2 * Copyright 2007 Google Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 package com.google.zxing.client.android;
19 import com.google.zxing.MonochromeBitmapSource;
20 import com.google.zxing.ReaderException;
21 import com.google.zxing.common.BitMatrix;
22 import com.google.zxing.qrcode.detector.AlignmentPattern;
23 import com.google.zxing.qrcode.detector.FinderPattern;
24 import com.google.zxing.qrcode.detector.GridSampler;
26 import android.graphics.Matrix;
29 * Implementation based on Android's
30 * {@link Matrix#setPolyToPoly(float[], int, float[], int, int)}
31 * class, which should offer faster performance for these matrix
34 * @author srowen@google.com (Sean Owen)
36 public final class AndroidGraphicsGridSampler extends GridSampler {
39 protected BitMatrix sampleGrid(MonochromeBitmapSource image,
40 FinderPattern topLeft,
41 FinderPattern topRight,
42 FinderPattern bottomLeft,
43 AlignmentPattern alignmentPattern,
44 int dimension) throws ReaderException {
45 float dimMinusThree = (float) dimension - 3.5f;
46 float bottomRightX, bottomRightY;
47 float sourceBottomRightX, sourceBottomRightY;
48 if (alignmentPattern != null) {
49 bottomRightX = alignmentPattern.getX();
50 bottomRightY = alignmentPattern.getY();
51 sourceBottomRightX = sourceBottomRightY = dimMinusThree - 3.0f;
53 // Don't have an alignment pattern, just make up the bottom-right point
54 bottomRightX = (topRight.getX() - topLeft.getX()) + bottomLeft.getX();
55 bottomRightY = (topRight.getY() - topLeft.getY()) + bottomLeft.getY();
56 sourceBottomRightX = sourceBottomRightY = dimMinusThree;
59 Matrix transformMatrix = new Matrix();
60 boolean succeeded = transformMatrix.setPolyToPoly(
86 throw new ReaderException("Could not establish transformation matrix");
89 BitMatrix bits = new BitMatrix(dimension);
90 float[] points = new float[dimension << 1];
91 for (int i = 0; i < dimension; i++) {
92 int max = points.length;
93 float iValue = (float) i + 0.5f;
94 for (int j = 0; j < max; j += 2) {
95 points[j] = (float) (j >> 1) + 0.5f;
96 points[j + 1] = iValue;
98 transformMatrix.mapPoints(points);
99 // Quick check to see if points transformed to something inside the image;
100 // sufficent to check the endpoints
101 checkEndpoint(image, points);
102 for (int j = 0; j < max; j += 2) {
103 if (image.isBlack((int) points[j], (int) points[j + 1])) {