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/* |
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* write-bytes: Functions to turn data into bytes. |
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* Copyright (c) 2017 Rafael da Silva Rocha. |
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* https://github.com/rochars/byte-data |
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*/ |
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const floats = require("../src/floats.js"); |
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const intBits = require("int-bits"); |
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const BitWriter = { |
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// https://github.com/majimboo/c-struct |
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"write48Bit": function (bytes, number, j) { |
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bytes[j++] = number & 0xFF; |
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bytes[j++] = number >> 8 & 0xFF; |
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bytes[j++] = number >> 16 & 0xFF; |
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bytes[j++] = number >> 24 & 0xFF; |
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bytes[j++] = number / 0x100000000 & 0xFF; |
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bytes[j++] = number / 0x10000000000 & 0xFF; |
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return j; |
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}, |
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// https://github.com/majimboo/c-struct |
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"write40Bit": function (bytes, number, j) { |
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bytes[j++] = number & 0xFF; |
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bytes[j++] = number >> 8 & 0xFF; |
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bytes[j++] = number >> 16 & 0xFF; |
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bytes[j++] = number >> 24 & 0xFF; |
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bytes[j++] = number / 0x100000000 & 0xFF; |
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return j; |
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}, |
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"write32BitFloat": function (bytes, number, j) { |
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let bits = intBits.unpack(number); |
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bytes[j++] = bits & 0xFF; |
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bytes[j++] = bits >>> 8 & 0xFF; |
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bytes[j++] = bits >>> 16 & 0xFF; |
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bytes[j++] = bits >>> 24 & 0xFF; |
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return j; |
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}, |
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"write32Bit": function (bytes, number, j) { |
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bytes[j++] = number & 0xFF; |
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bytes[j++] = number >>> 8 & 0xFF; |
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bytes[j++] = number >>> 16 & 0xFF; |
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bytes[j++] = number >>> 24 & 0xFF; |
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return j; |
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}, |
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"write24Bit": function (bytes, number, j) { |
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bytes[j++] = number & 0xFF; |
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bytes[j++] = number >>> 8 & 0xFF; |
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bytes[j++] = number >>> 16 & 0xFF; |
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return j; |
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}, |
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"write16Bit": function (bytes, number, j) { |
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bytes[j++] = number & 0xFF; |
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bytes[j++] = number >>> 8 & 0xFF; |
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return j; |
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}, |
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"write16BitFloat": function (bytes, number, j) { |
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let bits = floats.toHalf(number); |
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bytes[j++] = bits >>> 8 & 0xFF; |
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bytes[j++] = bits & 0xFF; |
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return j; |
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}, |
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"write8Bit": function (bytes, number, j) { |
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bytes[j++] = number & 0xFF; |
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return j; |
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}, |
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"write4Bit": function (bytes, number, j) { |
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bytes[j++] = number & 0xF; |
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return j; |
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}, |
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"write2Bit": function (bytes, number, j) { |
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bytes[j++] = number < 0 ? number + 4 : number; |
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return j; |
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}, |
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"write1Bit": function (bytes, number, j) { |
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bytes[j++] = number ? 1 : 0; |
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return j; |
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}, |
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"writeString": function (bytes, string, j) { |
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bytes[j++] = string.charCodeAt(0); |
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return j; |
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}, |
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"write64BitFloat": function(bytes, number, j) { |
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let bits = floats.toFloat64(number); |
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j = BitWriter["write32Bit"](bytes, bits[1], j); |
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return BitWriter["write32Bit"](bytes, bits[0], j); |
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}, |
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}; |
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module.exports = BitWriter; |
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rochars /
byte-data
