GLuint framebuffer1;
extern GLuint textureZ;
// ...
/// init
glGenFramebuffers( 1, &framebuffer1 );
glBindFramebuffer( GL_FRAMEBUFFER, framebuffer1 );
glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, textureZ );
// ...
/// render
glBindFramebuffer( GL_FRAMEBUFFER, framebuffer1 );
glViewport( 0, 0, 1024, 1024 );
///@todo ... render your stuff ...
glBindFramebuffer( GL_FRAMEBUFFER, 0 );
glViewport( 0, 0, 1920, 1080 );
// ...
/// shutdown
glDeleteFramebuffers( 1, &framebuffer1 );
framebuffer1= 0;