TwistyPuzzleLib

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

// Copyright 2022 Leszek Koltunski                                                               //

//                                                                                               //

// This file is part of Magic Cube.                                                              //

//                                                                                               //

// Magic Cube is proprietary software licensed under an EULA which you should have received      //

// along with the code. If not, check https://distorted.org/magic/License-Magic-Cube.html        //

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

package org.distorted.objectlib.touchcontrol;

import org.distorted.library.main.QuatHelper;

import org.distorted.library.type.Static3D;

import org.distorted.library.type.Static4D;

import org.distorted.objectlib.main.TwistyObject;

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

// Ball-shaped objects: map the 2D swipes of user's fingers to 3D rotations

public class TouchControlBall extends TouchControl

{

  private final Static3D[] mRotAxis;

  private final float[] mPoint, mCamera;

  private float mLongitude, mLatitude;

  private final int[] mEnabledRotAxis;

  private final int[][][] mEnabled;

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

  public TouchControlBall(TwistyObject object)

    {

    super(object.getObjectRatio());

    mRotAxis = object.getRotationAxis();

    mEnabled = object.getEnabled();

    mPoint = new float[3];

    mCamera= new float[3];

    mEnabledRotAxis = new int[mRotAxis.length+1];

    }

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

// Longitude spans from 0 (at Guinea Bay) increasing to the east all the way to 2PI

// Latitude - from -PI/2 (South Pole) to +PI/2 (North Pole)

  private void computeLongitudeAndLatitude(float A, float B, float C)

    {

    float sqrt = (float)Math.sqrt(B*B - 4*A*C);

    float alpha= (-B+sqrt)/(2*A); // this is the closer point

    float cx = mCamera[0];

    float cy = mCamera[1];

    float cz = mCamera[2];

    float vx = mCamera[0]-mPoint[0];

    float vy = mCamera[1]-mPoint[1];

    float vz = mCamera[2]-mPoint[2];

    float px = cx + alpha*vx;

    float py = cy + alpha*vy;

    float pz = cz + alpha*vz;

    mLongitude = pz==0 ? 0 : (float)Math.atan(px/pz);

    mLatitude  = (float)Math.asin(2*py);

    if( pz<0 ) mLongitude += Math.PI;

    else if( px<0 ) mLongitude += 2*Math.PI;

    }

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

// this is Masterball-specific. See TwistyMasterball.getEnabled()

  private int returnTouchedFace()

    {

    float t = (float)(mLongitude + Math.PI/8);

    if( t>2*Math.PI ) t-=(2*Math.PI);

    int ret = (int)(t/(Math.PI/4));

    return ret<8 ? ret : 7;

    }

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

// this is Masterball-specific. No parts in any faces.

  private int returnTouchedPart()

    {

    return 0;

    }

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

  private void computeEnabledAxis()

    {

    int face = returnTouchedFace();

    int part = returnTouchedPart();

    int num = mEnabled[face][0].length;

    mEnabledRotAxis[0] = num;

    System.arraycopy(mEnabled[face][part], 0, mEnabledRotAxis, 1, num);

    }

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

  public float returnRotationFactor(int[] numLayers, int row)

    {

    return 1.0f;

    }

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

  public int getTouchedCubitFace()

    {

    return 0;

    }

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

  public int getTouchedCubit()

    {

    return 0;

    }

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

  public boolean objectTouched(Static4D rotatedTouchPoint, Static4D rotatedCamera)

    {

    mPoint[0]  = rotatedTouchPoint.get0()/mObjectRatio;

    mPoint[1]  = rotatedTouchPoint.get1()/mObjectRatio;

    mPoint[2]  = rotatedTouchPoint.get2()/mObjectRatio;

    mCamera[0] = rotatedCamera.get0()/mObjectRatio;

    mCamera[1] = rotatedCamera.get1()/mObjectRatio;

    mCamera[2] = rotatedCamera.get2()/mObjectRatio;

    float vx = mCamera[0]-mPoint[0];

    float vy = mCamera[1]-mPoint[1];

    float vz = mCamera[2]-mPoint[2];

    float R = 0.5f;

    float A = vx*vx + vy*vy + vz*vz;

    float B = 2*(vx*mCamera[0] + vy*mCamera[1] + vz*mCamera[2]);

    float C = (mCamera[0]*mCamera[0] + mCamera[1]*mCamera[1] + mCamera[2]*mCamera[2]) - R*R;

    if( B*B >= 4*A*C )

      {

      computeLongitudeAndLatitude(A,B,C);

      return true;

      }

    return false;

    }

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

// TODO

  public void newRotation(int[] output, Static4D rotatedTouchPoint, Static4D quat)

    {

    computeEnabledAxis();

/*

    int rotIndex = computeRotationIndex( mCastedRotAxis[mLastTouchedFace], mMove2D, mEnabledRotAxis);

    float offset = computeOffset(mPoint2D, mCastedRotAxis[mLastTouchedFace][rotIndex]);

    int row      = computeRowFromOffset(mLastTouchedFace,rotIndex,offset);

*/

    int rotIndex = 0;

    int row = 0;

    output[0] = rotIndex;

    output[1] = row;

    }

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

// simply cast the appropriate rotational axis of the object to the screen surface.

  public void getCastedRotAxis(float[] output, Static4D quat, int axisIndex)

    {

    Static3D a = mRotAxis[axisIndex];

    Static4D result = QuatHelper.rotateVectorByQuat(a.get0(),a.get1(),a.get2(),0,quat);

    float cx = result.get0();

    float cy = result.get1();

    float len= (float)Math.sqrt(cx*cx+cy*cy);

    if( len!=0 )

      {

      output[0] = cx/len;

      output[1] = cy/len;

      }

    else

      {

      output[0] = 1;

      output[1] = 0;

      }

    }

}