Add difficult terrain support for pathfinding on gridded scenes

js/api.js

@@ -2,7 +2,7 @@ import {measureDistances} from "./compatibility.js";
 import {getMovementHistory} from "./movement_tracking.js";
 import {GenericSpeedProvider, SpeedProvider} from "./speed_provider.js"
 import {settingsKey} from "./settings.js"
-import {getTokenShape} from "./util.js";
+import {getAreaFromPositionAndShape, getTokenShape} from "./util.js";
 
 export const availableSpeedProviders = {}
 export let currentSpeedProvider = undefined
@@ -140,6 +140,10 @@ export function getMovedDistanceFromToken(token) {
 	return distances.reduce((acc, val) => acc + val, 0);
 }
 
+export function buildCostFunction(token, shape) {
+	return (x, y, costOptions={}) => getCostFromSpeedProvider(token, getAreaFromPositionAndShape({x, y}, shape), costOptions);
+}
+
 export function registerModule(moduleId, speedProvider) {
 	// Check if a module with the given id exists and is currently enabled
 	const module = game.modules.get(moduleId)

js/compatibility.js

@@ -1,6 +1,6 @@
-import {getCostFromSpeedProvider} from "./api.js";
+import {buildCostFunction} from "./api.js";
 import {settingsKey} from "./settings.js";
-import {getAreaFromPositionAndShape, highlightTokenShape} from "./util.js";
+import {highlightTokenShape} from "./util.js";
 
 export function getHexSizeSupportTokenGridCenter(token) {
 	const tokenCenterOffset = CONFIG.hexSizeSupport.getCenterOffset(token)
@@ -27,7 +27,7 @@ export function measureDistances(segments, entity, shape, options={}) {
 		const newSegments = segments.slice(firstNewSegmentIndex);
 		const distances = previousSegments.map(segment => segment.ray.dragRulerVisitedSpaces[segment.ray.dragRulerVisitedSpaces.length - 1].distance);
 		previousSegments.forEach(segment => segment.ray.terrainRulerVisitedSpaces = duplicate(segment.ray.dragRulerVisitedSpaces));
-		opts.costFunction = (x, y, costOptions={}) => {	return getCostFromSpeedProvider(entity, getAreaFromPositionAndShape({x, y}, shape), costOptions); }
+		opts.costFunction = buildCostFunction(entity, shape);
 		if (previousSegments.length > 0)
 			opts.terrainRulerInitialState = previousSegments[previousSegments.length - 1].ray.dragRulerFinalState;
 		return distances.concat(terrainRuler.measureDistances(newSegments, opts));

js/pathfinding.js

@@ -1,11 +1,12 @@
-import {getGridPositionFromPixelsObj, getPixelsFromGridPositionObj} from "./foundry_fixes.js";
+import {getCenterFromGridPositionObj, getGridPositionFromPixelsObj, getPixelsFromGridPositionObj} from "./foundry_fixes.js";
 import {moveWithoutAnimation, togglePathfinding} from "./keybindings.js";
 import {debugGraphics} from "./main.js";
 import {settingsKey} from "./settings.js";
-import {buildSnapPointTokenData, getSnapPointForTokenDataObj, isModuleActive, iterPairs} from "./util.js";
+import {buildSnapPointTokenData, getSnapPointForTokenDataObj, getTokenShape, getTokenShapeForTokenData, isModuleActive, iterPairs} from "./util.js";
 
 import * as GridlessPathfinding from "../wasm/gridless_pathfinding.js";
 import {PriorityQueueSet, ProcessOnceQueue} from "./data_structures.js";
+import {buildCostFunction} from "./api.js";
 
 class CacheLayer {
 	constructor(tokenData, cacheId) {
@@ -79,7 +80,18 @@ class Cache {
 	 */
 	getCacheLayer(token) {
 		const tokenData = buildTokenData(token);
-		const cacheId = JSON.stringify(tokenData);
+		// TODO Request this from the speed providers so they can set their own options
+		let terrainData = canvas.terrain.listAllTerrain({token});
+		terrainData = terrainData.map(data => {
+			return {
+				x: data.object.x,
+				y: data.object.y,
+				cost: data.cost,
+				shape: data.shape,
+			};
+		});
+		const cacheIdData = {tokenData, terrainData};
+		const cacheId = GridlessPathfinding.sha1(JSON.stringify(cacheIdData));
 		let cacheLayer = this.layers.get(cacheId);
 		// If we don't already have a cache layer for this cache ID, create one now
 		if (!cacheLayer) {
@@ -255,13 +267,37 @@ export function findPath(from, to, token, previousWaypoints) {
 		const path = [];
 		let currentNode = firstNode;
 		while (currentNode) {
-			// TODO Check if the distance doesn't change
 			if (path.length >= 2 && !stepCollidesWithWall(path[path.length - 2], currentNode.node, cacheLayer.tokenData)) {
-				// Replace last waypoint if the current waypoint leads to a valid path
+				// Replace last waypoint if the current waypoint leads to a valid path that isn't longer than the old path
-				path[path.length - 1] = {x: currentNode.node.x, y: currentNode.node.y};
+				if (window.terrainRuler) {
-			} else {
+					let startNode = getCenterFromGridPositionObj(path[path.length - 2]);
-				path.push({x: currentNode.node.x, y: currentNode.node.y});
+					let middleNode = getCenterFromGridPositionObj(path[path.length - 1]);
+					let endNode = getCenterFromGridPositionObj(currentNode.node);
+					let oldPath = [{ray: new Ray(startNode, middleNode)}, {ray: new Ray(middleNode, endNode)}];
+					let newPath = [{ray: new Ray(startNode, endNode)}];
+					let costFunction = buildCostFunction(token, getTokenShape(token));
+					// TODO Cache the used measurement for use in the next loop to improve performance
+					let oldDistance = terrainRuler.measureDistances(oldPath, {costFunction}).reduce((a, b) => a + b);
+					let newDistance = terrainRuler.measureDistances(newPath, {costFunction})[0];
+
+					// TODO We might need to check if the diagonal count has increased on 5-10-5
+					if (newDistance < oldDistance)  {
+						path.pop();
+					}
+					else if (newDistance === oldDistance) {
+						let oldNoDiagonals = oldPath[1].ray.terrainRulerFinalState?.noDiagonals;
+						let newNoDiagonals = newPath[0].ray.terrainRulerFinalState?.noDiagonals;
+						// This uses === && < instead of <= because the variables might be undefined (which shall lead to a true result)
+						if (oldNoDiagonals === newNoDiagonals || newNoDiagonals < oldNoDiagonals) {
+							path.pop();
+						}
+					}
+				}
+				else {
+					path.pop();
+				}
 			}
+			path.push({x: currentNode.node.x, y: currentNode.node.y});
 			currentNode = currentNode.next;
 		}
 		return path;
@@ -295,11 +331,25 @@ function getNode(pos, cacheLayer, initialize = true) {
 			// TODO Work with pixels instead of grid locations
 			if (!stepCollidesWithWall(pos, neighborPos, cacheLayer.tokenData)) {
 				const isDiagonal = node.x !== neighborPos.x && node.y !== neighborPos.y && canvas.grid.type === CONST.GRID_TYPES.SQUARE;
+				let edgeCost;
+				if (window.terrainRuler) {
+					let ray = new Ray(getCenterFromGridPositionObj(pos), getCenterFromGridPositionObj(neighborPos));
+					let measuredDistance = terrainRuler.measureDistances([{ray}], {costFunction: buildCostFunction(cacheLayer.tokenData, getTokenShapeForTokenData(cacheLayer.tokenData))})[0];
+					edgeCost = Math.round(measuredDistance / canvas.dimensions.distance);
+					if (ray.terrainRulerFinalState?.noDiagonals === 1) {
+						edgeCost = 1.5;
+					}
+					// Charge 1.0001 instead of 1 for diagonals to discourage unnecessary diagonals
+					if (isDiagonal && edgeCost == 1) {
+						edgeCost = 1.0001;
+					}
+				}
+				else {
+					// Count 5-10-5 diagonals as 1.5 (so two add up to 3) and 5-5-5 diagonals as 1.0001 (to discourage unnecessary diagonals)
+					// TODO Account for difficult terrain
+					edgeCost = isDiagonal ? (use5105 ? 1.5 : 1.0001) : 1;
+				}
 				const neighbor = getNode(neighborPos, cacheLayer, false);
-
-				// Count 5-10-5 diagonals as 1.5 (so two add up to 3) and 5-5-5 diagonals as 1.0001 (to discourage unnecessary diagonals)
-				// TODO Account for difficult terrain
-				let edgeCost = isDiagonal ? (use5105 ? 1.5 : 1.0001) : 1;
 				node.edges.push({target: neighbor, cost: edgeCost});
 			}
 		}

js/util.js

@@ -167,15 +167,19 @@ export function getAreaFromPositionAndShape(position, shape) {
 }
 
 export function getTokenShape(token) {
-	if (token.scene.data.gridType === CONST.GRID_TYPES.GRIDLESS) {
+	return getTokenShapeForTokenData(buildSnapPointTokenData(token), token.scene);
+}
+
+export function getTokenShapeForTokenData(tokenData, scene=canvas.scene) {
+	if (scene.data.gridType === CONST.GRID_TYPES.GRIDLESS) {
 		return [{x: 0, y: 0}]
 	}
-	else if (token.scene.data.gridType === CONST.GRID_TYPES.SQUARE) {
+	else if (scene.data.gridType === CONST.GRID_TYPES.SQUARE) {
-		const topOffset = -Math.floor(token.data.height / 2)
+		const topOffset = -Math.floor(tokenData.height / 2)
-		const leftOffset = -Math.floor(token.data.width / 2)
+		const leftOffset = -Math.floor(tokenData.width / 2)
 		const shape = []
-		for (let y = 0;y < token.data.height;y++) {
+		for (let y = 0;y < tokenData.height;y++) {
-			for (let x = 0;x < token.data.width;x++) {
+			for (let x = 0;x < tokenData.width;x++) {
 				shape.push({x: x + leftOffset, y: y + topOffset})
 			}
 		}
@@ -183,8 +187,8 @@ export function getTokenShape(token) {
 	}
 	else {
 		// Hex grids
-		if (game.modules.get("hex-size-support")?.active && CONFIG.hexSizeSupport.getAltSnappingFlag(token)) {
+		if (game.modules.get("hex-size-support")?.active && tokenData.hexSizeSupport.altSnappingFlag) {
-			const borderSize = token.data.flags["hex-size-support"].borderSize;
+			const borderSize = tokenData.hexSizeSupport.borderSize;
 			let shape = [{x: 0, y: 0}];
 			if (borderSize >= 2)
 				shape = shape.concat([{x: 0, y: -1}, {x: -1, y: -1}]);
@@ -193,7 +197,7 @@ export function getTokenShape(token) {
 			if (borderSize >= 4)
 				shape = shape.concat([{x: -2, y: -1}, {x: 1, y: -1}, {x: -1, y: -2}, {x: 0, y: -2}, {x: 1, y: -2}])
 
-			if (Boolean(CONFIG.hexSizeSupport.getAltOrientationFlag(token)) !== canvas.grid.grid.options.columns)
+			if (Boolean(tokenData.hexSizeSupport.altOrientationFlag) !== canvas.grid.grid.options.columns)
 				shape.forEach(space => space.y *= -1);
 			if (canvas.grid.grid.options.columns)
 				shape = shape.map(space => {return {x: space.y, y: space.x}});

rust/Cargo.lock

@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "block-buffer"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bf7fe51849ea569fd452f37822f606a5cabb684dc918707a0193fd4664ff324"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "bumpalo"
 version = "3.9.1"
@@ -24,6 +33,45 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "cpufeatures"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59a6001667ab124aebae2a495118e11d30984c3a653e99d86d58971708cf5e4b"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "crypto-common"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57952ca27b5e3606ff4dd79b0020231aaf9d6aa76dc05fd30137538c50bd3ce8"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
+[[package]]
+name = "digest"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2fb860ca6fafa5552fb6d0e816a69c8e49f0908bf524e30a90d97c85892d506"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
+[[package]]
+name = "generic-array"
+version = "0.14.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd48d33ec7f05fbfa152300fdad764757cbded343c1aa1cff2fbaf4134851803"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
 [[package]]
 name = "gridless-pathfinding"
 version = "1.12.8"
@@ -31,6 +79,7 @@ dependencies = [
  "console_error_panic_hook",
  "js-sys",
  "rustc-hash",
+ "sha1",
  "wasm-bindgen",
 ]
 
@@ -49,6 +98,12 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
+[[package]]
+name = "libc"
+version = "0.2.125"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5916d2ae698f6de9bfb891ad7a8d65c09d232dc58cc4ac433c7da3b2fd84bc2b"
+
 [[package]]
 name = "log"
 version = "0.4.14"
@@ -82,6 +137,17 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "sha1"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c77f4e7f65455545c2153c1253d25056825e77ee2533f0e41deb65a93a34852f"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.86"
@@ -93,12 +159,24 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "typenum"
+version = "1.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcf81ac59edc17cc8697ff311e8f5ef2d99fcbd9817b34cec66f90b6c3dfd987"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
+[[package]]
+name = "version_check"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.79"

rust/Cargo.toml

@@ -16,4 +16,5 @@ lto = true
 console_error_panic_hook = "0.1.7"
 js-sys = "0.3.56"
 rustc-hash = "1.1.0"
+sha1 = "0.10.1"
 wasm-bindgen = "0.2.79"

rust/src/js_api.rs

@@ -1,4 +1,5 @@
 use js_sys::Array;
+use sha1::{Sha1, Digest};
 use wasm_bindgen::prelude::*;
 
 use crate::{
@@ -262,6 +263,14 @@ pub fn debug_get_pathfinding_points(pathfinder: &Pathfinder) -> Array {
 		.collect()
 }
 
+#[allow(dead_code)]
+#[wasm_bindgen]
+pub fn sha1(input: &str) -> String {
+	let mut hasher = Sha1::new();
+	hasher.update(input);
+	format!("{:x}", hasher.finalize())
+}
+
 trait IteratePath {
 	fn iter_path(&self) -> PathIterator;
 }