3 var hasSyncZlib = true;
4 var zlib = require('zlib');
5 if (!zlib.deflateSync) {
8 var constants = require('./constants');
9 var Packer = require('./packer');
11 module.exports = function(metaData, opt) {
14 throw new Error('To use the sync capability of this library in old node versions, please pin pngjs to v2.3.0');
17 var options = opt || {};
19 var packer = new Packer(options);
24 chunks.push(new Buffer(constants.PNG_SIGNATURE));
27 chunks.push(packer.packIHDR(metaData.width, metaData.height));
30 chunks.push(packer.packGAMA(metaData.gamma));
33 var filteredData = packer.filterData(metaData.data, metaData.width, metaData.height);
36 var compressedData = zlib.deflateSync(filteredData, packer.getDeflateOptions());
39 if (!compressedData || !compressedData.length) {
40 throw new Error('bad png - invalid compressed data response');
42 chunks.push(packer.packIDAT(compressedData));
45 chunks.push(packer.packIEND());
47 return Buffer.concat(chunks);