Texture position of a sprite shifted [cocos2d v3] - cocos2d-iphone

I've been struggling for days with that problem: I have CCNode >> StateComponent and in the StateComponent I have a CCSprite as an attribute and add it as a child in StateComponent. When I set the position of an StateComponent object and NOT of the sprite, the bounding box of the StateComponent object appears at the right place. The default values for a sprite position are set on (0,0). The bounding box of the sprite appears at (0,0) but the sprite texture is shifted from (0,0).
I add the StateComponent object afterwards to a CCScene.
Could maybe someone help me with advice: how can I set the sprite position so that the texture and bounding box appears at the same position as the StateComponent object? Later I'd like to detect if there is a touch on the node(sprite) and then rotate the node with the sprite.
Any help would be really appreciated!!!
#interface StateComponent : CCNode {
}
#end
#implementation StateComponent
-(instancetype) initWithGestureStatewithSprite:(CCSprite*) sprite andPosition: (CGPoint) spritePosition RelativeAngle:(float) angle {
self = [super init];
if (!self) {
return nil;
}
self.sprite = sprite;
self.relativeAngle = angle;
self.position = spritePosition;
[self addChild:sprite];
return self;
}
#end
#interface StateViewScene : CCScene {
}
#end
#implementation StateViewScene
-(id) init {
self = [super init];
if (!self) {
return nil;
}
StateComponent * body = [[StateComponent alloc] initWithGestureStatewithSprite [CCSprite spriteWithImageNamed:#"body.png"] andPosition: CGPointMake(512,384) RelativeAngle:0];
[self addChild:body];
return self;
}

Have you tried to set the content Size of the Node to the Sprite content Size?
-(instancetype) initWithGestureStatewithSprite:(CCSprite*) sprite andPosition: (CGPoint) spritePosition RelativeAngle:(float) angle {
...
self.contentSize = sprite.contentSize;
...

I managed to solve the problem by converting to node space the StateComponent position couple of times as I actually have a tree like structure of StateComponents with sprites.
Thanks for the help! :)
---Edit---
This article helped me and might be interesting: http://www.koboldtouch.com/display/IDCAR/Converting+Between+Coordinate+Spaces

Related

Collision with sprite having another sprite as parent

Seems impossible but there has to be a solution.
I have the following classes:
#interface EnemiesEntities : CCSprite {
bool isFunctional;
CCSprite * laserBeam; // <----------- !!!!! That's where I want to check the collision.
CCSprite * leftRingEffect;
CCSprite * rightRingEffect;
}
#interface ShipEntity : CCSprite
{}
And I simply want to verify the collision between the ShipEntity and the laserBeam sprite (laserBeam is a member variable and child of EnemiesEntities class).
The method [laserBeam boundingBox] doesn't work as the boundingBox converts the coordinates relative to the parent node.
I tried thend adding to CCNode a method computing the boundingBox relative to the world but also this one did not work:
- (CGRect) worldBoundingBox
{
CGRect rect = CGRectMake(0, 0, contentSize_.width, contentSize_.height);
return CGRectApplyAffineTransform(rect, [self nodeToWorldTransform]);
}
I checked online and found only unuseful (to me) answers to the same question.
I then tried a different approach and tried to start from the boudningBox and change the position of the rectangle so obtained in respect to the parent position as following:
-(BOOL) collidesWithLaser:(CCSprite*)laserBeam
{
CGPoint newPosition = [laserBeam convertToWorldSpace:laserBeam.position];
[laserBeam worldBoundingBox];
CGRect laserBoundingBox = [laserBeam boundingBox];
CGRect laserBox = CGRectMake(laserBeam.parent.position.x, laserBeam.parent.position.y, laserBoundingBox.size.width, laserBoundingBox.size.height);
CGRect hitBox = [self hitBox];
if(CGRectIntersectsRect([self boundingBox], laserBox))
{
laserBeam.showCollisionBox=TRUE;
return TRUE;
}
else {
return FALSE;
}
}
Unfortunately this does work only when the rotation of the parent sprite is set to 0.0 but when it actually changes then it doesn't work (is probably because the boundingBox is relative to the parent node and not world).
I am a bit lost and was wondering if any of you had better luck in solving this problem and which solution (code snippets please :)) you used.
EDIT in Response to #LearnCocos2D answer:
I followed the suggestion and added the following code which doesn't work properly (e.g. try with an EnemiesEntities object is rotated to -130.0f).
-(BOOL) collidesWithLaser:(CCSprite*)laserBeam
{
CCLOG(#"rotation %f", laserBeam.rotation);
CGRect laserBoundingBox = [laserBeam boundingBox];
laserBoundingBox.origin = [self convertToWorldSpace:laserBeam.position];
CGRect shipBoundingBox = [self boundingBox]; //As we are in ShipEntity class
shipBoundingBox.origin = [self convertToWorldSpace:shipBoundingBox.origin];
//As this method is in the ShipEntity class there is no need to convert the origin to the world space. I added a breakpoint here and doing in this way the CGRect of both ShipEntity and gets misplaced.
if(CGRectIntersectsRect(shipBoundingBox, laserBoundingBox))
{
return TRUE;
}
else {
return FALSE;
}
}
The problem is in this line I think:
CGPoint newPosition = [laserBeam convertToWorldSpace:laserBeam.position];
laserBeam isn't in laserBeam's space but laserBeams parent space. So the correct is:
CGPoint newPosition = [[laserBeam parent] convertToWorldSpace:laserBeam.position];
The whole code
-(BOOL) collidesWithLaser:(CCSprite*)laserBeam
{
CGPoint newPosition = [laserBeam convertToWorldSpace:laserBeam.position];
CGRect laserBoundingBox = [laserBeam boundingBox];
laserBoundingBox.origin = newPosition;
CGRect hitBox = [self boundingBox];
hitbox.origin = [[self parent] convertToWorldSpace:hitbox.origin];
if(CGRectIntersectsRect(hitbox, laserBoundingBox))
{
laserBeam.showCollisionBox=TRUE;
return TRUE;
}
else {
return FALSE;
}
}
for both boundingboxes do:
bbox.origin = [self convertToWorldSpace:bbox.origin];
now you can compare the rects...
Update to update:
The boundingBox is an axis-aligned bounding box.
If the entity is rotated, the bounding box size increases to encompass all of the sprite's corners. Therefore collision (intersection) may be detected even relatively far away from the node when testing axis-aligned bounding boxes.
In ccConfig.h there's an option you can turn on to draw sprite bounding boxes, you should set this to 1 to see the bounding boxes: #define CC_SPRITE_DEBUG_DRAW 1
For oriented rectangles you need a different data structure and different intersection test, see for example this tutorial.

Cocos2d - Orbiting/spinning one sprite around another

I've got to sprites, essentially a nucleus (parent) and an electron (child). I'm trying to find a way to have the electron orbit the nucleus. I've found a few posts here and there on moving anchor points, but that is apparently related to the texture of the sprite, not the sprite itself.
This is my current init method for my parent sprite:
self = [super init];
if (self) {
CCSprite *orbitAnchor = [CCSprite new];
[self addChild:orbitAnchor];
orbitAnchor.position = ccp(32,32);
CCSprite *orbiter = [CCSprite spriteWithFile:#"line.png" rect:CGRectMake(0, 0, 8, 8)];
[orbitAnchor addChild:orbiter];
orbiter.position = ccp(40,40);
CCAction *orbitAction = [CCRepeatForever actionWithAction:[CCRotateTo actionWithDuration:1 angle:720]];
[orbitAnchor runAction:orbitAction];
[self initAnimations];
}
return self;
Those numbers are all totally arbitrary though - I just stuck them in there and got what looked best. I'm sure there's a more programatic way to do what I want.
Basically, I'm looking for a way to set the child's axis point at the center of the parent, and then have it rotate around that point. It seems like a relatively simple thing to do using CCRotate and such, but I think I'm missing what to search for in order to move the anchor point of the child. Any suggestions/other posts?
Thanks
You have [CCSprite new] which is an unusual use, probably not supported. Unless the orbit anchor node should display a texture, you can just use a CCNode as anchor.
Technically you're doing everything correct from what I can see. You might want to try without the rotate actions and instead change the direction manually in a scheduled update method.
CCNode *orbitAnchor = [CCNode node];
[self addChild:orbitAnchor z:0 tag:1];
orbitAnchor.position = ccp(32,32);
CCSprite *orbiter = [CCSprite spriteWithFile:#"line.png" rect:CGRectMake(0, 0, 8, 8)];
[orbitAnchor addChild:orbiter z:0 tag:2];
orbiter.position = ccp(40,40);
[self scheduleUpdate];
Update method:
-(void) update:(ccTime)delta
{
CCNode* orbitAnchor = [self getChildByTag:1];
orbitAnchor.direction += 5;
}
From the image filename it looks like you're trying to draw a line from the orbitAnchor to the orbiter. You can do that with ccDrawLine:
-(void) draw
{
CCNode* orbitAnchor = [self getChildByTag:1];
CCNode* orbiter = [self getChildByTag:2];
ccDrawLine(orbitAnchor.position, orbiter.position);
}
Anchor points. Automatically, objects are placed based on the center of an object right? with anchor points you can move that around, so if you rotate the object it will rotate around the anchorpoint. http://www.qcmat.com/understanding-anchorpoint-in-cocos2d/

iPhone dev> Getting a CCSprite position from an other object in cocos2d?

Hey people,
I'm creating a game in cocos2d, (I'm very new to it, and was trying to solve this thing)
in the game I'm making I created a "Bomb" class, and a "Player" class,
I want the bomb to check for collision with the player, if a collision detected, explode.
My problem is that I have no idea how to get the player's position from the bomb class,
I'd be happy if you guys could help me out here,
Thanks!
You did add the CCSprites to a CCLayer, didn't you? Then that CCLayer should have the access to both of them. So, you can use the CCLayer's tick function to track the positions of the CCSprites and trigger actions if their bounding boxes overlap.
Some sample code to illustrate:
#interface MyLayer : CCLayer {
BombSprite *bomb;
PlayerSprite *player;
}
...
#end
#implementation MyLayer
- (id)init {
if ((self = [super init])) {
bomb = ...
player = ...
[self schedule:#selector(tick:)];
}
return self;
}
- (id)tick:(ccTime)dt {
if (CGRectContainsRect([bomb boundingBox], [player boundingBox])) {
NSLog(#"Collision!");
// call [player didCollideWith:bomb] or something
...
}
}
#end

cocos2d: Why can't I change a scaled node's position?

I think I'm just understanding scaling/positioning nodes/layers incorrectly. I'm setting up my node like this (node class is derived from CCNode):
-(id) init
{
if ((self = [super init]))
{
// Create parallax background node.
background = [BackgroundNode node];
[self addChild:background z:0];
// Create foreground node.
foreground = [ForegroundLayer node];
[self addChild:foreground z:0];
self.position.y = 500.0f;
self.scaleX = 1.5f;
self.scaleY = 1.5f;
}
return self;
}
It doesn't seem to matter what I set the self.position.y to - the scaled node is always displayed as though it was positioned in the bottom-left of the screen. I've tried playing around with anchorPoint as well, but it doesn't really seem to change anything.
The reason I'm asking is because I'd like to be able to pan vertically when I'm zoomed in - this doesn't seem to really be the right way to accomplish it, though. Any ideas?
self.position.y = 500.0f;
doesn't work. It should be
self.position = ccp(self.position.x, 500.0f);
Please refer to "Cocoa Objective-c Property C structure assign fails".

Stroke in Cocos2d

How to Stroke a line in Cocos2d? Is it possible to convert the stroke into sprite?
You can draw lines by overriding the "draw" method, which would in turn result in the "stroke" effect you appear to be after. The question is a bit lacking in detail, so I'll try to make the best of it.
Let's say you want to draw a simple line on the screen, you could do the following:
#interface MyLine: CCNode
{
CGRect lineRect;
}
#property(nonatomic) CGRect lineRect;
+(id)lineWithRect:(CGRect)rect;
#end
#implementation MyLine
#synthesize lineRect
+(id)lineWithRect:(CGRect)rect
{
MyLine *node = [MyLine node];
[node setRect: rect];
return node];
}
-(void)draw
{
glEnable(GL_LINE_SMOOTH);
ccDrawLine(ccp(rect.origin.x, rect.origin.y), ccp(rect.size.width, rect.size.height));
}
#end
With this class, you'd be able to call:
MyLine *line = [MyLine lineWithRect:CGRectMake(0, 0, winSize.width, winSize.height)];
Which would then draw a line from the bottom left of the screen to the top right of the screen.
You would not convert this into a "sprite", as it would be unnecessary to do so - but you could then treat this as if it were any other graphic in your game, as it is now it's own subclass of CCNode ... containing all the goodness that comes with that (positioning, etc).