Cocos2D - filling a sprite - iphone

UIImageViews have a property called contentMode that you can use as
imageView.contentMode = UIViewContentModeScaleAspectFit;
and it will fill the entire view with your image without distorting, even if it has to bleed the image to do that.
Is there any similar stuff on Cocos2D? Sorry about the question, but I am new to Cocos2d.
I am creating the sprite like this:
CCTexture2D *textBack = [[CCTexture2D alloc] initWithImage:image];
CCSprite *sprite = [CCSprite spriteWithTexture:textBack];
thanks.

The equivalent method to performing a UIViewContentModeScaleAspectFit would be the .scale property. When a CCNode (or any of the sub nodes such as CCSprite etc.) is first created, the scale property is 1. Keep increasing it to scale the sprite up proportionally.
sprite.scale = 2.0f; // Scales the sprite proportionally at a factor of 2
As for it fitting to a specific size, you would have to write a routine:
Pass in desired rect and CCSprite bounding box rect.
Scale the box rect to aspect fit the desired rect.
Return the scaling factor
The result can then be applied to the CCSprite.scale property.

You can certainly scale the sprite to do that...
sprite.scale = ?
sprite.scaleX = ?
sprite.scaleY = ?
but I don't believe there is a function to automatically fill the entire screen. If you don't get a definitive reply here I would suggest posting on the Cocos2D forums (http://www.cocos2d-iphone.org/forum/).

Related

Is there a way to make a soft body with Spritekit using SKSpriteNode and PhysicsBody parameters?

I have the following sprite that falls to the bottom of the screen:
// The View
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];
self.physicsWorld.contactDelegate = self;
// The Sprite
SKSpriteNode *cube = [[SKSpriteNode alloc] initWithImageNamed:#"cube"];
[cube setPosition:CGPointMake(160,250);
[self addChild:cube];
// The Physics
cube.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:cube.frame.size];
cube.physicsBody.dynamic = YES;
cube.physicsBody.affectedByGravity = YES;
cube.physicsBody.mass = 0.02;
Is there a way to make it so its sides are bulging when it hits the bottom border of the screen? Something that would be Jelly like or a soft body that still maintains its shape to some extent but bulges out under its own weight? I hope this makes sense....
Visit the site https://gist.github.com/kazukitanaka0611/4b9d4ac9dff0cd317b6c it have explanation and source code for soft bodies (jelly) in sprite kit
quick and easy way without math:
1 use flash to tween your box warping.
2 export the tweened frames as a sprite sheet (texture atlas)
3 animate the texture atlas on contact with an edge physics body in your scene.
your box will fall and on contact animate the separate images to give the impression its warping/bulging sides.
i used this method and it works - in other words it gives the desired effect, which in my view is what is important - your gamers don't care how you did it, as long as it looks great.

Cocos2d, Weird position offset when using CCParallaxNode

I'm using cocos2d for iOS. Not sure if I'm doing something wrong here or if CCParallaxNode does something strange that I just don't understand.
I'm trying to create a few layers of parallax scrolling in the background of my game, at the moment I just have one layer added to the parallax node till I can figure out what's going wrong. When the game loads the layer it's always offset down and left by about 30% of the image size. I've uploaded an image demonstrating the difference in position here http://oi42.tinypic.com/29dz1av.jpg.
Here is my code:
background = [CCParallaxNode node];
background.anchorPoint = ccp(0,0);
background.position = ccp(0,0);
[self addChild: background];
background_image = [CCSprite spriteWithFile: #"layer01.png"
rect: CGRectMake(0, 0, 100, 100)];
background_image.anchorPoint = ccp(0,0);
background_image.position = ccp(0,0);
[background addChild: background_image z:0 parallaxRatio: ccp(0,0) positionOffset:ccp(0,0)];
The cocos2d icon is attached to the same layer as the parallax node and it's position and anchor point are set to 0,0 so the bottom left of the icon should be in the same location as the bottom left of the blue background image.
I have tested this using a basic sprite in place of the parallax node and everything lines up as it should so it's not the image itself.
Any help with this would be appreciated.
First, I don't suggest you to set parallax node & its children's anchor point & position directly because it will cause some unexpected results. You should add the parallax node to a layer as its child, and set the layer's anchor point & position to place your parallax.
Second, CCParallaxNode also provides a positionOffset that you can place your picture in parallax at first. This can help if you want to align several layers of pictures' view center.
So I think you should do something like this(Since I'm using cocos2d-x, I'm not sure its right with obj-C):
layer = [[CCLayer alloc]init];
background = [CCParallaxNode node];
[layer addChild: background];
[self addChild: layer];
Then you just have to add the picture sprite in background, and set layer's position & anchor point.
Hope it can help.
Make sure the background image size is 480x320.
Why did you write CGRectMake(0, 0, 100, 100) ? Why 100 and 100 ? You're limiting your 'CGRect', that's probably wrong..

Antialiasing edges of UIView after transformation using CALayer's transform

I have a UIView object that rotates using CALayer's transform:
// Create uiview object.
UIImageView *block = [[UIImageView alloc] initWithFrame....]
// Apply rotation.
CATransform3D basicTrans = CATransform3DIdentity;
basicTrans.m34 = 1.0/-distance;
blockImage.layer.transform = CATransform3DRotate(basicTrans, rangle, 1.0f, 0.0f, 0.0f);
After rotating the edges of the object are not antialiasing. I need to antialias them.
Help me, please. How can it be done?
One way to do this is by placing the image inside another view that's 5 pixels bigger. The bigger view should have a transparent rasterized border that will smooth the edges of the UIImageView:
view.layer.borderWidth = 3;
view.layer.borderColor = [UIColor clearColor].CGColor;
view.layer.shouldRasterize = YES;
view.layer.rasterizationScale = [[UIScreen mainScreen] scale];
Then, place your UIImageView inside this parent view and center it (With 2.5 pixels around each edge).
Finally, rotate the parent view instead of the image view.
It works very well - you can also encapsulate the whole thing in class that creates the hierarchy.
Simply add this key-value pair to your Info.plist: UIViewEdgeAntialiasing set to YES.
check allowsEdgeAntialiasing property of CALayer.
block.layer.allowsEdgeAntialiasing = YES; // iOS7 and above.
I had a similar issue when rotating around the z-axis. Setting shouldRasterize = YES prevented the jagged edges however it came at a performance cost. In my case I was re-using the views (and its layers) and keeping the shouldRasterize = YES was slowing things down.
The solution was, to turn off rasterization right after I didn't need it anymore. However since animation runs on another thread, there was no way of knowing when the animation was complete...until I found out about an extremely useful CATransaction method. This is an actual code that I used and it should illustrate its use:
// Create a key frame animation
CAKeyframeAnimation *wiggle = [CAKeyframeAnimation animationWithKeyPath:#"transform"];
NSInteger frequency = 5; // Higher value for faster vibration
NSInteger amplitude = 25; // Higher value for lower amplitude
// Create the values it will pass through
NSMutableArray *valuesArray = [[NSMutableArray alloc] init];
NSInteger direction = 1;
[valuesArray addObject:#0.0];
for (NSInteger i = frequency; i > 0; i--, direction *= -1) {
[valuesArray addObject:#((direction * M_PI_4 * (CGFloat)i / (CGFloat)amplitude))];
}
[valuesArray addObject:#0.0];
[wiggle setValues:valuesArray];
// Set the duration
[wiggle setAdditive:YES];
[wiggle setValueFunction:[CAValueFunction functionWithName:kCAValueFunctionRotateZ]];
[wiggle setDuration:0.6];
// Turn on rasterization to prevent jagged edges (anti-aliasing issues)
viewToRotate.layer.shouldRasterize = YES;
// ************ Important step **************
// Very usefull method. Block returns after ALL animations have completed.
[CATransaction setCompletionBlock:^{
viewToRotate.layer.shouldRasterize = NO;
}];
// Animate the layer
[viewToRotate.layer addAnimation:wiggle forKey:#"wiggleAnimation"];
worked like a charm for me.
I have not tried using this with implicit animations (i.e. animations that happen due to value change in animatable property for a non-view associated layer), however I would expect it to work as long as the CATransaction method is called before the property change, just as a guarantee the block is given to CATransaction before an animation starts.

Increase the width of a sprite through an animation

I'd like to know how to increase the width of a sprite through an animation.
CCSprite *waterImage = [CCSprite spriteWithFile:#"water.png"];
waterImage.position = ccp(10,20);
waterImage.scaleY = 1.0;//6.5;
[self addChild:waterImage];
I want to scale the image of the sprite on the Y axis through an animation. Please, if you have any tutorials, then share them with me.
You can use runAction to animate the scaling of your image like this,
[waterImage runAction:[CCScaleTo actionWithDuration:5 scaleX:6.5 scaleY:1]];
Provide "scaleY:1" so that image only scale on x-axis.
Hope it helps

Is it possible to set the position of an UIImageView's image?

I have a UIImageView that displays a bigger image. It appears to be centered, but I would like to move that image inside that UIImageView. I looked at the MoveMe sample from Apple, but I couldn't figure out how they do it. It seems that they don't even have an UIImageView for that. Any ideas?
What you need is something like (e.g. showing the 30% by 30% of the top left corner of the original image):
imageView.layer.contentsRect = CGRectMake(0.0, 0.0, 0.3, 0.3);
Description of "contentsRect":
The rectangle, in the unit coordinate space, that defines the portion of the layer’s contents that should be used.
Original Answer has been superseded by CoreAnimation in iOS4.
So as Gold Thumb says: you can do this by accessing the UIView's CALayer. Specifically its contentRect:
From the Apple Docs: The rectangle, in the unit coordinate space, that defines the portion of the layer’s contents that should be used. Animatable.
Do you want to display the image so that it is contained within the UIImageView? In that case just change the contectMode of UIImageView to UIViewContentModeScaleToFill (if aspect ratio is inconsequential) or UIViewContentModeScaleAspectFit (if you want to maintain the aspect ratio)
In IB, this can be done by setting the Mode in Inspector.
In code, it can be done as
yourImageView.contentMode = UIViewContentModeScaleToFill;
In case you want to display the large image as is inside a UIImageView, the best and easiest way to do this would be to have the image view inside a UIScrollView. That ways you will be able to zoom in and out in the image and also move it around.
Hope that helps.
It doesn't sound like the MoveMe sample does anything like what you want. The PlacardView in it is the same size as the image used. The only size change done to it is a view transform, which doesn't effect the viewport of the image. As I understand it, you have a large picture, and want to show a small viewport into it. There isn't a simple class method to do this, but there is a function that you can use to get the desired results: CGImageCreateWithImageInRect(CGImageRef, CGRect) will help you out.
Here's a short example using it:
CGImageRef imageRef = CGImageCreateWithImageInRect([largeImage CGImage], cropRect);
[UIImageView setImage:[UIImage imageWithCGImage:imageRef]];
CGImageRelease(imageRef);
Thanks a lot. I have found a pretty simple solution that looks like this:
CGRect frameRect = myImage.frame;
CGPoint rectPoint = frameRect.origin;
CGFloat newXPos = rectPoint.x - 0.5f;
myImage.frame = CGRectMake(newXPos, 0.0f, myImage.frame.size.width, myImage.frame.size.height);
I just move the frame around. It happens that portions of that frame go out of the iPhone's view port, but I hope that this won't matter much. There is a mask over it, so it doesn't look weird. The user doesn't totice how it's done.
You can accomplish the same by:
UIImageView *imgVw=[[UIImageView alloc]initwithFrame:CGRectMake(x,y,height,width)];
imgVw.image=[UIImage imageNamed:#""];
[self.view addSubView imgVw];
imgVw.contentMode = UIViewContentModeScaleToFill;
You can use NSLayoutConstraint to set the position of UIImageView , it can be relative to other elements or with respect to the frame.
Here's an example snippet:
let logo = UIImage(imageLiteralResourceName: "img")
let logoImage = UIImageView(image: logo)
logoImage.translatesAutoresizingMaskIntoConstraints = false
self.view.addSubview(logoImage)
NSLayoutConstraint.activate([logoImage.topAnchor.constraint(equalTo: view.topAnchor,constant: 30),
logoImage.centerXAnchor.constraint(equalTo: view.centerXAnchor),logoImage.widthAnchor.constraint(equalToConstant: 100),logoImage.heightAnchor.constraint(equalToConstant: 100)
])
This way you can also resize the image easily. The constant parameter represents, how far should a certain anchor be positioned relative to the specified anchor.
Consider this,
logoImage.topAnchor.constraint(equalTo: view.topAnchor,constant: 30)
The above line is setting the top anchor of the instance logoImage to be 30 (constant) below the parent view. A negative value would mean opposite direction.