Added some transitions.

src/display/animation/timeline.c

@@ -7,6 +7,32 @@
 
 #include "timeline.h"
 
+void _timelineActionDeltaUpdateStart(
+  timeline_t *timeline, timelineaction_t *action, uint8_t i
+) {
+  if(action->data == NULL) return;
+  *((float *)action->data) = timeline->initials[i];
+}
+
+void _timelineActionDeltaUpdateDuration(
+  timeline_t *timeline, timelineaction_t *action, uint8_t i
+) {
+  float n;
+  if(action->data == NULL) return;
+  n = timeline->easings[i](
+    timelineActionGetTimeRaw(timeline, action)
+  );
+  *((float *)action->data) = timeline->initials[i] + (timeline->deltas[i] * n);
+}
+
+void _timelineActionDeltaUpdateEnd(
+  timeline_t *timeline, timelineaction_t *action, uint8_t i
+) {
+  if(action->data == NULL) return;
+  *((float *)action->data) = timeline->initials[i] + timeline->deltas[i];
+}
+
+
 void timelineInit(timeline_t *timeline) {
   timeline->current = 0;
   timeline->diff = 0;
@@ -68,10 +94,48 @@ bool timelineIsFinished(timeline_t *timeline) {
 timelineaction_t * timelineAddAction(timeline_t *timeline, float start,
   float duration
 ) {
-  if(timeline->actionCount == TIMELINE_ACTION_COUNT_MAX) return NULL;
   timelineaction_t *action = timeline->actions + (timeline->actionCount++);
   action->loop = false;
   action->start = start, action->duration = duration;
   action->onStart = action->onEnd = action->onDuration = NULL;
   return action;
+}
+
+timelineaction_t * timelineAddDeltaAction(timeline_t *timeline,
+  float start, float duration, float initial, float delta,
+  easefunction_t *easing, float *destination
+) {
+  timelineaction_t *action;
+  timeline->initials[timeline->actionCount] = initial;
+  timeline->deltas[timeline->actionCount] = delta;
+  timeline->easings[timeline->actionCount] = (
+    easing == NULL ? &easeLinear : easing
+  );
+  action = timelineAddAction(timeline, start, duration);
+  action->data = destination;
+  action->onStart = &_timelineActionDeltaUpdateStart;
+  action->onDuration = &_timelineActionDeltaUpdateDuration;
+  action->onEnd = &_timelineActionDeltaUpdateEnd;
+  return action;
+}
+
+timelineaction_t * timelineAddDeltaActionTo(timeline_t *timeline,
+  float start, float duration, float initial, float end,
+  easefunction_t *easing, float *destination
+) {
+  return timelineAddDeltaAction(
+    timeline, start, duration, initial, end-initial, easing, destination
+  );
+}
+
+float timelineActionGetTimeRaw(timeline_t *timeline, timelineaction_t *action) {
+  return (timeline->current - action->start) / action->duration;
+}
+
+float timelineActionGetTime(timeline_t *tl, timelineaction_t *at) {
+  return mathClamp(timelineActionGetTimeRaw(tl, at), 0, 1);
+}
+
+void timelineClear(timeline_t *timeline) {
+  timeline->actionCount = 0;
 }