Add WEBGL constants for some technique.states

examples/js/loaders/GLTFLoader.js

@@ -345,6 +345,48 @@ THREE.GLTFLoader = ( function () {
 		10497: THREE.RepeatWrapping
 	};
 
+	var WEBGL_SIDES = {
+		1028: THREE.BackSide,  // Culling front
+		1029: THREE.FrontSide  // Culling back
+		//1032: THREE.NoSide   // Culling front and back, what to do?
+	};
+
+	var WEBGL_DEPTH_FUNCS = {
+		512: THREE.NeverDepth,
+		513: THREE.LessDepth,
+		514: THREE.EqualDepth,
+		515: THREE.LessEqualDepth,
+		516: THREE.GreaterEqualDepth,
+		517: THREE.NotEqualDepth,
+		518: THREE.GreaterEqualDepth,
+		519: THREE.AlwaysDepth
+	};
+
+	var WEBGL_BLEND_EQUATIONS = {
+		32774: THREE.AddEquation,
+		32778: THREE.SubtractEquation,
+		32779: THREE.ReverseSubtractEquation
+	};
+
+	var WEBGL_BLEND_FUNCS = {
+		0: THREE.ZeroFactor,
+		1: THREE.OneFactor,
+		768: THREE.SrcColorFactor,
+		769: THREE.OneMinusSrcColorFactor,
+		770: THREE.SrcAlphaFactor,
+		771: THREE.OneMinusSrcAlphaFactor,
+		772: THREE.DstAlphaFactor,
+		773: THREE.OneMinusDstAlphaFactor,
+		774: THREE.DstColorFactor,
+		775: THREE.OneMinusDstColorFactor,
+		776: THREE.SrcAlphaSaturateFactor
+		// The followings are not supported by Three.js yet
+		//32769: CONSTANT_COLOR,
+		//32770: ONE_MINUS_CONSTANT_COLOR,
+		//32771: CONSTANT_ALPHA,
+		//32772: ONE_MINUS_CONSTANT_COLOR
+	};
+
 	var WEBGL_TYPE_SIZES = {
 		'SCALAR': 1,
 		'VEC2': 2,
@@ -366,6 +408,15 @@ THREE.GLTFLoader = ( function () {
 		STEP: THREE.InterpolateDiscrete
 	};
 
+	var STATES_ENABLES = {
+		2884: 'CULL_FACE',
+		2929: 'DEPTH_TEST',
+		3042: 'BLEND',
+		3089: 'SCISSOR_TEST',
+		32823: 'POLYGON_OFFSET_FILL',
+		32926: 'SAMPLE_ALPHA_TO_COVERAGE'
+	};
+
 	/* UTILITY FUNCTIONS */
 
 	function _each( object, callback, thisObj ) {