OpenGL Es Init probelm.

[austriancoder]

Hi guys.

I have here some trouble wih opengl es. I dont want to use a xib file so I changed main() to use my defined AppDelegate.

int retVal = UIApplicationMain(argc, argv, nil, @"GameAppDelegate");

In my GameAppDelegate I create a window and a glview:

	// create window
	self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
	
	// create view
    glview = [[eglView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
	[window addSubview:glview];
    
	// show window
	[window makeKeyAndVisible];

Now you are want to see some source of the eglView Here they are:

#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#include <OpenGLES/ES1/gl.h>

#include <renderer/OglEsGlue.h>

/*
 This class wraps the CAEAGLLayer from CoreAnimation into a convenient UIView subclass.
 The view content is basically an EAGL surface you render your OpenGL scene into.
 Note that setting the view non-opaque will only work if the EAGL surface has an alpha channel.
 */
@interface eglView : UIView {
@private
	GLint backingWidth;
	GLint backingHeight;
	EAGLContext *context;
	GLuint viewRenderbuffer, viewFramebuffer;
	GLuint depthRenderbuffer;
}

#include "OglEsView.h"

#include "OpenGLES/ES1/glext.h"

static id g_context;
static int g_frame;
static int g_render;

// A class extension to declare private methods

@interface eglView ()
@property (nonatomic, retain) EAGLContext *context;

- (BOOL) createFramebuffer;
- (void) destroyFramebuffer;

@end



@implementation eglView

@synthesize context;

+ (Class) layerClass 
{
	return [CAEAGLLayer class];
}

- (id) initWithFrame:(CGRect)frame
{
	self = [super initWithFrame:frame];
	if ( self != nil )
	{
        // Get the layer
        CAEAGLLayer *eaglLayer = (CAEAGLLayer *)self.layer;

        eaglLayer.opaque = YES;
        eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:
                                        [NSNumber numberWithBool:NO], kEAGLDrawablePropertyRetainedBacking, kEAGLColorFormatRGBA8, kEAGLDrawablePropertyColorFormat, nil];
		
        context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES1];
		
        if (!context || ![EAGLContext setCurrentContext:context]) {			
            [self release];
            return nil;
        }	
		
		// store context, so that it is possible to acces it from c/c++
		g_context = context;
	
		// init framebuffers
		[self createFramebuffer];		
	}
	
	return self;
}

- (BOOL) createFramebuffer {
	
	glGenFramebuffersOES(1, &viewFramebuffer);
	glGenRenderbuffersOES(1, &viewRenderbuffer);
	
	// store for c/c++ access
	g_render = viewRenderbuffer;
	g_frame = viewFramebuffer;
	
	glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);
	glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);
	[context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:(CAEAGLLayer*)self.layer];
	glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, viewRenderbuffer);
	
	glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);
	glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);
	
	glGenRenderbuffersOES(1, &depthRenderbuffer);
	glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);
	glRenderbufferStorageOES(GL_RENDERBUFFER_OES, GL_DEPTH_COMPONENT16_OES, backingWidth, backingHeight);
	glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);
	
	if (glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) != GL_FRAMEBUFFER_COMPLETE_OES) {
		NSLog(@"failed to make complete framebuffer object %x", glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES));
		return NO;
	}
	
	glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);
	
	return YES;
}

- (void) destroyFramebuffer {
	
	glDeleteFramebuffersOES(1, &viewFramebuffer);
	viewFramebuffer = 0;
	glDeleteRenderbuffersOES(1, &viewRenderbuffer);
	viewRenderbuffer = 0;
	glDeleteRenderbuffersOES(1, &depthRenderbuffer);
	depthRenderbuffer = 0;
}

- (void) dealloc
{
	[self destroyFramebuffer];
	
    if ([EAGLContext currentContext] == context) {
        [EAGLContext setCurrentContext:nil];
    }
	
    [context release];  
    [super dealloc];
}

@end

void makeCurrent()
{
	[EAGLContext setCurrentContext:g_context];
	glBindFramebufferOES(GL_FRAMEBUFFER_OES, g_frame);
}

void swapBuffers()
{
	glBindRenderbufferOES(GL_RENDERBUFFER_OES, g_render);
	[g_context presentRenderbuffer:GL_RENDERBUFFER_OES];
}

So I should now have a window with my eglview. This seems to work. Now if I do something like:

void cIntroState::Render()
{	
	makeCurrent();

	glClearColor(1.0, 0.0, 1.0, 1.0);
	glClear(GL_COLOR_BUFFER_BIT);   

	swapBuffers();
}

Nothing happens... screen stays black... but it should have an other color then black - see glClearColor.

it would be very cool, if someone could help me.
ac

[smasher]

Your OpenGL and drawing code looks tip-top; I pasted it into the GLSprite example, and it works fine (pink background.) Maybe there's something wrong with the changes you made to eliminate the .xib file - I tried to integrate those changes into the same project, and got nothing but a white screen.

[austriancoder]

I think I will switch back to the xib file as time is running out and this problem needs to be fixed now. Maybe I will find time later to find a fix.
Oh.. in GLSprite i also get a white screen

[billyzelsnack]

Originally Posted by austriancoder

I think I will switch back to the xib file as time is running out and this problem needs to be fixed now. Maybe I will find time later to find a fix.
Oh.. in GLSprite i also get a white screen

I've been trying to get this to work as well and get the same results. I think that the xib might be doing some voodoo to make it work.

[fili]

Did you look at GLPaint sample? It's not using .xib and inits OpenGL ES. I'm using that as a startup point and it works

[billyzelsnack]

Originally Posted by fili

Did you look at GLPaint sample? It's not using .xib and inits OpenGL ES. I'm using that as a startup point and it works

I did not. I'll go look at it now. Thanks for the heads-up.