void ofxTLKeyframes::updateDragOffsets(ofVec2f screenpoint, long grabMillis){
for(int k = 0; k < selectedKeyframes.size(); k++){
//selectedKeyframes[k]->grabOffset = screenpoint - coordForKeyframePoint(selectedKeyframes[k]->position);
selectedKeyframes[k]->grabTimeOffset = grabMillis - selectedKeyframes[k]->time;
selectedKeyframes[k]->grabValueOffset = screenpoint.y - valueToScreenY(selectedKeyframes[k]->value);
}
}
ofVec2f ofxTLKeyframes::screenPositionForKeyframe(ofxTLKeyframe* keyframe){
return ofVec2f(millisToScreenX(keyframe->time),
valueToScreenY(keyframe->value));
}