AutoGen Three.js Shader Uniforms

ShaderUtils.js

// https://github.com/mrdoob/three.js/issues/4145
// based on https://github.com/unconed/ShaderGraph.js/blob/master/src/Snippet.js

var typeMaps = {
	'float':       'f',
	'vec2':        'v2',
	'vec3':        'v3',
	'vec4':        'v4',
	'mat3':        'm3',
	'mat4':        'm4',
	'sampler2D':   't',
	'samplerCube': 't',
}

var typeNatives = {
	'v2': THREE.Vector2,
	'v3': THREE.Vector3,
	'm3': THREE.Matrix3,
	'm4': THREE.Matrix4
}


function parseUniforms(code, uniforms) {
	if (!uniforms) uniforms = {};

	// Remove all comments and normalize newlines
	code = code.replace(/\r\n?/g, '\n').replace(/\/\/[^\n]*\n/g, ' ').replace(/\/\*(.|\n)*?\*\//g, ' ');

	var match_uniforms = /(?:^|;)\s*uniform\s+(([A-Za-z0-9]+)\s+([A-Za-z0-9_]+)\s*(?:\[([^\]]+)\])?)(?:$|(?=;))/g;
	
	var match, type, name, array, shortType;
	
	while (match = match_uniforms.exec(code)) {
		type = match[2];
		name = match[3];
		array = match[4];
		shortType = typeMaps[type];
		
		if (!uniforms[name]) uniforms[name] = {};
		
		uniforms[name].type = shortType + ( array ? 'v' : '' );
		if (uniforms[name].value == undefined) // don't overwrite exisiting uniform values
			uniforms[name].value = shortType in typeNatives ? new typeNatives[ shortType ] : 0;
	};

	return uniforms;
}