FBO 深度测试

opengl fbo 测试程序，前几天别人问，帮写的

头文件

const int   SCREEN_WIDTH    = 400;
const int   SCREEN_HEIGHT   = 400;
const float CAMERA_DISTANCE = 6.0f;
const int   TEXT_WIDTH      = 8;
const int   TEXT_HEIGHT     = 8;
const int   TEXTURE_WIDTH   = 400;  // NOTE: texture size cannot be larger than
const int   TEXTURE_HEIGHT  = 400;  // the rendering window size in non-FBO mode
const int   DATA_SIZE       = TEXTURE_WIDTH * TEXTURE_HEIGHT * sizeof(float);
class GAMEINFO
{
public:
    GAMEINFO(){}
    ~GAMEINFO(){}
    void init_game();
    void init_light();
    void Draw();
    void Clear();
private:
    void initGL();
    void initFBO();
    

private:
    CVector3  m_eye,m_look;
    
    
    
    
    
    glInfo       OglInfo;
    
private:
    
  GLuint fboId;                       // ID of FBO
GLuint textureId;                   // ID of texture
GLuint rboId;                       // ID of Renderbuffer object
    GLuint pboId;
};

实现

#include"GAME.h"
#include"FreeType.h"
#include"FreeTypeReal.h"
void DrawBox();
void GAMEINFO::init_game()
{
    
    LOG::Instance()->OutputError("OpenGL 1.3 required");
    initGL();
    
    init_light();
    TimerInit();
    
    
    

    /*vbo_supported();
    FBO_supported(); */
    OglInfo.getInfo();
    //OglInfo.printSelf();
    

    

    if(GLEE_ARB_vertex_buffer_object)
    {
        printf("Supput VBO! \n");
    
    }
    if(GLEE_ARB_pixel_buffer_object)
    {
        printf("Supput PBO! \n");
    }
    if(GLEE_ARB_framebuffer_object)
    {
        printf("Supput FBO! \n");

        
    }
    
}

void GAMEINFO::initGL()
{
    int height=WINDOWSWIDTH;
    if(height==0)
        height=1;

    glViewport(0, 0, WINDOWSWIDTH, WINDOWSHEIGHT);

    //Set up projection matrix
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(    45.0f, (GLfloat)WINDOWSWIDTH/(GLfloat)WINDOWSHEIGHT,1.0f, 3000.0f);
                    
    // glOrtho(0, 500, 0, 500, -1, 100); 
    //Load identity modelview
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    //Shading states
    glShadeModel(GL_SMOOTH);
    glClearColor(0.0, 0.0f, 0.0f, 1.0f);
    glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
    glDepthFunc(GL_LEQUAL);

    
    glClearDepth(1.0f);
    
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LEQUAL);
    
    //our_font.init("C:\\WINDOWS\\Fonts\\simhei.TTF",16);
    
    init_light();
    
    initFBO();
    
}


void GAMEINFO::initFBO()
{

     glGenTextures(1, &textureId);
    glBindTexture(GL_TEXTURE_2D, textureId);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    //glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE); // automatic mipmap generation included in OpenGL v1.4
    //glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, TEXTURE_WIDTH, TEXTURE_HEIGHT, 0, GL_RGBA, GL_UNSIGNED_BYTE, 0);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, TEXTURE_WIDTH, TEXTURE_HEIGHT, 0, GL_DEPTH_COMPONENT, GL_FLOAT, 0);
    //glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, TEXTURE_WIDTH, TEXTURE_HEIGHT, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_INT, 0);
    glBindTexture(GL_TEXTURE_2D, 0);



     glGenFramebuffers(1, &fboId);
        glBindFramebuffer(GL_FRAMEBUFFER, fboId);

        // create a renderbuffer object to store depth info
        // NOTE: A depth renderable image should be attached the FBO for depth test.
        // If we don't attach a depth renderable image to the FBO, then
        // the rendering output will be corrupted because of missing depth test.
        // If you also need stencil test for your rendering, then you must
        // attach additional image to the stencil attachement point, too.
        glGenRenderbuffers(1, &rboId);
        glBindRenderbuffer(GL_RENDERBUFFER, rboId);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, TEXTURE_WIDTH, TEXTURE_HEIGHT);
        glBindRenderbuffer(GL_RENDERBUFFER, 0);

        // attach a texture to FBO depth attachement point
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, textureId, 0);

        // attach a renderbuffer to depth attachment point
        //glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER_EXT, rboId);

        //@@ disable color buffer if you don't attach any color buffer image,
        //@@ for example, rendering depth buffer only to a texture.
        //@@ Otherwise, glCheckFramebufferStatusEXT will not be complete.
        glDrawBuffer(GL_NONE);
        glReadBuffer(GL_NONE);

        // check FBO status
      
        glBindFramebuffer(GL_FRAMEBUFFER, 0);


         glGenBuffersARB(1, &pboId);
        glBindBufferARB(GL_PIXEL_PACK_BUFFER_ARB, pboId);
        glBufferDataARB(GL_PIXEL_PACK_BUFFER_ARB, DATA_SIZE, 0, GL_STREAM_READ_ARB);

        glBindBufferARB(GL_PIXEL_PACK_BUFFER_ARB, 0);

}
void GAMEINFO::init_light()
{
    static GLfloat LightAmbient[]= { 0.5f, 0.5f, 0.5f, 1.0f };                 // 环境光参数
    static GLfloat LightDiffuse[]= { 1.0f, 1.0f, 1.0f, 1.0f };                 // 漫射光参数
    static GLfloat LightPosition[]= { 0.0f, 100.0f, 2.0f, 1.0f };                 // 光源位置



    glLightfv(GL_LIGHT1, GL_AMBIENT, LightAmbient);                // 设置环境光
    glLightfv(GL_LIGHT1, GL_DIFFUSE, LightDiffuse);                // 设置漫射光
    glLightfv(GL_LIGHT1, GL_POSITION,LightPosition);            // 设置光源位置

    glEnable(GL_LIGHT1);                            // 启用一号光源
    glEnable(GL_LIGHTING);

}


void GAMEINFO::Clear()
{
    

}

void GAMEINFO::Draw()
{
    static float xrot=0,yrot=0,zrot=0,angle=0.0;
    
    static  float abc;

    /*glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);    
    
    
    
    ////glOrtho(0,WINDOWSWIDTH,0,WINDOWSHEIGHT,1,1000);
    
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    
    glTranslatef(0,0,-20);
    //glRotatef(xrot++,1.0f,0.0f,0.0f);
    //glRotatef(yrot++,0.0f,1.0f,0.0f);
    //glRotatef(zrot++,0.0f,0.0f,1.0f);
    //
    glEnable(GL_TEXTURE_2D);
    glBindTexture(GL_TEXTURE_2D,0);
    glEnable(GL_LIGHTING);
    glColor3f(1.0f,1.0f,1.0f);
    glPushMatrix();*/
    /*
    glScalef(0.5f,0.5f,0.5f);
    glBegin(GL_QUADS);
        // Front Face
    
        glNormal3f( 0.0f, 0.0f, 1.0f);                    // 法线指向观察者
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    
        // 后侧面
        
        glNormal3f( 0.0f, 0.0f,-1.0f);                    // 法线背向观察者
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    
        // 顶面
        
        glNormal3f( 0.0f, 1.0f, 0.0f);                    // 法线向上
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    
        // 底面
        
        glNormal3f( 0.0f,-1.0f, 0.0f);                    // 法线朝下
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    
        // 右侧面
        glNormal3f( 1.0f, 0.0f, 0.0f);                    // 法线朝右
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    
        // 左侧面
        glNormal3f(-1.0f, 0.0f, 0.0f);                    // 法线朝左
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
    glEnd();
    
    
    */
    /*
    glPopMatrix();
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_TEXTURE_2D);

    glDisable(GL_LIGHTING);
    
    abc+=0.1f;
    //glScalef(0.5f,0.5f,0.5f);
    
    glEnable(GL_MULTISAMPLE_ARB);
    glColor3f(1.0,0.0f,0.0);
    
    mFont.print(100,10,"C_Dragon fps:%d ",nfps);
    
    
    fpsCount();*/
    
                glViewport(0, 0, 400, 400);
                glMatrixMode(GL_PROJECTION);
                glLoadIdentity();
                gluPerspective(60.0f, (float)(400)/400, 1.0f, 100.0f);

    // with FBO
    // render directly to a texture
 
        // set the rendering destination to FBO
        glBindFramebuffer(GL_FRAMEBUFFER, fboId);

        // clear buffer
        glClearColor(1, 1, 1, 1);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        // draw a rotating teapot
      glTranslatef(0, 0, -CAMERA_DISTANCE);
                    
        glRotatef(angle*0.5f, 1, 0, 0);
    glRotatef(angle, 0, 1, 0);
    glRotatef(angle*0.7f, 0, 0, 1);
    glEnable(GL_TEXTURE_2D);
        glBindTexture(GL_TEXTURE_2D, 0);
    // draw a cube with the dynamic texture
    // glScalef(10.0f,10.0f,10.0f);
    DrawBox();
        glBindTexture(GL_TEXTURE_2D, 0);
        
        // back to normal window-system-provided framebuffer
        glBindFramebuffer(GL_FRAMEBUFFER, 0); // unbind

       
        glBindTexture(GL_TEXTURE_2D, textureId);
        glGenerateMipmap(GL_TEXTURE_2D);
        glBindTexture(GL_TEXTURE_2D, 0);
          glClearColor(0, 0, 0, 1);
// glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
          glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glColor3f(1.0f,0.0f,0.0);
        for(int ii=0 ;ii<2 ;ii++)
        {
            if(ii==0)
            {
                 glViewport(0, 0, 400, 400);
                glMatrixMode(GL_PROJECTION);
                glLoadIdentity();
                gluPerspective(60.0f, (float)(400)/400, 1.0f, 100.0f);
                
            }

            if(ii==1)
            {
                 glViewport(400, 0, 800, 400);
                glMatrixMode(GL_PROJECTION);
                glLoadIdentity();
                glOrtho(0, 400, 0, 400, -1, 100); 
                //gluPerspective(60.0f, (float)(400)/400, 1.0f, 100.0f);
                
            
            }

            glMatrixMode (GL_MODELVIEW);                                    // Select The Modelview Matrix
            glLoadIdentity ();        
            
             glClear (GL_DEPTH_BUFFER_BIT);
             // glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
            if(ii==0)
            {
                    glTranslatef(0, 0, -CAMERA_DISTANCE);
                    
                     glRotatef(angle*0.5f, 1, 0, 0);
                    glRotatef(angle, 0, 1, 0);
                    glRotatef(angle*0.7f, 0, 0, 1);
                    glEnable(GL_TEXTURE_2D);
                     glBindTexture(GL_TEXTURE_2D, 0);
                    // draw a cube with the dynamic texture
                    // glScalef(10.0f,10.0f,10.0f);
                    DrawBox();
                     glBindTexture(GL_TEXTURE_2D, 0);

    
                
            
            }

            if(ii==1)
            {
                        
    
                        glEnable(GL_TEXTURE_2D);
                         glBindTexture(GL_TEXTURE_2D,textureId);
                        // draw a cube with the dynamic texture
                         glBegin(GL_QUADS);    
                             glNormal3f( 0.0f, 0.0f, 1.0f);                    // 法线指向观察者
                            glTexCoord2f(0.0f, 0.0f); glVertex3f(    0.0f,      0.0f,  0.0f);    
                            glTexCoord2f(1.0f, 0.0f); glVertex3f( 200.0f,     0.0f,  0.0f);    
                            glTexCoord2f(1.0f, 1.0f); glVertex3f( 200.0f,  400.0f,  0.0f);    
                            glTexCoord2f(0.0f, 1.0f); glVertex3f(     0.0f,  400.0f,  0.0f);    
                            glEnd();
                         glBindTexture(GL_TEXTURE_2D, 0);

    
                        
            
            }
        
        }

         angle+=5.0f;

}
void DrawBox()
{

    glBegin(GL_QUADS);
        // Front Face
        glNormal3f( 0.0f, 0.0f, 1.0f);                    // 法线指向观察者
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    
        // 后侧面
        glNormal3f( 0.0f, 0.0f,-1.0f);                    // 法线背向观察者
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    
        // 顶面
        glNormal3f( 0.0f, 1.0f, 0.0f);                    // 法线向上
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    
        // 底面
        glNormal3f( 0.0f,-1.0f, 0.0f);                    // 法线朝下
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    
        // 右侧面
        glNormal3f( 1.0f, 0.0f, 0.0f);                    // 法线朝右
        glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, -1.0f, -1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f, -1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);    
        glTexCoord2f(0.0f, 0.0f); glVertex3f( 1.0f, -1.0f,  1.0f);    
        // 左侧面
        glNormal3f(-1.0f, 0.0f, 0.0f);                    // 法线朝左
        glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f, -1.0f);    
        glTexCoord2f(1.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  1.0f);    
        glTexCoord2f(1.0f, 1.0f); glVertex3f(-1.0f,  1.0f,  1.0f);    
        glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  1.0f, -1.0f);
    glEnd();

}

效果图