move color type constants to constants. Revert change requiring default options on null.

lib/constants.js

@@ -12,9 +12,23 @@ module.exports = {
   TYPE_tRNS: 0x74524e53, // eslint-disable-line camelcase
   TYPE_gAMA: 0x67414d41, // eslint-disable-line camelcase
 
-  COLOR_PALETTE: 1,
+  // color-type bits
-  COLOR_COLOR: 2,
+  COLORTYPE_GRAYSCALE: 0,
-  COLOR_ALPHA: 4,
+  COLORTYPE_PALETTE: 1,
+  COLORTYPE_COLOR: 2,
+  COLORTYPE_ALPHA: 4, // e.g. grayscale and alpha
+
+  // color-type combinations
+  COLORTYPE_PALETTE_COLOR: 3,
+  COLORTYPE_COLOR_ALPHA: 6,
+
+  COLORTYPE_TO_BPP_MAP: {
+    0: 1,
+    2: 3,
+    3: 1,
+    4: 2,
+    6: 4
+  },
 
   GAMMA_DIVISION: 100000
 };

lib/packer.js

@@ -1,6 +1,5 @@
 'use strict';
 
-
 var util = require('util');
 var Stream = require('stream');
 var zlib = require('zlib');
@@ -8,20 +7,24 @@ var filter = require('./filter-pack');
 var CrcStream = require('./crc');
 var constants = require('./constants');
 
-var COLORTYPE_TRUECOLOR = 2;
-var COLORTYPE_TRUECOLOR_ALPHA = 6;
-
 var Packer = module.exports = function(options) {
   Stream.call(this);
 
   this._options = options;
 
   options.deflateChunkSize = options.deflateChunkSize || 32 * 1024;
-  options.deflateLevel = options.deflateLevel !== null ? options.deflateLevel : 9;
+  options.deflateLevel = options.deflateLevel != null ? options.deflateLevel : 9;
-  options.deflateStrategy = options.deflateStrategy !== null ? options.deflateStrategy : 3;
+  options.deflateStrategy = options.deflateStrategy != null ? options.deflateStrategy : 3;
   options.deflateFactory = options.deflateFactory || zlib.createDeflate;
   options.bitDepth = options.bitDepth || 8;
-  options.colorType = (typeof options.colorType === 'number') ? options.colorType : COLORTYPE_TRUECOLOR_ALPHA;
+  options.colorType = (typeof options.colorType === 'number') ? options.colorType : constants.COLORTYPE_COLOR_ALPHA;
+
+  if (options.colorType !== constants.COLORTYPE_COLOR && options.colorType !== constants.COLORTYPE_COLOR_ALPHA) {
+    throw new Error('option color type:' + options.colorType + ' is not supported at present');
+  }
+  if (options.bitDepth !== 8) {
+    throw new Error('option bit depth:' + options.bitDepth + ' is not supported at present');
+  }
 
   this.readable = true;
 };
@@ -38,10 +41,7 @@ Packer.prototype.pack = function(data, width, height, gamma) {
   }
 
   // filter pixel data
-  var bpp = 4;
+  var bpp = constants.COLORTYPE_TO_BPP_MAP[this._options.colorType];
-  if (this._options.colorType === COLORTYPE_TRUECOLOR) {
-    bpp = 3;
-  }
   var filteredData = filter(data, width, height, this._options, bpp);
 
   // compress it

lib/parser.js

@@ -36,14 +36,6 @@ var Parser = module.exports = function(options, dependencies) {
   this.finished = dependencies.finished;
 };
 
-var colorTypeToBppMap = {
-  0: 1,
-  2: 3,
-  3: 1,
-  4: 2,
-  6: 4
-};
-
 Parser.prototype.start = function() {
   this.read(constants.PNG_SIGNATURE.length,
     this._parseSignature.bind(this)
@@ -150,7 +142,7 @@ Parser.prototype._parseIHDR = function(data) {
     this.error(new Error('Unsupported bit depth ' + depth));
     return;
   }
-  if (!(colorType in colorTypeToBppMap)) {
+  if (!(colorType in constants.COLORTYPE_TO_BPP_MAP)) {
     this.error(new Error('Unsupported color type'));
     return;
   }
@@ -169,7 +161,7 @@ Parser.prototype._parseIHDR = function(data) {
 
   this._colorType = colorType;
 
-  var bpp = colorTypeToBppMap[this._colorType];
+  var bpp = constants.COLORTYPE_TO_BPP_MAP[this._colorType];
 
   this._hasIHDR = true;
 
@@ -178,9 +170,9 @@ Parser.prototype._parseIHDR = function(data) {
     height: height,
     depth: depth,
     interlace: Boolean(interlace),
-    palette: Boolean(colorType & constants.COLOR_PALETTE),
+    palette: Boolean(colorType & constants.COLORTYPE_PALETTE),
-    color: Boolean(colorType & constants.COLOR_COLOR),
+    color: Boolean(colorType & constants.COLORTYPE_COLOR),
-    alpha: Boolean(colorType & constants.COLOR_ALPHA),
+    alpha: Boolean(colorType & constants.COLORTYPE_ALPHA),
     bpp: bpp,
     colorType: colorType
   });
@@ -221,7 +213,7 @@ Parser.prototype._parseTRNS = function(data) {
   this._crc.write(data);
 
   // palette
-  if (this._colorType === 3) {
+  if (this._colorType === constants.COLORTYPE_PALETTE_COLOR) {
     if (this._palette.length === 0) {
       this.error(new Error('Transparency chunk must be after palette'));
       return;
@@ -238,11 +230,11 @@ Parser.prototype._parseTRNS = function(data) {
 
   // for colorType 0 (grayscale) and 2 (rgb)
   // there might be one gray/color defined as transparent
-  if (this._colorType === 0) {
+  if (this._colorType === constants.COLORTYPE_GRAYSCALE) {
     // grey, 2 bytes
     this.transColor([data.readUInt16BE(0)]);
   }
-  if (this._colorType === 2) {
+  if (this._colorType === constants.COLORTYPE_COLOR) {
     this.transColor([data.readUInt16BE(0), data.readUInt16BE(2), data.readUInt16BE(4)]);
   }
 
@@ -267,7 +259,7 @@ Parser.prototype._parseIDAT = function(length, data) {
 
   this._crc.write(data);
 
-  if (this._colorType === 3 && this._palette.length === 0) {
+  if (this._colorType === constants.COLORTYPE_PALETTE_COLOR && this._palette.length === 0) {
     throw new Error('Expected palette not found');
   }
 

test/png-parse-spec.js

@@ -55,6 +55,7 @@ test("should correctly parse an 1-bit colormap png", function (t) {
         if (getPixel(png, x, y) !== 0x000000FF) {
           t.fail("pixel does not match - " + getPixel(png, x, y) + " !== 0x000000FF");
           isOk = false;
+          break;
         }
     }
     t.ok(isOk, "The pixels should all be black");
@@ -82,6 +83,7 @@ test("should correctly parse an 8-bit grayscale png", function (t) {
         if (getPixel(png, x, y) !== (x ^ y) * 286331136 + 255) {
           t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + ((x ^ y) * 286331136 + 255));
           isOk = false;
+          break;
         }
       }
     }
@@ -110,6 +112,7 @@ test("should correctly parse an 8-bit truecolor png", function (t) {
         if (getPixel(png, x, y) !== x * 285212672 + y * 1114112 + (x ^ y) * 4352 + 255) {
           t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + (x * 285212672 + y * 1114112 + (x ^ y) * 4352 + 255));
           isOk = false;
+          break;
         }
       }
     }
@@ -138,12 +141,8 @@ test("should correctly parse an 8-bit truecolor png with alpha", function (t) {
         if (getPixel(png, x, y) !== x * 285212672 + y * 1114112 + (x ^ y) * 17) {
           t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + (x * 285212672 + y * 1114112 + (x ^ y) * 17));
           isOk = false;
+          break;
         }
-
-        t.equal(
-          getPixel(png, x, y),
-          x * 285212672 + y * 1114112 + (x ^ y) * 17
-        )
       }
     }
     t.ok(isOk, "The pixels should match");
@@ -205,6 +204,7 @@ test("should correctly read an indexed color image", function (t) {
         if (getPixel(png, x, y) !== expected) {
           t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + expected);
           isOk = false;
+          break;
         }
       }
     }
@@ -249,6 +249,7 @@ test("should correctly read an indexed color image with alpha", function (t) {
         if (getPixel(png, x, y) !== expected) {
           t.fail("pixel does not match - " + getPixel(png, x, y) + " !== " + expected);
           isOk = false;
+          break;
         }
       }
     }