1 /*

     2  SDL - Simple DirectMedia Layer

     3  Copyright (C) 1997-2009 Sam Lantinga

     4  

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

     6  modify it under the terms of the GNU Lesser General Public

     7  License as published by the Free Software Foundation; either

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

     9  

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

    11  but WITHOUT ANY WARRANTY; without even the implied warranty of

    12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    13  Lesser General Public License for more details.

    14  

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

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

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

    18  

    19  Sam Lantinga

    20  slouken@libsdl.org

    21  */

    22 

    23 #import <QuartzCore/QuartzCore.h>

    24 #import <OpenGLES/EAGLDrawable.h>

    25 #import "SDL_uikitopenglview.h"

    26 

    27 @interface SDL_uikitopenglview (privateMethods)

    28 

    29 - (BOOL) createFramebuffer;

    30 - (void) destroyFramebuffer;

    31 

    32 @end

    33 

    34 

    35 @implementation SDL_uikitopenglview

    36 

    37 @synthesize context;

    38 

    39 + (Class)layerClass {

    40 	return [CAEAGLLayer class];

    41 }

    42 

    43 - (id)initWithFrame:(CGRect)frame \

    44 retainBacking:(BOOL)retained \

    45 rBits:(int)rBits \

    46 gBits:(int)gBits \

    47 bBits:(int)bBits \

    48 aBits:(int)aBits \

    49 depthBits:(int)depthBits \

    50 {

    51 	

    52 	NSString *colorFormat=nil;

    53 	GLuint depthBufferFormat;

    54 	BOOL useDepthBuffer;

    55 	

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

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

    58 		colorFormat = kEAGLColorFormatRGBA8;

    59 	}

    60 	else {

    61 		/* default case (faster) */

    62 		colorFormat = kEAGLColorFormatRGB565;

    63 	}

    64 	

    65 	if (depthBits == 24) {

    66 		useDepthBuffer = YES;

    67 		depthBufferFormat = GL_DEPTH_COMPONENT24_OES;

    68 	}

    69 	else if (depthBits == 0) {

    70 		useDepthBuffer = NO;

    71 	}

    72 	else {

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

    74 		/* 

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

    76 		 perhaps that's the only depth format iPhone actually supports

    77 		 */

    78 		useDepthBuffer = YES;

    79 		depthBufferFormat = GL_DEPTH_COMPONENT16_OES;

    80 	}

    81 	

    82 	

    83 	// we invert heigh and size to get q landscape mode up

    84 	CGRect rect = [[UIScreen mainScreen] bounds];

    85 	float swapTemp = rect.size.height;

    86 	rect.size.width = rect.size.height;

    87 	rect.size.height = swapTemp;

    88 	

    89 	if ((self = [super initWithFrame:rect])) {

    90 		// Get the layer

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

    92 		

    93 		eaglLayer.opaque = YES;

    94 		eaglLayer.drawableProperties = [NSDictionary dictionaryWithObjectsAndKeys:

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

    96 		

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

    98 		

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

   100 			[self release];

   101 			return nil;

   102 		}

   103 		

   104 		/* create the buffers */

   105 		glGenFramebuffersOES(1, &viewFramebuffer);

   106 		glGenRenderbuffersOES(1, &viewRenderbuffer);

   107 		

   108 		glBindFramebufferOES(GL_FRAMEBUFFER_OES, viewFramebuffer);

   109 		glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);

   110 		[context renderbufferStorage:GL_RENDERBUFFER_OES fromDrawable:(CAEAGLLayer*)self.layer];

   111 		glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_COLOR_ATTACHMENT0_OES, GL_RENDERBUFFER_OES, viewRenderbuffer);

   112 		

   113 		glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_WIDTH_OES, &backingWidth);

   114 		glGetRenderbufferParameterivOES(GL_RENDERBUFFER_OES, GL_RENDERBUFFER_HEIGHT_OES, &backingHeight);

   115 		

   116 		if (useDepthBuffer) {

   117 			glGenRenderbuffersOES(1, &depthRenderbuffer);

   118 			glBindRenderbufferOES(GL_RENDERBUFFER_OES, depthRenderbuffer);

   119 			glRenderbufferStorageOES(GL_RENDERBUFFER_OES, depthBufferFormat, backingWidth, backingHeight);

   120 			glFramebufferRenderbufferOES(GL_FRAMEBUFFER_OES, GL_DEPTH_ATTACHMENT_OES, GL_RENDERBUFFER_OES, depthRenderbuffer);

   121 		}

   122 		

   123 		if(glCheckFramebufferStatusOES(GL_FRAMEBUFFER_OES) != GL_FRAMEBUFFER_COMPLETE_OES) {

   124 			return NO;

   125 		}

   126 		/* end create buffers */

   127 	}

   128 	return self;

   129 }

   130 

   131 - (void)setCurrentContext {

   132 	[EAGLContext setCurrentContext:context];

   133 }

   134 

   135 

   136 - (void)swapBuffers {

   137 	glBindRenderbufferOES(GL_RENDERBUFFER_OES, viewRenderbuffer);

   138 	[context presentRenderbuffer:GL_RENDERBUFFER_OES];

   139 }

   140 

   141 

   142 - (void)layoutSubviews {

   143 	[EAGLContext setCurrentContext:context];

   144 }

   145 

   146 - (void)destroyFramebuffer {

   147 	

   148 	glDeleteFramebuffersOES(1, &viewFramebuffer);

   149 	viewFramebuffer = 0;

   150 	glDeleteRenderbuffersOES(1, &viewRenderbuffer);

   151 	viewRenderbuffer = 0;

   152 	

   153 	if (depthRenderbuffer) {

   154 		glDeleteRenderbuffersOES(1, &depthRenderbuffer);

   155 		depthRenderbuffer = 0;

   156 	}

   157 }

   158 

   159 

   160 - (void)dealloc {

   161 	

   162 	[self destroyFramebuffer];

   163 	if ([EAGLContext currentContext] == context) {

   164 		[EAGLContext setCurrentContext:nil];

   165 	}

   166 	[context release];	

   167 	[super dealloc];

   168 	

   169 }

   170 

   171 @end