Clip a CCSprite added to CCSpriteBatchNode - cocos2d-iphone

I'm clipping my sprite with this code:
//At my CCSprite subclass m.
-(void)visit
{
CGPoint worldOrg = [self convertToWorldSpace:ccp(0, 0)];
CGPoint dest = [self convertToWorldSpace:ccp(self.contentSize.width, self.contentSize.height)];
CGPoint dims = ccpSub(dest, worldOrg);
glEnable(GL_SCISSOR_TEST);
glScissor(worldOrg.x, worldOrg.y, dims.x, dims.y);
#define SHOW_CLIPPED_AREA 1
#if SHOW_CLIPPED_AREA
//Draws a red rectangle showing clipped area
ccDrawSolidRect(ccp(0, 0), ccp(1024, 1024), ccc4f(64, 0, 0, 128));
#endif
[super visit];
glDisable(GL_SCISSOR_TEST);
}
Then just create the sprite as usual, adjust the sprite.contentSize property to whatever I need:
CCSprite aSprite = [CCSprite spriteWith...];
aSprite.contentSize = CGSizeMake(20,20);
//Add it to my layer
[self addChild:aSprite];
And it works as expected!
Problem...
When adding it to a CCSpriteBatchNode, it wont clip the sprite... it shows the sprite but without clipping it.
Can someone please help me out with this, I've googled everywhere with no answer to this.
I've also used the ClippingNode class from Steffen Itterheim, but I'm also having issues adding it to a CCSpriteBatchNode.
Any help will be appreciated.

Clipping or any custom drawing won't work with sprite-batched sprites.
The CCSpriteBatchNode will not call visit (nor draw) methods on their children because the batch node takes over rendering of the children. Therefore any code you write in draw or visit methods of a CCSprite will have no effect when you sprite-batch the sprite.

Related

How can I display the bounding box for a CCNode in cocos2d?

As a follow-on question to my previous question about displaying the anchor point, I subclassed CCSprite and changed its draw method as follows:
[super draw];
ccDrawColor4F(0, 1, 0, 1);
ccDrawCircle(self.anchorPointInPoints, 20, 0, 8, YES);
This works great. For extra credit, I added the following to display its bounding box:
CGRect bb = self.boundingBox;
CGPoint vertices[4] = {
[self convertToNodeSpace:ccp(bb.origin.x, bb.origin.y)],
[self convertToNodeSpace:ccp(bb.origin.x + bb.size.width, bb.origin.y)],
[self convertToNodeSpace:ccp(bb.origin.x + bb.size.width, bb.origin.y + bb.size.height)],
[self convertToNodeSpace:ccp(bb.origin.x, bb.origin.y + bb.size.height)],
};
ccDrawPoly(vertices, 4, YES);
This also works great, until I reparent a sprite:
CGPoint oldPosition = [sprite convertToWorldSpace:sprite.position];
[sprite removeFromParentAndCleanup:NO];
[parentSprite addChild:sprite];
sprite.position = [sprite convertToNodeSpace:oldPosition];
The sprite's now in the proper position and its anchor point draws where it should, but the bounding box draws in the wrong place. What am I doing wrong?
Bounding box of a node is relative to its parent. Drawing done in draw method is in node's local space. convertToNodeSpace: converts coordinates from world space to local space, not from parent's space.
When you reparent node to a parent with different origin while maintaining same "world" position of this node, origin of its bounding box changes.
Your mistake is that you treat your sprite's bounding box as if its coordinates were in world space.
Second, you don't need to do the convert-to-x-space dance to draw bounding box of a sprite. Open ccConfig.h file in cocos2d folder of your project and change
#define CC_SPRITE_DEBUG_DRAW 0
line to
#define CC_SPRITE_DEBUG_DRAW 1
Third, coordinates of sprite.position point are relative to its parent, not to the sprite. When you call [node convertToWorldSpace:aPoint], it will treat aPoint as if it were in node's local space. If you want to get world coordinates of a node's position, you should call convertToWorldSpace: on node's parent: [node.parent convertToWorldSpace:node.position].
I normally draw AABBs with:
Rect aabb = someNode->getBoundingBox();
DrawNode* drawNode = DrawNode::create();
drawNode->drawRect(aabb.origin, aabb.origin + aabb.size, Color4F(1, 0, 0, 1));
parentNode->addChild(drawNode, 100);
Note: If the Rect aabb size is (0,0) then the rectangle will not be drawn.

How To Have The Same Sprite In Multiple Locations Cocos2d

How To Have The Same Sprite In Multiple Locations Cocos2d Please Help
I have searched all over and cannot find answer
Just create multiple Sprites (CCSprite instances). They can all use the same texture (bitmap-file).
CCSprite * mySprite1;
CCSprite * mySprite2;
CCSprite * mySprite3;
// create several sprites from the same bitmap file
mySprite1 = [CCSprite spriteWithFile:#"spriteBitmap.png"];
mySprite2 = [CCSprite spriteWithFile:#"spriteBitmap.png"];
mySprite3 = [CCSprite spriteWithFile:#"spriteBitmap.png"];
mySprite1.position = ccp(100, 100);
mySprite2.position = ccp(200, 200);
mySprite3.position = ccp(300, 300);
You can not add the same CCSprite as a child to multiple CCNodes but you can make Cocos2D render the same CCSprite multiple times.
To achieve this you need to create a subclass of CCNode that will store the reference to your CCSprite and draw it in its -draw method applying required transformations.
For example
-(void)draw
{
[super draw];
CGPoint initialPosition = [_node position];
float initialScale = [_node scale];
[_node setScale:self.scale];
[_node setPosition:self.position];
[_node visit];
[_node setPosition:initialPosition];
[_node setScale:initialScale];
}
You may have to to use glScissor if you need picture-in-picture appearance.
Then you just need to addChild an instance of this class for every time you want an additional copy of your original CCSprite rendered.
Put a method on a for loop.
Inside the method create the CCSprite and modify it.
This is best suited for static sprites, since I don't know how you would access these outside of the method.

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/

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".

Cocos2d iPhone - Sprite cliping/mask/frame

how can i clip/crop/mask or just set the frame of a CCSprite in Cocos2D?
Something similar to:
setting the frame for UIView, with clipping subviews = TRUE
My CCSprite Main Sprite have multiple Child Sprite added to it.
I only want Mask part of that Main Sprite Sprite visible.
Is there a way to clip or use a mask for CCSprite?
I could cut the background and layer that on top, leaving only that visible area, but is that the only way?!
here's a sample image demonstrating what I'm trying to achieve:
(source: dnamique.com)
I ended up using GL_SCISSOR.
in MainSprite I impemented:
- (void) visit
{
if (!self.visible) {
return;
}
glEnable(GL_SCISSOR_TEST);
glScissor(x, y, width, height);
[super visit];
glDisable(GL_SCISSOR_TEST);
}
This will clip or mask the specified area.
The only tricky bit is that in Landscape mode Cocos2D has 0,0 at the bottom-left side of the screen, while OpenGL has it at the bottom-right corner as it doesn't consider the orientation of the screen.
In other words, for OpenGL consider you have a rotated portrait Screen.
I wrote a ClippingNode class which does exactly that. You can add other nodes (sprites, labels, etc.) to the ClippingNode and they will only be drawn in the region specified by the ClippingNode. It also takes device rotation into account.
Internally it uses GL_SCISSOR_TEST like in Bach's answer.
http://www.learn-cocos2d.com/2011/01/cocos2d-gem-clippingnode/
I tried using Steffen Itterheim's ClippingNode, but was unable to get to work in a sufficiently robust
enough fashion for my needs.
Believe it or not, the below code works fairly well and should be code complete. It handles device orientation changes, anchorPoint, position, scale (scaleX, scaleY). For cocos2d v2, you may just need to
comment out the glPushMatrix and glPopMatrix calls..
To use, simply set the position and contentSize properties and add the child/children you want clipped to this ClippingNode instance. The contentSize property is used to define the dimensions of the clipping region.
example of usage:
ClippingNode *clipNode = [[ClippingNode alloc] init];
clipNode.anchorPoint = ccp(0.5f, 0);
clipNode.position = ccp(100, 25);
clipNode.contentSize = CGSizeMake(120, 120);
// add clipNode to your node hierarchy.
[parentNode addChild:clipNode];
// add one or more children to your clipNode:
[clipNode addChild:child1];
// ClippingNode.h
// CC0 - (public domain. Use in anyway you see fit.)
// No warranty of any kind is expressed or implied.
//
// by UChin Kim.
//
// the caller can simply set the regular cocos2d
// properties: position and contentSize to define the clipping region implicitly (i.e. the
// position and contentSize of the ClippingNode is the clipping region to be used).
// as an added bonus, position seems to work as expected (relative to parent node, instead of
// requiring absolute positioning).
//
// also, anchorPoint and scale properties seem to work as expected as well..
// no special code is neeed to handle device orientation changes correctly..
//
// To visually see exactly what is being clipped, set the following #define
// #define SHOW_CLIPPED_REGION_IN_LIGHT_RED 1
//
#import "cocos2d.h"
#interface ClippingNode : CCNode
#end
//
// ClippingNode.m
//
#import "ClippingNode.h"
#implementation ClippingNode
-(void) visit
{
CGPoint worldOrg = [self convertToWorldSpace:ccp(0, 0)];
CGPoint dest = [self convertToWorldSpace:ccp(self.contentSize.width, self.contentSize.height)];
CGPoint dims = ccpSub(dest, worldOrg);
glPushMatrix();
glEnable(GL_SCISSOR_TEST);
glScissor(worldOrg.x, worldOrg.y, dims.x, dims.y);
#if SHOW_CLIPPED_REGION_IN_LIGHT_RED
glColor4ub(64, 0, 0, 128);
ccDrawSolidRect(ccp(0, 0), ccp(1024, 1024));
#endif
[super visit];
glDisable(GL_SCISSOR_TEST);
glPopMatrix();
}
#end