Use named arguments for animation constructors.

www/js/animation.ts

@@ -25,10 +25,10 @@ export abstract class AnimationSegment {
     this.endPosition = endPosition;
   }
 
-  protected abstract interpolateOffset(progress: number);
+  abstract interpolateOffset(progress: number);
 
   // TODO Not sure this interpolation is actually right for arms...
-  protected interpolateHandOffset(progress: number, hand: Hand) : Offset | undefined {
+  interpolateHandOffset(progress: number, hand: Hand) : Offset | undefined {
     let prev = hand === Hand.Left ? this.startPosition.leftArmEnd : this.startPosition.rightArmEnd;
     let next = hand === Hand.Left ? this.endPosition.leftArmEnd : this.endPosition.rightArmEnd;
 
@@ -39,7 +39,7 @@ export abstract class AnimationSegment {
     return interpolateLinearOffset(progress, prev, next);
   }
 
-  protected interpolateRotation(progress: number) {
+  interpolateRotation(progress: number) {
     return interpolateLinear(progress, this.startPosition.rotation, this.endPosition.rotation);
   }
 
@@ -65,19 +65,120 @@ function interpolateLinearOffset(progress: number, prev: Offset, next: Offset):
 }
 
 export class LinearAnimationSegment extends AnimationSegment {
-  constructor(beats: number, startPosition: DancerSetPosition, endPosition: DancerSetPosition) {
+  constructor({ beats, startPosition, endPosition }: {
+    beats: number;
+    startPosition: DancerSetPosition;
+    endPosition: DancerSetPosition;
+  }) {
     super(beats, startPosition, endPosition);
   }
 
   public static standStill(startAndEndPosition: DancerSetPosition, beats?: number) {
-    return new LinearAnimationSegment(beats ?? 0, startAndEndPosition, startAndEndPosition);
+    return new LinearAnimationSegment({
+      beats: beats ?? 0,
+      startPosition: startAndEndPosition,
+      endPosition: startAndEndPosition
+    });
   }
 
-  protected interpolateOffset(progress: number) {
+  override interpolateOffset(progress: number) {
     return interpolateLinearOffset(progress, this.startPosition.position, this.endPosition.position);
   }
 }
 
+export interface AnimationTransitionFlags {
+  rotation?: boolean;
+  hands?: boolean;
+}
+export class TransitionAnimationSegment extends AnimationSegment {
+  private readonly actualAnimation: AnimationSegment;
+  private readonly flags: AnimationTransitionFlags;
+  private readonly startTransitionProgress: number;
+  private readonly endTransitionProgress: number;
+  private readonly startRotation: number;
+  private readonly endRotation: number;
+
+  constructor({ actualAnimation, flags, startTransitionBeats, endTransitionBeats }: {
+    actualAnimation: AnimationSegment;
+    flags: AnimationTransitionFlags;
+    startTransitionBeats: number;
+    endTransitionBeats?: number;
+  }) {
+    super(actualAnimation.beats, actualAnimation.startPosition, actualAnimation.endPosition);
+
+    this.actualAnimation = actualAnimation;
+    this.flags = flags;
+    this.startTransitionProgress = startTransitionBeats / actualAnimation.beats;
+    this.endTransitionProgress = endTransitionBeats === undefined ? this.startTransitionProgress : endTransitionBeats / actualAnimation.beats;
+
+    this.startRotation = this.startPosition.rotation;
+    this.endRotation = this.endPosition.rotation;
+    if (this.flags.rotation) {
+      const actualStart = this.actualAnimation.interpolateRotation(0);
+      const actualEnd = this.actualAnimation.interpolateRotation(1);
+
+      const rotationPositive = actualEnd > actualStart;
+
+      const transitionStart = this.actualAnimation.interpolateRotation(this.startTransitionProgress);
+      const transitionEnd = this.actualAnimation.interpolateRotation(1 - this.endTransitionProgress);
+
+      if (rotationPositive) {
+        while (transitionStart < this.startRotation) {
+          this.startRotation -= 360;
+        }
+        while (transitionEnd > this.endRotation) {
+          this.endRotation += 360;
+        }
+      } else {
+        while (transitionStart > this.startRotation) {
+          this.startRotation += 360;
+        }
+        while (transitionEnd < this.endRotation) {
+          this.endRotation -= 360;
+        }
+      }
+    }
+  }
+
+  override interpolateOffset(progress: number) {
+    return this.actualAnimation.interpolateOffset(progress);
+  }
+
+  override interpolateRotation(progress: number): number {
+    const actualRotation = this.actualAnimation.interpolateRotation(progress);
+
+    if (this.flags.rotation) {
+      if (progress < this.startTransitionProgress) {
+        return interpolateLinear(progress / this.startTransitionProgress, this.startRotation, actualRotation);
+      } else if ((1 - progress) < this.endTransitionProgress) {
+        return interpolateLinear((1 - progress) / this.endTransitionProgress, this.endRotation, actualRotation);
+      }
+    }
+
+    return actualRotation;
+  }
+
+  override interpolateHandOffset(progress: number, hand: Hand): Offset | undefined {
+    const actualHandOffset = this.actualAnimation.interpolateHandOffset(progress, hand);
+
+    if (this.flags.hands) {
+      if (progress < this.startTransitionProgress) {
+        const startHand = hand === Hand.Left
+          ? this.startPosition.leftArmEnd ?? leftShoulder
+          : this.startPosition.rightArmEnd ?? rightShoulder;
+        return interpolateLinearOffset(progress / this.startTransitionProgress, startHand, actualHandOffset ?? hand.shoulderPosition());
+      } else if (1 - progress < this.endTransitionProgress) {
+        const endHand = hand === Hand.Left
+          ? this.endPosition.leftArmEnd ?? leftShoulder
+          : this.endPosition.rightArmEnd ?? rightShoulder;
+        return interpolateLinearOffset((1 - progress) / this.endTransitionProgress, endHand, actualHandOffset ?? hand.shoulderPosition());
+      }
+    }
+
+    return actualHandOffset;
+  }
+}
+
 // TODO Not sure this really belongs here instead of on some Semantic* type.
 export enum RotationAnimationFacing {
   Linear = "Linear", // Default, linearly interpolate.
@@ -95,12 +196,7 @@ interface Closer {
   transitionProgress: number,
 }
 export interface HandAnimation {
-  kind: "Linear" | "Center" | "None",
-  transitionBeats?: number,
-}
-interface HandAnimationInternal {
-  kind: "Linear" | "Center" | "None",
-  transitionProgress: number,
+  kind: "Linear" | "Center" | "None" | "Start" | "End"
 }
 
 export class RotationAnimationSegment extends AnimationSegment {
@@ -114,27 +210,21 @@ export class RotationAnimationSegment extends AnimationSegment {
   private readonly facing: RotationAnimationFacing;
   private readonly startFacing: Rotation;
   private readonly closer?: Closer;
-  private readonly hands: Map<Hand, HandAnimationInternal>;
-  private readonly rotationTransitionProgress: number;
+  private readonly hands: Map<Hand, HandAnimation>;
 
-  constructor(beats: number, startPosition: DancerSetPosition, endPosition: DancerSetPosition,
-              rotation: number, around: RotationAround, facing: RotationAnimationFacing,
-              closer?: CloserDuringRotation, hands?: Map<Hand, HandAnimation>,
-              rotationTransitionBeats?: number) {
+  constructor({ beats, startPosition, endPosition, rotation, around, facing, closer, hands }: {
+    beats: number;
+    startPosition: DancerSetPosition;
+    endPosition: DancerSetPosition;
+    rotation: number; around: RotationAround;
+    facing: RotationAnimationFacing;
+    closer?: CloserDuringRotation;
+    hands?: Map<Hand, HandAnimation>;
+  }) {
     super(beats, startPosition, endPosition);
 
-    function convertHandAnimation(anim: HandAnimation | undefined): HandAnimationInternal {
-      if (!anim) {
-        return { kind: "Linear", transitionProgress: 0 };
-      } else {
-        return {
-          ...anim,
-          transitionProgress: (anim.transitionBeats ?? 0) / beats
-        }
-      }
-    }
-    this.hands = new Map<Hand, HandAnimationInternal>(
-      [Hand.Left, Hand.Right].map(h => [h, convertHandAnimation(hands?.get(h))]));
+    this.hands = new Map<Hand, HandAnimation>(
+      [Hand.Left, Hand.Right].map(h => [h, hands?.get(h) ?? { kind: "Linear" }]));
 
     this.facing = facing;
     this.xRadius = around.width / 2;
@@ -148,7 +238,6 @@ export class RotationAnimationSegment extends AnimationSegment {
       // Canvas rotation is backwards of what we expect, so take the negative here.
       return -radiansToDegrees(radians);
     }
-    this.rotationTransitionProgress = (rotationTransitionBeats ?? 0) / beats;
     this.startRotation = positionToDegrees(startPosition.position);
     this.startFacing = startPosition.rotation;
     const actualRotation = normalizeRotation(positionToDegrees(endPosition.position) - this.startRotation,
@@ -169,7 +258,7 @@ export class RotationAnimationSegment extends AnimationSegment {
     }
   }
 
-  protected interpolateOffset(progress: number) {
+  override interpolateOffset(progress: number) {
     const radians = -degreesToRadians(interpolateLinear(progress, this.startRotation, this.endRotation));
     let distance: number;
     if (!this.closer) {
@@ -189,7 +278,7 @@ export class RotationAnimationSegment extends AnimationSegment {
     }
   }
 
-  protected interpolateRotation(progress: number): number {
+  override interpolateRotation(progress: number): number {
     if (this.facing === RotationAnimationFacing.Linear) {
       return super.interpolateRotation(progress);
     } else {
@@ -197,41 +286,27 @@ export class RotationAnimationSegment extends AnimationSegment {
       let rotation : number;
       switch (this.facing) {
         case RotationAnimationFacing.Center:
-          rotation = degrees - 90;
-          break;
+          return degrees - 90;
         case RotationAnimationFacing.CenterRelative:
-          rotation = degrees - this.startRotation + this.startFacing;
-          break;
+          return degrees - this.startRotation + this.startFacing;
         case RotationAnimationFacing.Forward:
-          rotation = degrees + 180;
-          break;
+          return degrees + 180;
         case RotationAnimationFacing.Backward:
-          rotation = degrees;
-          break;
-      }
-
-      if (progress < this.rotationTransitionProgress) {
-        return interpolateLinear(progress / this.rotationTransitionProgress, this.startRotation, rotation);
-      } else if ((1 - progress) < this.rotationTransitionProgress) {
-        return interpolateLinear((1 - progress) / this.rotationTransitionProgress, this.endRotation, rotation);
-      } else {
-        return rotation;
+          return degrees;
       }
     }
   }
 
-  protected interpolateHandOffset(progress: number, hand: Hand): Offset | undefined {
-    const handAnim : HandAnimationInternal = this.hands.get(hand)!;
+  override interpolateHandOffset(progress: number, hand: Hand): Offset | undefined {
+    const handAnim : HandAnimation = this.hands.get(hand)!;
     let middlePos : Offset;
     switch (handAnim.kind) {
+      case "Start":
+        return hand === Hand.Left ? this.startPosition.leftArmEnd : this.startPosition.rightArmEnd;
+      case "End":
+        return hand === Hand.Left ? this.endPosition.leftArmEnd : this.endPosition.rightArmEnd;
       case "Linear":
-        if (handAnim.transitionProgress === 0) {
         return super.interpolateHandOffset(progress, hand);
-        } else if (progress < handAnim.transitionProgress) {
-          return super.interpolateHandOffset(progress / handAnim.transitionProgress, hand);
-        } else {
-          return super.interpolateHandOffset(1, hand);
-        }
       case "Center":
         const position = this.interpolateOffset(progress);
         const offset = {
@@ -244,28 +319,10 @@ export class RotationAnimationSegment extends AnimationSegment {
           x: -Math.cos(rotation) * offset.x + Math.sin(rotation) * offset.y,
           y: -Math.sin(rotation) * offset.x - Math.cos(rotation) * offset.y,
         }
-        middlePos = centerPos;
-        break;
+        return centerPos;
       case "None":
-        middlePos = hand === Hand.Left ? leftShoulder : rightShoulder;
-        break;
+        return hand === Hand.Left ? leftShoulder : rightShoulder;
     }
-
-    if (handAnim.transitionProgress) {
-      if (progress < handAnim.transitionProgress) {
-        const startHand = hand === Hand.Left
-          ? this.startPosition.leftArmEnd ?? leftShoulder
-          : this.startPosition.rightArmEnd ?? rightShoulder;
-        return interpolateLinearOffset(progress / handAnim.transitionProgress, startHand, middlePos);
-      } else if (1 - progress < handAnim.transitionProgress) {
-        const endHand = hand === Hand.Left
-          ? this.endPosition.leftArmEnd ?? leftShoulder
-          : this.endPosition.rightArmEnd ?? rightShoulder;
-        return interpolateLinearOffset((1 - progress) / handAnim.transitionProgress, endHand, middlePos);
-      }
-    }
-
-    return middlePos;
   }
 }
 

www/js/lowLevelMove.ts

@@ -287,11 +287,13 @@ export function animateLowLevelMove(move: LowLevelMove): animation.AnimationSegm
           + JSON.stringify(move.startPosition) + ", end=" + JSON.stringify(move.endPosition);
         }
         return [
-          new animation.LinearAnimationSegment(move.beats,
-            startSetPosition,
-            {
+          new animation.LinearAnimationSegment({
+            beats: move.beats,
+            startPosition: startSetPosition,
+            endPosition: {
               ...endSetPosition,
               rotation: startSetPosition.rotation + rotation,
+            }
           }),
         ];
       case SemanticAnimationKind.Circle:
@@ -300,22 +302,27 @@ export function animateLowLevelMove(move: LowLevelMove): animation.AnimationSegm
         }
 
         return [
-          new animation.RotationAnimationSegment(move.beats,
-            startSetPosition,
-            endSetPosition,
-            move.movementPattern.places * 90,
-            {
+          new animation.TransitionAnimationSegment({
+            actualAnimation: new animation.RotationAnimationSegment({
+              beats: move.beats,
+              startPosition: startSetPosition,
+              endPosition: endSetPosition,
+              rotation: move.movementPattern.places * 90,
+              around: {
                 center: CenterOfSet(move.startPosition.setOffset, move.startPosition.lineOffset),
                 width: setWidth,
                 height: setHeight,
               },
-            animation.RotationAnimationFacing.Center,
-            undefined,
-            new Map<Hand, animation.HandAnimation>([
-              [Hand.Left, { kind: "Linear", transitionBeats: 1 }],
-              [Hand.Right, { kind: "Linear", transitionBeats: 1 }],
+              facing: animation.RotationAnimationFacing.Center, closer: undefined, hands: new Map<Hand, animation.HandAnimation>([
+                [Hand.Left, { kind: "End" }],
+                [Hand.Right, { kind: "End" }],
               ])
-          ),
+            }),
+            flags: {
+              hands: true
+            },
+            startTransitionBeats: 1
+          }),
         ];
       case SemanticAnimationKind.DoSiDo:
         // TODO Rotation
@@ -326,17 +333,18 @@ export function animateLowLevelMove(move: LowLevelMove): animation.AnimationSegm
         }
         const center = CenterOf(move.startPosition.which.leftRightSide(), move.startPosition.setOffset, move.startPosition.lineOffset);
         return [
-          new animation.RotationAnimationSegment(move.beats,
-            startSetPosition,
-            endSetPosition,
-            move.movementPattern.amount,
-            {
+          new animation.RotationAnimationSegment({
+            beats: move.beats,
+            startPosition: startSetPosition,
+            endPosition: endSetPosition,
+            rotation: move.movementPattern.amount,
+            around: {
               center,
               width: setWidth / 3,
               height: setHeight,
             },
-            animation.RotationAnimationFacing.Linear,
-          ),
+            facing: animation.RotationAnimationFacing.Linear
+          }),
         ];
       case SemanticAnimationKind.RotateAround:
         // TODO Rotation
@@ -349,31 +357,37 @@ export function animateLowLevelMove(move: LowLevelMove): animation.AnimationSegm
         const rotateCenter = CenterOf(move.movementPattern.around, move.startPosition.setOffset, move.startPosition.lineOffset);
         const hands = move.movementPattern.byHand
           ? new Map<Hand, animation.HandAnimation>([
-            [move.movementPattern.byHand, { kind: "Center", transitionBeats: 1 }],
-            [move.movementPattern.byHand.opposite(), { kind: "None", transitionBeats: 1 }],
+            [move.movementPattern.byHand, { kind: "Center" }],
+            [move.movementPattern.byHand.opposite(), { kind: "None" }],
           ])
           : new Map<Hand, animation.HandAnimation>([
-            [Hand.Left, { kind: "None", transitionBeats: 1 }],
-            [Hand.Right, { kind: "None", transitionBeats: 1 }],
+            [Hand.Left, { kind: "None" }],
+            [Hand.Right, { kind: "None" }],
           ]);
         return [
-          new animation.RotationAnimationSegment(move.beats,
-            startSetPosition,
-            endSetPosition,
-            move.movementPattern.minAmount,
-            {
+          new animation.TransitionAnimationSegment({
+            actualAnimation: new animation.RotationAnimationSegment({
+              beats: move.beats,
+              startPosition: startSetPosition,
+              endPosition: endSetPosition,
+              rotation: move.movementPattern.minAmount,
+              around: {
                 center: rotateCenter,
                 width: setWidth / 5,
                 height: setHeight / 5,
               },
-            animation.RotationAnimationFacing.Center,
-            {
+              facing: animation.RotationAnimationFacing.Center, closer: {
                 transitionBeats: 1,
                 minDistance: setWidth,
               },
-            hands,
-            1,
-          ),
+              hands
+            }),
+            flags: {
+              hands: true,
+              rotation: true
+            },
+            startTransitionBeats: 1
+          }),
         ];
       case SemanticAnimationKind.Swing:
         if (move.startPosition.kind !== PositionKind.Circle || move.endPosition.kind !== PositionKind.Circle) {
@@ -400,29 +414,33 @@ export function animateLowLevelMove(move: LowLevelMove): animation.AnimationSegm
         });
 
         return [
-          new animation.LinearAnimationSegment(1,
-            startSetPosition,
-            swingStart,
-          ),
-          new animation.RotationAnimationSegment(move.beats - 3,
-            swingStart,
-            beforeUnfold,
-            move.movementPattern.minAmount, // TODO base minAmount on number of beats?
-            {
+          new animation.LinearAnimationSegment({
+            beats: 1,
+            startPosition: startSetPosition,
+            endPosition: swingStart,
+          }),
+          new animation.RotationAnimationSegment({
+            beats: move.beats - 3,
+            startPosition: swingStart,
+            endPosition: beforeUnfold,
+            rotation: move.movementPattern.minAmount,
+            around: {
               center: rotateSwingCenter,
               width: setWidth / 5,
               height: setHeight / 5,
             },
-            animation.RotationAnimationFacing.CenterRelative,
-          ),
-          new animation.LinearAnimationSegment(1,
-            beforeUnfold,
-            unfolded,
-          ),
-          new animation.LinearAnimationSegment(1,
-            unfolded,
-            endSetPosition,
-          ),
+            facing: animation.RotationAnimationFacing.CenterRelative
+          }),
+          new animation.LinearAnimationSegment({
+            beats: 1,
+            startPosition: beforeUnfold,
+            endPosition: unfolded,
+          }),
+          new animation.LinearAnimationSegment({
+            beats: 1,
+            startPosition: unfolded,
+            endPosition: endSetPosition,
+          }),
         ];
       case SemanticAnimationKind.TwirlSwap:
         const twirlCenter =
@@ -435,25 +453,26 @@ export function animateLowLevelMove(move: LowLevelMove): animation.AnimationSegm
           rightArmEnd: startSetPosition.rightArmEnd === undefined ? undefined : endSetPosition.rightArmEnd,
         };
         return [
-          new animation.RotationAnimationSegment(move.beats - 1,
-            startSetPosition,
-            {
+          new animation.RotationAnimationSegment({
+            beats: move.beats - 1,
+            startPosition: startSetPosition,
+            endPosition: {
               ...postTwirlPos,
               rotation: endSetPosition.rotation - (move.startPosition.hands?.has(Hand.Left) ? 360 : 0)
             },
-            180,
-            {
+            rotation: 180,
+            around: {
               center: twirlCenter,
               width: aroundTopOrBottom ? setWidth : setWidth / 4,
               height: aroundTopOrBottom ? setHeight / 4 : setHeight,
             },
-            animation.RotationAnimationFacing.Linear,
-            undefined,
-            new Map<Hand, animation.HandAnimation>([[[...move.startPosition.hands!.keys()][0], {kind: "Center"}]]),
-          ),
-          new animation.LinearAnimationSegment(1,
-            postTwirlPos,
-            endSetPosition)
+            facing: animation.RotationAnimationFacing.Linear, closer: undefined, hands: new Map<Hand, animation.HandAnimation>([[[...move.startPosition.hands!.keys()][0], { kind: "Center" }]])
+          }),
+          new animation.LinearAnimationSegment({
+            beats: 1,
+            startPosition: postTwirlPos,
+            endPosition: endSetPosition
+          })
         ];
     }