feat: implement state machine for creatures
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								static/index.js
								
								
								
								
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			@ -5,6 +5,24 @@ const CREATURE_WIDTH = 32; // in px
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const FRAME_RATE = 6; // in FPS
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const FRAME_DELAY = 1 / FRAME_RATE * 1000; // in ms
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const DEFAULT_SPRITE_SHEET_COUNT = 1; // number of default sprite sheets
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const WALK_SIZE = 8; // magnitude of position change, in px
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const NUMERICAL_TOLERANCE = 0.01;
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/**
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 * Enum of directions
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 * @readonly
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 * @enum {number}
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 */
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const Direction = Object.freeze({
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    NORTH: 0,
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    EAST: 1,
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    SOUTH: 2,
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    WEST: 3,
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    NORTHEAST: 4,
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    SOUTHEAST: 5,
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    SOUTHWEST: 6,
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    NORTHWEST: 7,
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})
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/**
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 * Enum of creature states
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			@ -31,9 +49,20 @@ const CreatureState = Object.freeze({
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    WALK_NORTHWEST: 16,
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})
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const WALKING_CREATURE_STATES = Object.freeze([
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    CreatureState.WALK_NORTH,
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    CreatureState.WALK_NORTHEAST,
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    CreatureState.WALK_EAST,
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    CreatureState.WALK_SOUTHEAST,
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    CreatureState.WALK_SOUTH,
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    CreatureState.WALK_SOUTHWEST,
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    CreatureState.WALK_WEST,
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    CreatureState.WALK_NORTHWEST,
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])
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/**
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 * @typedef {[number, number]} SpriteFrameOffset the offset of the sprite with respect to
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 *                                               the left/top background position offset (off by factor of sprite size)
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 * @typedef {[number, number]} SpriteFrameOffset the client of the sprite with respect to
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 *                                               the left/top background position client (off by factor of sprite size)
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 * @type {Object.<number, Array<SpriteFrameOffset>>}
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 */
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const CREATURE_STATE_TO_SPRITE_FRAME_OFFSET_INDICES = Object.freeze({
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			@ -109,6 +138,8 @@ const CREATURE_STATE_TO_SPRITE_FRAME_OFFSET_INDICES = Object.freeze({
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// === <TYPES> ===
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/** @typedef {[number, number]} vec2 a vector 2 components */
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/**
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 * Properties for creatures running around the screen
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 * @typedef {Object} Creature
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			@ -116,10 +147,11 @@ const CREATURE_STATE_TO_SPRITE_FRAME_OFFSET_INDICES = Object.freeze({
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 * @property {string} spriteSheet the file name of the sprite sheet. should exist in {@link /static/sprites}
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 * @property {number} state the current state of the creature (should be member of {@link CreatureState} enum)
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 * @property {number} stateDuration the number of frames the creature has been in its current state
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 * @property {number} positionX the number of pixels away from the left side of the container element
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 * @property {number} positionY the number of pixels away from the top of the container element
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 * @property {number} positionX x component of the center of the creature position
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 * @property {number} positionY y component of the center of the creature position
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 * @property {HTMLElement} element the HTML element rendering the creature in the DOM
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 * @property {HTMLElement} container the HTML element containing the creature (the kennel, if you will)
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 * @property {?vec2} walkDirection the (normed) direction a creature is walking in, if it's walking. otherwise null.
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 */
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// === <TYPES> ===
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			@ -127,15 +159,26 @@ const CREATURE_STATE_TO_SPRITE_FRAME_OFFSET_INDICES = Object.freeze({
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// === <MATH_UTILS> ===
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/**
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 * Returns random number between min (inclusive) and max (exclusive)
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 * Returns a random number between min (inclusive) and max (exclusive).
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 * If max is less than or equal to min, return min
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 * @param {number} min inclusive lower bound
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 * @param {number} max exclusive upper bound
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 * @return {number} number in [min, max)
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 */
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const randomInt = (min, max) => {
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const getRandomInRange = (min, max) => {
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    if (max <= min) return min;
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    return Math.floor(Math.random() * (max - min) + min);
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    return Math.random() * (max - min) + min;
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}
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/**
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 * Returns random number between min (inclusive) and max (exclusive)
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 * If max is less than or equal to min, return Math.floor(min)
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 * @param {number} min inclusive lower bound
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 * @param {number} max exclusive upper bound
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 * @return {number} integer in [min, max)
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 */
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const getRandomInt = (min, max) => {
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    return Math.floor(getRandomInRange(min, max));
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}
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/**
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			@ -161,10 +204,136 @@ const normalize = (...components) => {
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    return components.map(component => component / magnitude)
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}
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/**
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 * Recursive helper for {@link getRandomChoice}
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 * @template {!*} T
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 * @param {Array<number>} weights
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 * @param {Array<T>} choices
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 * @param {number} random
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 * @param {number} cumulativeSum
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 * @return {undefined|T}
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 * @ignore
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 */
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const _getRandomChoice = (weights, choices, random, cumulativeSum) => {
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    const choice = choices.shift();
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    if (choice === undefined) {
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        return undefined;
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    }
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    const newCumulativeSum = (weights.shift() ?? 0) + cumulativeSum;
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    if (random < newCumulativeSum) {
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        return choice;
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    }
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    return _getRandomChoice(weights, choices, random, newCumulativeSum);
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}
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/**
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 * Given an array of weights and an array of the same length of choices,
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 * randomly pick an element from the choices whose probability of picking it corresponds
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 * to the corresponding weight (given position in the array).
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 * Returns undefined when there are fewer choices than weights
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 * @template {!*} T type of the choice elements
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 * @param {?Array<number>} weights if undefined, default to equal probability distribution of weights
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 * @param {Array<T>} choices
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 * @return {undefined|T} the chosen element, or undefined if there are more weights than choices
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 */
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const getRandomChoice = (weights, choices) => {
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    weights = weights ?? Array(choices.length).fill(1 / choices.length);
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    const weightSum = weights.reduce((sum, probability) => sum + probability, 0);
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    const random = Math.random() * weightSum;
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    return _getRandomChoice([...weights], [...choices], random, 0);
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}
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/**
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 * Roll an n-sided, 1-indexed die.
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 * Return true if it's a nat n (ie the die lands on side n).
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 * False otherwise.
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 * @param {number} n number of faces on the die.
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 * @return {boolean}
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 */
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const rollForNatN = (n) => {
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    return Math.random() < 1 / n;
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}
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/**
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 * Returns true if two circles intersect, false otherwise.
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 * We consider circles to intersect iff there exists a point p that lies in both circles
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 * @param {number} x0 x component of the center of circle 1
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 * @param {number} y0 y component of the center of circle 1
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 * @param {number} r0 radius of circle 1
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 * @param {number} x1 x component of the center of circle 1
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 * @param {number} y1 y component of the center of circle 1
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 * @param {number} r1 radius of circle 1
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 * @return {boolean}
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 */
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const isIntersectingCircles = (x0, y0, r0, x1, y1, r1) => {
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    return (x0 - x1) * (x0 - x1) + (y0 - y1) * (y0 - y1) < (r0 + r1) * (r0 + r1);
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}
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/**
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 * Return true if val in [min, max)
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 * @param {number} val
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 * @param {number} min
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 * @param {number} max
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 * @return {boolean}
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 */
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const isBetween = (val, min, max) => {
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    return val >= min && val < max;
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}
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// === </MATH_UTILS> ===
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// === <CREATURE_UTILS> ===
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/**
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 * Given a normalized direction a creature is walking in, return
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 * the creature state that corresponds closest to the direction.
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 * Defaults to WALK_NORTH if something goes wrong.
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 * @param {vec2} direction
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 * @return {number} corresponding {@link CreatureState}
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 */
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const getWalkStateFromDirection = (direction) => {
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    const directionAngle = Math.atan2(direction.at(0), direction.at(1));
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    if (Number.isNaN(directionAngle)) {
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        return CreatureState.WALK_NORTH; // default
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    }
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    if (isBetween(directionAngle, Math.PI * 5/8, Math.PI * 7/8)) {
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        return CreatureState.WALK_NORTHEAST;
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    }
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    if (isBetween(directionAngle, Math.PI * 3/8, Math.PI * 5/8)) {
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        return CreatureState.WALK_EAST;
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    }
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    if (isBetween(directionAngle, Math.PI / 8, Math.PI * 3/8)) {
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        return CreatureState.WALK_SOUTHEAST;
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    }
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    if (isBetween(directionAngle, -Math.PI / 8, Math.PI / 8)) {
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        return CreatureState.WALK_SOUTH;
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    }
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    if (isBetween(directionAngle, -Math.PI * 3/8, -Math.PI / 8)) {
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        return CreatureState.WALK_SOUTHWEST;
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    }
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    if (isBetween(directionAngle, -Math.PI * 5/8, -Math.PI * 3/8)) {
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        return CreatureState.WALK_WEST;
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    }
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    if (isBetween(directionAngle, -Math.PI * 5/8, -Math.PI * 7/8)) {
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        return CreatureState.WALK_NORTHWEST;
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    }
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    return CreatureState.WALK_NORTH;
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}
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/**
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 * Return a new updateCreature function that implicitly accepts the context
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 * of all other creatures being rendered.
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			@ -194,8 +363,10 @@ const renderCreature = (creature) => {
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    creature.element.style.setProperty('display', 'block');
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    // set position
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    creature.element.style.setProperty('left', `${creature.positionX}px`);
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    creature.element.style.setProperty('top', `${creature.positionY}px`);
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    const positionX = creature.positionX - (0.5 * CREATURE_WIDTH) + creature.container.clientLeft
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    const positionY = creature.positionY - (0.5 * CREATURE_HEIGHT) + creature.container.clientTop
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    creature.element.style.setProperty('left', `${positionX}px`);
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    creature.element.style.setProperty('top', `${positionY}px`);
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    // set sprite
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    const spriteFrames = CREATURE_STATE_TO_SPRITE_FRAME_OFFSET_INDICES[creature.state]
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			@ -229,7 +400,7 @@ const createCreature = (
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    const creatureEle = document.createElement('div');
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    const spriteSheetUrl = spriteSheet
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        ? `url('/static/sprites/${spriteSheet}')`
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        : `url('/static/sprites/defaults/${randomInt(1, DEFAULT_SPRITE_SHEET_COUNT)}.gif')`;
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        : `url('/static/sprites/defaults/${getRandomInt(1, DEFAULT_SPRITE_SHEET_COUNT)}.gif')`;
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    creatureEle.setAttribute('id', name);
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    creatureEle.style.setProperty('width', `${CREATURE_WIDTH}px`);
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			@ -274,43 +445,378 @@ const beginCreatureAnimation = (
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// === </CREATURE_UTILS> ===
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/**
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 * Returns true if any point in creature 1's collision box is in creature 2's collision box
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 * @param {Creature} creature1
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 * @param {Creature} creature2
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 * @return {boolean}
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 */
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const isCreaturesColliding = (creature1, creature2) => {
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    return isIntersectingCircles(
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      creature1.positionX, creature1.positionY, CREATURE_WIDTH * 3/4,
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      creature2.positionX, creature2.positionY, CREATURE_WIDTH * 3/4,
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    )
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}
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/**
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 * Returns the direction of the wall of collision if it collides. Otherwise, return undefined.
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 * @param {Creature} creature
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 * @return {number | undefined}
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 */
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const isCreatureOutOfBounds = (creature) => {
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    if (creature.positionX - CREATURE_WIDTH / 2 < creature.container.clientLeft) {
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        return Direction.WEST;
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    }
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    if (creature.positionX + CREATURE_WIDTH / 2 > creature.container.clientLeft + creature.container.clientWidth) {
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        return Direction.EAST;
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    }
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    if (creature.positionY - CREATURE_HEIGHT / 2 < creature.container.clientTop) {
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        return Direction.NORTH;
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    }
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    if (creature.positionY + CREATURE_HEIGHT / 2 > creature.container.clientTop + creature.container.clientHeight) {
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        return Direction.SOUTH;
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    }
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    return undefined;
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}
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/**
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 * Get the creature in the walk state moving toward a destination
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 * @param {Creature} creature
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 * @param {vec2} destination
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 * @return {Creature} the creature in a walking state
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 */
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const startCreatureWalkTowardDirection = (creature, destination) => {
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    const walkDirection = /** @type {vec2} */ normalize(
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      destination.at(0) - creature.positionX,
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      destination.at(1) - creature.positionY,
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    );
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    const state = getWalkStateFromDirection(walkDirection);
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    return {
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        ...creature,
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        walkDirection,
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        state,
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        stateDuration: state === creature.state ? creature.stateDuration + 1 : 0,
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        positionX: creature.positionX + walkDirection.at(0) * WALK_SIZE,
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        positionY: creature.positionY + walkDirection.at(1) * WALK_SIZE,
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    };
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}
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/**
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 * Update function for creatures in any scratch state. * @param {Creature} creature current creature
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 * @param {Creature} creature
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 * @return {Creature} updated creature
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 */
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const updateScratchStateCreature = (creature) => {
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    if (creature.stateDuration % 2 < 1) {
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        // animation hasn't finished playing. let it finish.
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        return { ...creature, stateDuration: creature.stateDuration + 1 };
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    }
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    if (rollForNatN(4)) {
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       return { ...creature, state: CreatureState.IDLE, stateDuration: 0 };
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    }
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    return { ...creature, stateDuration: creature.stateDuration + 1 };
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}
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/**
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 * Used for {@link updateWalkStateCreature} to map the output of wall collision to new state
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 * @type {Readonly<Object.<number, number>>}
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 * @ignore
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 */
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const WALL_DIRECTION_TO_SCRATCH_STATE = Object.freeze({
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    [Direction.NORTH]: CreatureState.SCRATCH_NORTH,
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    [Direction.EAST]: CreatureState.SCRATCH_EAST,
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    [Direction.SOUTH]: CreatureState.SCRATCH_SOUTH,
 | 
			
		||||
    [Direction.WEST]: CreatureState.SCRATCH_WEST,
 | 
			
		||||
})
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * Update function for creatures in any walk state.
 | 
			
		||||
 * @param {Creature} creature current creature
 | 
			
		||||
 * @param {Array<Creature>} allCreatures all creatures in kennel
 | 
			
		||||
 * @return {Creature} updated creature
 | 
			
		||||
 */
 | 
			
		||||
const updateWalkStateCreature = (creature, allCreatures) => {
 | 
			
		||||
    const newPositionX = creature.positionX + (creature.walkDirection?.at(0) ?? 0) * WALK_SIZE;
 | 
			
		||||
    const newPositionY = creature.positionY + (creature.walkDirection?.at(1) ?? 0) * WALK_SIZE;
 | 
			
		||||
    const newPositionCreature = {
 | 
			
		||||
        ...creature,
 | 
			
		||||
        positionX: newPositionX,
 | 
			
		||||
        positionY: newPositionY,
 | 
			
		||||
        stateDuration: creature.stateDuration + 1,
 | 
			
		||||
    }
 | 
			
		||||
 | 
			
		||||
    const wallCollisionDirection = isCreatureOutOfBounds({
 | 
			
		||||
        ...creature, positionX: newPositionX, positionY: newPositionY
 | 
			
		||||
    })
 | 
			
		||||
 | 
			
		||||
    if (wallCollisionDirection !== undefined) {
 | 
			
		||||
        return {
 | 
			
		||||
            ...creature,
 | 
			
		||||
            state: WALL_DIRECTION_TO_SCRATCH_STATE[wallCollisionDirection] ?? CreatureState.IDLE,
 | 
			
		||||
            walkDirection: undefined,
 | 
			
		||||
            stateDuration: 0,
 | 
			
		||||
            positionX: constrain(
 | 
			
		||||
                newPositionX,
 | 
			
		||||
                creature.container.clientLeft + CREATURE_WIDTH / 2,
 | 
			
		||||
                creature.container.clientLeft + creature.container.clientWidth - CREATURE_WIDTH / 2,
 | 
			
		||||
            ),
 | 
			
		||||
            positionY: constrain(
 | 
			
		||||
              newPositionY,
 | 
			
		||||
              creature.container.clientTop + CREATURE_HEIGHT / 2,
 | 
			
		||||
              creature.container.clientTop + creature.container.clientHeight - CREATURE_HEIGHT / 2,
 | 
			
		||||
            ),
 | 
			
		||||
        }
 | 
			
		||||
    }
 | 
			
		||||
 | 
			
		||||
    const collidedCreature = allCreatures.reduce((prevCollidedCreature, currentCreature) => {
 | 
			
		||||
        if (prevCollidedCreature !== undefined) {
 | 
			
		||||
            return prevCollidedCreature;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        if (currentCreature.name === creature.name) {
 | 
			
		||||
            return undefined;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        if (isCreaturesColliding(newPositionCreature, currentCreature)) {
 | 
			
		||||
            return currentCreature;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        return undefined;
 | 
			
		||||
    }, undefined);
 | 
			
		||||
 | 
			
		||||
    if (collidedCreature !== undefined) {
 | 
			
		||||
        return { ...creature, walkDirection: undefined, stateDuration: 0, state: CreatureState.ALERT };
 | 
			
		||||
    }
 | 
			
		||||
 | 
			
		||||
    if (creature.stateDuration < 8 || !rollForNatN(10)) {
 | 
			
		||||
        // always play for at least 8 frames
 | 
			
		||||
        return newPositionCreature;
 | 
			
		||||
    }
 | 
			
		||||
 | 
			
		||||
    return { ...creature, walkDirection: undefined, stateDuration: 0, state: CreatureState.IDLE };
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
/**
 | 
			
		||||
 * Creature state transitions
 | 
			
		||||
 * @type {Object.<number, function(creature: Creature, allCreatures: Array<Creature>): Creature>}
 | 
			
		||||
 */
 | 
			
		||||
const CREATURE_STATE_TO_UPDATE_CREATURE_FUNCTION = Object.freeze({
 | 
			
		||||
    [CreatureState.IDLE]: (creature, allCreatures) => {
 | 
			
		||||
        if (creature.stateDuration < 8) {
 | 
			
		||||
            // play for at least 8 frames
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        const spottedCreatures = allCreatures
 | 
			
		||||
          .filter((otherCreature) => isIntersectingCircles(
 | 
			
		||||
            // circle at creature position with a view distance radius
 | 
			
		||||
            creature.positionX, creature.positionY, CREATURE_WIDTH * 4,
 | 
			
		||||
            otherCreature.positionX, otherCreature.positionY, 0,
 | 
			
		||||
          ))
 | 
			
		||||
          .filter((otherCreature) => otherCreature.name !== creature.name)
 | 
			
		||||
 | 
			
		||||
        if (spottedCreatures.length > 1) {
 | 
			
		||||
            // run away from the centroid of close creatures
 | 
			
		||||
            const centroidX = spottedCreatures.reduce(
 | 
			
		||||
                (sum, spottedCreature) => sum + spottedCreature.positionX, 0,
 | 
			
		||||
            ) / spottedCreatures.length;
 | 
			
		||||
            const centroidY = spottedCreatures.reduce(
 | 
			
		||||
                (sum, spottedCreature) => sum + spottedCreature.positionY, 0
 | 
			
		||||
            ) / spottedCreatures.length;
 | 
			
		||||
            return startCreatureWalkTowardDirection(creature, [
 | 
			
		||||
                creature.positionX - centroidX,
 | 
			
		||||
                creature.positionY - centroidY,
 | 
			
		||||
            ])
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        // move toward spotted creature, so long as doing so won't cause collision
 | 
			
		||||
        const updatedTowardSpottedCreature = spottedCreatures
 | 
			
		||||
            .map((otherCreature) => {
 | 
			
		||||
                const updatedCreature = startCreatureWalkTowardDirection(creature, [
 | 
			
		||||
                    otherCreature.positionX, otherCreature.positionY,
 | 
			
		||||
                ]);
 | 
			
		||||
                if (isCreaturesColliding(updatedCreature, otherCreature)) {
 | 
			
		||||
                    return undefined;
 | 
			
		||||
                }
 | 
			
		||||
                return updatedCreature;
 | 
			
		||||
            })
 | 
			
		||||
            .filter((updatedCreature) => updatedCreature !== undefined)
 | 
			
		||||
            .shift();
 | 
			
		||||
 | 
			
		||||
        if (updatedTowardSpottedCreature !== undefined && rollForNatN(4)) {
 | 
			
		||||
            // if there's a creature in the view radius, move toward it 25% of the time
 | 
			
		||||
            return updatedTowardSpottedCreature;
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        const newState = getRandomChoice(
 | 
			
		||||
          [0.1, 0.1, 0.1, 0.1, 0.6],
 | 
			
		||||
          [
 | 
			
		||||
              CreatureState.ALERT, // 0.1
 | 
			
		||||
              CreatureState.SCRATCH_SELF, // 0.1
 | 
			
		||||
              CreatureState.TIRED, // 0.1
 | 
			
		||||
              CreatureState.WALK_NORTH, // 0.1
 | 
			
		||||
              CreatureState.IDLE, // 0.1
 | 
			
		||||
          ],
 | 
			
		||||
        )
 | 
			
		||||
 | 
			
		||||
        if (newState === CreatureState.IDLE || newState === undefined) {
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        if (newState !== CreatureState.WALK_NORTH) {
 | 
			
		||||
            return {
 | 
			
		||||
                ...creature,
 | 
			
		||||
                stateDuration: 0,
 | 
			
		||||
                state: newState,
 | 
			
		||||
            }
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        const updatedWalkingCreature = startCreatureWalkTowardDirection(creature, [
 | 
			
		||||
            getRandomInRange(creature.container.clientLeft, creature.container.clientLeft + creature.container.clientWidth),
 | 
			
		||||
            getRandomInRange(creature.container.clientTop, creature.container.clientTop + creature.container.clientHeight),
 | 
			
		||||
        ]);
 | 
			
		||||
 | 
			
		||||
        // check for collision
 | 
			
		||||
        const collidingCreature = allCreatures
 | 
			
		||||
            .filter((otherCreature) => otherCreature.name !== updatedWalkingCreature.name)
 | 
			
		||||
            .filter((otherCreature) => isCreaturesColliding(updatedWalkingCreature, otherCreature))
 | 
			
		||||
            .shift();
 | 
			
		||||
 | 
			
		||||
        if (collidingCreature !== undefined) {
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        return updatedWalkingCreature;
 | 
			
		||||
    },
 | 
			
		||||
    [CreatureState.ALERT]: (creature, allCreatures) => {
 | 
			
		||||
        if (creature.stateDuration < 3) {
 | 
			
		||||
            // always play for at three frames
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        const newState = getRandomChoice(
 | 
			
		||||
          [0.1, 0.1, 0.3, 0.5],
 | 
			
		||||
          [
 | 
			
		||||
            CreatureState.SCRATCH_SELF, // 0.1
 | 
			
		||||
            CreatureState.TIRED, // 0.1
 | 
			
		||||
            CreatureState.IDLE, // 0.3
 | 
			
		||||
            CreatureState.WALK_NORTH, // 0.5
 | 
			
		||||
          ]
 | 
			
		||||
        )
 | 
			
		||||
 | 
			
		||||
        if (newState === undefined) {
 | 
			
		||||
            // default if something goes wrong
 | 
			
		||||
            return { ...creature, state: CreatureState.IDLE, stateDuration: 0 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        if (newState === CreatureState.WALK_NORTH) {
 | 
			
		||||
            // walk toward center with some random client
 | 
			
		||||
            return startCreatureWalkTowardDirection(creature, [
 | 
			
		||||
                getRandomInRange(creature.container.clientLeft, creature.container.clientLeft + creature.container.clientWidth),
 | 
			
		||||
                getRandomInRange(creature.container.clientTop, creature.container.clientTop + creature.container.clientHeight),
 | 
			
		||||
            ]);
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        return { ...creature, state: newState, stateDuration: 0 }
 | 
			
		||||
    },
 | 
			
		||||
    [CreatureState.SCRATCH_SELF]: (creature, allCreatures) =>  {
 | 
			
		||||
        if (creature.stateDuration % 3 < 2) {
 | 
			
		||||
            // animation hasn't finished playing play until complete
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        if (rollForNatN(4)) {
 | 
			
		||||
            return { ...creature, state: CreatureState.IDLE, stateDuration: 0 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
    },
 | 
			
		||||
    [CreatureState.SCRATCH_NORTH]: updateScratchStateCreature,
 | 
			
		||||
    [CreatureState.SCRATCH_SOUTH]: updateScratchStateCreature,
 | 
			
		||||
    [CreatureState.SCRATCH_EAST]: updateScratchStateCreature,
 | 
			
		||||
    [CreatureState.SCRATCH_WEST]: updateScratchStateCreature,
 | 
			
		||||
    [CreatureState.TIRED]: (creature, allCreatures) =>  {
 | 
			
		||||
        if (creature.stateDuration < 8) {
 | 
			
		||||
            // play for eight frames
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        if (rollForNatN(20)) {
 | 
			
		||||
            return { ...creature, state: CreatureState.ALERT, stateDuration: 0 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        return { ...creature, state: CreatureState.SLEEPING, stateDuration: 0 }
 | 
			
		||||
    },
 | 
			
		||||
    [CreatureState.SLEEPING]: (creature, allCreatures) =>  {
 | 
			
		||||
        if (creature.stateDuration < 8) {
 | 
			
		||||
            // play for at least eight frames
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        const newState = getRandomChoice(
 | 
			
		||||
            [0.01, 0.02, 0.02, 0.95],
 | 
			
		||||
            [
 | 
			
		||||
                CreatureState.TIRED, // 0.01
 | 
			
		||||
                CreatureState.ALERT, // 0.02
 | 
			
		||||
                CreatureState.IDLE, // 0.02
 | 
			
		||||
                CreatureState.SLEEPING, // 0.95
 | 
			
		||||
            ],
 | 
			
		||||
        );
 | 
			
		||||
 | 
			
		||||
        if (newState === CreatureState.SLEEPING || newState === undefined) {
 | 
			
		||||
            return { ...creature, stateDuration: creature.stateDuration + 1 };
 | 
			
		||||
        }
 | 
			
		||||
 | 
			
		||||
        return { ...creature, state: newState, stateDuration: 0 };
 | 
			
		||||
    },
 | 
			
		||||
    [CreatureState.WALK_NORTH]: updateWalkStateCreature,
 | 
			
		||||
    [CreatureState.WALK_NORTHEAST]: updateWalkStateCreature,
 | 
			
		||||
    [CreatureState.WALK_EAST]: updateWalkStateCreature,
 | 
			
		||||
    [CreatureState.WALK_SOUTHEAST]: updateWalkStateCreature,
 | 
			
		||||
    [CreatureState.WALK_SOUTH]: updateWalkStateCreature,
 | 
			
		||||
    [CreatureState.WALK_SOUTHWEST]: updateWalkStateCreature,
 | 
			
		||||
    [CreatureState.WALK_WEST]: updateWalkStateCreature,
 | 
			
		||||
    [CreatureState.WALK_NORTHWEST]: updateWalkStateCreature,
 | 
			
		||||
})
 | 
			
		||||
 | 
			
		||||
window.onload = () => {
 | 
			
		||||
    if (
 | 
			
		||||
      window.matchMedia(`(prefers-reduced-motion: reduce)`).matches
 | 
			
		||||
        || window.matchMedia(`(prefers-reduced-motion: reduce)`).matches
 | 
			
		||||
    ) {
 | 
			
		||||
        // user preference for low motion. do not render creatures
 | 
			
		||||
        return;
 | 
			
		||||
    }
 | 
			
		||||
 | 
			
		||||
    // EXAMPLE SCRIPT
 | 
			
		||||
    const kennelWindowEle = document.querySelector('#kennel-window');
 | 
			
		||||
    const creatures = ['test-creature-1', 'test-creature-2', 'test-creature-3']
 | 
			
		||||
      .map((name) => createCreature(
 | 
			
		||||
    const creatures = Array(32).fill('test-creature')
 | 
			
		||||
      .map((name, index) => createCreature(
 | 
			
		||||
        kennelWindowEle,
 | 
			
		||||
        name,
 | 
			
		||||
        name + index.toString(),
 | 
			
		||||
        undefined, // default sprite sheet
 | 
			
		||||
        randomInt(0, 17), // random state
 | 
			
		||||
        randomInt(0, 2) * kennelWindowEle.clientWidth, // randomly left or right side
 | 
			
		||||
        randomInt(0, 2) * kennelWindowEle.clientHeight, // randomly top or bottom
 | 
			
		||||
        getRandomChoice(undefined, [
 | 
			
		||||
            CreatureState.IDLE,
 | 
			
		||||
            CreatureState.TIRED,
 | 
			
		||||
            CreatureState.SCRATCH_SELF,
 | 
			
		||||
        ]),
 | 
			
		||||
        getRandomInRange(kennelWindowEle.clientLeft, kennelWindowEle.clientLeft + kennelWindowEle.clientWidth),
 | 
			
		||||
        getRandomInRange(kennelWindowEle.clientTop, kennelWindowEle.clientTop + kennelWindowEle.clientHeight),
 | 
			
		||||
      ))
 | 
			
		||||
 | 
			
		||||
    const updateCreature = updateCreatureWithAllCreaturesContext((creature, allCreatures) => {
 | 
			
		||||
        // example update creature script to bring creatures to the centroid
 | 
			
		||||
 | 
			
		||||
        const centroidX = allCreatures.reduce(
 | 
			
		||||
          (sum, creature) => sum + creature.positionX,
 | 
			
		||||
          0,
 | 
			
		||||
        ) / allCreatures.length;
 | 
			
		||||
        const centroidY = allCreatures.reduce(
 | 
			
		||||
          (sum, creature) => sum + creature.positionY,
 | 
			
		||||
          0,
 | 
			
		||||
        ) / allCreatures.length;
 | 
			
		||||
 | 
			
		||||
        const [deltaX, deltaY] = normalize(
 | 
			
		||||
          centroidX - creature.positionX,
 | 
			
		||||
          centroidY - creature.positionY,
 | 
			
		||||
        );
 | 
			
		||||
 | 
			
		||||
        return {
 | 
			
		||||
            ...creature,
 | 
			
		||||
            positionX: constrain(creature.positionX + deltaX, 0, creature.container.clientWidth),
 | 
			
		||||
            positionY: constrain(creature.positionY + deltaY, 0, creature.container.clientHeight),
 | 
			
		||||
            stateDuration: creature.stateDuration + 1,
 | 
			
		||||
        }
 | 
			
		||||
        const updatedCreature = CREATURE_STATE_TO_UPDATE_CREATURE_FUNCTION[creature.state](creature, allCreatures);
 | 
			
		||||
        return updatedCreature
 | 
			
		||||
    }, creatures);
 | 
			
		||||
 | 
			
		||||
    creatures.forEach((creature) => beginCreatureAnimation(creature, updateCreature))
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
window.onresize = () => {
 | 
			
		||||
    // TODO: dynamically change creature size based on window size
 | 
			
		||||
}
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
| 
						 | 
				
			
			@ -1,7 +1,12 @@
 | 
			
		|||
#kennel-window {
 | 
			
		||||
    width: 80vw;
 | 
			
		||||
    min-width: 8rem;
 | 
			
		||||
    height: 80vw;
 | 
			
		||||
    min-height: 8rem;
 | 
			
		||||
    margin: auto;
 | 
			
		||||
    width: 100%;
 | 
			
		||||
    height: 100vh;
 | 
			
		||||
    background-color: whitesmoke;
 | 
			
		||||
    margin: 0;
 | 
			
		||||
    padding: 0;
 | 
			
		||||
}
 | 
			
		||||
 | 
			
		||||
body {
 | 
			
		||||
    margin: 0;
 | 
			
		||||
    padding: 0;
 | 
			
		||||
}
 | 
			
		||||
		Loading…
	
		Reference in New Issue