Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 | 1x 1x 1x 1x 1x 1x 353x 353x 353x 353x 353x 353x 353x 353x 353x 353x 353x 353x 1x 353x 1x 353x 1x 325x 325x 325x 325x 1x 1592x 1592x 1592x 1592x 1592x 1267x 1592x 1592x 1x 290x 290x 290x 1x 325x 325x 325x 325x 325x 325x 325x 325x 325x 1x 652x 1x 325x | "use strict";
let constants = require("./constants");
let CrcStream = require("./crc");
let bitPacker = require("./bitpacker");
let filter = require("./filter-pack");
let zlib = require("zlib");
let 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;
Iif (
[
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"
);
}
Iif (
[
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"
);
}
Iif (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)
let packedData = bitPacker(data, width, height, this._options);
// filter pixel data
let bpp = constants.COLORTYPE_TO_BPP_MAP[this._options.colorType];
let filteredData = filter(packedData, width, height, this._options, bpp);
return filteredData;
};
Packer.prototype._packChunk = function (type, data) {
let len = data ? data.length : 0;
let buf = Buffer.alloc(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) {
let buf = Buffer.alloc(4);
buf.writeUInt32BE(Math.floor(gamma * constants.GAMMA_DIVISION), 0);
return this._packChunk(constants.TYPE_gAMA, buf);
};
Packer.prototype.packIHDR = function (width, height) {
let buf = Buffer.alloc(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);
};
|