Distorted Android

///////////////////////////////////////////////////////////////////////////////////////////////////

// Copyright 2016 Leszek Koltunski                                                               //

//                                                                                               //

// This file is part of Distorted.                                                               //

//                                                                                               //

// Distorted is free software: you can redistribute it and/or modify                             //

// it under the terms of the GNU General Public License as published by                          //

// the Free Software Foundation, either version 2 of the License, or                             //

// (at your option) any later version.                                                           //

//                                                                                               //

// Distorted is distributed in the hope that it will be useful,                                  //

// but WITHOUT ANY WARRANTY; without even the implied warranty of                                //

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                                 //

// GNU General Public License for more details.                                                  //

//                                                                                               //

// You should have received a copy of the GNU General Public License                             //

// along with Distorted.  If not, see <http://www.gnu.org/licenses/>.                            //

///////////////////////////////////////////////////////////////////////////////////////////////////

package org.distorted.library;

import java.util.Vector;

///////////////////////////////////////////////////////////////////////////////////////////////////

/** 

* A 1-dimensional implementation of the Interpolator class to interpolate between a list 

* of Float1Ds.

*/

public class Interpolator1D extends Interpolator 

  {

///////////////////////////////////////////////////////////////////////////////////////////////////

// the coefficients of the X(t) polynomials: X(t) = ax*T^3 + bx*T^2 + cx*t + dx  etc.

// (x) is the vector tangent to the path.

// (vx) is the original vector from vv (copied here so when interpolating we can see if it is 

// still valid and if not - rebuild the Cache

  private class VectorCache

    {

    float ax, bx, cx, dx;

    float x;

    float vx;

    }

  private class VectorNoise

    {

    float[] nx;

    public VectorNoise()

      {

      nx = new float[NUM_NOISE]; 

      nx[0] = mRnd.nextFloat();

      for(int i=1; i<NUM_NOISE; i++) nx[i] = nx[i-1]+mRnd.nextFloat();

      float sum = nx[NUM_NOISE-1] + mRnd.nextFloat();

      for(int i=0; i<NUM_NOISE; i++) nx[i] /=sum;

      }

    }

  private Vector<VectorCache> vc;

  private VectorCache tmp1, tmp2;

  private Vector<Float1D> vv;

  private Float1D prev, curr, next;

  private Vector<VectorNoise> vn;

  private VectorNoise tmpN;

///////////////////////////////////////////////////////////////////////////////////////////////////

  synchronized void createNoise()

    {

    if( vn==null )

      {

      vn = new Vector<VectorNoise>();

      for(int i=0; i<numPoints; i++) vn.add(new VectorNoise());

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// no array bounds checking!

  private void vec(int c)

    {

    int p = c>0 ? c-1: numPoints-1;

    int n = c<numPoints-1 ? c+1: 0;

    prev = vv.elementAt(p);

    curr = vv.elementAt(c);

    next = vv.elementAt(n);

    tmp1 = vc.elementAt(c);

    float px = curr.x - prev.x;

    float nx = next.x - curr.x;

    float d = nx*nx;

    if( d>0 )

      {

      float q = (float)Math.sqrt((px*px)/d);

      if( q>1 )

        {

        tmp1.x = nx+px/q;

        }

      else

        {

        tmp1.x = px+nx*q;

        }

      }

    else

      {

      tmp1.x = 0.0f;

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private void recomputeCache()

    {  

    if( numPoints==1 )

      {

      tmp1= vc.elementAt(0);

      curr= vv.elementAt(0);

      tmp1.ax = 0.0f;

      tmp1.bx = 0.0f;

      tmp1.cx = curr.x;

      tmp1.dx = 0.0f;

      }

    else if( numPoints==2 )

      {

      tmp1= vc.elementAt(0);

      tmp2= vc.elementAt(1);

      curr= vv.elementAt(0);

      next= vv.elementAt(1);

      tmp1.ax = 0.0f;

      tmp1.bx = 0.0f;

      tmp1.cx = next.x - curr.x;

      tmp1.dx = curr.x;

      tmp2.ax = 0.0f;

      tmp2.bx = 0.0f;

      tmp2.cx = curr.x - next.x;

      tmp2.dx = next.x;

      }

    else

      {

      int i, n;  

      for(i=0; i<numPoints; i++) vec(i);

      for(i=0; i<numPoints; i++)

        {

        n = i<numPoints-1 ? i+1:0;  

        tmp1= vc.elementAt(i);

        tmp2= vc.elementAt(n);

        curr= vv.elementAt(i);

        next= vv.elementAt(n);

        tmp1.vx = curr.x;

        tmp1.ax =  2*curr.x +   tmp1.x - 2*next.x + tmp2.x;

        tmp1.bx = -3*curr.x - 2*tmp1.x + 3*next.x - tmp2.x;

        tmp1.cx = tmp1.x;

        tmp1.dx = curr.x;

        }

      }

    cacheDirty = false;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private float noise(float time,int vecNum)

    {

    float lower, upper, len;  

    float d = time*(NUM_NOISE+1);

    int index = (int)d;

    if( index>=NUM_NOISE+1 ) index=NUM_NOISE;

    tmpN = vn.elementAt(vecNum);

    if( index==0 )

      {

      len = 1.0f/(NUM_NOISE+1);  

      return (len + mNoise*(tmpN.nx[0]-len))*d;

      }

    if( index==NUM_NOISE )

      {

      len = ((float)NUM_NOISE)/(NUM_NOISE+1);

      lower = len + mNoise*(tmpN.nx[NUM_NOISE-1]-len);   

      return (1.0f-lower)*(d-NUM_NOISE) + lower;   

      }

    len = ((float)index)/(NUM_NOISE+1);

    lower = len + mNoise*(tmpN.nx[index-1]-len);   

    len = ((float)index+1)/(NUM_NOISE+1); 

    upper = len + mNoise*(tmpN.nx[index  ]-len);

    return (upper-lower)*(d-index) + lower; 

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

// PUBLIC API

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Default constructor.

 */

  public Interpolator1D()

    {

    vv = new Vector<Float1D>();

    vc = new Vector<VectorCache>();

    vn = null;

    numPoints = 0;

    cacheDirty = false;

    mMode = MODE_LOOP;

    mDuration = 0;

    mCount = 0.5f;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Returns the location'th Float1D. 

 *   

 * @param location the index of the Point we are interested in.

 * @return The Float1D, if 0<=location&lt;getNumPoints(), or null otherwise. 

 */

  public synchronized Float1D getPoint(int location)

    {

    return (location>=0 && location<numPoints) ? vv.elementAt(location) : null;  

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Resets the location'th Point.

 * 

 * @param location the index of the Point we are setting.

 * @param x New value of its first float.

 */

  public synchronized void setPoint(int location, float x)

    {

    if( location>=0 && location<numPoints )

      {

      curr = vv.elementAt(location);

      if( curr!=null )

        {

        curr.set(x);

        cacheDirty=true;

        }

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Adds a new Float1D to the end of our list of Points to interpolate through.

 * <p>   

 * Only a reference to the Point gets added to the List; this means that one can add a Point 

 * here, and later on {@link Float1D#set(float)} it to some new value and the change will

 * be seamlessly reflected in the interpolated path.  

 * <p>

 * A Point can be added multiple times.

 *   

 * @param v The Point to add.

 */

  public synchronized void add(Float1D v)

    {

    if( v!=null )

      {

      vv.add(v);

      if( vn!=null ) vn.add(new VectorNoise());

      switch(numPoints)

        {

        case 0: 

        case 1: break;

        case 2: vc.add(new VectorCache());

                vc.add(new VectorCache());

                vc.add(new VectorCache());

                cacheDirty = true;

                break;

        default:vc.add(new VectorCache());

                cacheDirty = true;

        }

      numPoints++;

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Adds a new Float1D to the location'th place in our List of Points to interpolate through.  

 *   

 * @param location Index in our List to add the new Point at.

 * @param v The Point to add.

 */

  public synchronized void add(int location, Float1D v)

    {

    if( v!=null )

      {

      vv.add(location, v);

      if( vn!=null ) vn.add(new VectorNoise());

      switch(numPoints)

        {

        case 0:

        case 1: break;

        case 2: vc.add(new VectorCache());

                vc.add(new VectorCache());

                vc.add(new VectorCache());

                cacheDirty = true;

                break;

        default:vc.add(location,new VectorCache());

                cacheDirty = true;

        }

      numPoints++;

      }

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Removes all occurrences of Point v from the List of Points to interpolate through.  

 * 

 * @param v The Point to remove.

 * @return <code>true</code> if we have removed at least one Point.

 */

  public synchronized boolean remove(Float1D v)

    {

    int n = vv.indexOf(v);

    boolean found = false;

    while( n>=0 ) 

      {

      vv.remove(n);

      if( vn!=null ) vn.remove(0);

      switch(numPoints)

        {

        case 0:

        case 1:

        case 2: break;

        case 3: vc.removeAllElements();

                break;

        default:vc.remove(n);

                cacheDirty=true;

        }

      numPoints--;

      found = true;

      n = vv.indexOf(v);

      }

    return found;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Removes a location'th Point from the List of Points we interpolate through.

 * 

 * @param location index of the Point we want to remove. 

 * @return <code>true</code> if location is valid, i.e. if 0<=location&lt;getNumPoints().

 */

  public synchronized boolean remove(int location)

    {

    if( location>=0 && location<numPoints ) 

      {

      vv.removeElementAt(location);

      if( vn!=null ) vn.remove(0);

      switch(numPoints)

        {

        case 0:

        case 1: 

        case 2: break;

        case 3: vc.removeAllElements();

                break;

        default:vc.removeElementAt(location);

        }

      numPoints--;

      cacheDirty = true; 

      return true;

      }

   return false;

   }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Removes all Points.

 */

  public synchronized void removeAll()

    {

    numPoints = 0;

    vv.removeAllElements();

    vc.removeAllElements();

    cacheDirty = false;

    if( vn!=null ) vn.removeAllElements();

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

/**

 * Writes the results of interpolation between the Points at time 'time' to the passed float buffer.

 * <p>

 * Since this is a 1-dimensional Interpolator, the resulting interpolated Float1D gets written

 * to a single location in the buffer: buffer[offset]. 

 * 

 * @param buffer Float buffer we will write the resulting Float1D to.

 * @param offset Offset in the buffer where to write the result.

 * @param time Time of interpolation. Time=0.0 would return the first Point, Time=0.5 - the last,

 *             time=1.0 - the first again, and time 0.1 would be 1/5 of the way between the first and the last Points.

 */

  public synchronized void interpolate(float[] buffer, int offset, float time)

    {

    switch(numPoints)

      {

      case 0: buffer[offset] = 0.0f;

              break;

      case 1: curr = vv.elementAt(0);

              buffer[offset] = curr.x;

              break;

      case 2: curr = vv.elementAt(0);

              next = vv.elementAt(1);

              if( mMode==MODE_LOOP || mMode==MODE_PATH ) time = (time>0.5f ? 2-2*time : 2*time);

              if( vn!=null )

                {

                time = noise(time,0);

                }

              buffer[offset] = (next.x-curr.x)*time + curr.x;

              break;

      default:float t = time;

              switch(mMode)

                {

                case MODE_LOOP: time = time*numPoints;

                                break;

                case MODE_PATH: time = (time<=0.5f) ? 2*time*(numPoints-1) : 2*(1-time)*(numPoints-1);

                                break;

                case MODE_JUMP: time = time*(numPoints-1);

                                break;

                }

              int vecCurr = (int)time;

              time = time-vecCurr;

              if( vecCurr>=0 && vecCurr<numPoints )

                {

                if( cacheDirty ) recomputeCache();  // recompute cache if we have added or remove vectors since last computation

                else if( mVecCurr!= vecCurr )       // ...or if we have just passed a vector and the vector we are currently flying to has changed

                  {

                  int vecNext;   

                  mVecCurr = vecCurr;

                  switch(mMode)

                    {

                    case MODE_LOOP: vecNext = vecCurr==numPoints-1 ? 0:vecCurr+1; 

                                    break;

                    case MODE_PATH: if( t<0.5f ) vecNext = vecCurr==numPoints-1 ? numPoints-2: vecCurr+1;  

                                    else         vecNext = vecCurr==0 ? 1 : vecCurr-1;  

                                    break;

                    case MODE_JUMP: vecNext = vecCurr==numPoints-1 ? 1:vecCurr+1;

                                    break;

                    default       : vecNext = 0;                

                    }

                  next = vv.elementAt(vecNext);

                  tmp2 = vc.elementAt(vecNext);

                  if( tmp2.vx!=next.x ) recomputeCache();

                  }

                if( vn!=null )

                  {

                  time = noise(time,vecCurr);

                  }

                tmp1 = vc.elementAt(vecCurr);

                buffer[offset] = ((tmp1.ax*time+tmp1.bx)*time+tmp1.cx)*time+tmp1.dx;

                break;

                }

        }

     }  

  }

///////////////////////////////////////////////////////////////////////////////////////////////////

//