/** Alternative Relativity: Doppler Effect Demonstrator 
    by Robert John Morton (Belo Horizonte-MG 27 September 2006, 02 May 2012) */

// WAVE INSTANCE GENERATOR

import java.awt.*;  //f or graphics operations (GUI)

class wave {  // THIS CLASS CREATES AND MANAGES THE LIFE CYCLE OF ONE WAVE

  private static boolean 
    dm = false;  // false = classical mode, true = alternative mode

  private static int
    RMAX = 500,  // allow for maximum extent of fading waves

    /* 64 x-plots and y-plots respectively for the 
       circular quadrant for each of 400 radii. */
    CX[][] = new int[RMAX][64], 
    CY[][] = new int[RMAX][64], 

    Ymax = 95;  // extremity hight limit of the display area

  private static double

    // one 256th part of a circle as fraction of a radian
    Angle = 0.024933275028490422527481296692694;

  private static Color

    // colour value for each 64th of a quadrant at each of 400 radii
    CB[][] = new Color[RMAX][64],

    // intensities for the blue/green and the red/green hemispheres
    CR[][] = new Color[RMAX][64],

    // radial intensity levels for the pure green circles
    CG[]   = new Color[RMAX];

  private int
    r = 3,   // current radius of the wave circle
    X = 0,   // x-coord of start of display area
    Y = 95,  // y-coord of centre of display area
    ox = 0,  // old value of the x-coordinate
    oy = 0;  // old value of the y-coordinate

  private boolean 
    mh = false,  // true = signal to spawn the following wave
    pa = false,  // true means wave has reached its extremity 
    nl = false;  // false means new wave not yet launched from this instance

  private String RT = "CGPI/DIREX/DPF-V429810-2CPF01681522667"; //colour fader


  wave(int x){X = x;}  // set the horizontal starting position for the wave


  // these methods allow applet to access this class's flags
  boolean getmh(){return mh;}

  // returns true if wave has reached its final extremity
  boolean getah(){return pa;}

  // returns true if new succeeding wave has already been launched
  boolean getnl(){return nl;}

  // allows applet to set "new launch expedited" flag herein
  void setnl() { nl = true; }


  void atualizar(Graphics h) {
    if(r > 30) mh = true;  // signal to spawn the following wave object
    if(r > 400)            // maximum radius of an active wave
      pa = true;           // signal to kill this wave
    else {                 // else
      if(r > 10) 
        wipeWave(h,r-8);   // erase the fifth previous circle
      if(dm)
        drawGreen(h,r++);  // plot the next green circle
      else 
        drawWave(h,r++);   // plot the next multi-coloured circle
    }
  }


  /* The 3 following drawing methods are written separately 
  to maximize processing speed in their central loops. */

  void drawWave(Graphics h, int r) {
    ox = r; oy = 0;  // old values of the x,y coordinates

    // for each of 64 angular increments in a quadrant
    for(int i = 0; i < 64; i++) {
      int ny = CY[r][i];  // y-coordinate of the next primary plot

      // force top and bottom vertical limits on the y-coordinate
      if(ny > Ymax && oy <= Ymax) ny = Ymax;
      if(oy > Ymax && ny <= Ymax) oy = Ymax;

      int nx = CX[r][i],  // x-coordinate of the next primary plot

          // For the forward and rear semicircles, compute the
          nX = X + nx, Xn = X - nx,  // new x-coordinates
          oX = X + ox, Xo = X - ox,  // old x-coordinates
          nY = Y + ny, Yn = Y - ny,  // new y-coordinates
          oY = Y + oy, Yo = Y - oy;  // old y-coordinates

       // set phased and faded colour for the blue/green quadrants
       h.setColor( CB[r][i] );

       h.drawLine(oX,oY,nX,nY);  // draw line in first blue/green quadrant
       h.drawLine(oX,Yo,nX,Yn);  // draw line in second blue/green quadrant

       // set phased and faded colour for the red/green quadrants
       h.setColor( CR[r][i] );

       h.drawLine(Xo,oY,Xn,nY);  // draw line in first red/green quadrant
       h.drawLine(Xo,Yo,Xn,Yn);  // draw line in second red/green quadrant

       ox = nx;  // set the current x,y co-ordinates 
       oy = ny;  // as next time's old x,y coordinates end of 'for' loop
    }
  }


  void drawGreen(Graphics h, int r) {
    ox = r; oy = 0;  // old values of the x,y coordinates

    // for each of 64 angular increments in a quadrant...
    for(int i = 0; i < 64; i++) {
      int ny = CY[r][i];  // y-coordinate of the next primary plot

      // force top and bottom vertical limits on the y-coordinate
      if(ny > Ymax && oy <= Ymax) ny = Ymax;
      if(oy > Ymax && ny <= Ymax) oy = Ymax;

      int nx = CX[r][i],  // x-coordinate of the next primary plot

          // For the forward and rear semicircles, compute the
          nX = X + nx, Xn = X - nx,  // new x-coordinates 
          oX = X + ox, Xo = X - ox,  // old x-coordinates
          nY = Y + ny, Yn = Y - ny,  // new y-coordinates
          oY = Y + oy, Yo = Y - oy;  // old y-coordinates

      h.setColor( CG[r] );      // set radially-faded green colour
      h.drawLine(oX,oY,nX,nY);  // draw line in first blue/green quadrant
      h.drawLine(oX,Yo,nX,Yn);  // draw line in second blue/green quadrant
      h.drawLine(Xo,oY,Xn,nY);  // draw line in first red/green quadrant
      h.drawLine(Xo,Yo,Xn,Yn);  // draw line in second red/green quadrant

      ox = nx;  // set the current x,y co-ordinates 
      oy = ny;  // as next time's old x,y coordinates
    }
  }


  void wipeWave(Graphics h, int r) {
    ox = r; oy = 0;           // old values of the x,y coordinates
    h.setColor(Color.black);  // colour black for a wipe pass only

    // for each of 64 angular increments in a quadrant
    for(int i = 0; i < 64; i++) {
      int ny = CY[r][i];  // y-coordinate of the next primary plot

      // force top and bottom vertical limits on the y-coordinate
      if(ny > Ymax && oy <= Ymax) ny = Ymax;
      if(oy > Ymax && ny <= Ymax) oy = Ymax;

      int nx = CX[r][i],  // x-coordinate of the next primary plot

          // For the forward and rear semicircles, computer the
          nX = X + nx, Xn = X - nx,  // new x-coordinates
          oX = X + ox, Xo = X - ox,  // old x-coordinates
          nY = Y + ny, Yn = Y - ny,  // new y-coordinates
          oY = Y + oy, Yo = Y - oy;  // old y-coordinates

      h.drawLine(oX,oY,nX,nY);  // draw line in first blue/green quadrant
      h.drawLine(oX,Yo,nX,Yn);  // draw line in second blue/green quadrant
      h.drawLine(Xo,oY,Xn,nY);  // draw line in first red/green quadrant
      h.drawLine(Xo,Yo,Xn,Yn);  // draw line in second red/green quadrant

      ox = nx;  // set the current x,y co-ordinates 
      oy = ny;  // as next time's old x,y coordinates
    }
  }


  static void sineValues() {
    double angle = 0;  // angle variable for forming the angles array

    // for each of 64 angular divisions of the primary quadrant
    for(int i = 0; i < 64; i++) {
      double 
        s = Math.sin(angle),  // compute the next sine value
        c = Math.cos(angle),  // compute the next cosine value
        cc = 255 * c,         // cosine -modified colour value
        ss = 255 * s;         // sine-modified colour value

      // for each radius out as far as 400 pixels...
      for(int j = 0; j < 400; j++) {
        double r = (double)j;  // radius of quarter-circle

        // At this angle at this radius...
        CX[j][i] = (int)(r * c);  // x-coordinate
        CY[j][i] = (int)(r * s);  // y-coordinate

        // From the radius, form the colour fading factor
        double k = 1 - r / 440;

        // Colour values phased by sine and faded by radius
        int g  = (int)(ss * k),  // green
            rb = (int)(cc * k),  // red/blue
            q = (int)(255 * k);  // green faded only by radius

        // Colour arrays for:
        CR[j][i] = new Color(rb,g,0);  // the red/green quadrant
        CB[j][i] = new Color(0,g,rb);  // the blue/green quadrant

        // Green intensity array for each of the 400 possible radii
        CG[j] = new Color(0,q,0);
      }
      angle += Angle;  // increment the angle by one 64th of a quadrant
    }
  }


  static void setMode(int ds) {  // set the "relativity mode"
    if(ds == 0) dm = false;      // false = "classical relativity"
    else dm = true;              // true = "alternative relativity"
  }
}