text: /*
   * cocos2d for iPhone: http://www.cocos2d-iphone.org
   *
   * Copyright (c) 2011 Ricardo Quesada
   * Copyright (c) 2011 Zynga Inc.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #import "CCShaderCache.h"
  #import "ccShaders.h"
  #import "CCGLProgram.h"
  #import "ccMacros.h"
  #import "Support/OpenGL_Internal.h"
  
  static CCShaderCache *_sharedShaderCache;
  
  @implementation CCShaderCache
  
  #pragma mark CCShaderCache - Alloc, Init & Dealloc
  
  + (CCShaderCache *)sharedShaderCache
  {
  	if (!_sharedShaderCache)
  		_sharedShaderCache = [[CCShaderCache alloc] init];
  
  	return _sharedShaderCache;
  }
  
  +(void)purgeSharedShaderCache
  {
  	_sharedShaderCache = nil;
  }
  
  
  +(id)alloc
  {
  	NSAssert(_sharedShaderCache == nil, @"Attempted to allocate a second instance of a singleton.");
  	return [super alloc];
  }
  
  - (void)dealloc
  {
  	CCLOGINFO(@"cocos2d deallocing %@", self);
  
  }
  
  +(void)purgeSharedTextureCache
  {
  	_sharedShaderCache = nil;
  }
  
  -(id) init
  {
  	if( (self=[super init]) ) {
  		_programs = [[NSMutableDictionary alloc ] initWithCapacity: 10];
  
  		[self loadDefaultShaders];
  	}
  
  	return self;
  }
  
  -(void) loadDefaultShaders
  {
  	// Position Texture Color shader
  	CCGLProgram *p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPositionTextureColor_vert
  												fragmentShaderByteArray:ccPositionTextureColor_frag];
  
  	[p addAttribute:kCCAttributeNamePosition index:kCCVertexAttrib_Position];
  	[p addAttribute:kCCAttributeNameColor index:kCCVertexAttrib_Color];
  	[p addAttribute:kCCAttributeNameTexCoord index:kCCVertexAttrib_TexCoords];
  
  	[p link];
  	[p updateUniforms];
  
  	[_programs setObject:p forKey:kCCShader_PositionTextureColor];
  
  	CHECK_GL_ERROR_DEBUG();
  
  	// Position Texture Color alpha test
  	p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPositionTextureColor_vert
  								   fragmentShaderByteArray:ccPositionTextureColorAlphaTest_frag];
  
  	[p addAttribute:kCCAttributeNamePosition index:kCCVertexAttrib_Position];
  	[p addAttribute:kCCAttributeNameColor index:kCCVertexAttrib_Color];
  	[p addAttribute:kCCAttributeNameTexCoord index:kCCVertexAttrib_TexCoords];
  
  	[p link];
  	[p updateUniforms];
  
  	[_programs setObject:p forKey:kCCShader_PositionTextureColorAlphaTest];
  
  	CHECK_GL_ERROR_DEBUG();
  
  	//
  	// Position, Color shader
  	//
  	p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPositionColor_vert
  								   fragmentShaderByteArray:ccPositionColor_frag];
  
  	[p addAttribute:kCCAttributeNamePosition index:kCCVertexAttrib_Position];
  	[p addAttribute:kCCAttributeNameColor index:kCCVertexAttrib_Color];
  
  	[p link];
  	[p updateUniforms];
  
  	[_programs setObject:p forKey:kCCShader_PositionColor];
  
  	CHECK_GL_ERROR_DEBUG();
  
  	//
  	// Position Texture shader
  	//
  	p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPositionTexture_vert
  								   fragmentShaderByteArray:ccPositionTexture_frag];
  
  	[p addAttribute:kCCAttributeNamePosition index:kCCVertexAttrib_Position];
  	[p addAttribute:kCCAttributeNameTexCoord index:kCCVertexAttrib_TexCoords];
  
  	[p link];
  	[p updateUniforms];
  
  	[_programs setObject:p forKey:kCCShader_PositionTexture];
  
  	CHECK_GL_ERROR_DEBUG();
  
  	//
  	// Position, Texture attribs, 1 Color as uniform shader
  	//
  	p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPositionTexture_uColor_vert
  								   fragmentShaderByteArray:ccPositionTexture_uColor_frag];
  
  	[p addAttribute:kCCAttributeNamePosition index:kCCVertexAttrib_Position];
  	[p addAttribute:kCCAttributeNameTexCoord index:kCCVertexAttrib_TexCoords];
  
  	[p link];
  	[p updateUniforms];
  
  	[_programs setObject:p forKey:kCCShader_PositionTexture_uColor];
  	
  	CHECK_GL_ERROR_DEBUG();
  
  	//
  	// Position Texture A8 Color shader
  	//
  	p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPositionTextureA8Color_vert
  								   fragmentShaderByteArray:ccPositionTextureA8Color_frag];
  
  	[p addAttribute:kCCAttributeNamePosition index:kCCVertexAttrib_Position];
  	[p addAttribute:kCCAttributeNameColor index:kCCVertexAttrib_Color];
  	[p addAttribute:kCCAttributeNameTexCoord index:kCCVertexAttrib_TexCoords];
  
  	[p link];
  	[p updateUniforms];
  
  	[_programs setObject:p forKey:kCCShader_PositionTextureA8Color];
  
  	CHECK_GL_ERROR_DEBUG();
  	
  	//
  	// Position and 1 color passed as a uniform (to similate glColor4ub )
  	//
  	p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPosition_uColor_vert
  								   fragmentShaderByteArray:ccPosition_uColor_frag];	
  	
  	[p addAttribute:@"aVertex" index:kCCVertexAttrib_Position];
  	
  	[p link];
  	[p updateUniforms];
  
  	[_programs setObject:p forKey:kCCShader_Position_uColor];
  
  	CHECK_GL_ERROR_DEBUG();
  	
  	//
  	// Position, Legth(TexCoords, Color (used by Draw Node basically )
  	//
  	p = [[CCGLProgram alloc] initWithVertexShaderByteArray:ccPositionColorLengthTexture_vert
  								   fragmentShaderByteArray:ccPositionColorLengthTexture_frag];	
  	
  	[p addAttribute:kCCAttributeNamePosition index:kCCVertexAttrib_Position];
  	[p addAttribute:kCCAttributeNameTexCoord index:kCCVertexAttrib_TexCoords];
  	[p addAttribute:kCCAttributeNameColor index:kCCVertexAttrib_Color];
  	
  	[p link];
  	[p updateUniforms];
  	
  	[_programs setObject:p forKey:kCCShader_PositionLengthTexureColor];
  	CHECK_GL_ERROR_DEBUG();
  }
  
  -(CCGLProgram *) programForKey:(NSString*)key
  {
  	return [_programs objectForKey:key];
  }
  
  - (void) addProgram:(CCGLProgram*)program forKey:(NSString*)key
  {
      [_programs setObject:program forKey:key];
  }
  
  @end
  