smooth-moves.js

/**
🏃
@file smooth moves
@summary ease the player's movement
@license MIT
@version 2.0.0
@requires Bitsy Version: 6.3
@author Sean S. LeBlanc

@description
Makes the player avatar ease in between positions instead of moving immediately.
Speed and easing function are configurable.

HOW TO USE:
1. Copy-paste this script into a script tag after the bitsy source
2. Edit hackOptions below as needed
*/
this.hacks = this.hacks || {};
(function (exports, bitsy) {
'use strict';
var hackOptions = {
	// duration of ease in ms
	duration: 100,
	// max distance to allow tweens
	delta: 1.5,
	// easing function
	ease: function(t) {
		t = 1 - Math.pow(1 - t, 2);
		return t;
	},
};

bitsy = bitsy && bitsy.hasOwnProperty('default') ? bitsy['default'] : bitsy;

/**
@file utils
@summary miscellaneous bitsy utilities
@author Sean S. LeBlanc
*/

/*
Helper used to replace code in a script tag based on a search regex
To inject code without erasing original string, using capturing groups; e.g.
	inject(/(some string)/,'injected before $1 injected after')
*/
function inject(searchRegex, replaceString) {
	// find the relevant script tag
	var scriptTags = document.getElementsByTagName('script');
	var scriptTag;
	var code;
	for (var i = 0; i < scriptTags.length; ++i) {
		scriptTag = scriptTags[i];
		var matchesSearch = scriptTag.textContent.search(searchRegex) !== -1;
		var isCurrentScript = scriptTag === document.currentScript;
		if (matchesSearch && !isCurrentScript) {
			code = scriptTag.textContent;
			break;
		}
	}

	// error-handling
	if (!code) {
		throw 'Couldn\'t find "' + searchRegex + '" in script tags';
	}

	// modify the content
	code = code.replace(searchRegex, replaceString);

	// replace the old script tag with a new one using our modified code
	var newScriptTag = document.createElement('script');
	newScriptTag.textContent = code;
	scriptTag.insertAdjacentElement('afterend', newScriptTag);
	scriptTag.remove();
}

/**
 * Helper for getting an array with unique elements
 * @param  {Array} array Original array
 * @return {Array}       Copy of array, excluding duplicates
 */
function unique(array) {
	return array.filter(function (item, idx) {
		return array.indexOf(item) === idx;
	});
}

/**

@file kitsy-script-toolkit
@summary makes it easier and cleaner to run code before and after Bitsy functions or to inject new code into Bitsy script tags
@license WTFPL (do WTF you want)
@version 4.0.1
@requires Bitsy Version: 4.5, 4.6
@author @mildmojo

@description
HOW TO USE:
  import {before, after, inject, addDialogTag, addDeferredDialogTag} from "./helpers/kitsy-script-toolkit";

  before(targetFuncName, beforeFn);
  after(targetFuncName, afterFn);
  inject(searchRegex, replaceString);
  addDialogTag(tagName, dialogFn);
  addDeferredDialogTag(tagName, dialogFn);

  For more info, see the documentation at:
  https://github.com/seleb/bitsy-hacks/wiki/Coding-with-kitsy
*/

// Ex: before('load_game', function run() { alert('Loading!'); });
//     before('show_text', function run(text) { return text.toUpperCase(); });
//     before('show_text', function run(text, done) { done(text.toUpperCase()); });
function before(targetFuncName, beforeFn) {
	var kitsy = kitsyInit();
	kitsy.queuedBeforeScripts[targetFuncName] = kitsy.queuedBeforeScripts[targetFuncName] || [];
	kitsy.queuedBeforeScripts[targetFuncName].push(beforeFn);
}

// Ex: after('load_game', function run() { alert('Loaded!'); });
function after(targetFuncName, afterFn) {
	var kitsy = kitsyInit();
	kitsy.queuedAfterScripts[targetFuncName] = kitsy.queuedAfterScripts[targetFuncName] || [];
	kitsy.queuedAfterScripts[targetFuncName].push(afterFn);
}

function kitsyInit() {
	// return already-initialized kitsy
	if (bitsy.kitsy) {
		return bitsy.kitsy;
	}

	// Initialize kitsy
	bitsy.kitsy = {
		queuedInjectScripts: [],
		queuedBeforeScripts: {},
		queuedAfterScripts: {}
	};

	var oldStartFunc = bitsy.startExportedGame;
	bitsy.startExportedGame = function doAllInjections() {
		// Only do this once.
		bitsy.startExportedGame = oldStartFunc;

		// Rewrite scripts and hook everything up.
		doInjects();
		applyAllHooks();

		// Start the game
		bitsy.startExportedGame.apply(this, arguments);
	};

	return bitsy.kitsy;
}


function doInjects() {
	bitsy.kitsy.queuedInjectScripts.forEach(function (injectScript) {
		inject(injectScript.searchRegex, injectScript.replaceString);
	});
	_reinitEngine();
}

function applyAllHooks() {
	var allHooks = unique(Object.keys(bitsy.kitsy.queuedBeforeScripts).concat(Object.keys(bitsy.kitsy.queuedAfterScripts)));
	allHooks.forEach(applyHook);
}

function applyHook(functionName) {
	var functionNameSegments = functionName.split('.');
	var obj = bitsy;
	while (functionNameSegments.length > 1) {
		obj = obj[functionNameSegments.shift()];
	}
	var lastSegment = functionNameSegments[0];
	var superFn = obj[lastSegment];
	var superFnLength = superFn ? superFn.length : 0;
	var functions = [];
	// start with befores
	functions = functions.concat(bitsy.kitsy.queuedBeforeScripts[functionName] || []);
	// then original
	if (superFn) {
		functions.push(superFn);
	}
	// then afters
	functions = functions.concat(bitsy.kitsy.queuedAfterScripts[functionName] || []);

	// overwrite original with one which will call each in order
	obj[lastSegment] = function () {
		var returnVal;
		var args = [].slice.call(arguments);
		var i = 0;

		function runBefore() {
			// All outta functions? Finish
			if (i === functions.length) {
				return returnVal;
			}

			// Update args if provided.
			if (arguments.length > 0) {
				args = [].slice.call(arguments);
			}

			if (functions[i].length > superFnLength) {
				// Assume funcs that accept more args than the original are
				// async and accept a callback as an additional argument.
				return functions[i++].apply(this, args.concat(runBefore.bind(this)));
			} else {
				// run synchronously
				returnVal = functions[i++].apply(this, args);
				if (returnVal && returnVal.length) {
					args = returnVal;
				}
				return runBefore.apply(this, args);
			}
		}

		return runBefore.apply(this, arguments);
	};
}

function _reinitEngine() {
	// recreate the script and dialog objects so that they'll be
	// referencing the code with injections instead of the original
	bitsy.scriptModule = new bitsy.Script();
	bitsy.scriptInterpreter = bitsy.scriptModule.CreateInterpreter();

	bitsy.dialogModule = new bitsy.Dialog();
	bitsy.dialogRenderer = bitsy.dialogModule.CreateRenderer();
	bitsy.dialogBuffer = bitsy.dialogModule.CreateBuffer();
}





// smooth move
var tweens = {};
var sprites = {};
function addTween(spr, fromX, fromY, toX, toY) {
	if (Math.abs(toX - fromX) + Math.abs(toY - fromY) > hackOptions.delta) {
		delete tweens[spr];
	} else {
		var t = tweens[spr] = tweens[spr] || {};
		t.fromX = fromX;
		t.fromY = fromY;
		t.toX = toX;
		t.toY = toY;
		t.start = bitsy.prevTime;
	}
}
before('onready', function() {
	tweens = {};
	sprites = {};
});

// listen for changes in sprite positions to add tweens
before('update', function() {
	Object.values(bitsy.sprite).forEach(spr => {
		if (spr.room === bitsy.curRoom) {
			var s = sprites[spr.id] = sprites[spr.id] || {};
			s.x = spr.x;
			s.y = spr.y;
		} else {
			delete sprites[spr.id];
		}
	});
});
function addTweens() {
	Object.entries(sprites).forEach(function (entry) {
		var spr = bitsy.sprite[entry[0]];
		var pos = entry[1];
		if (pos.x !== spr.x || pos.y !== spr.y) {
			addTween(spr.id, pos.x, pos.y, spr.x, spr.y);
		}
	});
}
after('updateInput', addTweens);
after('update', addTweens);
// before drawing, update sprite positions to tweened values
before('drawRoom', function () {
	Object.entries(tweens).forEach(function (entry) {
		var tween = entry[1];
		var t = hackOptions.ease(Math.min(1, (bitsy.prevTime - tween.start) / hackOptions.duration));
		var sprite = bitsy.sprite[entry[0]];
		sprite.x = tween.fromX + (tween.toX - tween.fromX) * t;
		sprite.y = tween.fromY + (tween.toY - tween.fromY) * t;
	});
});
// after drawing, update sprite positions back to normal
after('drawRoom', function () {
	Object.entries(tweens).forEach(function (entry) {
		var tween = entry[1];
		var sprite = bitsy.sprite[entry[0]];
		sprite.x = tween.toX;
		sprite.y = tween.toY;
	});
});

exports.hackOptions = hackOptions;

}(this.hacks.smooth_moves = this.hacks.smooth_moves || {}, window));