Added timeline

src/display/animation/timeline.c

@@ -0,0 +1,79 @@
+/**
+ * Copyright (c) 2021 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "timeline.h"
+
+void onDone(timeline_t *test) {
+}
+
+void timelineInit(timeline_t *timeline) {
+  timeline->current = 0;
+  timeline->diff = 0;
+  timeline->previous = 0;
+  timeline->user = 0;
+  timeline->actionCount = 0;
+  
+  timeline->actions[0].onStart = &onDone;
+}
+
+void timelineUpdate(timeline_t *timeline, float delta) {
+  uint8_t i;
+  timelineaction_t *action;
+  float full;
+
+  timeline->diff = delta;
+  timeline->previous = timeline->current;
+  timeline->current = timeline->current + delta;
+
+  // Find all actions that would have started or ended in this timespan.
+  for(i = 0; i < timeline->actionCount; i++) {
+    action = timeline->actions +i;
+
+    // Has the action started yet?
+    if(action->start > timeline->current) continue;
+
+    // Did we start this frame?
+    if(action->start > timeline->previous && action->onStart != NULL) {
+      action->onStart(timeline);
+    }
+
+    // Durations of 0 only fire starts, never ends or durations.
+    if(action->duration == 0) continue;
+
+    // Is the end still in the future? Durations in negatives go forever
+    full = action->start+action->duration;
+    if(action->duration < 0 || full > timeline->current) {
+      if(action->onDuration != NULL) action->onDuration(timeline);
+    } else if(full > timeline->previous) {// Did we end this frame?
+      if(action->onEnd != NULL) action->onEnd(timeline);
+    }
+  }
+}
+
+bool timelineIsFinished(timeline_t *timeline) {
+  uint8_t i;
+  timelineaction_t *action;
+
+  for(i = 0; i < timeline->actionCount; i++) {
+    action = timeline->actions +i;
+    if(action->start > timeline->current) return false;
+    if(action->duration < 0) return false;
+    if(action->duration == 0) continue;
+    if(action->start+action->duration > timeline->current) return false;
+  }
+
+  return true;
+}
+
+timelineaction_t * timelineAddAction(timeline_t *timeline, float start,
+  float duration
+) {
+  timelineaction_t *action = timeline->actions + (timeline->actionCount++);
+  action->start = start, action->duration = duration;
+  action->onStart = action->onEnd = action->onDuration = NULL;
+  return action;
+}

src/display/animation/timeline.h

@@ -0,0 +1,15 @@
+// Copyright (c) 2021 Dominic Masters
+// 
+// This software is released under the MIT License.
+// https://opensource.org/licenses/MIT
+
+#pragma once
+#include <dawn/dawn.h>
+
+void timelineInit(timeline_t *timeline);
+void timelineUpdate(timeline_t *timeline, float delta);
+bool timelineIsFinished(timeline_t *timeline);
+
+timelineaction_t * timelineAddAction(timeline_t *timeline, float start,
+  float duration
+);