Smoothing and additive blending

Hi guys!

I'm not sure why but as soon as you enable smoothing, additive blending is disabled. In fact I think someone on the team is also unsure - see the comment "why do we need this?" in libs/openFrameworks/gl/ofGLRenderer.cpp :)

//----------------------------------------------------------
void ofGLRenderer::startSmoothing(){
    #ifndef TARGET_OPENGLES
        glPushAttrib(GL_COLOR_BUFFER_BIT | GL_ENABLE_BIT);
    #endif

    glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);
    glEnable(GL_LINE_SMOOTH);

    //why do we need this?
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

I commented it out and it seemed to work OK, but I'm sure there are other repercussions. But it would be nice to have smoothing and blendmodes.

cheers
Seb

Start in libs/openFrameworks/gl/ofGLRenderer.cpp at ofGLRenderer::startSmoothing() and inspect how smoothing changes blending state. Reproduce the interaction between smoothing and additive blending, then check the surrounding renderer state handling for repercussions. Done means smoothing and blend modes can be used together without unexpectedly replacing the selected blend mode.