gpu.js/src/js-fallback.js

// var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg;
// var ARGUMENT_NAMES = /([^\s,]+)/g;
// function getParamNames(func) {
//	 var fnStr = func.toString().replace(STRIP_COMMENTS, '');
//	 var result = fnStr.slice(fnStr.indexOf('(')+1, fnStr.indexOf(')')).match(ARGUMENT_NAMES);
//	 if(result === null)
//		 result = [];
//	 return result;
// }

var GPU_jsFallback = (function() {
	function clone(obj) {
	    if(obj === null || typeof(obj) !== 'object' || 'isActiveClone' in obj)
	        return obj;

	    var temp = obj.constructor(); // changed

	    for(var key in obj) {
	        if(Object.prototype.hasOwnProperty.call(obj, key)) {
	            obj['isActiveClone'] = null;
	            temp[key] = clone(obj[key]);
	            delete obj['isActiveClone'];
	        }
	    }

	    return temp;
	}
	
	/// JS fallback transformation, basically pure JS
	///
	/// @param inputFunction   The calling to perform the conversion
	/// @param _threadDim      The thread dim array configuration
	/// @param _blockDim       The block dim array configuration
	/// @param paramObj        The parameter object
	///
	/// @returns callable function if converted, else returns null
	function jsFallback(kernel, _threadDim, _blockDim, paramObj) {
		var threadDim = clone(_threadDim);
		var blockDim = clone(_blockDim);
		
		while (threadDim.length < 3) {
			threadDim.push(1);
		}
		
		while (blockDim.length < 3) {
			blockDim.push(1);
		}
		
		var globalDim = [
			threadDim[0] * blockDim[0],
			threadDim[1] * blockDim[1],
			threadDim[2] * blockDim[2]
		];
		
		return function() {
			var ret = new Array(globalDim[2]);
			for (var i=0; i<globalDim[2]; i++) {
				ret[i] = new Array(globalDim[1]);
				for (var j=0; j<globalDim[1]; j++) {
					ret[i][j] = new Array(globalDim[0]);
				}
			}
			
			var ctx = {
				thread: {
					x: 0,
					y: 0,
					z: 0
				},
				block: {
					x: 0,
					y: 0,
					z: 0
				}
			};
			
			// Note needed : thank goodness
			//var argNames = getParamNames(arguments.callee);
			
			for (ctx.block.z=0; ctx.block.z<blockDim[2]; ctx.block.z++) {
				for (ctx.block.y=0; ctx.block.y<blockDim[1]; ctx.block.y++) {
					for (ctx.block.x=0; ctx.block.x<blockDim[0]; ctx.block.x++) {
						for (ctx.thread.z=0; ctx.thread.z<threadDim[2]; ctx.thread.z++) {
							for (ctx.thread.y=0; ctx.thread.y<threadDim[1]; ctx.thread.y++) {
								for (ctx.thread.x=0; ctx.thread.x<threadDim[0]; ctx.thread.x++) {
									globalX = ctx.thread.x + ctx.block.x * blockDim[0];
									globalY = ctx.thread.y + ctx.block.y * blockDim[1];
									globalZ = ctx.thread.z + ctx.block.z * blockDim[2];
									
									ret[globalZ][globalY][globalX] = kernel.apply(ctx, arguments);
								}
							}
						}
					}
				}
			}
			
			if (_threadDim.length == 1) {
				ret = ret[0][0];
			} else if (_threadDim.length == 2) {
				ret = ret[0];
			}
			
			return ret;
		}
	};
	
	return jsFallback;
})();