49 lines
1.1 KiB
JavaScript
49 lines
1.1 KiB
JavaScript
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'use strict';
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var hasSyncZlib = true;
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var zlib = require('zlib');
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if (!zlib.deflateSync) {
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hasSyncZlib = false;
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}
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var constants = require('./constants');
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var Packer = require('./packer');
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module.exports = function(metaData, opt) {
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if (!hasSyncZlib) {
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throw new Error('To use the sync capability of this library in old node versions, please pin pngjs to v2.3.0');
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}
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var options = opt || {};
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var packer = new Packer(options);
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var chunks = [];
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// Signature
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chunks.push(new Buffer(constants.PNG_SIGNATURE));
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// Header
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chunks.push(packer.packIHDR(metaData.width, metaData.height));
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if (metaData.gamma) {
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chunks.push(packer.packGAMA(metaData.gamma));
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}
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var filteredData = packer.filterData(metaData.data, metaData.width, metaData.height);
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// compress it
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var compressedData = zlib.deflateSync(filteredData, packer.getDeflateOptions());
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filteredData = null;
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if (!compressedData || !compressedData.length) {
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throw new Error('bad png - invalid compressed data response');
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}
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chunks.push(packer.packIDAT(compressedData));
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// End
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chunks.push(packer.packIEND());
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return Buffer.concat(chunks);
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};
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