//check if OpenGL 2.0 is supported

if (glewIsSupported("GL_VERSION_2_0"))

{

    cout<<"OpenGL 2.0 is supported...\nGLSL is integrated in core...\n";

}

else

{

    cout<<"OpenGL 2.0 not supported\n";

}

// init window management

glutInit ( &argc, argv );

glutCreateWindow("IPGPU");

 

glMatrixMode(GL_PROJECTION);                                       // set up projection matrix

glLoadIdentity();

gluOrtho2D(0.0, renderTextureX_m, 0.0, renderTextureY_m);   // 2d projection  

   

glMatrixMode(GL_MODELVIEW);                         // set up modelview matrix

glLoadIdentity();

glViewport(0, 0, renderTextureX_m, renderTextureY_m);   // size of viewport

 

//create render texture

glGenTextures (1, &renderTexture_m);

glBindTexture(TexTarget_m, renderTexture_m);

// set up texture parameters, turn off filtering

glTexParameteri(TexTarget_m, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

glTexParameteri(TexTarget_m, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

glTexParameteri(TexTarget_m, GL_TEXTURE_WRAP_S, GL_CLAMP);

glTexParameteri(TexTarget_m, GL_TEXTURE_WRAP_T, GL_CLAMP);

// define texture with same size like viewport

glTexImage2D(TexTarget_m, 0, internes_Format , renderTextureX_m, renderTextureY_m, 0, Format, Datentyp_Deiner_Farben, 0);

//use original values of texture (no mix with default color of quad)

glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

 

//generate valid handle to fbo

glGenFramebuffersEXT(1, &Fbo_m);

//bind fbo to skip screen as render target and use the frame buffer

glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, dwFbo_m);

// attach texture to framebuffer(use texture/framebuffer as render target)

glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, TexTarget_m, renderTexture_m, 0);

 

//choose buffer/attachment point for drawing

glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);

 

glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);

glReadPixels(0, 0, renderTextureX_m, renderTextureY_m, Format, Datentyp_Deiner_Farben, Array_Im_Applikationsspeicher);