Final merge of Google Summer of Code 2008 work...

Bring SDL to iPhone and iPod Touch
by Holmes Futrell, mentored by Sam Lantinga

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403222

src/video/uikit/SDL_uikitopenglview.m

@@ -0,0 +1,164 @@
+/*
+ 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