更新

TongjiUniApp/node_modules/qrcode-reader/src/grid.js

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+/*
+  Ported to JavaScript by Lazar Laszlo 2011
+
+  lazarsoft@gmail.com, www.lazarsoft.info
+
+*/
+
+/*
+*
+* Copyright 2007 ZXing authors
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*      http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+import BitMatrix from './bitmat';
+
+var GridSampler = {};
+
+GridSampler.checkAndNudgePoints = function(image,  points) {
+  var width = image.width;
+  var height = image.height;
+  // Check and nudge points from start until we see some that are OK:
+  var nudged = true;
+  for (var offset = 0; offset < points.length && nudged; offset += 2) {
+    var x = Math.floor(points[offset]);
+    var y = Math.floor(points[offset + 1]);
+    if (x < -1 || x > width || y < -1 || y > height) {
+      throw "Error.checkAndNudgePoints ";
+    }
+    nudged = false;
+    if (x == -1) {
+      points[offset] = 0.0;
+      nudged = true;
+    } else if (x == width) {
+      points[offset] = width - 1;
+      nudged = true;
+    }
+    if (y == -1) {
+      points[offset + 1] = 0.0;
+      nudged = true;
+    } else if (y == height) {
+      points[offset + 1] = height - 1;
+      nudged = true;
+    }
+  }
+  // Check and nudge points from end:
+  nudged = true;
+  for (var offset = points.length - 2; offset >= 0 && nudged; offset -= 2) {
+    var x = Math.floor(points[offset]);
+    var y = Math.floor(points[offset + 1]);
+    if (x < -1 || x > width || y < -1 || y > height) {
+      throw "Error.checkAndNudgePoints ";
+    }
+    nudged = false;
+    if (x == -1) {
+      points[offset] = 0.0;
+      nudged = true;
+    } else if (x == width) {
+      points[offset] = width - 1;
+      nudged = true;
+    }
+    if (y == -1) {
+      points[offset + 1] = 0.0;
+      nudged = true;
+    } else if (y == height) {
+      points[offset + 1] = height - 1;
+      nudged = true;
+    }
+  }
+};
+
+
+
+GridSampler.sampleGrid3 = function(image,  dimension,  transform) {
+  var bits = new BitMatrix(dimension);
+  var points = new Array(dimension << 1);
+  for (var y = 0; y < dimension; y++) {
+    var max = points.length;
+    var iValue =  y + 0.5;
+    for (var x = 0; x < max; x += 2) {
+      points[x] =  (x >> 1) + 0.5;
+      points[x + 1] = iValue;
+    }
+    transform.transformPoints1(points);
+    // Quick check to see if points transformed to something inside the image
+    // sufficient to check the endpoints
+    GridSampler.checkAndNudgePoints(image, points);
+    try {
+      for (var x = 0; x < max; x += 2) {
+        var bit = image.data[Math.floor(points[x]) + image.width * Math.floor(points[x + 1])];
+        if (bit)
+          bits.set_Renamed(x >> 1, y);
+      }
+    } catch (aioobe) {
+      // This feels wrong, but, sometimes if the finder patterns are misidentified, the resulting
+      // transform gets "twisted" such that it maps a straight line of points to a set of points
+      // whose endpoints are in bounds, but others are not. There is probably some mathematical
+      // way to detect this about the transformation that I don't know yet.
+      // This results in an ugly runtime exception despite our clever checks above -- can't have
+      // that. We could check each point's coordinates but that feels duplicative. We settle for
+      // catching and wrapping ArrayIndexOutOfBoundsException.
+      throw "Error.checkAndNudgePoints";
+    }
+  }
+  return bits;
+};
+
+export default GridSampler;