Fix bad property swizzle-set

Author: dy

lib/index.js

@@ -23,7 +23,7 @@ var Descriptor = require('./descriptor')
 var prepr = require('prepr')
 
 var floatRE = /^-?[0-9]*(?:.[0-9]+)?(?:e-?[0-9]+)?$/i
-
+var swizzleRE = /^[xyzwstpdrgba]{1,4}$/
 
 /**
  * Create GLSL codegen instance
@@ -643,7 +643,7 @@ GLSL.prototype.transforms = {
 			var prop = node.children[1].data
 
 			//ab.xyz for example
-			if (/^[xyzwstpdrgba]{1,4}$/.test(prop)) {
+			if (swizzleRE.test(prop)) {
 				return this.unswizzle(node)
 			}
 
@@ -811,7 +811,7 @@ GLSL.prototype.transforms = {
 
 			//something[N] return as is
 			return Descriptor(`${left}[${right}]`, {
-				type: type,
+				type: type || null,
 				complexity: left.complexity + right.complexity + 1
 			})
 		}
@@ -836,7 +836,11 @@ GLSL.prototype.transforms = {
 		}
 
 		var target = left
-		var isSwizzle = node.children[0].type === 'operator' && /^[xyzwstpdrgba]{1,4}$/.test(node.children[0].children[1].data)
+
+		// here some targets may be unswizzled already, eg.
+		// [a[0], a[1]], a[0][0], etc.
+		var isSwizzle = node.children[0].type === 'operator' &&
+			swizzleRE.test(node.children[0].children[1].data)
 
 		//a *= b.x
 		if (!isSwizzle && this.types[right.type].length == 1 && this.types[target.type].length == 1) {
@@ -848,7 +852,7 @@ GLSL.prototype.transforms = {
 
 		//FIXME: left can be a structure property set a.prop
 
-		//in cases of setting swizzle - we gotta drop left unswizzle to the right
+		//in cases of setting swizzle - we have to place left unswizzle to the right
 		if (isSwizzle) {
 			var positions = this.swizzlePositions(node.children[0].children[1].data)
 			var len = this.types[this.process(node.children[0].children[0]).type].length
@@ -858,10 +862,15 @@ GLSL.prototype.transforms = {
 				ids[positions[i]] = i
 			}
 
-			target = Descriptor(node.children[0].children[0].data, {
-				type: right.type,
-				optimize: false
-			})
+			var targetType = node.children[0].children[0].type
+
+			// a.x = ...
+			if ((targetType === 'ident' || targetType === 'builtin')) {
+				target = Descriptor(node.children[0].children[0].data, {
+					type: right.type,
+					optimize: false
+				})
+			}
 
 			//a.wy *= a.zx →
 			//a = [null, 1, null, 0].map(function (idx, i) {
@@ -903,10 +912,17 @@ GLSL.prototype.transforms = {
 			}
 			//a.x *= b → a[0] *= b
 			else {
-				return Descriptor(`${target}[${positions[0]}] ${operator} ${right}`, {
-					type: right.type,
-					optimize: false
-				})
+				if (targetType === 'builtin' || targetType === 'ident') {
+					return Descriptor(`${target}[${positions[0]}] ${operator} ${right}`, {
+						type: right.type,
+						optimize: false
+					})
+				} else {
+					return Descriptor(`${target} ${operator} ${right}`, {
+						type: right.type,
+						optimize: false
+					})
+				}
 			}
 		}
 
@@ -1212,11 +1228,13 @@ GLSL.prototype.unswizzle = function (node) {
 		}
 		else {
 			if (args[0] == null) console.warn(`Cannot unswizzle '${ident.type}(${ident}).${prop}': ${prop} is outside the type range.`)
+
 			result = Descriptor(args[0] || `undefined`, {
 				type: 'float',
 				complexity: 1
 			})
 		}
+
 		return result
 	}
 

test/index.js

@@ -293,12 +293,30 @@ test('Episodes', function () {
 	})
 
 	test(`normalize(vec2(b));`, function () {
-		var compile = GLSL({includes: false});
+		var compile = GLSL({includes: false})
 
 		assert.equal(clean(compile(this.title)), clean(`
 			normalize([b, b]);
 		`))
 	})
+
+	test(`a[0].x = 0.0; a[1].y = 1.0;`, function () {
+		var compile = GLSL({includes: false})
+
+		assert.equal(clean(compile(this.title)), clean(`
+			a[0][0] = 0.0;
+			a[1][1] = 1.0;
+		`))
+	})
+
+	// TODO
+	test.skip(`a[2].zw = 2.0;`, function () {
+		var compile = GLSL({includes: false});
+
+		assert.equal(clean(compile(this.title)), clean(`
+			[a[2][2], a[2][3]] = [2.0, 2.0]
+		`))
+	})
 });