Add shape detection to token outline creation

src/components/map/MapToken.js

@@ -246,34 +246,68 @@ function MapToken({
     tokenName = tokenName + "-locked";
   }
 
-  let outline = tokenState.outline;
-  if (Array.isArray(tokenState.outline)) {
-    outline = [...outline]; // Copy array so we can edit it imutably
-    for (let i = 0; i < outline.length; i += 2) {
-      // Scale outline to the token
-      outline[i] = (outline[i] / tokenState.width) * tokenWidth;
-      outline[i + 1] = (outline[i + 1] / tokenState.height) * tokenHeight;
+  function getScaledOutline() {
+    let outline = tokenState.outline;
+    if (outline.type === "rect") {
+      return {
+        ...outline,
+        x: (outline.x / tokenState.width) * tokenWidth,
+        y: (outline.y / tokenState.height) * tokenHeight,
+        width: (outline.width / tokenState.width) * tokenWidth,
+        height: (outline.height / tokenState.height) * tokenHeight,
+      };
+    } else if (outline.type === "circle") {
+      return {
+        ...outline,
+        x: (outline.x / tokenState.width) * tokenWidth,
+        y: (outline.y / tokenState.height) * tokenHeight,
+        radius: (outline.radius / tokenState.width) * tokenWidth,
+      };
+    } else {
+      let points = [...outline.points]; // Copy array so we can edit it imutably
+      for (let i = 0; i < points.length; i += 2) {
+        // Scale outline to the token
+        points[i] = (points[i] / tokenState.width) * tokenWidth;
+        points[i + 1] = (points[i + 1] / tokenState.height) * tokenHeight;
+      }
+      return { ...outline, points };
     }
   }
 
   function renderOutline() {
+    const outline = getScaledOutline();
     const sharedProps = {
       fill: colors.black,
-      width: tokenWidth,
-      height: tokenHeight,
-      x: 0,
-      y: 0,
-      rotation: tokenState.rotation,
-      offsetX: tokenWidth / 2,
-      offsetY: tokenHeight / 2,
       opacity: 0.8,
     };
-    if (outline === "rect") {
-      return <Rect {...sharedProps} />;
-    } else if (outline === "circle") {
-      return <Circle {...sharedProps} offsetX={0} offsetY={0} />;
+    if (outline.type === "rect") {
+      return (
+        <Rect
+          width={outline.width}
+          height={outline.height}
+          x={outline.x}
+          y={outline.y}
+          {...sharedProps}
+        />
+      );
+    } else if (outline.type === "circle") {
+      return (
+        <Circle
+          radius={outline.radius}
+          x={outline.x}
+          y={outline.y}
+          {...sharedProps}
+        />
+      );
     } else {
-      return <Line {...sharedProps} points={outline} closed tension={0.33} />;
+      return (
+        <Line
+          points={outline.points}
+          closed
+          tension={outline.points < 200 ? 0 : 0.33}
+          {...sharedProps}
+        />
+      );
     }
   }
 
@@ -299,7 +333,17 @@ function MapToken({
       id={tokenState.id}
     >
       {!tokenImage ? (
-        renderOutline()
+        <Group
+          width={tokenWidth}
+          height={tokenHeight}
+          x={0}
+          y={0}
+          rotation={tokenState.rotation}
+          offsetX={tokenWidth / 2}
+          offsetY={tokenHeight / 2}
+        >
+          {renderOutline()}
+        </Group>
       ) : (
         <KonvaImage
           ref={imageRef}

src/helpers/Vector2.js

@@ -508,6 +508,66 @@ class Vector2 {
       return { x: -p.y, y: p.x };
     }
   }
+
+  /**
+   * Returns the centroid of the given points
+   * @param {Vector2[]} points
+   * @returns {Vector2}
+   */
+  static centroid(points) {
+    let center = { x: 0, y: 0 };
+    for (let point of points) {
+      center.x += point.x;
+      center.y += point.y;
+    }
+    if (points.length > 0) {
+      center = { x: center.x / points.length, y: center.y / points.length };
+    }
+    return center;
+  }
+
+  /**
+   * Determine whether given points are rectangular
+   * @param {Vector2[]} points
+   * @returns {boolean}
+   */
+  static rectangular(points) {
+    if (points.length !== 4) {
+      return false;
+    }
+    // Check whether distance to the center is the same for all four points
+    const centroid = this.centroid(points);
+    let prevDist;
+    for (let point of points) {
+      const dist = this.distance(point, centroid);
+      if (prevDist && dist !== prevDist) {
+        return false;
+      } else {
+        prevDist = dist;
+      }
+    }
+    return true;
+  }
+
+  /**
+   * Determine whether given points are circular
+   * @param {Vector2[]} points
+   * @returns {boolean}
+   */
+  static circular(points, threshold = 0.1) {
+    const centroid = this.centroid(points);
+    let distances = [];
+    for (let point of points) {
+      distances.push(this.distance(point, centroid));
+    }
+    if (distances.length > 0) {
+      const maxDistance = Math.max(...distances);
+      const minDistance = Math.min(...distances);
+      return maxDistance - minDistance < threshold;
+    } else {
+      return false;
+    }
+  }
 }
 
 export default Vector2;

src/helpers/image.js

@@ -1,4 +1,7 @@
+import imageOutline from "image-outline";
+
 import blobToBuffer from "./blobToBuffer";
+import Vector2 from "./Vector2";
 
 const lightnessDetectionOffset = 0.1;
 
@@ -152,3 +155,75 @@ export async function createThumbnail(image, type, size = 300, quality = 0.5) {
     mime: type,
   };
 }
+
+/**
+ * @typedef CircleOutline
+ * @property {"circle"} type
+ * @property {number} x - Center X of the circle
+ * @property {number} y - Center Y of the circle
+ * @property {number} radius
+ */
+
+/**
+ * @typedef RectOutline
+ * @property {"rect"} type
+ * @property {number} width
+ * @property {number} height
+ * @property {number} x - Leftmost X position of the rect
+ * @property {number} y - Topmost Y position of the rect
+ */
+
+/**
+ * @typedef PathOutline
+ * @property {"path"} type
+ * @property {number[]} points - Alternating x, y coordinates zipped together
+ */
+
+/**
+ * @typedef {CircleOutline|RectOutline|PathOutline} Outline
+ */
+
+/**
+ * Get the outline of an image
+ * @param {HTMLImageElement} image
+ * @returns {Outline}
+ */
+export function getImageOutline(image, maxPoints = 100) {
+  let baseOutline = imageOutline(image);
+
+  if (baseOutline) {
+    if (baseOutline.length > maxPoints) {
+      baseOutline = Vector2.resample(baseOutline, maxPoints);
+    }
+    const bounds = Vector2.getBoundingBox(baseOutline);
+    if (Vector2.rectangular(baseOutline)) {
+      return {
+        type: "rect",
+        x: Math.round(bounds.min.x),
+        y: Math.round(bounds.min.y),
+        width: Math.round(bounds.width),
+        height: Math.round(bounds.height),
+      };
+    } else if (
+      Vector2.circular(
+        baseOutline,
+        Math.max(bounds.width / 10, bounds.height / 10)
+      )
+    ) {
+      return {
+        type: "circle",
+        x: Math.round(bounds.center.x),
+        y: Math.round(bounds.center.y),
+        radius: Math.round(Math.min(bounds.width, bounds.height) / 2),
+      };
+    } else {
+      // Flatten and round outline to save on storage size
+      const points = baseOutline
+        .map(({ x, y }) => [Math.round(x), Math.round(y)])
+        .flat();
+      return { type: "path", points };
+    }
+  } else {
+    return { type: "rect", x: 0, y: 0, width: 1, height: 1 };
+  }
+}

src/helpers/token.js

@@ -1,10 +1,8 @@
 import { v4 as uuid } from "uuid";
 import Case from "case";
-import imageOutline from "image-outline";
 
 import blobToBuffer from "./blobToBuffer";
-import { createThumbnail } from "./image";
-import Vector2 from "./Vector2";
+import { createThumbnail, getImageOutline } from "./image";
 
 export function createTokenState(token, position, userId) {
   let tokenState = {
@@ -76,14 +74,7 @@ export async function createTokenFromFile(file, userId) {
       };
       assets.push(fileAsset);
 
-      let outline = imageOutline(image);
-      if (outline.length > 100) {
-        outline = Vector2.resample(outline, 100);
-      }
-      // Flatten and round outline to save on storage size
-      outline = outline
-        .map(({ x, y }) => [Math.round(x), Math.round(y)])
-        .flat();
+      const outline = getImageOutline(image);
 
       const token = {
         name,

src/tokens/index.js

@@ -97,7 +97,7 @@ export function getDefaultTokens(userId) {
       hideInSidebar: false,
       width: 256,
       height: 256,
-      outline: "circle",
+      outline: { type: "circle", x: 128, y: 128, radius: 128 },
       owner: userId,
       created: tokenKeys.length - i,
       lastModified: Date.now(),

src/upgrade.js

@@ -555,11 +555,8 @@ export const versions = {
           token.defaultCategory = token.category;
           delete token.category;
           token.defaultLabel = "";
-          if (token.width === token.height) {
-            token.outline = "circle";
-          } else {
-            token.outline = "rect";
-          }
+          // TODO: move to outline detection
+          token.outline = { type: "circle", x: 256, y: 256, radius: 256 };
           delete token.lastUsed;
         });
     });