first commit

node_modules/pngjs/lib/format-normaliser.js

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+"use strict";
+
+function dePalette(indata, outdata, width, height, palette) {
+  let pxPos = 0;
+  // use values from palette
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      let color = palette[indata[pxPos]];
+
+      if (!color) {
+        throw new Error("index " + indata[pxPos] + " not in palette");
+      }
+
+      for (let i = 0; i < 4; i++) {
+        outdata[pxPos + i] = color[i];
+      }
+      pxPos += 4;
+    }
+  }
+}
+
+function replaceTransparentColor(indata, outdata, width, height, transColor) {
+  let pxPos = 0;
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      let makeTrans = false;
+
+      if (transColor.length === 1) {
+        if (transColor[0] === indata[pxPos]) {
+          makeTrans = true;
+        }
+      } else if (
+        transColor[0] === indata[pxPos] &&
+        transColor[1] === indata[pxPos + 1] &&
+        transColor[2] === indata[pxPos + 2]
+      ) {
+        makeTrans = true;
+      }
+      if (makeTrans) {
+        for (let i = 0; i < 4; i++) {
+          outdata[pxPos + i] = 0;
+        }
+      }
+      pxPos += 4;
+    }
+  }
+}
+
+function scaleDepth(indata, outdata, width, height, depth) {
+  let maxOutSample = 255;
+  let maxInSample = Math.pow(2, depth) - 1;
+  let pxPos = 0;
+
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      for (let i = 0; i < 4; i++) {
+        outdata[pxPos + i] = Math.floor(
+          (indata[pxPos + i] * maxOutSample) / maxInSample + 0.5
+        );
+      }
+      pxPos += 4;
+    }
+  }
+}
+
+module.exports = function (indata, imageData, skipRescale = false) {
+  let depth = imageData.depth;
+  let width = imageData.width;
+  let height = imageData.height;
+  let colorType = imageData.colorType;
+  let transColor = imageData.transColor;
+  let palette = imageData.palette;
+
+  let outdata = indata; // only different for 16 bits
+
+  if (colorType === 3) {
+    // paletted
+    dePalette(indata, outdata, width, height, palette);
+  } else {
+    if (transColor) {
+      replaceTransparentColor(indata, outdata, width, height, transColor);
+    }
+    // if it needs scaling
+    if (depth !== 8 && !skipRescale) {
+      // if we need to change the buffer size
+      if (depth === 16) {
+        outdata = Buffer.alloc(width * height * 4);
+      }
+      scaleDepth(indata, outdata, width, height, depth);
+    }
+  }
+  return outdata;
+};