OpenGL es3.0 初始化及渲染

class FOpenglEs
{
public:

    /**
    *   初始化 OpenGLES3.0
    */
    bool    initOpenGLES30(HWND hwnd)
    {
        EGLConfig config;
        EGLint majorVersion;
        EGLint minorVersion;
        EGLint contextAttribs[] = { EGL_CONTEXT_CLIENT_VERSION, 3, EGL_NONE };

        if ( hwnd == NULL )
        {
            return GL_FALSE;
        }
        EGLNativeDisplayType  displaytype = GetDC(hwnd); 
        
        m_Display  = eglGetDisplay( displaytype );
        if ( m_Display == EGL_NO_DISPLAY )
        {
            return GL_FALSE;
        }

        // Initialize EGL
        if ( !eglInitialize ( m_Display, &majorVersion, &minorVersion ) )
        {
            return GL_FALSE;
        }

        GLuint flags = ES_WINDOW_RGB;
        {
            EGLint numConfigs = 0;
            EGLint attribList[] =
            {
                EGL_RED_SIZE,       5,
                EGL_GREEN_SIZE,     6,
                EGL_BLUE_SIZE,      5,
                EGL_ALPHA_SIZE,     ( flags & ES_WINDOW_ALPHA ) ? 8 : EGL_DONT_CARE,
                EGL_DEPTH_SIZE,     ( flags & ES_WINDOW_DEPTH ) ? 8 : EGL_DONT_CARE,
                EGL_STENCIL_SIZE,   ( flags & ES_WINDOW_STENCIL ) ? 8 : EGL_DONT_CARE,
                EGL_SAMPLE_BUFFERS, ( flags & ES_WINDOW_MULTISAMPLE ) ? 1 : 0,
                // if EGL_KHR_create_context extension is supported, then we will use
                // EGL_OPENGL_ES3_BIT_KHR instead of EGL_OPENGL_ES2_BIT in the attribute list
                EGL_RENDERABLE_TYPE, GetContextRenderableType ( m_Display),
                EGL_NONE
            };

            // Choose config
            if ( !eglChooseConfig (m_Display, attribList, &config, 1, &numConfigs ) )
            {
                return GL_FALSE;
            }

            if ( numConfigs < 1 )
            {
                return GL_FALSE;
            }
        }

        // Create a surface
        m_Surface = eglCreateWindowSurface (m_Display, config, 
            hwnd, NULL );

        if ( m_Surface == EGL_NO_SURFACE )
        {
            return GL_FALSE;
        }

        // Create a GL context
        m_Context = eglCreateContext (m_Display, config, 
            EGL_NO_CONTEXT, contextAttribs );

        if ( m_Context == EGL_NO_CONTEXT )
        {
            return GL_FALSE;
        }

        // Make the context current
        if ( !eglMakeCurrent (m_Display, m_Surface, 
             m_Surface, m_Context ) )
        {
            return GL_FALSE;
        }




        return  true;

    }

    EGLint GetContextRenderableType ( EGLDisplay eglDisplay )
    {
#ifdef EGL_KHR_create_context
        const char *extensions = eglQueryString ( eglDisplay, EGL_EXTENSIONS );

        // check whether EGL_KHR_create_context is in the extension string
        if ( extensions != NULL && strstr( extensions, "EGL_KHR_create_context" ) )
        {
            // extension is supported
            return EGL_OPENGL_ES3_BIT_KHR;
        }
#endif
        // extension is not supported
        return EGL_OPENGL_ES2_BIT;
    }
    /**
    *   销毁OpenGLES3.0
    */
    void    destroyOpenGLES20()
    {
        
    }

    void SwapBuffers()
    {
        eglSwapBuffers(m_Display,m_Surface);
    }

    void setViewPort( int x,int y,int width,int height )
    {
        glViewport(GLint(x),GLint(y),GLsizei(width),GLsizei(height));
    }

    void clear(unsigned int mask)
    {
        //! GL_DEPTH_BUFFER_BIT
        //! GL_COLOR_BUFFER_BIT
        //! GL_COLOR_BUFFER_BIT
        //! GL_STENCIL_BUFFER_BIT
        //! GL_ACCUM_BUFFER_BIT;
        //! GL_TRANSFORM_BIT
        //! GL_ENABLE_BIT
        //! GL_HINT_BIT
        //! GL_EVAL_BIT
        glClear(mask);
    }

    void clearColor(float r,float g,float b,float a)
    {
        glClearColor(r,g,b,a);
    }

    
    void CreateOglBuffer(OglBuffer* buf)
    {
          glGenBuffers(1, &buf->m_VertexBufferId);
        glBindBuffer(GL_ARRAY_BUFFER, buf->m_VertexBufferId);
        
        glBufferData(GL_ARRAY_BUFFER, sizeof(FVertex)* buf->m_vertexs.size(), &buf->m_vertexs[0].m_Pos.x, GL_DYNAMIC_DRAW);


        glBindBuffer(GL_ARRAY_BUFFER, 0);

        glGenBuffers(1, &buf->m_IndexBufferId);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buf->m_IndexBufferId);
        
        glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(FMeshTriangle) * buf->m_Indexs.size(), &buf->m_Indexs[0].index0, GL_DYNAMIC_DRAW);

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);

        
        glGenVertexArrays(1,&buf->m_VaoBufferId);
        glBindVertexArray(buf->m_VaoBufferId);

        glBindBuffer(GL_ARRAY_BUFFER,buf->m_VertexBufferId);
        
        glEnableVertexAttribArray(0);
        glEnableVertexAttribArray(1);
        glVertexAttribPointer(0,3,GL_FLOAT,(GLboolean)false,sizeof(FVertex),0);
        glVertexAttribPointer(1,3,GL_FLOAT,(GLboolean)false,sizeof(FVertex),(GLvoid*)(sizeof(float)*3));

        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,buf->m_IndexBufferId);


        glBindVertexArray(0);
        glBindBuffer(GL_ARRAY_BUFFER,0);
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,0);
        glDisableVertexAttribArray(0);
        glDisableVertexAttribArray(1);
        printf("vertex:%d bufId:%d 
",buf->m_vertexs.size(),buf->m_VertexBufferId);
        printf("index:%d  bufId:%d 
",buf->m_Indexs.size(),buf->m_IndexBufferId);

    }


    void bindVao(OglBuffer* buf)
    {
        glBindVertexArray(buf->m_VaoBufferId);
    }

    void destroyVertexBuffer( OglBuffer* buf )
    {
        
        glDeleteVertexArrays(1,&buf->m_VaoBufferId);
        glDeleteBuffers(1,&buf->m_IndexBufferId);
        glDeleteBuffers(1,&buf->m_VertexBufferId);
        
    }


    void drawBuffers(const OglBuffer* buf)
    {
        glBindVertexArray(buf->m_VaoBufferId);
        glDrawElements(GL_TRIANGLES,buf->m_Indexs.size() *3,GL_UNSIGNED_INT,0);
    }

    

public:
    /// Display handle
    EGLNativeDisplayType eglNativeDisplay;

    /// Window handle
    EGLNativeWindowType  eglNativeWindow;

    EGLConfig   m_Config;
    EGLSurface  m_Surface;
    EGLContext  m_Context;
    EGLDisplay  m_Display;

    /// Window width
    GLint       m_width;

    /// Window height
    GLint       m_height;
};

class FVertex
{
public:
    FVertex()
    {

    }
    vec3 m_Pos;
    vec3 m_Normal;
    vec2 m_Uv;
    vec3 m_tangent;
    vec3 m_bitangent;

};

class OglBuffer
{
public:
    OglBuffer()
    {
        m_VaoBufferId =0 ;
        m_VertexBufferId =0;
        m_IndexBufferId =0;

    
    }
    


   Fuint m_VaoBufferId;
   Fuint m_VertexBufferId;
   Fuint m_IndexBufferId;

   std::vector<FVertex>       m_vertexs;
   std::vector<FMeshTriangle> m_Indexs; 

   

};

用的时候直接这样就好了，比较方便

g_Opengles.setViewPort(0,0,800,600);
        g_Opengles.clearColor(0.1,1,0.1,0);
        g_Opengles.clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
        
        m_Shader.useProgram();
        
        m_Shader.setUniformMatrix4fv("_MVP",&m_ProjectMatrix.m00);

        g_Opengles.drawBuffers(&m_Buff);

        g_Opengles.SwapBuffers();

shader ，不能用varying，只能用in  out这样

const char* vs  =   
    {
        "#version 300 es                          
"
        "layout(location = 0) in vec4 vPosition;  
"
        "layout(location = 1) in vec3 vNormal;    
"
        "uniform mat4 _MVP;                        
"
        "out vec3 oNormal;                          
"
        "void main()                              
"
        "{                                        
"
        "   gl_Position = _MVP * vPosition;         
"
        "   oNormal  = vNormal;                      
"
        "}                                        
"
    };
    const char* ps  =   
    {
        "#version 300 es                              
"
        "precision mediump float;                     
"
        "out vec4 fragColor;                          
"
        "in  vec3 oNormal;                                
"
        "void main()                                  
"
        "{                                            
"
        "                                                 
"
        "    float dotN = dot(oNormal,vec3(0,1,0));         
"
        "   float realColor = max(0.0,dotN);            
"
        "   fragColor = vec4 ( realColor, realColor, realColor, 1.0 );  
"
        "}                                            
"
    };