csharp/ResultPoint.cs

   1 /*\r
   2 * Copyright 2007 ZXing authors\r
   3 *\r
   4 * Licensed under the Apache License, Version 2.0 (the "License");\r
   5 * you may not use this file except in compliance with the License.\r
   6 * You may obtain a copy of the License at\r
   7 *\r
   8 *      http://www.apache.org/licenses/LICENSE-2.0\r
   9 *\r
  10 * Unless required by applicable law or agreed to in writing, software\r
  11 * distributed under the License is distributed on an "AS IS" BASIS,\r
  12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\r
  13 * See the License for the specific language governing permissions and\r
  14 * limitations under the License.\r
  15 */\r
  16 using System;\r
  17 namespace com.google.zxing\r
  18 {\r
  19         \r
  20         /// <summary> <p>Encapsulates a point of interest in an image containing a barcode. Typically, this\r
  21         /// would be the location of a finder pattern or the corner of the barcode, for example.</p>\r
  22         /// \r
  23         /// </summary>\r
  24         /// <author>  Sean Owen\r
  25         /// </author>\r
  26         /// <author>www.Redivivus.in (suraj.supekar@redivivus.in) - Ported from ZXING Java Source \r
  27         /// </author>\r
  28 \r
  29         public class ResultPoint\r
  30         {\r
  31                 virtual public float X\r
  32                 {\r
  33                         get\r
  34                         {\r
  35                                 return x;\r
  36                         }\r
  37                         \r
  38                 }\r
  39                 virtual public float Y\r
  40                 {\r
  41                         get\r
  42                         {\r
  43                                 return y;\r
  44                         }\r
  45                         \r
  46                 }\r
  47                 \r
  48                 //UPGRADE_NOTE: Final was removed from the declaration of 'x '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
  49                 private float x;\r
  50                 //UPGRADE_NOTE: Final was removed from the declaration of 'y '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"\r
  51                 private float y;\r
  52                 \r
  53                 public ResultPoint(float x, float y)\r
  54                 {\r
  55                         this.x = x;\r
  56                         this.y = y;\r
  57                 }\r
  58                 \r
  59                 public  override bool Equals(System.Object other)\r
  60                 {\r
  61                         if (other is ResultPoint)\r
  62                         {\r
  63                                 ResultPoint otherPoint = (ResultPoint) other;\r
  64                                 return x == otherPoint.x && y == otherPoint.y;\r
  65                         }\r
  66                         return false;\r
  67                 }\r
  68                 \r
  69                 public override int GetHashCode()\r
  70                 {\r
  71             // Redivivus.in Java to c# Porting update\r
  72             // 30/01/2010 \r
  73             // Commented function body\r
  74 \r
  75                         //return 31 * Float.floatToIntBits(x) + Float.floatToIntBits(y);\r
  76             return 0;\r
  77                 }\r
  78                 \r
  79                 public override System.String ToString()\r
  80                 {\r
  81                         System.Text.StringBuilder result = new System.Text.StringBuilder(25);\r
  82                         result.Append('(');\r
  83                         result.Append(x);\r
  84                         result.Append(',');\r
  85                         result.Append(y);\r
  86                         result.Append(')');\r
  87                         return result.ToString();\r
  88                 }\r
  89                 \r
  90                 /// <summary> <p>Orders an array of three ResultPoints in an order [A,B,C] such that AB < AC and\r
  91                 /// BC < AC and the angle between BC and BA is less than 180 degrees.\r
  92                 /// </summary>\r
  93                 public static void  orderBestPatterns(ResultPoint[] patterns)\r
  94                 {\r
  95                         \r
  96                         // Find distances between pattern centers\r
  97                         float zeroOneDistance = distance(patterns[0], patterns[1]);\r
  98                         float oneTwoDistance = distance(patterns[1], patterns[2]);\r
  99                         float zeroTwoDistance = distance(patterns[0], patterns[2]);\r
 100                         \r
 101                         ResultPoint pointA, pointB, pointC;\r
 102                         // Assume one closest to other two is B; A and C will just be guesses at first\r
 103                         if (oneTwoDistance >= zeroOneDistance && oneTwoDistance >= zeroTwoDistance)\r
 104                         {\r
 105                                 pointB = patterns[0];\r
 106                                 pointA = patterns[1];\r
 107                                 pointC = patterns[2];\r
 108                         }\r
 109                         else if (zeroTwoDistance >= oneTwoDistance && zeroTwoDistance >= zeroOneDistance)\r
 110                         {\r
 111                                 pointB = patterns[1];\r
 112                                 pointA = patterns[0];\r
 113                                 pointC = patterns[2];\r
 114                         }\r
 115                         else\r
 116                         {\r
 117                                 pointB = patterns[2];\r
 118                                 pointA = patterns[0];\r
 119                                 pointC = patterns[1];\r
 120                         }\r
 121                         \r
 122                         // Use cross product to figure out whether A and C are correct or flipped.\r
 123                         // This asks whether BC x BA has a positive z component, which is the arrangement\r
 124                         // we want for A, B, C. If it's negative, then we've got it flipped around and\r
 125                         // should swap A and C.\r
 126                         if (crossProductZ(pointA, pointB, pointC) < 0.0f)\r
 127                         {\r
 128                                 ResultPoint temp = pointA;\r
 129                                 pointA = pointC;\r
 130                                 pointC = temp;\r
 131                         }\r
 132                         \r
 133                         patterns[0] = pointA;\r
 134                         patterns[1] = pointB;\r
 135                         patterns[2] = pointC;\r
 136                 }\r
 137                 \r
 138                 \r
 139                 /// <returns> distance between two points\r
 140                 /// </returns>\r
 141                 public static float distance(ResultPoint pattern1, ResultPoint pattern2)\r
 142                 {\r
 143                         float xDiff = pattern1.X - pattern2.X;\r
 144                         float yDiff = pattern1.Y - pattern2.Y;\r
 145                         //UPGRADE_WARNING: Data types in Visual C# might be different.  Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"\r
 146                         return (float) System.Math.Sqrt((double) (xDiff * xDiff + yDiff * yDiff));\r
 147                 }\r
 148                 \r
 149                 /// <summary> Returns the z component of the cross product between vectors BC and BA.</summary>\r
 150                 private static float crossProductZ(ResultPoint pointA, ResultPoint pointB, ResultPoint pointC)\r
 151                 {\r
 152                         float bX = pointB.x;\r
 153                         float bY = pointB.y;\r
 154                         return ((pointC.x - bX) * (pointA.y - bY)) - ((pointC.y - bY) * (pointA.x - bX));\r
 155                 }\r
 156         }\r
 157 }