Making Cocos2d Transparent « cocos2d for iPhone

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Making Cocos2d Transparent

(15 posts) (11 voices)

Started 2 years ago by malphigian
Latest reply from Tenorm

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malphigian
Member

For various reasons I need to get Cocos2d's openGL view on top of some other UIViews.

I've got this working, but I can't seem to get Cocos to be transparent. There was some discussion of this before in this thread: http://www.cocos2d-iphone.org/forum/topic/711 -- but attempts to just set backgroundColor to UIColor clearColor have no effect.

It's the openGLView (which is a EAGLView instance if I follow correctly) that I'm fairly sure is showing up with the black box. Is this something to do with openGL blend modes? I'm still really wobbly with direct openGL coding, something I obviously next to fix.

Any advice would be much appreciated!

Posted 2 years ago #
malphigian
Member

Answering my own question. I don't know enough about openGL to tell you exactly why, but this is what worked for me before getting my views in order:
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
glClearColor(0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

The idea I think is I'm making the glClearColor transparent, then telling it to clear. Like I said, I'm a big amateur at openGL, but it kind of makes sense.

Posted 2 years ago #
vinhsteven
Member

Thanks your answer. I'd met this problem :)

Posted 2 years ago #
licgfg
Member

Finally I could solve the problems. Thanks.

P.S. The above code is added after [[Director sharedDirector]attachInView:yourView];

Posted 2 years ago #
licgfg
Member

One more thing.
[Director sharedDirector].openGLView.backgroundColor = [UIColor clearColor];
is needed after adding the above code.

Posted 2 years ago #
Phlipee
Member

I tried testing this out on the attach demo, but it isnt working for me.

Right after the:
[[Director sharedDirector] attachInView:mainView withFrame:CGRectMake(0, 0, 250,350)];

I added the lines:
glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
[Director sharedDirector].openGLView.backgroundColor = [UIColor clearColor];

but it still shows up with a black background. Am I doing something wrong?

Posted 2 years ago #
Lam
Member

If you've ever looked at Apples iphone opengl template you would notice that there's an EAGLView that subclasses a CAEAGLLayer and what it does is make sure the view is opaque for performance reasons. So even if you changed a view backgroundColor it still wouldn't be transparent.

Posted 2 years ago #
leothenerd
Member

This works for my app:

// Get the size
CGSize size = [[CCDirector sharedDirector] winSize];
// For full screen
UITextView *textView = [[UITextView alloc] initWithFrame:CGRectMake(0,0, size.height,size.width)];
// Transparent
textView.backgroundColor = [UIColor clearColor];
// Attach the view
[[[CCDirector sharedDirector]openGLView]addSubview:textView];

Posted 2 years ago #
folcojp
Member

Hi, i have the same problem. I have two subViews in my Window. One with a button in the background and one with cocos, on top.

I tried with all of this and with http://www.cocos2d-iphone.org/wiki/doku.php/tips:director_transparentview

but couldnt make it ( v. 0.99.2 )

anyone could actually make this work?

Posted 2 years ago #
folcojp
Member

nevermind it works now.

Posted 2 years ago #
richardfu
Member

It works.Thanks for sharing.
I attached a transparent scene on a UIImageView.
Once the scene become transparent the performance also drop.
The fps drop from 60 to 40.
Any ideas?

Posted 1 year ago #
liquidfire
Member

I'm not the one to ask, but I have heard that mixing UIKit and Cocos2D is very slow, for uncontrollable reasons.

Posted 1 year ago #

leliksan
Member

in last versions of cocos2d you need to change CC_DIRECTOR_INIT() macro to:

#define CC_DIRECTOR_INIT()																		\
do	{																							\
	window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];					\
	if( ! [CCDirector setDirectorType:kCCDirectorTypeDisplayLink] )								\
		[CCDirector setDirectorType:kCCDirectorTypeNSTimer];									\
	CCDirector *__director = [CCDirector sharedDirector];										\
	[__director setDeviceOrientation:kCCDeviceOrientationPortrait];								\
	[__director setDisplayFPS:NO];																\
	[__director setAnimationInterval:1.0/60];													\
	EAGLView *__glView = [EAGLView viewWithFrame:[window bounds]								\
									pixelFormat:kEAGLColorFormatRGBA8							\
									depthFormat:0 /* GL_DEPTH_COMPONENT24_OES */				\
							 preserveBackbuffer:NO];											\
	[__director setOpenGLView:__glView];														\
	[window addSubview:__glView];																\
	[window makeKeyAndVisible];																	\
} while(0)

Posted 1 year ago #

Tenorm
Member

Would be great if someone could write a COMPLETE example or how-to, about adding cocos as a transparent subview to an existung UIKit-View, here. Thank you!

Posted 1 year ago #
Tenorm
Member

leliksan's code works, I had a wrong view-order xD

Posted 1 year ago #

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