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.qrcode.detector;
19 import com.google.zxing.ResultPoint;
22 * <p>Encapsulates an alignment pattern, which are the smaller square patterns found in
23 * all but the simplest QR Codes.</p>
25 * @author srowen@google.com (Sean Owen)
27 public final class AlignmentPattern implements ResultPoint {
29 private final float posX;
30 private final float posY;
31 private final float estimatedModuleSize;
33 AlignmentPattern(float posX, float posY, float estimatedModuleSize) {
36 this.estimatedModuleSize = estimatedModuleSize;
47 float getEstimatedModuleSize() {
48 return estimatedModuleSize;
52 * <p>Determines if this alignment pattern "about equals" an alignment pattern at the stated
53 * position and size -- meaning, it is at nearly the same center with nearly the same size.</p>
55 boolean aboutEquals(float moduleSize, float i, float j) {
57 Math.abs(i - posY) <= moduleSize &&
58 Math.abs(j - posX) <= moduleSize &&
59 (Math.abs(moduleSize - estimatedModuleSize) <= 1.0f ||
60 Math.abs(moduleSize - estimatedModuleSize) / estimatedModuleSize <= 0.1f);