import codeanticode.gsvideo.*;
GSCapture cam;
PFont font;
// on a mac uncomment this 
//import processing.video.*;
//Capture cam;

int videoSliceX;
int drawPositionX;
import java.util.ArrayList;

int current_set = 0;
StringBuffer result = new StringBuffer();
int checksum = 0;
int checksum_pos = 0;
int checksum_val = 0;

void setup() {
  size(720, 480);
  
  String[] parName = new String[1];
  String[] parValue = new String[1]; 
  parName[0] = "device";
  parValue[0] = "/dev/video1";
  cam = new GSCapture(this, 640, 480, "v4l2src", parName, parValue);
  
  // on a mac uncomment this  
  // cam = new Caputre( this, 640, 480);
  
  font = loadFont( "Verdana-48.vlw" );
  textFont( font, 48 );
}

String barcode = "";

void draw() {
  if ( cam.available()) {
    cam.read();
    background(255);

    // Display Camera image
    image( cam, 0, 0 );

    // display red line where we look for the barcode 
    stroke( 255, 0, 0);
    line( 0, height/2, width, height/2);
    stroke(0);
    // convert one line of the image to an rle encoded array of 
    // black and white pixel
    ArrayList data = convertData( cam );
    // find the first three bars from a start sequence
    int idx = find211( data );
    if ( idx > 0 ) {
      // check if we find a barcode 
      String res = parseCode( data, idx );
      if ( res != null ) {
         barcode = res;
      }
    }
  }

  fill( 0, 155, 0 );
  text( barcode, 30, 50 );
}

// convert pixels to black and white by checking if the 
// brighness of a given pixel is higher than the average of the surrounding
// 40 pixel (the actual values are the result of an hourlong tinkering 
// session - sorry, no rocketscience here)
ArrayList convertData( PImage img ) {
  int last = 0;
  int count = 0;
  ArrayList data = new ArrayList();
        
  for( int x = 0; x < img.width; x++ ) {
    int pos = (img.height/2)*img.width + x;
     
    float avg = 0;
    for ( int i = -20; i < 20; i ++ ) {
      avg += brightness( cam.pixels[pos + i] );
    }
    avg = avg / 40;
     
    float c = brightness( cam.pixels[pos] );
    int v = (c > avg * 0.96 ? 255 : 0 );
    count++;
    if (v != last) {
      data.add(count);
        
      count =0;
      last = v;
    }
  }
  return data;
}

// find the first three bars of a start sequence
int find211( ArrayList data ) {
  int idx = 0;
  while ( idx < data.size() - 2 ) {
    float f0 = float(((Integer)data.get(idx)).intValue());
    float f1 = float(((Integer)data.get(idx+1)).intValue());
    float f2 = float(((Integer)data.get(idx+2)).intValue());
    float w = (f0 + f1 + f2)/4;
    if ( f1/f2 > 0.9 && f1/f2 < 1.1  && f0/w > 1.8 && f0/w < 2.2 ) {      
      return idx;
    }
    idx++; 
  }
  return -1;
}

String parseCode(ArrayList data, int idx ) {
   while ( idx + 7 < data.size() ) {
     float[] block = new float[6];
     for (int i = 0; i<6; i++ ) {
       block[i] = float( ((Integer)data.get( idx + i )).intValue());
     }   

     // search for the character that matches best   
     float best = 0;
     int best_idx = 0;
     for ( int i = 0; i < target.length; i++ ) {
       float bm = blockMatch( target[i], block );
       if ( bm > best ) {
         best = bm;
         best_idx = i;
       }
     }
     if ( best > 0.1 ) {
       String val = "";
       if (current_set == 0 ) {
         val = res_a[best_idx];
       } else if ( current_set == 1 ) {
         val = res_b[best_idx];
       } else if ( current_set == 2 ) {
         val = res_c[best_idx];
       }
     
       if ("Start_A".equals( val ) || "CODE_A".equals( val )) {
         current_set = 0;
       } 
       if ("Start_B".equals( val ) || "CODE_B".equals( val )) {
         current_set = 1;
       } 
       if ("Start_C".equals( val ) || "CODE_C".equals( val )) {
         current_set = 2;
       } 
     
       if (val.startsWith( "Start" )) {
         result = new StringBuffer();
         checksum = best_idx;
         checksum_pos = 0;
       } else if ( val.equals( "Stop" )) {   
         if ( checksum_val == (checksum - checksum_pos * checksum_val ) % 103 ) {
           String cv = "";
           if (current_set == 0 ) {
             cv = res_a[checksum_val];
           } else if ( current_set == 1 ) {
             cv = res_b[checksum_val];
           } else if ( current_set == 2 ) {
             cv = res_c[checksum_val];
           }
           return result.toString().substring( 0, result.toString().length() - cv.length());
         }
       } else {
         result.append( val );
         checksum_val = best_idx;
         checksum_pos++;
         checksum += best_idx * checksum_pos;
       }
     }
 
     idx += 6; 
   }   
   return null;
}

// return the matching value between the two arrays
// the second array is normalized and compared to the
// first one
float blockMatch( float[] m, float[] b ) {
  boolean res = true;
  float sum = 0;
  for(int i=0; i < 6; i++) {
    sum += b[i];
  }
  float ma = 1;
  for(int i=0; i < 6; i++) {
    float err = m[i] - b[i] / ( sum / 11 );
    ma -= err*err;
  } 
  return ma;
}

float[][] target = new float[][]{
  new float[]{2,1,2,2,2,2},
  new float[]{2,2,2,1,2,2},
  new float[]{2,2,2,2,2,1},
  new float[]{1,2,1,2,2,3},
  new float[]{1,2,1,3,2,2},
  new float[]{1,3,1,2,2,2},
  new float[]{1,2,2,2,1,3},
  new float[]{1,2,2,3,1,2},
  new float[]{1,3,2,2,1,2},
  new float[]{2,2,1,2,1,3},
  new float[]{2,2,1,3,1,2},
  new float[]{2,3,1,2,1,2},
  new float[]{1,1,2,2,3,2},
  new float[]{1,2,2,1,3,2},
  new float[]{1,2,2,2,3,1},
  new float[]{1,1,3,2,2,2},
  new float[]{1,2,3,1,2,2},
  new float[]{1,2,3,2,2,1},
  new float[]{2,2,3,2,1,1},
  new float[]{2,2,1,1,3,2},
  new float[]{2,2,1,2,3,1},
  new float[]{2,1,3,2,1,2},
  new float[]{2,2,3,1,1,2},
  new float[]{3,1,2,1,3,1},
  new float[]{3,1,1,2,2,2},
  new float[]{3,2,1,1,2,2},
  new float[]{3,2,1,2,2,1},
  new float[]{3,1,2,2,1,2},
  new float[]{3,2,2,1,1,2},
  new float[]{3,2,2,2,1,1},
  new float[]{2,1,2,1,2,3},
  new float[]{2,1,2,3,2,1},
  new float[]{2,3,2,1,2,1},
  new float[]{1,1,1,3,2,3},
  new float[]{1,3,1,1,2,3},
  new float[]{1,3,1,3,2,1},
  new float[]{1,1,2,3,1,3},
  new float[]{1,3,2,1,1,3},
  new float[]{1,3,2,3,1,1},
  new float[]{2,1,1,3,1,3},
  new float[]{2,3,1,1,1,3},
  new float[]{2,3,1,3,1,1},
  new float[]{1,1,2,1,3,3},
  new float[]{1,1,2,3,3,1},
  new float[]{1,3,2,1,3,1},
  new float[]{1,1,3,1,2,3},
  new float[]{1,1,3,3,2,1},
  new float[]{1,3,3,1,2,1},
  new float[]{3,1,3,1,2,1},
  new float[]{2,1,1,3,3,1},
  new float[]{2,3,1,1,3,1},
  new float[]{2,1,3,1,1,3},
  new float[]{2,1,3,3,1,1},
  new float[]{2,1,3,1,3,1},
  new float[]{3,1,1,1,2,3},
  new float[]{3,1,1,3,2,1},
  new float[]{3,3,1,1,2,1},
  new float[]{3,1,2,1,1,3},
  new float[]{3,1,2,3,1,1},
  new float[]{3,3,2,1,1,1},
  new float[]{3,1,4,1,1,1},
  new float[]{2,2,1,4,1,1},
  new float[]{4,3,1,1,1,1},
  new float[]{1,1,1,2,2,4},
  new float[]{1,1,1,4,2,2},
  new float[]{1,2,1,1,2,4},
  new float[]{1,2,1,4,2,1},
  new float[]{1,4,1,1,2,2},
  new float[]{1,4,1,2,2,1},
  new float[]{1,1,2,2,1,4},
  new float[]{1,1,2,4,1,2},
  new float[]{1,2,2,1,1,4},
  new float[]{1,2,2,4,1,1},
  new float[]{1,4,2,1,1,2},
  new float[]{1,4,2,2,1,1},
  new float[]{2,4,1,2,1,1},
  new float[]{2,2,1,1,1,4},
  new float[]{4,1,3,1,1,1},
  new float[]{2,4,1,1,1,2},
  new float[]{1,3,4,1,1,1},
  new float[]{1,1,1,2,4,2},
  new float[]{1,2,1,1,4,2},
  new float[]{1,2,1,2,4,1},
  new float[]{1,1,4,2,1,2},
  new float[]{1,2,4,1,1,2},
  new float[]{1,2,4,2,1,1},
  new float[]{4,1,1,2,1,2},
  new float[]{4,2,1,1,1,2},
  new float[]{4,2,1,2,1,1},
  new float[]{2,1,2,1,4,1},
  new float[]{2,1,4,1,2,1},
  new float[]{4,1,2,1,2,1},
  new float[]{1,1,1,1,4,3},
  new float[]{1,1,1,3,4,1},
  new float[]{1,3,1,1,4,1},
  new float[]{1,1,4,1,1,3},
  new float[]{1,1,4,3,1,1},
  new float[]{4,1,1,1,1,3},
  new float[]{4,1,1,3,1,1},
  new float[]{1,1,3,1,4,1},
  new float[]{1,1,4,1,3,1},
  new float[]{3,1,1,1,4,1},
  new float[]{4,1,1,1,3,1},
  new float[]{2,1,1,4,1,2},
  new float[]{2,1,1,2,1,4},
  new float[]{2,1,1,2,3,2},
//  new float[]{2,3,3,1,1,1,2}, 
  new float[]{2,3,3,1,1,1}, 
  // This is a hack. the stop sequence is the onlyone
  // that has 7 bars but we check only for the first 6 
  // to make all arrays the same length

};

String[] res_a = new String[]{
  " ", 
  "!", 
  "\"", 
  "#", 
  "$", 
  "%", 
  "&", 
  "'", 
  "(", 
  ")", 
  "*", 
  "+", 
  ",", 
  "-", 
  ".", 
  "/", 
  "0", 
  "1", 
  "2", 
  "3", 
  "4", 
  "5", 
  "6", 
  "7", 
  "8", 
  "9", 
  ":", 
  ";", 
  "<", 
  "=", 
  ">", 
  "?", 
  "@", 
  "A", 
  "B", 
  "C", 
  "D", 
  "E", 
  "F", 
  "G", 
  "H", 
  "I", 
  "J", 
  "K", 
  "L", 
  "M", 
  "N", 
  "O", 
  "P", 
  "Q", 
  "R", 
  "S", 
  "T", 
  "U", 
  "V", 
  "W", 
  "X", 
  "Y", 
  "Z", 
  "[", 
  "\\", 
  "]", 
  "^", 
  "_", 
  "NUL", 
  "SOH", 
  "STX", 
  "ETX", 
  "EOT", 
  "ENQ", 
  "ACK", 
  "BEL", 
  "BS", 
  "HT", 
  "LF", 
  "VT", 
  "FF", 
  "CR", 
  "SO", 
  "SI", 
  "DLE", 
  "DC1", 
  "DC2", 
  "DC3", 
  "DC4", 
  "NAK", 
  "SYN", 
  "ETB", 
  "CAN", 
  "EM", 
  "SUB", 
  "ESC", 
  "FS", 
  "GS", 
  "RS", 
  "US", 
  "FNC_3", 
  "FNC_2", 
  "SHIFT", 
  "CODE_C", 
  "CODE_B", 
  "FNC 4", 
  "FNC_1", 
  "Start_A", 
  "Start_B", 
  "Start_C", 
  "Stop", 
};


String[] res_b = new String[]{
  " ", 
  "!", 
  "\"", 
  "#", 
  "$", 
  "%", 
  "&", 
  "'", 
  "(", 
  ")", 
  "*", 
  "+", 
  ",", 
  "-", 
  ".", 
  "/", 
  "0", 
  "1", 
  "2", 
  "3", 
  "4", 
  "5", 
  "6", 
  "7", 
  "8", 
  "9", 
  ":", 
  ";", 
  "<", 
  "=", 
  ">", 
  "?", 
  "@", 
  "A", 
  "B", 
  "C", 
  "D", 
  "E", 
  "F", 
  "G", 
  "H", 
  "I", 
  "J", 
  "K", 
  "L", 
  "M", 
  "N", 
  "O", 
  "P", 
  "Q", 
  "R", 
  "S", 
  "T", 
  "U", 
  "V", 
  "W", 
  "X", 
  "Y", 
  "Z", 
  "[", 
  "\\", 
  "]", 
  "^", 
  "_", 
  "`", 
  "a", 
  "b", 
  "c", 
  "d", 
  "e", 
  "f", 
  "g", 
  "h", 
  "i", 
  "j", 
  "k", 
  "I", 
  "m", 
  "n", 
  "o", 
  "p", 
  "q", 
  "r", 
  "s", 
  "t", 
  "u", 
  "v", 
  "w", 
  "x", 
  "y", 
  "z", 
  "{", 
  "|", 
  "}", 
  "~", 
  "DEL", 
  "FNC_3", 
  "FNC_2", 
  "SHIFT", 
  "CODE_C", 
  "FNC_4", 
  "CODE_A", 
  "FNC_1", 
  "Start_A", 
  "Start_B", 
  "Start_C", 
  "Stop", 
};

String[] res_c = new String[]{
  "00", 
  "01", 
  "02", 
  "03", 
  "04", 
  "05", 
  "06", 
  "07", 
  "08", 
  "09", 
  "10", 
  "11", 
  "12", 
  "13", 
  "14", 
  "15", 
  "16", 
  "17", 
  "18", 
  "19", 
  "20", 
  "21", 
  "22", 
  "23", 
  "24", 
  "25", 
  "26", 
  "27", 
  "28", 
  "29", 
  "30", 
  "31", 
  "32", 
  "33", 
  "34", 
  "35", 
  "36", 
  "37", 
  "38", 
  "39", 
  "40", 
  "41", 
  "42", 
  "43", 
  "44", 
  "45", 
  "46", 
  "47", 
  "48", 
  "49", 
  "50", 
  "51", 
  "52", 
  "53", 
  "54", 
  "55", 
  "56", 
  "57", 
  "58", 
  "59", 
  "60", 
  "61", 
  "62", 
  "63", 
  "64", 
  "65", 
  "66", 
  "67", 
  "68", 
  "69", 
  "70", 
  "71", 
  "72", 
  "73", 
  "74", 
  "75", 
  "76", 
  "77", 
  "78", 
  "79", 
  "80", 
  "81", 
  "82", 
  "83", 
  "84", 
  "85", 
  "86", 
  "87", 
  "88", 
  "89", 
  "90", 
  "91", 
  "92", 
  "93", 
  "94", 
  "95", 
  "96", 
  "97", 
  "98", 
  "99", 
  "CODE_B", 
  "CODE_A", 
  "FNC_1", 
  "Start_A", 
  "Start_B", 
  "Start_C", 
  "Stop", 
};