GLES-Render 是用来做 Box2D 的 debug draw 功能的，比较重要。
在 cocos2d-x 2.0 模板工程里面没有看到这个东西的影子，
而且我又有需要，便拿 cocos2d-iphone 2.0 的改了一个来用。
注意的一个地方是 shader 成员可以从 cocos2d shader 缓存里面拿，不用自己创建一个。
因为这里我是探索，所以就自己创建了一个玩玩儿。
代码如下：
GLES-Render.h
[cpp]
/*
* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
*
* iPhone port by Simon Oliver - http://www.simonoliver.com - http://www.handcircus.com
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
//
// File modified for cocos2d integration
// http://www.cocos2d-iphone.org
//
#ifndef GLES_RENDER_H
#define GLES_RENDER_H
#import "cocos2d.h"
#ifdef __CC_PLATFORM_IOS
#import <OpenGLES/EAGL.h>
#elif defined(__CC_PLATFORM_MAC)
#import <OpenGL/OpenGL.h>
#endif
#include "Box2D.h"
#include "ccShaders.h"
USING_NS_CC;
struct b2AABB;
// This class implements debug drawing callbacks that are invoked
// inside b2World::Step.
class GLESDebugDraw : public b2Draw {
float32 mRatio;
CCGLProgram* mShaderProgram;
GLint mColorLocation;
void initShader( void );
public:
GLESDebugDraw();
GLESDebugDraw( float32 ratio );
void DrawPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color);
void DrawSolidPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color);
void DrawCircle(const b2Vec2& center, float32 radius, const b2Color& color);
void DrawSolidCircle(const b2Vec2& center, float32 radius, const b2Vec2& axis, const b2Color& color);
void DrawSegment(const b2Vec2& p1, const b2Vec2& p2, const b2Color& color);
void DrawTransform(const b2Transform& xf);
void DrawPoint(const b2Vec2& p, float32 size, const b2Color& color);
void DrawString(int x, int y, const char* string, ...);
void DrawAABB(b2AABB* aabb, const b2Color& color);
};
#endif // GLES_RENDER_H
/*
* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
*
* iPhone port by Simon Oliver - http://www.simonoliver.com - http://www.handcircus.com
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
//
// File modified for cocos2d integration
// http://www.cocos2d-iphone.org
//
#ifndef GLES_RENDER_H
#define GLES_RENDER_H
#import "cocos2d.h"
#ifdef __CC_PLATFORM_IOS
#import <OpenGLES/EAGL.h>
#elif defined(__CC_PLATFORM_MAC)
#import <OpenGL/OpenGL.h>
#endif
#include "Box2D.h"
#include "ccShaders.h"
USING_NS_CC;
struct b2AABB;
// This class implements debug drawing callbacks that are invoked
// inside b2World::Step.
class GLESDebugDraw : public b2Draw {
float32 mRatio;
CCGLProgram* mShaderProgram;
GLint mColorLocation;
void initShader( void );
public:
GLESDebugDraw();
GLESDebugDraw( float32 ratio );
void DrawPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color);
void DrawSolidPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color);
void DrawCircle(const b2Vec2& center, float32 radius, const b2Color& color);
void DrawSolidCircle(const b2Vec2& center, float32 radius, const b2Vec2& axis, const b2Color& color);
void DrawSegment(const b2Vec2& p1, const b2Vec2& p2, const b2Color& color);
void DrawTransform(const b2Transform& xf);
void DrawPoint(const b2Vec2& p, float32 size, const b2Color& color);
