src/ai/pathfinding.js

// Note: three-pathfinding is not available via CDN, using basic pathfinding instead

/**
 * A* Pathfinding Implementation for Village Navigation
 *
 * This implementation uses a navigation mesh approach for efficient pathfinding
 * in complex 3D environments like medieval villages.
 */
class VillagePathfinder {
    constructor() {
        // Simple pathfinding implementation without external library
        this.zoneName = 'village';
    }

    /**
     * Initialize the navigation mesh
     * @param {Object} navMeshGeometry - The navigation mesh geometry
     */
    initNavMesh(navMeshGeometry) {
        // Store the navigation mesh for future use
        this.navMesh = navMeshGeometry;
        console.log('Navigation mesh initialized');
    }

    /**
     * Find a path between two points
     * @param {Array} start - Start position [x, y, z]
     * @param {Array} end - End position [x, y, z]
     * @returns {Array<Array>} Path as array of points [[x, y, z], ...]
     */
    findPath(start, end) {
        // Simple direct path for now
        // In a real implementation, this would use A* algorithm
        return [
            [start[0], start[1], start[2]],
            [end[0], end[1], end[2]]
        ];
    }

    /**
     * Move an entity along a path
     * @param {Object} entity - The entity to move
     * @param {Array<Array>} path - Path to follow [[x, y, z], ...]
     * @param {number} speed - Movement speed
     * @param {number} deltaTime - Time since last frame
     */
    moveAlongPath(entity, path, speed, deltaTime) {
        if (path.length === 0) return;

        const target = path[0];
        const direction = this.normalize([
            target[0] - entity.position[0],
            target[1] - entity.position[1],
            target[2] - entity.position[2]
        ]);
        const moveDistance = speed * deltaTime;
        
        // Move towards the target
        entity.position[0] += direction[0] * moveDistance;
        entity.position[1] += direction[1] * moveDistance;
        entity.position[2] += direction[2] * moveDistance;
        
        // Check if we've reached the target point
        const distance = Math.sqrt(
            Math.pow(entity.position[0] - target[0], 2) +
            Math.pow(entity.position[1] - target[1], 2) +
            Math.pow(entity.position[2] - target[2], 2)
        );
        
        if (distance < 0.1) {
            path.shift(); // Remove the reached point
        }
    }

    /**
     * Normalize a vector
     * @param {Array} vector - Vector to normalize [x, y, z]
     * @returns {Array} Normalized vector [x, y, z]
     */
    normalize(vector) {
        const length = Math.sqrt(vector[0] * vector[0] + vector[1] * vector[1] + vector[2] * vector[2]);
        if (length === 0) return [0, 0, 0];
        return [vector[0] / length, vector[1] / length, vector[2] / length];
    }
}

export default VillagePathfinder;