void render( base::ContextPtr context, base::CameraPtr cam )
{
// render to texture
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClearStencil( 0 );
multisampleFBO->begin( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );
glDisable( GL_DEPTH_TEST );
// initialize stencil buffer ---
glEnable(GL_STENCIL_TEST);
glEnable( GL_MULTISAMPLE );
glColorMask( GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE );
glEnable(GL_SAMPLE_MASK);
for(int i = 0; i < 4; ++i)
{
glStencilFunc(GL_ALWAYS, i + 1, 0xff);
glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);
glSampleMaski(0, 0x1 << i);
context->renderScreen(initializeStencilShader);
}
glSampleMaski(0, 0xFFFFFF);
glDisable(GL_SAMPLE_MASK);
glColorMask( GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE );
glDisable( GL_MULTISAMPLE );
// now render geometry using stencil routing ---
glStencilFunc(GL_EQUAL, 1, 0xff);
glStencilOp(GL_DECR, GL_DECR, GL_DECR );
context->setCamera( cam );
context->render( geometry, shader );
glDisable(GL_STENCIL_TEST);
multisampleFBO->end();
// final render the shader
// NB: the multisampleTestShader in its pixel section fetches a single sample for each fragment. change the sample index in the
// fetchTexture function to check the values for the different samples
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClearStencil( 0 );
//we also clear the stencil buffer
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );
context->renderScreen( multisampleTestShader );
}
