Add native camera support

[~andy/freeotp] / src / com / google / zxing / ResultPoint.java

diff --git a/src/com/google/zxing/ResultPoint.java b/src/com/google/zxing/ResultPoint.java
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+++ b/src/com/google/zxing/ResultPoint.java
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+/*
+ * 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.
+ */
+
+package com.google.zxing;
+
+import com.google.zxing.common.detector.MathUtils;
+
+/**
+ * <p>Encapsulates a point of interest in an image containing a barcode. Typically, this
+ * would be the location of a finder pattern or the corner of the barcode, for example.</p>
+ *
+ * @author Sean Owen
+ */
+public class ResultPoint {
+
+  private final float x;
+  private final float y;
+
+  public ResultPoint(float x, float y) {
+    this.x = x;
+    this.y = y;
+  }
+
+  public final float getX() {
+    return x;
+  }
+
+  public final float getY() {
+    return y;
+  }
+
+  @Override
+  public final boolean equals(Object other) {
+    if (other instanceof ResultPoint) {
+      ResultPoint otherPoint = (ResultPoint) other;
+      return x == otherPoint.x && y == otherPoint.y;
+    }
+    return false;
+  }
+
+  @Override
+  public final int hashCode() {
+    return 31 * Float.floatToIntBits(x) + Float.floatToIntBits(y);
+  }
+
+  @Override
+  public final String toString() {
+    StringBuilder result = new StringBuilder(25);
+    result.append('(');
+    result.append(x);
+    result.append(',');
+    result.append(y);
+    result.append(')');
+    return result.toString();
+  }
+
+  /**
+   * <p>Orders an array of three ResultPoints in an order [A,B,C] such that AB < AC and
+   * BC < AC and the angle between BC and BA is less than 180 degrees.
+   */
+  public static void orderBestPatterns(ResultPoint[] patterns) {
+
+    // Find distances between pattern centers
+    float zeroOneDistance = distance(patterns[0], patterns[1]);
+    float oneTwoDistance = distance(patterns[1], patterns[2]);
+    float zeroTwoDistance = distance(patterns[0], patterns[2]);
+
+    ResultPoint pointA;
+    ResultPoint pointB;
+    ResultPoint pointC;
+    // Assume one closest to other two is B; A and C will just be guesses at first
+    if (oneTwoDistance >= zeroOneDistance && oneTwoDistance >= zeroTwoDistance) {
+      pointB = patterns[0];
+      pointA = patterns[1];
+      pointC = patterns[2];
+    } else if (zeroTwoDistance >= oneTwoDistance && zeroTwoDistance >= zeroOneDistance) {
+      pointB = patterns[1];
+      pointA = patterns[0];
+      pointC = patterns[2];
+    } else {
+      pointB = patterns[2];
+      pointA = patterns[0];
+      pointC = patterns[1];
+    }
+
+    // Use cross product to figure out whether A and C are correct or flipped.
+    // This asks whether BC x BA has a positive z component, which is the arrangement
+    // we want for A, B, C. If it's negative, then we've got it flipped around and
+    // should swap A and C.
+    if (crossProductZ(pointA, pointB, pointC) < 0.0f) {
+      ResultPoint temp = pointA;
+      pointA = pointC;
+      pointC = temp;
+    }
+
+    patterns[0] = pointA;
+    patterns[1] = pointB;
+    patterns[2] = pointC;
+  }
+
+
+  /**
+   * @return distance between two points
+   */
+  public static float distance(ResultPoint pattern1, ResultPoint pattern2) {
+    return MathUtils.distance(pattern1.x, pattern1.y, pattern2.x, pattern2.y);
+  }
+
+  /**
+   * Returns the z component of the cross product between vectors BC and BA.
+   */
+  private static float crossProductZ(ResultPoint pointA,
+                                     ResultPoint pointB,
+                                     ResultPoint pointC) {
+    float bX = pointB.x;
+    float bY = pointB.y;
+    return ((pointC.x - bX) * (pointA.y - bY)) - ((pointC.y - bY) * (pointA.x - bX));
+  }
+
+
+}