Check for Ongoing Transitions

[shawna-p]

I have a special Dynamic Displayable for blinks which I don't want animating during transitions (since having a half-faded in eye blink while transitioning to the next expression looks bad). However, I am unable to find any reliable ways of checking for ongoing transitions. Ideally, I would like to check on a per-layer basis (including None).

Of my efforts, the following yielded incomplete results:

• Checking for renpy.game.interface.ongoing_transition works well up until you use config variables like config.say_attribute_transition and _scene_show_hide_transition with dict transitions. These transitions won't trigger the end_transitions method and thus sit around in the ongoing_transition dictionary long after they're done animating.
• renpy.game.interface.transition_delay has very inconsistent information and almost never seems to read out the actual transition times per-layer.
• renpy.get_transition() seems to always return None even when transitions are actively happening

I would like an official way of checking for this so I can have my DynamicDisplayable account for transitions when determining which image to show, though I imagine this check may be useful for other circumstances as well especially when it comes to animations.