levReader.js

"use strict";

var bin = require("./binReader");

var ticker = function(){
	var n = 0;
	return function(m){
		n += m;
		return n - m;
	};
}();

var offsType = ticker(5);
ticker(2);
var offsIdent = ticker(4);
var offsIntegrities = ticker(4*8);
var offsDesc = ticker(51);
var offsLgr = ticker(16);
var offsGround = ticker(10);
var offsSky = ticker(10);
var offsPolyCount = ticker(8);
var offsPolys = ticker(0);

exports.reader = function levReader(data){
	var br = bin.reader(data);

	function polyCount(){
		br.seek(offsPolyCount);
		return Math.floor(br.binFloat64le());
	}

	function objCount(){
		br.seek(offsObjCount);
		return Math.floor(br.binFloat64le());
	}

	function picCount(){
		br.seek(offsPicCount);
		return Math.floor(br.binFloat64le());
	}

	var offsObjCount = function(){
		var pc = polyCount();
		br.seek(offsPolys);
		for(var x = 0; x < pc; x++){
			br.skip(4); // grass
			br.skip(br.word32le()*(8 + 8));
		}
		return br.pos();
	}();
	var offsObjs = offsObjCount + 8;
	var offsPicCount = function(){
		br.seek(offsObjCount);
		return offsObjs + Math.floor(br.binFloat64le())*((8 + 8) + (4 + 4 + 4));
	}();
	var offsPics = offsPicCount + 8;

	var obj, pic; // initialised in the object literal :\

	//return window.lrd = {
	return {
		rightType: function(){
			br.seek(offsType);
			return br.seq(5) == "POT14";
		},

		ident: function(){
			br.seek(offsIdent);
			return br.seq(4);
		},

		integrities: function(){
			br.seek(offsIntegrities);
			var o = [];
			for(var x = 0; x < 4; x++)
				o.push(br.binFloat64le());
			return o;
		},

		desc: function(){
			br.seek(offsDesc);
			return br.string(51);
		},

		lgr: function(){
			br.seek(offsLgr);
			return br.string(16);
		},

		ground: function(){
			br.seek(offsGround);
			return br.string(10);
		},

		sky: function(){
			br.seek(offsSky);
			return br.string(10);
		},

		polyCount: polyCount,
		objCount: objCount,
		picCount: picCount,

		polyReader: function(forEachPoly){
			/* lr.polyReader(function(grass, vcount, vertices){
			 *   // for each polygon
			 *   vertices(function(x, y){
			 *     // for each vertex in it
			 *   });
			 * });
			 */

			var count = polyCount();
			br.seek(offsPolys);
			for(var x = 0; x < count; x++){
				var grass = br.word32le(), vcount = br.word32le(), pos = br.pos();
				void function(grass, vcount, pos){
					br.seek(pos);
					forEachPoly(grass != 0, vcount, function(forEachVertex){
						for(var y = 0; y < vcount; y++){
							br.seek(pos + y*(8 + 8));
							forEachVertex(br.binFloat64le(), br.binFloat64le());
						}
					});
				}(grass, vcount, pos);
				br.seek(pos + vcount*(8 + 8));
			}
		},

		obj: obj = function(n, onFlower, onApple, onKiller, onStart){ // onError? maybe
			br.seek(offsObjs + n*((8 + 8) + (4 + 4 + 4)));
			var vx = br.binFloat64le(), vy = br.binFloat64le();
			var obj = br.word32le(), grav = br.word32le(), anim = br.word32le();
			switch(obj){
				case 1: return onFlower(vx, vy);
				case 2: return onApple(vx, vy, grav, anim);
				case 3: return onKiller(vx, vy);
				case 4: return onStart(vx, vy);
				default: throw new Error("hmm: " + obj + ", x = " + vx + ", y = " + vy);
			}
		},

		obj_: function(n){
			function h(s){
				return function(vx, vy, grav, anim){
					var o = { type: s, x: vx, y: vy };
					if(grav !== undefined){
						o.grav = grav;
						o.anim = anim;
					}
					return o;
				};
			}

			return obj(n, h("flower"), h("apple"), h("killer"), h("start"));
		},

		pic: pic = function(n, onPic){
			br.seek(offsPics + n*(10 + 10 + 10 + 8 + 8 + 4 + 4));
			var picture = br.pstring(10), texture = br.pstring(10), mask = br.pstring(10);
			var vx = br.binFloat64le(), vy = br.binFloat64le();
			var dist = br.word32le(), clipping = br.word32le();
			clipping = ["u", "g", "s"][clipping];
			return onPic(picture, texture, mask, vx, vy, dist, clipping);
		},

		pic_: function(n){
			return pic(n, function(picture, texture, mask, vx, vy, dist, clipping){
				return {
					picture: picture,
					texture: texture,
					mask: mask,
					x: vx,
					y: vy,
					dist: dist,
					clipping: clipping
				};
			});
		}
	};
};