In openFrameworks, is it possible to change the opacity of my fbo sources while using ofxPiMapper?

Question

In openFrameworks, is it possible to change the opacity of my fbo sources while using ofxPiMapper?

Answer 1

Figured it out:

Go into addons/ofxPiMapper/src/Surfaces/SurfaceStack.cpp In SurfaceStack::draw(), add ofEnableAlphaBlending() to the if statement inside the for loop right under all the glblend stuff.

void SurfaceStack::draw(){
    for(int i = 0; i < _surfaces.size(); ++i){
        if(_surfaces[i]->getSource()->getType() == SourceType::SOURCE_TYPE_FBO){
            glEnable(GL_BLEND); 
            glBlendFuncSeparate(GL_ONE, GL_ZERO, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
            ofEnableAlphaBlending(); //<-- here
        }else{
            ofEnableAlphaBlending();
        }
        _surfaces[i]->draw();
    }
}