gistfile1.txt

ofEnableBlendMode(OF_BLENDMODE_ALPHA);
ofEnableAlphaBlending();

_internalImage.allocate(ofGetWidth(), ofGetHeight(), OF_IMAGE_COLOR_ALPHA);
_internalImage.setUseTexture(true);

_internalImage.setColor(ofColor(0, 0, 0, 0));
  
_internalImage.bind();

ofSetColor(0, 255, 0);
ofFill();
ofRect(100, 100, 100, 100);

_internalImage.unbind();

_internalImage.update();

_internalImage.draw(0.0f, 0.0f);

ofDisableBlendMode(OF_BLENDMODE_ALPHA);
ofDisableAlphaBlending();