Colorspace: optimize default color initialization

This patch avoids the creation of extra arrays when initializing an
array with default (zero) values. Doing this additionally makes the code
more readable by allocating enough space for the number of color
components.

src/core/colorspace.js

@@ -547,7 +547,7 @@ var IndexedCS = (function IndexedCSClosure() {
   function IndexedCS(base, highVal, lookup) {
     this.name = 'Indexed';
     this.numComps = 1;
-    this.defaultColor = new Uint8Array([0]);
+    this.defaultColor = new Uint8Array(this.numComps);
     this.base = base;
     this.highVal = highVal;
 
@@ -613,7 +613,7 @@ var DeviceGrayCS = (function DeviceGrayCSClosure() {
   function DeviceGrayCS() {
     this.name = 'DeviceGray';
     this.numComps = 1;
-    this.defaultColor = new Float32Array([0]);
+    this.defaultColor = new Float32Array(this.numComps);
   }
 
   DeviceGrayCS.prototype = {
@@ -655,7 +655,7 @@ var DeviceRgbCS = (function DeviceRgbCSClosure() {
   function DeviceRgbCS() {
     this.name = 'DeviceRGB';
     this.numComps = 3;
-    this.defaultColor = new Float32Array([0, 0, 0]);
+    this.defaultColor = new Float32Array(this.numComps);
   }
   DeviceRgbCS.prototype = {
     getRgb: ColorSpace.prototype.getRgb,
@@ -748,7 +748,9 @@ var DeviceCmykCS = (function DeviceCmykCSClosure() {
   function DeviceCmykCS() {
     this.name = 'DeviceCMYK';
     this.numComps = 4;
-    this.defaultColor = new Float32Array([0, 0, 0, 1]);
+    this.defaultColor = new Float32Array(this.numComps);
+    // Set the fourth component to the maximum value for a black color.
+    this.defaultColor[3] = 1;
   }
   DeviceCmykCS.prototype = {
     getRgb: ColorSpace.prototype.getRgb,
@@ -788,7 +790,7 @@ var CalGrayCS = (function CalGrayCSClosure() {
   function CalGrayCS(whitePoint, blackPoint, gamma) {
     this.name = 'CalGray';
     this.numComps = 1;
-    this.defaultColor = new Float32Array([0]);
+    this.defaultColor = new Float32Array(this.numComps);
 
     if (!whitePoint) {
       error('WhitePoint missing - required for color space CalGray');
@@ -911,7 +913,7 @@ var CalRGBCS = (function CalRGBCSClosure() {
   function CalRGBCS(whitePoint, blackPoint, gamma, matrix) {
     this.name = 'CalRGB';
     this.numComps = 3;
-    this.defaultColor = new Float32Array(3);
+    this.defaultColor = new Float32Array(this.numComps);
 
     if (!whitePoint) {
       error('WhitePoint missing - required for color space CalRGB');
@@ -1187,7 +1189,7 @@ var LabCS = (function LabCSClosure() {
   function LabCS(whitePoint, blackPoint, range) {
     this.name = 'Lab';
     this.numComps = 3;
-    this.defaultColor = new Float32Array([0, 0, 0]);
+    this.defaultColor = new Float32Array(this.numComps);
 
     if (!whitePoint) {
       error('WhitePoint missing - required for color space Lab');