- When Preview is clicked on the Transitions ribbon, initialize Show with
start_transition_preview from the prior slide into the selected slide
(or from black for slide 0).
- If tr.old is unset for a non-part transition with tr.from, render the
previous slide texture on the first frame so the transition blends cleanly.
- Indicate active playback on the Preview button while previewing.
- Regression tests for transitions from previous slide and from black on slide 0.
Naseq
ea9dad8ef9