Initial support for ricochet in hey.

www/js/interpreter.ts

@@ -1972,16 +1972,14 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
 
     case "hey":
       type HeyStep = {
-        kind: "StandStill" | "Loop" | "CenterPass" | "EndsPassIn" | "EndsPassOut",
+        kind: "StandStill" | "Loop" | "CenterPass" | "EndsPassIn" | "EndsPassOut" | "Ricochet",
         endPosition: SemanticPosition,
       }
 
       if (move.parameters.dir !== "across") {
         throw new Error("Unsupported hey direction: " + move.parameters.dir);
       }
-      if (move.parameters.rico1 || move.parameters.rico2 || move.parameters.rico3 || move.parameters.rico4) {
-        throw new Error("Ricochet hey is unsupported.");
-      }
+
       let heyParts: number;
       switch (move.parameters.until) {
         case "half":
@@ -2080,6 +2078,14 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
               // TODO Loop should probably be its own kind? Or RotateAround?
               kind: SemanticAnimationKind.Linear,
               minRotation: endsShoulder === Hand.Right ? +180 : -180,
+            } : heyStep.kind === "Ricochet" ? {
+              // TODO This is a hack.
+              kind: SemanticAnimationKind.PassBy,
+              around: heyStep.endPosition.which.leftRightSide(),
+              withHands: false,
+              otherPath: "Swap",
+              facing: "Start",
+              side: endsShoulder,
             } : {
               kind: SemanticAnimationKind.PassBy,
               around: heyStep.kind === "CenterPass" ? "Center" : heyStep.endPosition.which.leftRightSide(),
@@ -2091,7 +2097,10 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
             heyStep,
           };
         }
-        function continueHey(prevStep: HeyStep, stepsLeft: number): HeyStep {
+        function continueHey(prevStep: HeyStep, stepsLeft: number, beenInCenter: boolean): HeyStep {
+          // TODO Not sure why type checker requires rechecking this here.
+          if (move.move !== "hey") throw new Error("Unreachable.");
+
           // Continuing hey so everyone is either passing (in center or on ends) or looping on ends.
           if (prevStep.endPosition.kind === PositionKind.Circle) {
             if (prevStep.endPosition.facing === prevStep.endPosition.which.facingAcross()) {
@@ -2155,12 +2164,44 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
                 },
               }
             }
+            else if (!isFacingSide) {
+              const rico = inCenterFirst
+                ? beenInCenter
+                  ? move.parameters.rico3
+                  : move.parameters.rico1
+                : beenInCenter
+                  ? move.parameters.rico4
+                  : move.parameters.rico2;
+
+              if (rico) {
+                const onLeftSide = prevStep.endPosition.which.isLeft();
+                return {
+                  kind: "Ricochet",
+                  endPosition: {
+                    ...prevStep.endPosition,
+                    kind: PositionKind.Circle,
+                    which: CirclePosition.fromSides(prevStep.endPosition.which.leftRightSide(),
+                      // TODO might be swapped
+                      (endsShoulder === Hand.Left) === onLeftSide ? CircleSide.Top : CircleSide.Bottom),
+                    facing: onLeftSide ? Facing.Left : Facing.Right,
+                  }
+                }
+              } else {
+                return {
+                  kind: "CenterPass",
+                  endPosition: {
+                    ...prevStep.endPosition,
+                    which: prevStep.endPosition.which.swapSides()
+                  },
+                }
+              }
+            }
             else {
               return {
-                kind: isFacingSide ? (inMiddle ? "EndsPassOut" : "EndsPassIn") : "CenterPass",
+                kind: inMiddle ? "EndsPassOut" : "EndsPassIn",
                 endPosition: {
                   ...prevStep.endPosition,
-                  which: isFacingSide ? prevStep.endPosition.which.swapOnSide() : prevStep.endPosition.which.swapSides()
+                  which: prevStep.endPosition.which.swapOnSide()
                 },
               }
             }
@@ -2169,13 +2210,15 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
           }
         }
 
+        const inCenterFirst = firstPassInCenter && findPairOpposite(move.parameters.who, id) !== null
+          || move.parameters.who2 && findPairOpposite(move.parameters.who2, id) !== null;
+
         let firstHeyStep: HeyStep;
         let startingPos: SemanticPosition;
         if (firstPassInCenter) {
           if (startPos.kind !== PositionKind.Circle) {
             throw new Error("Hey starting in center not from circle is unsupported.");
           }
-          const inCenterFirst = findPairOpposite(move.parameters.who, id) !== null;
           startingPos = {
             kind: startPos.kind,
             which: startPos.which,
@@ -2184,16 +2227,29 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
             lineOffset: startPos.lineOffset,
           };
           if (inCenterFirst) {
-            firstHeyStep = {
-              kind: "CenterPass",
-              endPosition: {
-                kind: PositionKind.ShortLines,
-                which: startPos.which.isLeft() ? ShortLinesPosition.MiddleRight : ShortLinesPosition.MiddleLeft,
-                facing: startingPos.facing,
-                setOffset: startPos.setOffset,
-                lineOffset: startPos.lineOffset,
-              }
-            };
+            if (move.parameters.rico1) {
+              firstHeyStep = {
+                kind: "Ricochet",
+                endPosition: {
+                  kind: PositionKind.Circle,
+                  which: startPos.which.swapUpAndDown(),
+                  facing: startPos.which.facingOut(),
+                  setOffset: startPos.setOffset,
+                  lineOffset: startPos.lineOffset,
+                }
+              };
+            } else {
+              firstHeyStep = {
+                kind: "CenterPass",
+                endPosition: {
+                  kind: PositionKind.ShortLines,
+                  which: startPos.which.isLeft() ? ShortLinesPosition.MiddleRight : ShortLinesPosition.MiddleLeft,
+                  facing: startingPos.facing,
+                  setOffset: startPos.setOffset,
+                  lineOffset: startPos.lineOffset,
+                }
+              };
+            }
           } else {
             firstHeyStep = {
               kind: "StandStill",
@@ -2220,9 +2276,11 @@ function moveAsLowLevelMoves({ move, nextMove, startingPos, numProgessions }: {
         }
 
         const heySteps: HeyStep[] = [firstHeyStep];
+        let beenInCenter = firstHeyStep.kind === "CenterPass" || firstHeyStep.kind === "Ricochet";
         for(let i = 1; i < heyParts; i++) {
           const isLast = i === heyParts - 1;
-          const nextHeyStep = continueHey(heySteps[i - 1], heyParts - i - 1);
+          const nextHeyStep = continueHey(heySteps[i - 1], heyParts - i - 1, beenInCenter);
+          beenInCenter ||= nextHeyStep.kind === "CenterPass" || nextHeyStep.kind === "Ricochet";
           heySteps.push(nextHeyStep);
         }
         return combine(heySteps.map(heyStepToPartialLowLevelMove), { ...startingPos, hands: undefined });

www/js/interpreterCommon.ts

@@ -38,9 +38,9 @@ export class CirclePosition {
       ? topBottomSide === CircleSide.Top
         ? CirclePosition.TopLeft
         : CirclePosition.BottomLeft
-      : topBottomSide === CircleSide.Bottom
-        ? CirclePosition.BottomLeft
-        : CirclePosition.BottomLeft;
+      : topBottomSide === CircleSide.Top
+        ? CirclePosition.TopRight
+        : CirclePosition.BottomRight;
   }
 
   private static enumValueToNumber(enumValue: CirclePositionEnum) : number {