Improved box circulate animation.

www/js/interpreter.ts

@@ -64,6 +64,20 @@ function handsInLine(args: { wavy: boolean } & ({ which: ShortLinesPosition, fac
     ]);
   }
 }
+function handToDancerToSideInCircleFacingAcross(which: CirclePosition): Map<Hand, HandConnection> {
+  return new Map<Hand, HandConnection>([
+    which.isOnLeftLookingAcross()
+      ? [Hand.Right, { hand: Hand.Left, to: HandTo.DancerRight }]
+      : [Hand.Left, { hand: Hand.Right, to: HandTo.DancerLeft }]
+  ]);
+}
+function handToDancerToSideInCircleFacingUpOrDown(which: CirclePosition): Map<Hand, HandConnection> {
+  return new Map<Hand, HandConnection>([
+    which.isOnLeftLookingUpAndDown()
+      ? [Hand.Right, { hand: Hand.Left, to: HandTo.DancerRight }]
+      : [Hand.Left, { hand: Hand.Right, to: HandTo.DancerLeft }]
+  ]);
+}
 
 function balanceCircleInAndOut(move: Move, startPos: SemanticPosition, balanceBeats?: number): [LowLevelMove, LowLevelMove] {
   if (startPos.kind !== PositionKind.Circle) {
@@ -450,7 +464,8 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
           movementPattern: {
             // TODO Not sure loop should really be linear...
             kind: SemanticAnimationKind.Linear,
-            minRotation: isCrossing ? undefined : circulateRight ? 180 : -180
+            minRotation: isCrossing ? undefined : circulateRight ? 180 : -180,
+            handsDuring: "None",
           }
         };
         return combine([...balance, circulate], startingPos);
@@ -1240,6 +1255,45 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
         }], startingPos);
       });
 
+    case "slice":
+      if (move.parameters["slice increment"] === "dancer") {
+        // TODO Maybe this only actually gets used to move an entire couple by going diagonal back?
+        throw new Error("Slicing by a single dancer is unsupported.");
+      }
+
+      const sliceLeft = move.parameters.slide;
+      const sliceReturns = move.parameters["slice return"] !== "none";
+
+      const sliceForwardBeats = sliceReturns ? move.beats / 2 : move.beats;
+      const sliceBackwardBeats = move.beats - sliceForwardBeats;
+
+      return handleCircleMove(({ startPos }) => {
+        const startingPos: SemanticPosition & { setOffset: number } = {
+          kind: PositionKind.Circle,
+          which: startPos.which,
+          facing: startPos.which.facingAcross(),
+          hands: handToDancerToSideInCircleFacingAcross(startPos.which),
+          setOffset: startPos.setOffset ?? 0,
+          lineOffset: startPos.lineOffset,
+        };
+        const sliceAmount = startingPos.which.isLeft() === sliceLeft ? +0.5 : -0.5;
+        const forwardOffset = startingPos.setOffset + sliceAmount;
+        const endOffset = move.parameters["slice return"] === "diagonal" ? forwardOffset + sliceAmount : forwardOffset;
+
+        const sliceForward: PartialLowLevelMove = {
+          beats: sliceForwardBeats,
+          endPosition: { ...startingPos, setOffset: forwardOffset, longLines: LongLines.Forward },
+          movementPattern: { kind: SemanticAnimationKind.Linear },
+        };
+        const maybeSliceBackward: PartialLowLevelMove[] = sliceReturns ? [{
+          beats: sliceBackwardBeats,
+          endPosition: { ...startingPos, setOffset: endOffset },
+          movementPattern: { kind: SemanticAnimationKind.Linear },
+        }] : [];
+
+        return combine([sliceForward, ...maybeSliceBackward], startingPos);
+      });
+
     case "down the hall":
       if (move.parameters.who !== "everyone") {
         throw new Error("Don't know what it means for not everyone to go down the hall.");
@@ -1683,6 +1737,26 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
         return combine(heySteps.map(heyStepToPartialLowLevelMove), { ...startingPos, hands: undefined });
       });
 
+    case "turn alone":
+      if (move.parameters.who !== "everyone" || move.beats !== 0) {
+        throw new Error("turn alone unsupported except for changing to new circle.");
+      }
+      return handleCircleMove(({startPos}) => {
+        const which = startPos.which.swapUpAndDown();
+        const startAndEndPos: SemanticPosition = {
+          ...startPos,
+          which,
+          facing: which.facingUpOrDown(),
+          setOffset: (startPos.setOffset ?? 0) + (startPos.which.isTop() ? +0.5 : -0.5),
+        }
+
+        return combine([{
+          beats: move.beats,
+          endPosition: startAndEndPos,
+          movementPattern: { kind: SemanticAnimationKind.StandStill },
+        }], startAndEndPos);
+      })
+
     case "custom":
       if (move.parameters.custom.includes("mirrored mad robin")) {
         return handleCircleMove(({ id, startPos }) => {

www/js/lowLevelMove.ts

@@ -3,7 +3,7 @@ import * as common from "./danceCommon.js";
 import { DanceRole, DancerIdentity, Rotation } from "./danceCommon.js";
 import { BalanceWeight, CirclePosition, CircleSide, CircleSideOrCenter, DancerDistance, Facing, HandConnection, HandTo, LongLines, PositionKind, SemanticPosition, ShortLinesPosition, StarGrip } from "./interpreterCommon.js";
 import { Move } from "./libfigureMapper.js";
-import { DancerSetPosition, Hand, Offset, dancerWidth, lineDistance, setDistance, setHeight, setSpacing, setWidth } from "./rendererConstants.js";
+import { DancerSetPosition, Hand, Offset, OffsetPlus, OffsetRotate, OffsetTimes, OffsetTranspose, dancerWidth, lineDistance, offsetZero, setDistance, setHeight, setSpacing, setWidth } from "./rendererConstants.js";
 
 
 export enum SemanticAnimationKind {
@@ -238,6 +238,7 @@ function SemanticToSetPosition(semantic: SemanticPosition): DancerSetPosition {
         case LongLines.Forward:
           position.x *= 0.25;
       }
+      let balanceOffset: Offset = offsetZero;
       if (semantic.balance) {
         if (semantic.facing === Facing.CenterOfCircle) {
           if (semantic.balance === BalanceWeight.Forward) {
@@ -247,17 +248,40 @@ function SemanticToSetPosition(semantic: SemanticPosition): DancerSetPosition {
           }
         } else if ((semantic.facing === Facing.Up || semantic.facing === Facing.Down)
           && (semantic.balance === BalanceWeight.Backward || semantic.balance === BalanceWeight.Forward)) {
-          position = {
+          balanceOffset = {
-            x: position.x,
+            x: 0,
-            y: position.y + position.y * (
+            y: position.y * (
               semantic.balance === BalanceWeight.Forward
                 ? -balanceAmount
                 : balanceAmount)
           };
+        } else if ((semantic.facing === Facing.Left || semantic.facing === Facing.Right)
+          && (semantic.balance === BalanceWeight.Backward || semantic.balance === BalanceWeight.Forward)) {
+          balanceOffset = {
+            x: (semantic.balance === BalanceWeight.Forward) === (semantic.facing === Facing.Left)
+              ? -balanceAmount
+              : balanceAmount,
+            y: 0
+          };
+        } else if ((semantic.facing === Facing.Left || semantic.facing === Facing.Right)
+          && (semantic.balance === BalanceWeight.Left || semantic.balance === BalanceWeight.Right)) {
+          balanceOffset = {
+            x: 0,
+            y: (semantic.balance === BalanceWeight.Left) === (semantic.facing === Facing.Left)
+              ? -balanceAmount
+              : balanceAmount
+          };
+        } else if ((semantic.facing === Facing.Up || semantic.facing === Facing.Down)
+          && (semantic.balance === BalanceWeight.Left || semantic.balance === BalanceWeight.Right)) {
+          balanceOffset = {
+            x: (semantic.balance === BalanceWeight.Left) === (semantic.facing === Facing.Up)
+              ? -balanceAmount
+              : balanceAmount,
+            y: 0
+          };
         }
       }
-      position.x += setOffset.x;
+      position = OffsetPlus(position, balanceOffset, setOffset);
-      position.y += setOffset.y;
 
       const isFacingUpOrDown = semantic.facing === Facing.Up || semantic.facing === Facing.Down;
       if (semantic.dancerDistance === DancerDistance.SwingLark) {
@@ -292,11 +316,12 @@ function SemanticToSetPosition(semantic: SemanticPosition): DancerSetPosition {
         // TODO Hands. Might need more info? Or need context of nearby dancer SemanticPositions?
         if (!connection) return undefined;
 
+        const balanceHandAdjustment = OffsetRotate(balanceOffset, -rotation);
         switch (connection.to) {
           case HandTo.DancerLeft:
-            return { x: -1, y: 0 };
+            return OffsetPlus({ x: -1, y: 0 }, balanceHandAdjustment);
           case HandTo.DancerRight:
-            return { x: +1, y: 0 };
+            return OffsetPlus({ x: +1, y: 0 }, balanceHandAdjustment);
           case HandTo.DancerForward:
             if (hand === connection.hand) {
               return { x: 0, y: +0.5 };

www/js/rendererConstants.ts

@@ -1,32 +1,50 @@
-import { DancerIdentity } from "./danceCommon";
+import { DancerIdentity, Rotation } from "./danceCommon";
 
 export interface Offset {
   x: number;
   y: number;
 }
 
-export function OffsetPlus(a: Offset, b: Offset) {
+export function OffsetTranspose(a: Offset): Offset {
+  return { x: a.y, y: a.x };
+}
+
+export function OffsetRotate(a: Offset, r: Rotation): Offset {
+  const rad = degreesToRadians(r);
+  const sin = Math.sin(rad);
+  const cos = Math.cos(rad);
+  return {
+    x: a.x * cos - a.y * sin,
+    y: a.x * sin + a.y * cos,
+  };
+}
+
+function _OffsetPlus(a: Offset, b: Offset): Offset {
   return {
     x: a.x + b.x,
     y: a.y + b.y,
   };
 }
 
-export function OffsetTimes(a: Offset, b: number) {
+export function OffsetPlus(...args: Offset[]): Offset {
+  return args.reduce(_OffsetPlus, offsetZero);
+}
+
+export function OffsetTimes(a: Offset, b: number): Offset {
   return {
     x: a.x * b,
     y: a.y * b,
   };
 }
 
-export function OffsetMinus(a: Offset, b: Offset) {
+export function OffsetMinus(a: Offset, b: Offset): Offset {
   return {
     x: a.x - b.x,
     y: a.y - b.y,
   };
 }
 
-export function OffsetEquals(a: Offset, b: Offset) {
+export function OffsetEquals(a: Offset, b: Offset): boolean {
   return a.x === b.x && a.y === b.y;
 }