/*

 SDL - Simple DirectMedia Layer

 Copyright (C) 1997-2006 Sam Lantinga

 This library is free software; you can redistribute it and/or

 modify it under the terms of the GNU Lesser General Public

 License as published by the Free Software Foundation; either

 version 2.1 of the License, or (at your option) any later version.

 This library is distributed in the hope that it will be useful,

 but WITHOUT ANY WARRANTY; without even the implied warranty of

 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public

 License along with this library; if not, write to the Free Software

 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 Sam Lantinga

 slouken@libsdl.org

 */

#import <QuartzCore/QuartzCore.h>

#import <OpenGLES/EAGLDrawable.h>

#import "SDL_uikitopenglview.h"

@interface SDL_uikitopenglview (privateMethods)

- (BOOL) createFramebuffer;

- (void) destroyFramebuffer;

@end

@implementation SDL_uikitopenglview

@synthesize context;

+ (Class)layerClass {

	return [CAEAGLLayer class];

}

- (id)initWithFrame:(CGRect)frame \

	  retainBacking:(BOOL)retained \

	  rBits:(int)rBits \

	  gBits:(int)gBits \

	  bBits:(int)bBits \

	  aBits:(int)aBits \

	  depthBits:(int)depthBits \

{

	NSString *colorFormat=nil;

	GLuint depthBufferFormat;

	BOOL useDepthBuffer;

	if (rBits == 8 && gBits == 8 && bBits == 8) {

		/* if user specifically requests rbg888 or some color format higher than 16bpp */

		colorFormat = kEAGLColorFormatRGBA8;

	}

	else {

		/* default case (faster) */

		colorFormat = kEAGLColorFormatRGB565;

	}

	if (depthBits == 24) {

		useDepthBuffer = YES;

		depthBufferFormat = GL_DEPTH_COMPONENT24_OES;

	}

	else if (depthBits == 0) {

		useDepthBuffer = NO;

	}

	else {

		/* default case when depth buffer is not disabled */

		/* 

		   strange, even when we use this, we seem to get a 24 bit depth buffer on iPhone.

		   perhaps that's the only depth format iPhone actually supports

		*/

		useDepthBuffer = YES;

		depthBufferFormat = GL_DEPTH_COMPONENT16_OES;

	}

	if ((self = [super initWithFrame:frame])) {

		// Get the layer

		CAEAGLLayer *eaglLayer = (CAEAGLLayer *)self.layer;

		eaglLayer.opaque = YES;

		eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:

										[NSNumber numberWithBool: retained], kEAGLDrawablePropertyRetainedBacking, colorFormat, kEAGLDrawablePropertyColorFormat, nil];

		context = [[EAGLContext alloc] initWithAPI: kEAGLRenderingAPIOpenGLES1];

		if (!context || ![EAGLContext setCurrentContext:context]) {

			[self release];

			return nil;

		}

		/* create the buffers */

		glGenFramebuffersOES(1, &viewFramebuffer);

		glGenRenderbuffersOES(1, &viewRenderbuffer);

		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);

		if (useDepthBuffer) {

			glGenRenderbuffersOES(1, &depthRenderbuffer);

			glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);

			glRenderbufferStorageOES(GL_RENDERBUFFER_OES, depthBufferFormat, backingWidth, backingHeight);

			glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);

		}

		if(glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) != GL_FRAMEBUFFER_COMPLETE_OES) {

			return NO;

		}

		/* end create buffers */

	}

	return self;

}

- (void)setCurrentContext {

	[EAGLContext setCurrentContext:context];

}

- (void)swapBuffers {

	glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);

	[context presentRenderbuffer:GL_RENDERBUFFER_OES];

}

- (void)layoutSubviews {

	[EAGLContext setCurrentContext:context];

}

- (void)destroyFramebuffer {

	glDeleteFramebuffersOES(1, &viewFramebuffer);

	viewFramebuffer = 0;

	glDeleteRenderbuffersOES(1, &viewRenderbuffer);

	viewRenderbuffer = 0;

	if (depthRenderbuffer) {

		glDeleteRenderbuffersOES(1, &depthRenderbuffer);

		depthRenderbuffer = 0;

	}

}

- (void)dealloc {

	[self destroyFramebuffer];

	if ([EAGLContext currentContext] == context) {

		[EAGLContext setCurrentContext:nil];

	}

	[context release];	

	[super dealloc];

}

@end