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node_modules/pngjs/lib/bitmapper.js

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+"use strict";
+
+let interlaceUtils = require("./interlace");
+
+let pixelBppMapper = [
+  // 0 - dummy entry
+  function () {},
+
+  // 1 - L
+  // 0: 0, 1: 0, 2: 0, 3: 0xff
+  function (pxData, data, pxPos, rawPos) {
+    if (rawPos === data.length) {
+      throw new Error("Ran out of data");
+    }
+
+    let pixel = data[rawPos];
+    pxData[pxPos] = pixel;
+    pxData[pxPos + 1] = pixel;
+    pxData[pxPos + 2] = pixel;
+    pxData[pxPos + 3] = 0xff;
+  },
+
+  // 2 - LA
+  // 0: 0, 1: 0, 2: 0, 3: 1
+  function (pxData, data, pxPos, rawPos) {
+    if (rawPos + 1 >= data.length) {
+      throw new Error("Ran out of data");
+    }
+
+    let pixel = data[rawPos];
+    pxData[pxPos] = pixel;
+    pxData[pxPos + 1] = pixel;
+    pxData[pxPos + 2] = pixel;
+    pxData[pxPos + 3] = data[rawPos + 1];
+  },
+
+  // 3 - RGB
+  // 0: 0, 1: 1, 2: 2, 3: 0xff
+  function (pxData, data, pxPos, rawPos) {
+    if (rawPos + 2 >= data.length) {
+      throw new Error("Ran out of data");
+    }
+
+    pxData[pxPos] = data[rawPos];
+    pxData[pxPos + 1] = data[rawPos + 1];
+    pxData[pxPos + 2] = data[rawPos + 2];
+    pxData[pxPos + 3] = 0xff;
+  },
+
+  // 4 - RGBA
+  // 0: 0, 1: 1, 2: 2, 3: 3
+  function (pxData, data, pxPos, rawPos) {
+    if (rawPos + 3 >= data.length) {
+      throw new Error("Ran out of data");
+    }
+
+    pxData[pxPos] = data[rawPos];
+    pxData[pxPos + 1] = data[rawPos + 1];
+    pxData[pxPos + 2] = data[rawPos + 2];
+    pxData[pxPos + 3] = data[rawPos + 3];
+  },
+];
+
+let pixelBppCustomMapper = [
+  // 0 - dummy entry
+  function () {},
+
+  // 1 - L
+  // 0: 0, 1: 0, 2: 0, 3: 0xff
+  function (pxData, pixelData, pxPos, maxBit) {
+    let pixel = pixelData[0];
+    pxData[pxPos] = pixel;
+    pxData[pxPos + 1] = pixel;
+    pxData[pxPos + 2] = pixel;
+    pxData[pxPos + 3] = maxBit;
+  },
+
+  // 2 - LA
+  // 0: 0, 1: 0, 2: 0, 3: 1
+  function (pxData, pixelData, pxPos) {
+    let pixel = pixelData[0];
+    pxData[pxPos] = pixel;
+    pxData[pxPos + 1] = pixel;
+    pxData[pxPos + 2] = pixel;
+    pxData[pxPos + 3] = pixelData[1];
+  },
+
+  // 3 - RGB
+  // 0: 0, 1: 1, 2: 2, 3: 0xff
+  function (pxData, pixelData, pxPos, maxBit) {
+    pxData[pxPos] = pixelData[0];
+    pxData[pxPos + 1] = pixelData[1];
+    pxData[pxPos + 2] = pixelData[2];
+    pxData[pxPos + 3] = maxBit;
+  },
+
+  // 4 - RGBA
+  // 0: 0, 1: 1, 2: 2, 3: 3
+  function (pxData, pixelData, pxPos) {
+    pxData[pxPos] = pixelData[0];
+    pxData[pxPos + 1] = pixelData[1];
+    pxData[pxPos + 2] = pixelData[2];
+    pxData[pxPos + 3] = pixelData[3];
+  },
+];
+
+function bitRetriever(data, depth) {
+  let leftOver = [];
+  let i = 0;
+
+  function split() {
+    if (i === data.length) {
+      throw new Error("Ran out of data");
+    }
+    let byte = data[i];
+    i++;
+    let byte8, byte7, byte6, byte5, byte4, byte3, byte2, byte1;
+    switch (depth) {
+      default:
+        throw new Error("unrecognised depth");
+      case 16:
+        byte2 = data[i];
+        i++;
+        leftOver.push((byte << 8) + byte2);
+        break;
+      case 4:
+        byte2 = byte & 0x0f;
+        byte1 = byte >> 4;
+        leftOver.push(byte1, byte2);
+        break;
+      case 2:
+        byte4 = byte & 3;
+        byte3 = (byte >> 2) & 3;
+        byte2 = (byte >> 4) & 3;
+        byte1 = (byte >> 6) & 3;
+        leftOver.push(byte1, byte2, byte3, byte4);
+        break;
+      case 1:
+        byte8 = byte & 1;
+        byte7 = (byte >> 1) & 1;
+        byte6 = (byte >> 2) & 1;
+        byte5 = (byte >> 3) & 1;
+        byte4 = (byte >> 4) & 1;
+        byte3 = (byte >> 5) & 1;
+        byte2 = (byte >> 6) & 1;
+        byte1 = (byte >> 7) & 1;
+        leftOver.push(byte1, byte2, byte3, byte4, byte5, byte6, byte7, byte8);
+        break;
+    }
+  }
+
+  return {
+    get: function (count) {
+      while (leftOver.length < count) {
+        split();
+      }
+      let returner = leftOver.slice(0, count);
+      leftOver = leftOver.slice(count);
+      return returner;
+    },
+    resetAfterLine: function () {
+      leftOver.length = 0;
+    },
+    end: function () {
+      if (i !== data.length) {
+        throw new Error("extra data found");
+      }
+    },
+  };
+}
+
+function mapImage8Bit(image, pxData, getPxPos, bpp, data, rawPos) {
+  // eslint-disable-line max-params
+  let imageWidth = image.width;
+  let imageHeight = image.height;
+  let imagePass = image.index;
+  for (let y = 0; y < imageHeight; y++) {
+    for (let x = 0; x < imageWidth; x++) {
+      let pxPos = getPxPos(x, y, imagePass);
+      pixelBppMapper[bpp](pxData, data, pxPos, rawPos);
+      rawPos += bpp; //eslint-disable-line no-param-reassign
+    }
+  }
+  return rawPos;
+}
+
+function mapImageCustomBit(image, pxData, getPxPos, bpp, bits, maxBit) {
+  // eslint-disable-line max-params
+  let imageWidth = image.width;
+  let imageHeight = image.height;
+  let imagePass = image.index;
+  for (let y = 0; y < imageHeight; y++) {
+    for (let x = 0; x < imageWidth; x++) {
+      let pixelData = bits.get(bpp);
+      let pxPos = getPxPos(x, y, imagePass);
+      pixelBppCustomMapper[bpp](pxData, pixelData, pxPos, maxBit);
+    }
+    bits.resetAfterLine();
+  }
+}
+
+exports.dataToBitMap = function (data, bitmapInfo) {
+  let width = bitmapInfo.width;
+  let height = bitmapInfo.height;
+  let depth = bitmapInfo.depth;
+  let bpp = bitmapInfo.bpp;
+  let interlace = bitmapInfo.interlace;
+  let bits;
+
+  if (depth !== 8) {
+    bits = bitRetriever(data, depth);
+  }
+  let pxData;
+  if (depth <= 8) {
+    pxData = Buffer.alloc(width * height * 4);
+  } else {
+    pxData = new Uint16Array(width * height * 4);
+  }
+  let maxBit = Math.pow(2, depth) - 1;
+  let rawPos = 0;
+  let images;
+  let getPxPos;
+
+  if (interlace) {
+    images = interlaceUtils.getImagePasses(width, height);
+    getPxPos = interlaceUtils.getInterlaceIterator(width, height);
+  } else {
+    let nonInterlacedPxPos = 0;
+    getPxPos = function () {
+      let returner = nonInterlacedPxPos;
+      nonInterlacedPxPos += 4;
+      return returner;
+    };
+    images = [{ width: width, height: height }];
+  }
+
+  for (let imageIndex = 0; imageIndex < images.length; imageIndex++) {
+    if (depth === 8) {
+      rawPos = mapImage8Bit(
+        images[imageIndex],
+        pxData,
+        getPxPos,
+        bpp,
+        data,
+        rawPos
+      );
+    } else {
+      mapImageCustomBit(
+        images[imageIndex],
+        pxData,
+        getPxPos,
+        bpp,
+        bits,
+        maxBit
+      );
+    }
+  }
+  if (depth === 8) {
+    if (rawPos !== data.length) {
+      throw new Error("extra data found");
+    }
+  } else {
+    bits.end();
+  }
+
+  return pxData;
+};