cocos2dx学习笔记（着色器水纹效果）

转载：http://blog.csdn.net/qq_17749439/article/details/37933937

着色器

转载  http://www.25kx.com/art/2424495

参考：

 //   ShaderNode.h
 #include
 #include "cocos2d.h"
 USING_NS_CC;
 class ShaderNode : public CCNode
 {
 public:
     ShaderNode();
     bool initWithVertex(const char *vert, const char *frag);
     void loadShaderVertex(const char *vert, const char *frag);
     virtual void update(float delta);
     virtual void setContentSize(const CCSize& var);
     virtual void setColor(ccColor4F newColor);
     virtual void draw();
     static ShaderNode* shaderNodeWithVertex(const char *vert,
                                             const char *frag);

 private:
 //    标示符
     GLuint      m_uniformResolution, m_uniformTime, m_uniformTex0;
     GLuint      m_attributeColor, m_attributePosition;
 //    取值
     float       m_time;
     ccVertex2F  m_resolution,m_center;
     GLuint      m_texture;
     GLfloat     color[4];
 };

 //   ShaderNode.cpp
 #include "ShaderNode.h"
 ShaderNode::ShaderNode()
 {

 }

 ShaderNode* ShaderNode::shaderNodeWithVertex(const char *vert, const char *frag)
 {
     ShaderNode* shader = new ShaderNode();
     if(shader && shader->initWithVertex(vert,frag))
     {
         shader->autorelease();
         return shader;
     }

     CC_SAFE_DELETE(shader);
     return NULL;
 }

 void ShaderNode::loadShaderVertex(const char *vert, const char *frag)
 {
     CCGLProgram* shader = new CCGLProgram();
     shader->initWithVertexShaderFilename(vert, frag);   //载入着色器程序
 //    链接着色器程序之前一定要先绑定attribute变量
     //绑定attribute变量
     shader->addAttribute("a_position", 0);
     shader->addAttribute("a_color", 1);
     shader->link();

     //获取attribute变量标识
     m_attributeColor = glGetAttribLocation(shader->getProgram(), "a_color");
     m_attributePosition = glGetAttribLocation(
                                               shader->getProgram(), "a_position");
     shader->updateUniforms();

     //获取uniform变量标识
     m_uniformResolution = glGetUniformLocation(shader->getProgram(), "resolution");
     m_uniformTime = glGetUniformLocation(shader->getProgram(), "time");
     m_uniformTex0 = glGetUniformLocation(shader->getProgram(), "tex0");

     //使用着色器程序
     this->setShaderProgram(shader);
     shader->release();
 }

 void ShaderNode::setColor(ccColor4F newColor)
 {
     color[0] = newColor.r;
     color[1] = newColor.g;
     color[2] = newColor.b;
     color[3] = newColor.a;
 }

 bool ShaderNode::initWithVertex(const char *vert, const char *frag)
 {
 //    获取shader程序
     loadShaderVertex(vert,frag);
 //aaaa.png为透明图片
     m_texture = CCTextureCache::sharedTextureCache()->addImage("aaaa.png")->getName();

     setContentSize(CCSizeMake(1024,768));
     setColor(ccc4f(0.5,0.5,1,1));
     m_time = 0;
     scheduleUpdate();
     return true;
 }

 void ShaderNode::update(float dt)
 {
     m_time += dt;
 }

 void ShaderNode::setContentSize(const CCSize& var)
 {
     CCNode::setContentSize(var);
     m_resolution = vertex2(getContentSize().width,getContentSize().height);
 //    m_center.x = m_resolution.x/2;
 //    m_center.y = m_resolution.y/2;
 }

 void ShaderNode::draw()
 {
     CC_NODE_DRAW_SETUP();

     //传递uniform变量
     CCGLProgram* shader = getShaderProgram();
     shader->setUniformLocationWith2f(m_uniformResolution, m_resolution.x,
                                      m_resolution.y);
     shader->setUniformLocationWith1i(m_uniformTex0, 0);
     glUniform1f(m_uniformTime, m_time);

     //获取attribute变量
     CCSize size = this->getContentSize();
     float w = size.width;
     float h = size.height;

     ccGLBindTexture2D(m_texture);               //绑定纹理到槽位
     glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 0, 0, w, h, 0); //截取屏幕数据到纹理
     glEnableVertexAttribArray(m_attributePosition);
     glDisableVertexAttribArray(m_attributeColor);

     //传递attribute变量
     GLfloat vertices[12] = {
         0, 0, //左下0
         w, 0, //右下1
         w, h, //右上2
         0, 0, //左下0
         0, h, //左上3
         w, h, //右上2
     };
     glVertexAttribPointer(m_attributePosition, 2, GL_FLOAT, GL_FALSE, 0, vertices);
     glVertexAttrib4fv(m_attributeColor, color);

     //绘制
     glDrawArrays(GL_TRIANGLES, 0, 6);
 }

 //shader.fsh
 //段着色器
 varying vec4 v_color;
 //背景纹理
 uniform sampler2D tex0;
 precision highp float;
 //时间
 uniform float time;
 //分辨率
 uniform vec2 resolution;
 const float PI = 3.1415926535897932;
 //速度
 const float speed = 0.2;
 const float speed_x = 0.3;
 const float speed_y = 0.3;
 //几何参数
 const float intensity = 3.0;
 const int steps = 8;
 const float frequency = 4.0;
 const int angle = 7;
 //反射与凸起参数
 const float delta = 20.0;
 const float intence = 400.0;
 const float emboss = 0.3;
 //水波效果
 float col(vec2 coord)
 {
     float delta_theta = 2.0 * PI / float(angle);
     float col = 0.0;
     float theta = 0.0;
     for (int i = 0; i < steps; i++)
     {
         vec2 adjc = coord;
         theta = delta_theta * float(i);
         adjc.x += cos(theta)*time*speed + time * speed_x;
         adjc.y -= sin(theta)*time*speed - time * speed_y;
         col = col + cos((adjc.x*cos(theta) - adjc.y*sin(theta))
                         *frequency)*intensity;
     }
     return cos(col);
 }
 //main函数
 void main(void)
 {
     vec2 p = (gl_FragCoord.xy) / resolution.xy, c1 = p, c2 = p;
     float cc1 = col(c1);

     c2.x += resolution.x/delta;
     float dx = emboss*(cc1-col(c2))/delta;

     c2.x = p.x;
     c2.y += resolution.y/delta;
     float dy = emboss*(cc1-col(c2))/delta;

     c1.x += dx;
     c1.y += dy;
     float alpha = 1.+dot(dx,dy)*intence;
     gl_FragColor = texture2D(tex0,c1)*(alpha) *v_color*(alpha);
 }

 //shader.vsh
 //顶点着色器
 //水纹颜色
 attribute vec4 a_color;
 //顶点坐标
 attribute vec4 a_position;
 varying vec4 v_color;
 //坐标变换矩阵
 //uniform mat4 u_MVPMatrix;
 void main()
 {
     v_color = a_color;
     gl_Position = CC_MVPMatrix * a_position;
 }

测试代码：

 ShaderNode* shader = ShaderNode::shaderNodeWithVertex("shader.vsh","shader.fsh");
     shader->setContentSize(getContentSize());
     shader->setColor(ccc4f(1,1,1.0,.5));
     this->addChild(shader,2);

除此之外，引擎封装了一个特殊段动作类CCActionGrid3D，里面模拟了一些简单的3d特效。

引擎Demo中的EffectsTest演示了这些3D动作类。

引擎中的水纹效果

在场景中加入

 // CCWaves3D::create(时间,晃动网格大小,波动速度,振幅);
     CCGrid3DAction *grid = CCWaves3D::create(50, ccp(10, 10),40 , 10);
     this->runAction(grid);