Attempt at using variants for swing.

* Different shapes for larks/robins: robins are now domes, larks still
   triangles.
 * Related: partners the same color (might try very close colors?)
 * Attempt to have a color scheme so Ones are warm colors and Twos are
   cool colors to make neighbor vs. shadow interactions more clear at a
   glance.

www/index.html

@@ -58,29 +58,58 @@
         position: sticky;
         top: 0;
       }
-      th.Ones.Lark {
+
-        background-color: hsl(0, 80%, 50%);
+      th.Ones {
+        background-color: hsl(27, 99%, 59%);
       }
-      td.Ones.Lark {
+      td.Ones {
-        background-color: hsl(0, 90%, 70%);
+        background-color: hsl(27, 99%, 85%);
       }
-      th.Ones.Robin {
+      th.Twos {
-        background-color: hsl(39, 80%, 50%);
+        background-color: hsl(249, 42%, 57%);
       }
-      td.Ones.Robin {
+      td.Twos {
-        background-color: hsl(39, 90%, 70%);
+        background-color: hsl(249, 52%, 85%);
       }
-      th.Twos.Lark {
+
-        background-color: hsl(240, 70%, 65%);
+      th.Lark::before {
+        content: "◠";
+        text-decoration: line-through;
+        padding-right: 1ex;
       }
-      td.Twos.Lark {
+      th.Robin::before {
-        background-color: hsl(240, 90%, 80%);
+        content: "△";
+        padding-right: 1ex;
       }
-      th.Twos.Robin {
+
-        background-color: hsl(180, 80%, 50%);
+      td.Lark.Ones {
+        background:
+          radial-gradient(circle at bottom left, hsl(27, 99%, 75%) 15%, transparent 16%),
+          radial-gradient(circle at bottom right, hsl(27, 99%, 75%) 15%, transparent 16%),
+          hsl(27, 99%, 85%);
+        background-size: 6em 3em;
       }
-      td.Twos.Robin {
+      td.Lark.Twos {
-        background-color: hsl(180, 90%, 70%);
+        background:
+          radial-gradient(circle at bottom left, hsl(249, 42%, 75%) 15%, transparent 16%),
+          radial-gradient(circle at bottom right,hsl(249, 42%, 75%) 15%, transparent 16%),
+          hsl(249, 52%, 85%);
+        background-size: 6em 3em;
+      }
+
+      td.Robin.Ones {
+        background:
+          linear-gradient(45deg,hsl(27, 99%, 75%) 10%, transparent 10%),
+          linear-gradient(135deg, transparent 90%,hsl(27, 99%, 75%) 90%),
+          hsl(27, 99%, 85%);
+        background-size: 6em 3em;
+      }
+      td.Robin.Twos {
+        background:
+          linear-gradient(45deg,hsl(249, 42%, 75%) 10%, transparent 10%),
+          linear-gradient(135deg, transparent 90%,hsl(249, 42%, 75%) 90%),
+          hsl(249, 52%, 85%);
+        background-size: 6em 3em;
       }
 
       .move {

www/js/interpreter.ts

@@ -6,7 +6,7 @@ import { nameLibFigureParameters, Move, chooser_pairz } from "./libfigureMapper.
 import { LowLevelMove, SemanticAnimation, SemanticAnimationKind, animateFromLowLevelMoves } from "./lowLevelMove.js";
 import { BalanceWeight, CirclePosition, CircleSide, CircleSideOrCenter, DancerDistance, Facing, HandConnection, HandTo, LongLines, PositionKind, SemanticPosition, ShortLinesPosition, StarGrip, handToDancerToSideInCircleFacingAcross, handsFourImproper, handsInCircle, handsInLine, handsInShortLine, oppositeFacing } from "./interpreterCommon.js";
 import { ContraDBDance } from "./danceLibrary.js";
-import { errorMoveInterpreterCtor, moveInterpreters } from "./moves/_moveInterpreter.js";
+import { AllVariantsForMoveArgs, ErrorMoveInterpreter, LowLevelMovesForAllDancers, MoveAsLowLevelMovesArgs, SemanticPositionsForAllDancers, Variant, VariantCollection, errorMoveInterpreterCtor, moveInterpreters } from "./moves/_moveInterpreter.js";
 
 // Import all individual move files.
 // ls [a-z]*.js | sed 's@.*@import "./moves/\0";@'
@@ -46,62 +46,111 @@ import "./moves/turnAlone.js";
 import "./moves/upTheHall.js";
 
 
-function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: { move: Move; nextMove: Move; startingPos: Map<DancerIdentity, SemanticPosition>; numProgessions: number; }): Map<DancerIdentity, LowLevelMove[]> {
+// TODO Get rid of nextMove here once variants are actually supported by Swing.
+function allVariantsForMove({ move, nextMove, startingVariants, numProgessions }: { move: Move; nextMove: Move; startingVariants: AllVariantsForMoveArgs; numProgessions: number; }): VariantCollection {
   const moveInterpreter = moveInterpreters.get(move.move) ?? errorMoveInterpreterCtor;
-  return new moveInterpreter({ move, nextMove, numProgessions }).moveAsLowLevelMoves({ startingPos });
+  return new moveInterpreter({ move, nextMove, numProgessions }).allVariantsForMove(startingVariants);
 }
 
-function danceAsLowLevelMoves(moves: Move[], startingPos: Map<DancerIdentity, SemanticPosition>): Map<DancerIdentity, LowLevelMove[]> {
+
-  const res = new Map<DancerIdentity, LowLevelMove[]>([...startingPos.keys()].map(id => [id, []]));
+function danceAsLowLevelMoves(moves: Move[], startingVariants: AllVariantsForMoveArgs): Map<DancerIdentity, LowLevelMove[]> {
-  let currentPos = new Map<DancerIdentity, SemanticPosition>(startingPos);
+  let currentVariants = new Map<string, MoveAsLowLevelMovesArgs>(startingVariants);
+  let currentVariantMoves: Map<string, LowLevelMovesForAllDancers> = new Map<string, LowLevelMovesForAllDancers>(
+    [...startingVariants.keys()].map(name => [name, new Map<DancerIdentity, LowLevelMove[]>(DancerIdentity.all().map(id => [id, []]))]));
   let numProgessions = 0;
   for (let i = 0; i < moves.length; i++) {
     const move = moves[i];
     const nextMove = i === moves.length - 1 ? moves[0] : moves[i + 1];
+
+    function updateVariants(newVariants: VariantCollection) {
+      let previousVariants = currentVariants;
+      let previousVariantMoves = currentVariantMoves;
+      try {
+        currentVariants = new Map<string, MoveAsLowLevelMovesArgs>();
+        currentVariantMoves = new Map<string, LowLevelMovesForAllDancers>();
+
+        variant: for (const [name, variant] of newVariants) {
+          const oldMoves = previousVariantMoves.get(variant.previousMoveVariant);
+          const oldPos = previousVariants.get(variant.previousMoveVariant);
+          if (!oldMoves || !oldPos) {
+            throw new Error("Referenced unknown previous variant: " + variant.previousMoveVariant);
+          }
+
+          const newMoves: LowLevelMovesForAllDancers = new Map<DancerIdentity, LowLevelMove[]>();
+          const newPositions = new Map<DancerIdentity, SemanticPosition>();
+          for (const [id, newMoveList] of variant.lowLevelMoves.entries()) {
+            const prevEnd = oldPos.startingPos.get(id)!;
+            const newStart = newMoveList[0].startPosition;
+
+            if ((prevEnd.setOffset ?? 0) != (newStart.setOffset ?? 0)
+              || (prevEnd.lineOffset ?? 0) != (newStart.lineOffset ?? 0)
+              || prevEnd.kind != newStart.kind
+              || prevEnd.which != newStart.which
+              || prevEnd.balance != newStart.balance
+              || prevEnd.dancerDistance != newStart.dancerDistance) {
+              // TODO Should this be considered a bug?
+              // TODO Require more properties to match? facing? probably not hands.
+              continue variant;
+            }
+
+            newMoves.set(id, [...oldMoves.get(id)!, ...newMoveList]);
+            newPositions.set(id, newMoveList.at(-1)!.endPosition);
+          }
+
+          currentVariants.set(name, { startingPos: newPositions });
+          currentVariantMoves.set(name, newMoves);
+        }
+      } catch (ex) {
+        currentVariants = previousVariants;
+        currentVariantMoves = previousVariantMoves;
+        throw ex;
+      }
+    }
+
     try {
       if (i > 0 && move.beats === 0 && move.move === "slide along set") {
         const slideLeft: boolean = move.parameters.slide;
-        for (const [id, currPos] of currentPos.entries()) {
+        for (const [name, currentPos] of currentVariants.entries()) {
-          const slideAmount = (currPos.which.leftRightSide() === CircleSide.Left) === slideLeft ? +0.5 : -0.5;
+          for (const [id, currPos] of currentPos.startingPos.entries()) {
-          const setOffset = (currPos.setOffset ?? 0) + slideAmount;
+            const slideAmount = (currPos.which.leftRightSide() === CircleSide.Left) === slideLeft ? +0.5 : -0.5;
-          currentPos.set(id, { ...currPos, setOffset });
+            const setOffset = (currPos.setOffset ?? 0) + slideAmount;
+            currentPos.startingPos.set(id, { ...currPos, setOffset });
 
-          const prevMove = res.get(id)!.at(-1)!;
+            const prevMove = currentVariantMoves.get(name)!.get(id)!.at(-1)!;
-          prevMove.movementPattern.setSlideAmount = slideAmount;
+            prevMove.movementPattern.setSlideAmount = slideAmount;
-          prevMove.endPosition.setOffset = setOffset;
+            prevMove.endPosition.setOffset = setOffset;
+          }
         }
-
       } else {
-        const newMoves = moveAsLowLevelMoves({ move, nextMove, startingPos: currentPos, numProgessions });
+        const newMoves = allVariantsForMove({ move, nextMove, startingVariants: currentVariants, numProgessions });
-        for (const [id, newMoveList] of newMoves.entries()) {
+        if (newMoves.size === 0) {
-          res.get(id)!.push(...newMoveList);
+          updateVariants(new ErrorMoveInterpreter({ move, nextMove, numProgessions },
-          currentPos.set(id, newMoveList.at(-1)!.endPosition);
+            "ERROR: " + move.move + " has no valid starting variants.").allVariantsForMove(currentVariants));
+        } else {
+          updateVariants(newMoves);
         }
       }
     }
     catch (ex) {
       // catch exception so something can be displayed
-      for (const [id, pos] of currentPos.entries()) {
+      const errorMessage: string = ex instanceof Error ? ex.message : ex;
-        res.get(id)!.push({
+      const errorVariants = new ErrorMoveInterpreter({ move, nextMove, numProgessions }, errorMessage).allVariantsForMove(currentVariants);
-          beats: move.beats,
+      updateVariants(errorVariants);
-          startPosition: pos,
-          endPosition: pos,
-          movementPattern: { kind: SemanticAnimationKind.StandStill },
-          move,
-          startBeat: 0,
-          interpreterError: ex instanceof Error ? ex.message : ex,
-        });
-      }
     }
     if (move.progression) numProgessions++;
   }
 
+  const res = [...currentVariantMoves.values()].at(-1)!;
+  if (currentVariantMoves.size !== 1) {
+    res.get(DancerIdentity.OnesRobin)![0].interpreterError = "Expected exactly one variant. Found "
+            + currentVariantMoves.size + ": " + [...currentVariantMoves.keys()].join(", ");
+  }
+
   try {
     const progression = animateFromLowLevelMoves(res).progression;
     const progressionInSets = progression.y / setDistance;
 
     // fixup end positions to match start of next move
-    // TODO Handle progression.
     for (const [id, lowLevelMoves] of res.entries()) {
       for (let i = 0; i < lowLevelMoves.length - 1; i++) {
         if (!lowLevelMoves[i].endPosition) throw "endPosition is undefined";
@@ -198,6 +247,15 @@ function StartingPosForFormation(formation: common.StartFormation, dance?: Contr
   }
 }
 
+function startingVariantsForFormation(formation: common.StartFormation, dance?: ContraDBDance) : AllVariantsForMoveArgs {
+  // TODO Handle various different starting position that all count as "improper" like short/long waves, etc.
+  const pos = StartingPosForFormation(formation, dance);
+
+  return new Map<string, MoveAsLowLevelMovesArgs>([
+    ["Initial", { startingPos: pos }]
+  ]);
+}
+
 export let mappedDance: Move[];
 
 export let interpretedDance: Map<DancerIdentity, LowLevelMove[]>;
@@ -205,7 +263,7 @@ export let interpretedAnimation: animation.Animation;
 
 export function loadDance(dance: ContraDBDance): animation.Animation {
   mappedDance = dance.figures.map(nameLibFigureParameters);
-  interpretedDance = danceAsLowLevelMoves(mappedDance, StartingPosForFormation(dance.start_type, dance));
+  interpretedDance = danceAsLowLevelMoves(mappedDance, startingVariantsForFormation(dance.start_type, dance));
   interpretedAnimation = animateFromLowLevelMoves(interpretedDance);
 
   return interpretedAnimation;

www/js/moves/_moveInterpreter.ts

@@ -9,7 +9,7 @@ export const moveInterpreters: Map<MoveName, MoveInterpreterCtor<MoveName>> = ne
 
 export interface MoveInterpreterCtorArgs<N extends MoveName> {
   move: Move & { move: N };
-  nextMove: Move;
+  nextMove?: Move;
   numProgessions: number;
 }
 export type SemanticPositionsForAllDancers = Map<DancerIdentity, SemanticPosition>;
@@ -18,11 +18,13 @@ export interface MoveAsLowLevelMovesArgs {
 }
 export type LowLevelMovesForAllDancers = Map<DancerIdentity, LowLevelMove[]>;
 export interface Variant {
-  previousMoveVariant?: string,
+  previousMoveVariant: string,
   lowLevelMoves: LowLevelMovesForAllDancers,
 };
 export type VariantCollection = Map<string, Variant>;
 
+export type AllVariantsForMoveArgs = Map<string, MoveAsLowLevelMovesArgs>;
+
 export type PartialLowLevelMove = {
   remarks?: string,
   beats: number,
@@ -32,8 +34,7 @@ export type PartialLowLevelMove = {
 };
 
 export interface ISingleVariantMoveInterpreter {
-  moveAsLowLevelMoves: () => LowLevelMovesForAllDancers;
+  moveAsVariants: (previousMoveVariant: string | undefined) => VariantCollection;
-  moveAsVariants: () => VariantCollection;
 };
 
 export abstract class SingleVariantMoveInterpreter<T extends MoveInterpreter<N>, N extends MoveName> implements ISingleVariantMoveInterpreter {
@@ -49,11 +50,15 @@ export abstract class SingleVariantMoveInterpreter<T extends MoveInterpreter<N>,
     return this.moveInterpreter.move;
   }
 
-  abstract moveAsLowLevelMoves(): LowLevelMovesForAllDancers;
+  moveAsLowLevelMoves(): LowLevelMovesForAllDancers {
+    throw new Error("You must implement either moveAsLowLevelMoves() or moveAsVariants().");
+  }
 
-  moveAsVariants(): VariantCollection {
+  // TODO It would make more sense for previousMoveVariant to get passed into the constructor...
+  //      ... but that requires touching every subclass, so it's an annoying refactor.
+  moveAsVariants(previousMoveVariant: string): VariantCollection {
     return new Map<string, Variant>([
-      ["default", { lowLevelMoves: this.moveAsLowLevelMoves() }]
+      ["default", { lowLevelMoves: this.moveAsLowLevelMoves(), previousMoveVariant }]
     ]);
   }
 
@@ -293,10 +298,10 @@ export abstract class SingleVariantMoveInterpreter<T extends MoveInterpreter<N>,
     } : undefined);
   }
 
-  errorStandStill() {
+  errorStandStill(error?: string) {
     return this.handleMove(({ startPos }) => {
       return [{
-        interpreterError: "UNKNOWN MOVE '" + this.move.move + "': standing still",
+        interpreterError: error ?? ("UNKNOWN MOVE '" + this.move.move + "': standing still"),
         move: this.move,
         startBeat: 0,
         beats: this.move.beats,
@@ -312,7 +317,7 @@ export abstract class SingleVariantMoveInterpreter<T extends MoveInterpreter<N>,
 
 export abstract class MoveInterpreter<N extends MoveName> {
   public readonly move: Move & { move: N };
-  public readonly nextMove: Move;
+  public readonly nextMove?: Move;
   public readonly numProgressions: number;
 
   constructor({ move, nextMove, numProgessions }: MoveInterpreterCtorArgs<N>) {
@@ -323,19 +328,61 @@ export abstract class MoveInterpreter<N extends MoveName> {
 
   abstract buildSingleVariantMoveInterpreter(startingPos: SemanticPositionsForAllDancers): ISingleVariantMoveInterpreter;
 
-  moveAsLowLevelMoves({ startingPos }: MoveAsLowLevelMovesArgs): LowLevelMovesForAllDancers {
+  // TODO Better name?
-    return this.buildSingleVariantMoveInterpreter(startingPos).moveAsLowLevelMoves();
+  moveAsVariants({ startingPos }: MoveAsLowLevelMovesArgs, previousMoveVariant: string): VariantCollection {
+    return this.buildSingleVariantMoveInterpreter(startingPos).moveAsVariants(previousMoveVariant);
+  }
+
+  allVariantsForMove(args: AllVariantsForMoveArgs): VariantCollection {
+    const res = new Map<string, Variant>();
+    let error;
+
+    for (const [variantName, variantArgs] of args.entries()) {
+      let newVariants: VariantCollection;
+      try {
+        newVariants = this.moveAsVariants(variantArgs, variantName);
+      } catch (ex) {
+        // TODO Maybe have a way to distinguish invalid start from error processing move?
+        error = ex;
+        // If this variant can't be processed, just continue.
+        continue;
+      }
+
+      for (const [newVariantName, variant] of newVariants) {
+        let combinedVariantName: string;
+        if (args.size === 1) {
+          combinedVariantName = newVariantName;
+        } else if (newVariants.size === 1) {
+          combinedVariantName = variantName;
+        } else {
+          combinedVariantName = newVariantName + "_from_" + variantName;
+        }
+
+        res.set(combinedVariantName, variant);
+      }
+    }
+
+    if (res.size === 0) throw error;
+    return res;
   }
 }
 
-class DefaultSingleVariantMoveInterpreter extends SingleVariantMoveInterpreter<DefaultMoveInterpreter, MoveName> {
+class ErrorSingleVariantMoveInterpreter extends SingleVariantMoveInterpreter<ErrorMoveInterpreter, MoveName> {
   moveAsLowLevelMoves(): LowLevelMovesForAllDancers {
-    return this.errorStandStill();
+    return this.errorStandStill(this.moveInterpreter.error);
   }
 }
-class DefaultMoveInterpreter extends MoveInterpreter<MoveName> {
+export class ErrorMoveInterpreter extends MoveInterpreter<MoveName> {
+  public readonly error?: string;
+
+  constructor(args: MoveInterpreterCtorArgs<MoveName>, error?: string) {
+    super(args);
+    this.error = error;
+  }
+
   buildSingleVariantMoveInterpreter(startingPos: SemanticPositionsForAllDancers): ISingleVariantMoveInterpreter {
-    throw new Error("Method not implemented.");
+    //throw new Error("Method not implemented.");
+    return new ErrorSingleVariantMoveInterpreter(this, startingPos);
   }
 }
-export const errorMoveInterpreterCtor: MoveInterpreterCtor<MoveName> = DefaultMoveInterpreter;
+export const errorMoveInterpreterCtor: MoveInterpreterCtor<MoveName> = ErrorMoveInterpreter;Error

www/js/moves/allemande.ts

@@ -1,4 +1,4 @@
-import { SemanticPosition, PositionKind, CircleSide, Facing, CirclePosition, LongLines, HandConnection } from "../interpreterCommon.js";
+import { SemanticPosition, PositionKind, CircleSide, Facing, CirclePosition, LongLines, HandConnection, DancerDistance } from "../interpreterCommon.js";
 import { SemanticAnimationKind } from "../lowLevelMove.js";
 import { Hand } from "../rendererConstants.js";
 import { ISingleVariantMoveInterpreter, LowLevelMovesForAllDancers, MoveInterpreter, SemanticPositionsForAllDancers, SingleVariantMoveInterpreter, moveInterpreters } from "./_moveInterpreter.js";
@@ -24,6 +24,15 @@ class AllemandeSingleVariant extends SingleVariantMoveInterpreter<Allemande, all
     }
 
     return this.handlePairedMove(move.parameters.who, ({ startPos, around, withId, withPos }) => {
+      if (startPos.kind === PositionKind.ShortLines && withPos.kind === PositionKind.ShortLines
+        && startPos.which.leftRightSide() != withPos.which.leftRightSide()
+        && (!startPos.which.isMiddle() || !withPos.which.isMiddle())) {
+          throw new Error("Allemande in short lines must either be on same side of set or in the middle.");
+        }
+      if (startPos.dancerDistance && startPos.dancerDistance !== DancerDistance.Normal) {
+        throw new Error(this.move.move + " can only start in normal DancerDistance.");
+      }
+
       let endPosition: SemanticPosition = startPos;
       let startingPos = startPos;
       if (swap) {

www/js/moves/madRobin.ts

@@ -1,4 +1,4 @@
-import { SemanticPosition, PositionKind } from "../interpreterCommon.js";
+import { SemanticPosition, PositionKind, DancerDistance } from "../interpreterCommon.js";
 import { Move } from "../libfigureMapper.js";
 import { SemanticAnimationKind } from "../lowLevelMove.js";
 import { ISingleVariantMoveInterpreter, LowLevelMovesForAllDancers, MoveInterpreter, SemanticPositionsForAllDancers, SingleVariantMoveInterpreter, moveInterpreters } from "./_moveInterpreter.js";
@@ -12,6 +12,10 @@ class MadRobinSingleVariant extends SingleVariantMoveInterpreter<MadRobin, typeo
     }
 
     return this.handleCircleMove(({ id, startPos }) => {
+      if (startPos.dancerDistance && startPos.dancerDistance !== DancerDistance.Normal) {
+        throw new Error(this.move.move + " can only start in normal DancerDistance.");
+      }
+
       // Read who of mad robin to decide direction.
       const madRobinClockwise: boolean = (this.findPairOpposite(this.move.parameters.who, id) !== null) === startPos.which.isOnLeftLookingAcross();
 

www/js/moves/swing.ts

@@ -3,26 +3,52 @@ import { LongLines, CircleSide, SemanticPosition, CirclePosition, Facing, Positi
 import { Move } from "../libfigureMapper.js";
 import { SemanticAnimationKind } from "../lowLevelMove.js";
 import { Hand } from "../rendererConstants.js";
-import { ISingleVariantMoveInterpreter, LowLevelMovesForAllDancers, MoveInterpreter, PartialLowLevelMove, SemanticPositionsForAllDancers, SingleVariantMoveInterpreter, moveInterpreters } from "./_moveInterpreter.js";
+import { ISingleVariantMoveInterpreter, LowLevelMovesForAllDancers, MoveAsLowLevelMovesArgs, MoveInterpreter, PartialLowLevelMove, SemanticPositionsForAllDancers, SingleVariantMoveInterpreter, Variant, VariantCollection, moveInterpreters } from "./_moveInterpreter.js";
 
 const moveName: Move["move"] = "swing";
 
+interface SwingEnd {
+  facing: "Across" | Facing.Up | Facing.Down,
+  close: boolean,
+}
+function swingEndString(swingEnd: SwingEnd): string {
+  return swingEnd.facing + (swingEnd.close ? "Close" : "");
+}
+const swingEndValues: SwingEnd[] = [
+  { facing: "Across", close: false},
+  { facing: "Across", close: true},
+  { facing: Facing.Up, close: false},
+  { facing: Facing.Up, close: true},
+  { facing: Facing.Down, close: false},
+  { facing: Facing.Down, close: true},
+];
+
 class SwingSingleVariant extends SingleVariantMoveInterpreter<Swing, typeof moveName> {
-  moveAsLowLevelMoves(): LowLevelMovesForAllDancers {
+  moveAsVariants(previousMoveVariant: string): VariantCollection {
-    // TODO Use variants instead of nextMove
+    const res = new Map<string, Variant>();
-    const nextMove = this.moveInterpreter.nextMove;
 
+    for (const swingEnd of swingEndValues) {
+      try {
+        res.set(swingEndString(swingEnd), {
+          lowLevelMoves: this.moveAsLowLevelMovesFacing(swingEnd),
+          previousMoveVariant
+        });
+      }
+      catch { }
+    }
+
+    return res;
+  }
+
+  moveAsLowLevelMovesFacing(swingEnd: SwingEnd): LowLevelMovesForAllDancers {
     return this.handlePairedMove(this.move.parameters.who, ({ id, startPos, around, withId, withPos }) => {
-      // TODO swing can start from non-circle positions.
-      // TODO swing end is only in notes / looking at next move.
-
-      // TODO better way to detect swing end?
-      // TODO more structured way to do this than enumerating next moves here?
-      //      maybe instead of nextMove an optional endPosition for fixing up positions?
-      //      ... but then every move would have to handle that...
       const afterTake = startPos.longLines === LongLines.Near || withPos.longLines === LongLines.Near;
-      const toShortLines = nextMove.move === "down the hall" || nextMove.move === "up the hall";
+      // Swing in center ends facing up/down but not in short lines.
+      const toShortLines = around !== "Center" && (swingEnd.facing === Facing.Down || swingEnd.facing === Facing.Up);
       const endFacingAcross = (around === CircleSide.Left || around === CircleSide.Right) && !toShortLines;
+      if ((swingEnd.facing === "Across") !== endFacingAcross) {
+        throw new Error("Expected to end facing across.");
+      }
 
       const startWhich = startPos.which;
       const startPosition: SemanticPosition = {
@@ -49,7 +75,7 @@ class SwingSingleVariant extends SingleVariantMoveInterpreter<Swing, typeof move
 
       // TODO This assumes swing around right/left, not center or top/bottom.
       let endPosition: SemanticPosition;
-      if (endFacingAcross) {
+      if (swingEnd.facing === "Across") {
         endPosition = {
           ...startPos,
           kind: PositionKind.Circle,
@@ -62,16 +88,14 @@ class SwingSingleVariant extends SingleVariantMoveInterpreter<Swing, typeof move
               : (swingRole === DanceRole.Lark ? CirclePosition.TopRight : CirclePosition.BottomRight)),
           facing: startWhich.leftRightSide() === CircleSide.Left ? Facing.Right : Facing.Left,
           balance: undefined,
-          dancerDistance: undefined,
+          dancerDistance: swingEnd.close ? DancerDistance.Compact : undefined,
           longLines: undefined,
           hands: new Map<Hand, HandConnection>([swingRole === DanceRole.Lark
             ? [Hand.Right, { to: HandTo.DancerRight, hand: Hand.Left }]
             : [Hand.Left, { to: HandTo.DancerLeft, hand: Hand.Right }]]),
         };
       } else if (toShortLines) {
-        const endFacing = nextMove.move === "down the hall" !== (nextMove.parameters.facing === "backward")
+        const endFacing = swingEnd.facing;
-          ? Facing.Down
-          : Facing.Up;
         const endWhich = startWhich.isLeft()
           ? ((endFacing === Facing.Down) === (swingRole === DanceRole.Lark) ? ShortLinesPosition.FarLeft : ShortLinesPosition.MiddleLeft)
           : ((endFacing === Facing.Down) === (swingRole === DanceRole.Lark) ? ShortLinesPosition.MiddleRight : ShortLinesPosition.FarRight)
@@ -81,12 +105,11 @@ class SwingSingleVariant extends SingleVariantMoveInterpreter<Swing, typeof move
           which: endWhich,
           facing: endFacing,
           balance: undefined,
-          dancerDistance: undefined,
+          dancerDistance: swingEnd.close ? DancerDistance.Compact : undefined,
           longLines: undefined,
           hands: handsInLine({ wavy: false, which: endWhich, facing: endFacing }),
         };
-      }
+      } else {
-      else {
         // TODO Need to figure out the logic of knowing if this should be facing up or down.
         //  Probably based on knowing Ones vs. Twos? Also then the not-participating-dancers need their
         //  "standing still" to update that they are in a new set...

www/js/renderer.ts

@@ -1,40 +1,48 @@
 import { Animation } from "./animation.js";
 import { CoupleRole, DanceRole, DancerIdentity, ExtendedDancerIdentity } from "./danceCommon.js";
-import * as exampleAnimations from "./exampleAnimations.js";
 import { DancerSetPosition, DancersSetPositions, dancerHeight, dancerHeightOffset, leftShoulder, lineDistance, rightShoulder, setDistance, degreesToRadians } from "./rendererConstants.js";
 
 
 
-function hueForDancer(identity: DancerIdentity): number {
+function baseColorForDancer(identity: ExtendedDancerIdentity): {hue: number, sat: number, lum: number} {
-  if (identity.coupleRole == CoupleRole.Ones) {
+  if (identity.setIdentity.coupleRole == CoupleRole.Ones) {
-    if (identity.danceRole == DanceRole.Lark) {
+    if (identity.relativeSet < 0)
-      return 0; //red
+      return { hue: 340, sat: 67, lum: 56 };
-    } else {
+    if (identity.relativeSet === 0)
-      return 39; //orange
+      return { hue: 27, sat: 99, lum: 59 };
-    }
+    if (identity.relativeSet > 0)
+      return { hue: 54, sat: 97, lum: 49 };
   } else {
-    if (identity.danceRole == DanceRole.Lark) {
+    if (identity.relativeSet < 0)
-      return 240; //blue
+      return { hue: 183, sat: 88, lum: 23 };
-    } else {
+    if (identity.relativeSet === 0)
-      return 180; //teal
+      return { hue: 249, sat: 42, lum: 37 };
-    }
+    if (identity.relativeSet > 0)
+      return { hue: 13, sat: 33, lum: 29 };
   }
+
+  throw new Error("Unreachable: relativeSet must be one of <, ===, or > 0.");
 }
 
 function colorForDancer(identity: ExtendedDancerIdentity) : string {
-  const hue = hueForDancer(identity.setIdentity);
+  const baseColor = baseColorForDancer(identity);
-  const sat = 100 - Math.abs(identity.relativeLine * 40);
+
-  const unclampedLum = 50 + identity.relativeSet * 20;
+  const hue = baseColor.hue;
+  const sat = baseColor.sat - Math.abs(identity.relativeLine * 40);
+  const unclampedLum = baseColor.lum + (Math.abs(identity.relativeSet) <= 1 ? 0 : identity.relativeSet * 20);
   const lum = unclampedLum < 10 ? 10 : unclampedLum > 90 ? 90 : unclampedLum;
   return `hsl(${hue}, ${sat}%, ${lum}%)`;
 }
 
 function colorForDancerLabel(identity: ExtendedDancerIdentity) : string {
-  const hue = (hueForDancer(identity.setIdentity) + 180) % 360;
+  const dancerColor = baseColorForDancer(identity);
+  const hue = (dancerColor.hue + 180) % 360;
   const sat = 100;
-  const lum = hueForDancer(identity.setIdentity) === 240 && identity.relativeSet < 2 || identity.relativeSet < 0
+  const unclampedLum = ((dancerColor.hue >= 215 && dancerColor.hue <= 285) || (identity.relativeSet < 0)
+                      || dancerColor.lum < 40) && identity.relativeSet < 2
               ? 100
               : 20 - identity.relativeSet * 40;
+  const lum = unclampedLum < 0 ? 0 : unclampedLum > 100 ? 100 : unclampedLum;
   return `hsl(${hue}, ${sat}%, ${lum}%)`;
 }
 
@@ -54,13 +62,21 @@ export class Renderer {
   drawDancerBody(identity: ExtendedDancerIdentity, drawText: boolean) {
     this.ctx.beginPath();
     this.ctx.moveTo(leftShoulder.x, leftShoulder.y);
-    this.ctx.lineTo(rightShoulder.x, rightShoulder.y);
+    if (identity.setIdentity.danceRole === DanceRole.Robin) {
-    this.ctx.lineTo(0, dancerHeight-dancerHeightOffset);
+      // Draw triangle for robin.
+      this.ctx.lineTo(rightShoulder.x, rightShoulder.y);
+      this.ctx.lineTo(0, dancerHeight-dancerHeightOffset);
+    } else {
+      // Draw dome for lark.
+      this.ctx.arcTo(0, dancerHeight*2-dancerHeightOffset, rightShoulder.x, rightShoulder.y, dancerHeight * 1.5);
+      this.ctx.lineTo(rightShoulder.x, rightShoulder.y);
+    }
     this.ctx.fill();
 
     // Draw dot at origin to identify "center" point of dancer.
     const backupFillStyle = this.ctx.fillStyle;
     this.ctx.fillStyle = 'black';
+
     const pointSize = 0.05;
     this.ctx.fillRect(-pointSize/2, -pointSize/2, pointSize, pointSize);
 
@@ -199,9 +215,9 @@ export class Renderer {
     for (var relativeLine = -extraLines; relativeLine <= extraLines; relativeLine++) {
       for (var relativeSet = -extraSets; relativeSet <= extraSets; relativeSet++) {
         this.ctx.save();
-        const hue = (relativeLine + relativeSet) % 2 === 0 ? 60 : 170;
+        const hue = 0;
-        const sat = 100 - Math.abs(relativeLine * 40);
+        const sat = 0;
-        const lum = Math.min(98, 90 + Math.abs(relativeSet) * 5);
+        const lum = Math.min(98, 90 + Math.abs(Math.abs(relativeSet) + Math.abs(relativeLine)) * 5);
         this.ctx.fillStyle = `hsl(${hue}, ${sat}%, ${lum}%)`;
         this.ctx.translate(relativeLine * lineDistance,
                            relativeSet * setDistance);