初始化fy

uni_modules/UniDevTools/node_modules/pngjs/lib/packer.js

@@ -0,0 +1,107 @@
+'use strict';
+
+var constants = require('./constants');
+var CrcStream = require('./crc');
+var bitPacker = require('./bitpacker');
+var filter = require('./filter-pack');
+var zlib = require('zlib');
+
+var Packer = module.exports = function(options) {
+  this._options = options;
+
+  options.deflateChunkSize = options.deflateChunkSize || 32 * 1024;
+  options.deflateLevel = options.deflateLevel != null ? options.deflateLevel : 9;
+  options.deflateStrategy = options.deflateStrategy != null ? options.deflateStrategy : 3;
+  options.inputHasAlpha = options.inputHasAlpha != null ? options.inputHasAlpha : true;
+  options.deflateFactory = options.deflateFactory || zlib.createDeflate;
+  options.bitDepth = options.bitDepth || 8;
+  // This is outputColorType
+  options.colorType = (typeof options.colorType === 'number') ? options.colorType : constants.COLORTYPE_COLOR_ALPHA;
+  options.inputColorType = (typeof options.inputColorType === 'number') ? options.inputColorType : constants.COLORTYPE_COLOR_ALPHA;
+
+  if ([
+    constants.COLORTYPE_GRAYSCALE,
+    constants.COLORTYPE_COLOR,
+    constants.COLORTYPE_COLOR_ALPHA,
+    constants.COLORTYPE_ALPHA
+  ].indexOf(options.colorType) === -1) {
+    throw new Error('option color type:' + options.colorType + ' is not supported at present');
+  }
+  if ([
+    constants.COLORTYPE_GRAYSCALE,
+    constants.COLORTYPE_COLOR,
+    constants.COLORTYPE_COLOR_ALPHA,
+    constants.COLORTYPE_ALPHA
+  ].indexOf(options.inputColorType) === -1) {
+    throw new Error('option input color type:' + options.inputColorType + ' is not supported at present');
+  }
+  if (options.bitDepth !== 8 && options.bitDepth !== 16) {
+    throw new Error('option bit depth:' + options.bitDepth + ' is not supported at present');
+  }
+};
+
+Packer.prototype.getDeflateOptions = function() {
+  return {
+    chunkSize: this._options.deflateChunkSize,
+    level: this._options.deflateLevel,
+    strategy: this._options.deflateStrategy
+  };
+};
+
+Packer.prototype.createDeflate = function() {
+  return this._options.deflateFactory(this.getDeflateOptions());
+};
+
+Packer.prototype.filterData = function(data, width, height) {
+  // convert to correct format for filtering (e.g. right bpp and bit depth)
+  var packedData = bitPacker(data, width, height, this._options);
+
+  // filter pixel data
+  var bpp = constants.COLORTYPE_TO_BPP_MAP[this._options.colorType];
+  var filteredData = filter(packedData, width, height, this._options, bpp);
+  return filteredData;
+};
+
+Packer.prototype._packChunk = function(type, data) {
+
+  var len = (data ? data.length : 0);
+  var buf = new Buffer(len + 12);
+
+  buf.writeUInt32BE(len, 0);
+  buf.writeUInt32BE(type, 4);
+
+  if (data) {
+    data.copy(buf, 8);
+  }
+
+  buf.writeInt32BE(CrcStream.crc32(buf.slice(4, buf.length - 4)), buf.length - 4);
+  return buf;
+};
+
+Packer.prototype.packGAMA = function(gamma) {
+  var buf = new Buffer(4);
+  buf.writeUInt32BE(Math.floor(gamma * constants.GAMMA_DIVISION), 0);
+  return this._packChunk(constants.TYPE_gAMA, buf);
+};
+
+Packer.prototype.packIHDR = function(width, height) {
+
+  var buf = new Buffer(13);
+  buf.writeUInt32BE(width, 0);
+  buf.writeUInt32BE(height, 4);
+  buf[8] = this._options.bitDepth; // Bit depth
+  buf[9] = this._options.colorType; // colorType
+  buf[10] = 0; // compression
+  buf[11] = 0; // filter
+  buf[12] = 0; // interlace
+
+  return this._packChunk(constants.TYPE_IHDR, buf);
+};
+
+Packer.prototype.packIDAT = function(data) {
+  return this._packChunk(constants.TYPE_IDAT, data);
+};
+
+Packer.prototype.packIEND = function() {
+  return this._packChunk(constants.TYPE_IEND, null);
+};