushidogirl, then resetting her center position
pos.x = 260;
bushidogirl.center = pos;
//running animations
[UIView commitAnimations];
//playing gong sound
[self.audioplayer play];
//enabling button
self.movegirlbtn.enabled = YES;
[self collisiondetection: bushidogirl : topbox];
}
- (void)collisiondetection:(UIImageView *)item1 : (UIImageView *)item2
{
CGRect item1frame = item1.frame;
CGRect item2frame = item2.frame;
NSLog(#"Item1 frame = %d and Item 2 frame = %d", item1frame, item2frame);
}
How about:
if (CGRectIntersectsRect(item1frame, item2frame))
{
// collision!!
}