I have in my scene playing board (for Tetris) - smaller then scene (750x510px). I need to frame it with bodyWithEdgeLoopFromRect. Here is a code :
SKSpriteNode *herniPlocha = [[SKSpriteNode alloc]initWithImageNamed:#"Plocha"];
herniPlocha.anchorPoint = CGPointMake(0, 0);
herniPlocha.position = CGPointMake(10, self.size.height-450);
herniPlocha.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:herniPlocha.frame];
[self addChild:herniPlocha];
but when I try to put block inside this board, the physicsBody doesn't match my board, it is about 40px moved to the right and up. Can you help me solve this problem, please?
Don't change the anchorPoint. The anchorPoint shifts the texture relative to the node's position and does nothing else. It certainly does not change where the physics shape is relative to the node.
Related
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.
I have a SKShapeNode, and a label under one generic SKNode. If I try to scale that node, its position changes for no reason!. If I try to scale only the nodes it contains under it, it scales properly but not from the center, so it grows out to the up and right.
What am I doing wrong?
First before scale
After scale
Notice its position moves up. Can't figure out why, does it even if I do it as an action or not. Also, the position is not changing based on log, but it appears the frame got bigger (though that is expected)
Steps to recreate issue:
set height and width
#h = 50
#w = 256
create rect with height and width
CGRectMake(0, 0, #w, #h)
get path for rect
UIBezierPath.bezierPathWithRect(rect).CGPath
create skshape node with path, set position
antialiased: false,
lineWidth: 1.0,
strokeColor: SKColor.blackColor,
fillColor: SKColor.whiteColor
Create sklabel, vertical center alignment, set position
create generic SKNode, no properties, add skshapenode and sklabel to it as children
Scale the generic SKNode.
I had a similar problem: I created an SKShapeNode.ellipseInRect which look perfectly fine when I didn't need to scale it. Yet as soon as I tried to scale it down to fit the text it was behind, it would randomly shrink towards the bottom left of the screen!
I did a little debugging, and the number that surprised me was that the position was set to (0, 0) even though the ellipse was in the top left corner of the screen! I then realized that by initializing with a rect the "anchor point" (even though SKShapeNodes don't technically have them) was at (0, 0) too. This behavior would explain my shrinking towards that point and your growing away from that point.
What solved this problem for me was instead of putting my position in the rect, set the position afterwards. Then it scaled around my node's center-point and not the screen origin. Hope that helps!
Try this
SKLabelNode *labNode = [SKLabelNode labelNodeWithFontNamed:#"Arial"];
labNode.fontSize = 12.0f;
labNode.fontColor = [SKColor blackColor];
labNode.text = #"SMASH";
SKSpriteNode *topWithText = [SKSpriteNode spriteNodeWithColor:[SKColor greenColor] size:CGSizeMake(100, 30)];
topWithText.position = CGPointMake(100, 110);
[topWithText addChild:labNode];
SKSpriteNode *bottom = [SKSpriteNode spriteNodeWithColor:[SKColor redColor] size:CGSizeMake(100, 10)];
bottom.position = CGPointMake(100, 100);
[self addChild:topWithText];
[self addChild:bottom];
[topWithText runAction:[SKAction sequence:#[
[SKAction waitForDuration:3.0],
[SKAction scaleBy:3.0 duration:3]
]]];
With the SKShapeNode, this is impossible.
I solved it by adding a move Action to center the node manually.
You need to apply this to the y and x coordinates
I have a standard cocos2d startup layer( HelloWorldLayer). I created another class of type CCNode named "Terrain" for my terrain. Then i add it to my layer in the layer's init:
terrain = [[Terrain alloc] initWithWorld:world AndLevel:0];
[self addChild:terrain z:1];
i add a 'CarObject' class (a CCSprite class), and add a car object to my terrain
car = [[CarObject alloc] initWithWorld:world];
[terrain addChild:car];
-i.e. in both the initWithWorld for terrain and car, i initialize some Box2d code
I then try to center my car object to my screen when i move it, i do this in my update method:
float offsetX = car.position.x;
float offsetY = car.position.y;
[terrain setOffsetX:(int)offsetX andOffsetY:(int)offsetY];
where the setOffsetX.. method is:
- (void) setOffsetX:(int)newOffsetX andOffsetY:(int)newOffsetY {
_offsetX = newOffsetX;
_offsetY = newOffsetY;
CGSize winSize = [CCDirector sharedDirector].winSize;
self.position = CGPointMake(-(_offsetX - winSize.width/2), -(_offsetY - winSize.height/2));
}
When i use a NSLog to see if the terrain position changes, i can see that the position actually chages, but the view does not. What am i doing wrong? am sure it's a dumb mistake!
btw, if i try this in my HelloWorldLayer's update method (instead of [terrain setOffsetX..])
self.position = CGPointMake(self.position.x-1, self.position.y);
the terrain is moving.
Car is a child of Terrain. Car's position is therefore relative to Terrain's position. Since you base Terrain's position on Car's position, which is actually relative to Terrain's position, you may be simply running into the effect that your position updates simply cancel each other out.
If you want to move the Terrain while keeping the Car centered, you shouldn't add the Car as a child of Terrain. Instead add it to the same node as the Terrain (HelloWorldLayer). Then you can move the Car and Terrain independently of each other.
I am new in cocos2d i have created a simple example
CGSize winSize = [[CCDirector sharedDirector] winSize];
CCSprite *player = [CCSprite spriteWithFile:#"Player.jpg"
rect:CGRectMake(0, 0, 27, 40)];
player.position = ccp(player.contentSize.width/2, winSize.height/2);
[self addChild:player];
but I am not clear about the position of sprite how to manager it
Your code will create a sprite and position it within the parent node so that its lower-left corner is at ccp(player.contentSize.width/2, winSize.height/2).
If you wonder why your sprite is not centered respect to the coordinate you provide, the answer is that it is the lower-left corner which is positioned, not the sprite center.
You can tweak this behavior by defining the anchorPoint property of the sprite, like this:
player.anchorPoint = ccp(0.5,0.5);
player.position = ...
EDIT:
You can think of the anchor point as the "center of gravity" of the sprite: the texture is centered around it, any scaling or other kind of transformation will be relative to it.
If the anchor point is set at (0,0), then it coincides with the lower-left corner (default); if it is (0.5, 0.5) then it is exactly in the middle of the sprite (50% width, 50% height). Its coordinates are not point, but the relative displacement within the sprite; the coordinates can go from 0.0 to 1.0.
The problem that I have is that when ever I change the anchor point sprite automatically rotates with respect to the current anchor point. And I don't want that to happen.
The steps that I followed
create a sprite with anchor point (0.5, 0.5)
Changed the anchor point to (0,1)
Rotated the sprite to 90 degree. (Using CCRotateBy. Sprite rotated correctly)
Changed the anchor point to (0.5, 0.5) (Every thing is fine till now. And this is the position that I need to keep). Now sprite.rotation is 90.
I changed the anchor point to (1,0) (Sprite automatically rotates to 90 degree with respect to the given anchor point - I need to stop this behavior)
Is there any way to reset the rotation of sprite to 0, without actually rotating the texture(ie., to keep the texture in its current form - actual texture rotated to 90 degrees) and changing anchor point or position along with step 4, so that I can continue from point 5.
As Lukman says, the anchor point will always affect rotation, since your goal is to be able to specify the sprite position with a different anchor point from the rotation I would suggest making an empty CCNode as a parent of your sprite.
This way, you can set the position on sprite to be relative to this parent node to compensate for your anchor point change and then keep the anchor point for rotation on the sprite but use the parent node for position.
anchorPoint affects both position and rotation. You cannot stop it from affecting either one of them.
But from reading your question, since you want to prevent anchorPoint from affecting the rotation, I'm assuming here that the reason you change the anchorPoint is for the position, for example you are setting it to be ccp(1, 0) because you want to the sprite bottom right corner, instead of the sprite center, to be where you set the position is.
My suggestion is: don't change the anchorPoint at all, but change the way you set the sprite position. You can use this small function to adjust the position:
CGPoint adjustedPosition(const CGPoint position, const CGPoint anchor, const CGSize size) {
return CGPointMake(position.x - (anchor.x - 0.5) * size.width, position.y - (anchor.y - 0.5) * size.height);
}
Now, assuming you wanted to use anchorPoint of (1,0) when doing the positioning, instead of sprite.position = ccp(200, 300), you just need to do:
sprite.position = adjustedPosition(ccp(200, 300), ccp(1.0, 0.0), sprite.contentSize);
If you want, I'll post the logic behind the math later. Otherwise, I hope this will help.
Maybe it will help you to install an anchor for the sprites in the correct coordinate.
void SetAnchorPosition(CCSprite * sprite, const CCPoint & point)
{
static CCSize winSize = CCDirector::sharedDirector()->getWinSize();
double x = ((double)1/(double)winSize.width)*(double)point.x;
double y = ((double)1/(double)winSize.height)*(double)point.y;
sprite->setAnchorPoint(ccp(x,y));
sprite->setPosition(point);
}
You can add a line in the touchEnded method as a forceful alternative:
-(void)touchEnded:(UITouch *)touch withEvent:(UIEvent *)event{
_yourSprite.rotation = 90;
}