Magic Cube

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

// Copyright 2019 Leszek Koltunski                                                               //

//                                                                                               //

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

//                                                                                               //

// Magic Cube 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.                                                           //

//                                                                                               //

// Magic Cube 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 Magic Cube.  If not, see <http://www.gnu.org/licenses/>.                           //

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

package org.distorted.magic;

import android.app.ActivityManager;

import android.content.Context;

import android.content.SharedPreferences;

import android.content.pm.ConfigurationInfo;

import android.graphics.PorterDuff;

import android.graphics.drawable.Drawable;

import android.opengl.GLSurfaceView;

import android.support.v4.content.ContextCompat;

import android.util.AttributeSet;

import android.util.DisplayMetrics;

import android.view.LayoutInflater;

import android.view.MotionEvent;

import android.view.View;

import android.view.ViewGroup;

import android.widget.Button;

import android.widget.ImageButton;

import android.widget.LinearLayout;

import org.distorted.component.HorizontalNumberPicker;

import org.distorted.library.type.Static2D;

import org.distorted.library.type.Static4D;

import org.distorted.object.RubikCube;

import org.distorted.object.RubikCubeMovement;

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

public class RubikSurfaceView extends GLSurfaceView

{

    public static final int BUTTON_ID_BACK= 1023;

    public static final int MIN_SCRAMBLE =  1;

    public static final int DEF_SCRAMBLE =  1;

    public static final int MAX_SCRAMBLE = 18;

    // Moving the finger from the middle of the vertical screen to the right edge will rotate a

    // given face by SWIPING_SENSITIVITY/2 degrees.

    private final static int SWIPING_SENSITIVITY  = 240;

    // Moving the finger by 1/12 the distance of min(scrWidth,scrHeight) will start a Rotation.

    private final static int ROTATION_SENSITIVITY =  12;

    // Every 1/12 the distance of min(scrWidth,scrHeight) the direction of cube rotation will reset.

    private final static int DIRECTION_SENSITIVITY=  12;

    private final Static4D CAMERA_POINT = new Static4D(0, 0, RubikRenderer.CAMERA_DISTANCE, 0);

    private RubikRenderer mRenderer;

    private RubikCubeMovement mMovement;

    private boolean mDragging, mBeginningRotation, mContinuingRotation;

    private float mX, mY;

    private int mScreenWidth, mScreenHeight, mScreenMin;

    private HorizontalNumberPicker mPicker;

    private int mScrambleValue;

    private static int mButton = RubikSize.SIZE3.ordinal();

    private static Static4D mQuatCurrent    = new Static4D(0,0,0,1);

    private static Static4D mQuatAccumulated= new Static4D(-0.25189602f,0.3546389f,0.009657208f,0.90038127f);

    private static Static4D mTempCurrent    = new Static4D(0,0,0,1);

    private static Static4D mTempAccumulated= new Static4D(0,0,0,1);

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

    void scramble()

      {

      int scramble = mPicker.getValue();

      mRenderer.scrambleCube(scramble);

      }

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

    void savePreferences(SharedPreferences.Editor editor)

      {

      editor.putInt("scramble", mScrambleValue );

      }

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

    void restorePreferences(SharedPreferences preferences)

      {

      mScrambleValue= preferences.getInt("scramble", DEF_SCRAMBLE);

      }

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

    void setScreenSize(int width, int height)

      {

      mScreenWidth = width;

      mScreenHeight= height;

      mScreenMin = width<height ? width:height;

      }

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

    RubikRenderer getRenderer()

      {

      return mRenderer;

      }

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

    static int getRedButton()

      {

      return mButton;

      }

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

    void setQuatAccumulated()

      {

      mQuatAccumulated.set(mTempAccumulated);

      }

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

    void setQuatCurrent()

      {

      mQuatCurrent.set(mTempCurrent);

      }

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

    Static4D getQuatAccumulated()

      {

      return mQuatAccumulated;

      }

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

    Static4D getQuatCurrent()

      {

      return mQuatCurrent;

      }

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

    private Static4D quatFromDrag(float dragX, float dragY)

      {

      float axisX = dragY;  // inverted X and Y - rotation axis is perpendicular to (dragX,dragY)

      float axisY = dragX;  // Why not (-dragY, dragX) ? because Y axis is also inverted!

      float axisZ = 0;

      float axisL = (float)Math.sqrt(axisX*axisX + axisY*axisY + axisZ*axisZ);

      if( axisL>0 )

        {

        axisX /= axisL;

        axisY /= axisL;

        axisZ /= axisL;

        float ratio = axisL;

        ratio = ratio - (int)ratio;     // the cos() is only valid in (0,Pi)

        float cosA = (float)Math.cos(Math.PI*ratio);

        float sinA = (float)Math.sqrt(1-cosA*cosA);

        return new Static4D(axisX*sinA, axisY*sinA, axisZ*sinA, cosA);

        }

      return new Static4D(0f, 0f, 0f, 1f);

      }

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

// return quat1*quat2

    public static Static4D quatMultiply( Static4D quat1, Static4D quat2 )

      {

      float qx = quat1.get0();

      float qy = quat1.get1();

      float qz = quat1.get2();

      float qw = quat1.get3();

      float rx = quat2.get0();

      float ry = quat2.get1();

      float rz = quat2.get2();

      float rw = quat2.get3();

      float tx = rw*qx - rz*qy + ry*qz + rx*qw;

      float ty = rw*qy + rz*qx + ry*qw - rx*qz;

      float tz = rw*qz + rz*qw - ry*qx + rx*qy;

      float tw = rw*qw - rz*qz - ry*qy - rx*qx;

      return new Static4D(tx,ty,tz,tw);

      }

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

// rotate 'vector' by quat  ( i.e. return quat*vector*(quat^-1) )

    public static Static4D rotateVectorByQuat(Static4D vector, Static4D quat)

      {

      float qx = quat.get0();

      float qy = quat.get1();

      float qz = quat.get2();

      float qw = quat.get3();

      Static4D quatInverted= new Static4D(-qx,-qy,-qz,qw);

      Static4D tmp = quatMultiply(quat,vector);

      return quatMultiply(tmp,quatInverted);

      }

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

// rotate 'vector' by quat^(-1)  ( i.e. return (quat^-1)*vector*quat )

    public static Static4D rotateVectorByInvertedQuat(Static4D vector, Static4D quat)

      {

      float qx = quat.get0();

      float qy = quat.get1();

      float qz = quat.get2();

      float qw = quat.get3();

      Static4D quatInverted= new Static4D(-qx,-qy,-qz,qw);

      Static4D tmp = quatMultiply(quatInverted,vector);

      return quatMultiply(tmp,quat);

      }

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

    void markButton(int button)

      {

      mButton = button;

      RubikActivity act = (RubikActivity)getContext();

      for(int b=0; b<RubikSize.LENGTH; b++)

        {

        Drawable d = act.findViewById(b).getBackground();

        if( b==button )

          {

          d.setColorFilter(ContextCompat.getColor(act,R.color.red), PorterDuff.Mode.MULTIPLY);

          }

        else

          {

          d.clearColorFilter();

          }

        }

      }

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

    void enterState(RubikActivity act, RubikState state)

      {

      switch(state)

        {

        case MAIN: enterMainState(act); break;

        case PLAY: enterPlayState(act); break;

        }

      }

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

    private void enterMainState(RubikActivity act)

      {

      LayoutInflater inflater = act.getLayoutInflater();

      // TOP ////////////////////////////

      LinearLayout layoutTop = act.findViewById(R.id.mainTitle);

      layoutTop.removeAllViews();

      final View viewTop = inflater.inflate(R.layout.main_title, null);

      layoutTop.addView(viewTop);

      // BOT ////////////////////////////

      LinearLayout layoutBot = act.findViewById(R.id.mainBar);

      layoutBot.removeAllViews();

      DisplayMetrics metrics = getResources().getDisplayMetrics();

      float scale = metrics.density;

      int size = (int)(60*scale +0.5f);

      int padding = (int)(5*scale + 0.5f);

      LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT,size,0.5f);

      Button buttonL = new Button(act);

      buttonL.setLayoutParams(params);

      buttonL.setId(BUTTON_ID_BACK);

      buttonL.setPadding(padding,0,padding,0);

      buttonL.setText(R.string.back);

      buttonL.setOnClickListener(act);

      layoutBot.addView(buttonL);

      Button buttonR = new Button(act);

      buttonR.setLayoutParams(params);

      buttonR.setId(BUTTON_ID_BACK);

      buttonR.setPadding(padding,0,padding,0);

      buttonR.setText(R.string.exit);

      buttonR.setOnClickListener(act);

      layoutBot.addView(buttonR);

      buttonL.setVisibility(INVISIBLE);

      }

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

    private void enterPlayState(RubikActivity act)

      {

      LayoutInflater inflater = act.getLayoutInflater();

      // TOP ////////////////////////////

      LinearLayout layoutTop = act.findViewById(R.id.mainTitle);

      layoutTop.removeAllViews();

      final View viewTop = inflater.inflate(R.layout.play_title, null);

      layoutTop.addView(viewTop);

      // BOT ////////////////////////////

      LinearLayout layoutBot = act.findViewById(R.id.mainBar);

      layoutBot.removeAllViews();

      DisplayMetrics metrics = getResources().getDisplayMetrics();

      float scale = metrics.density;

      int size = (int)(60*scale +0.5f);

      int padding = (int)(3*scale + 0.5f);

      ViewGroup.LayoutParams params = new ViewGroup.LayoutParams(size,size);

      for(int i=0; i<RubikSize.LENGTH; i++)

        {

        ImageButton button = new ImageButton(act);

        button.setLayoutParams(params);

        button.setId(i);

        button.setPadding(padding,0,padding,0);

        int iconID = RubikSize.getSize(i).getIconID();

        button.setImageResource(iconID);

        button.setOnClickListener(act);

        layoutBot.addView(button);

        }

      ViewGroup.LayoutParams params2 = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,size);

      Button button = new Button(act);

      button.setLayoutParams(params2);

      button.setId(BUTTON_ID_BACK);

      button.setPadding(padding,0,padding,0);

      button.setText(R.string.back);

      button.setOnClickListener(act);

      layoutBot.addView(button);

      markButton(mButton);

      mPicker = act.findViewById(R.id.rubikNumberPicker);

      if( mPicker!=null )

        {

        mPicker.setMin(MIN_SCRAMBLE);

        mPicker.setMax(MAX_SCRAMBLE);

        mPicker.setValue(mScrambleValue);

        }

      }

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

// PUBLIC API

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

    public RubikSurfaceView(Context context, AttributeSet attrs)

      {

      super(context,attrs);

      if(!isInEditMode())

        {

        mRenderer = new RubikRenderer(this);

        mMovement = new RubikCubeMovement();

        final ActivityManager activityManager     = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);

        final ConfigurationInfo configurationInfo = activityManager.getDeviceConfigurationInfo();

        setEGLContextClientVersion( (configurationInfo.reqGlEsVersion>>16) >= 3 ? 3:2 );

        setRenderer(mRenderer);

        }

      }

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

    @Override

    public boolean onTouchEvent(MotionEvent event)

      {

      int action = event.getAction();

      float x = (event.getX() - mScreenWidth*0.5f)/mScreenMin;

      float y = (mScreenHeight*0.5f -event.getY())/mScreenMin;

      switch(action)

         {

         case MotionEvent.ACTION_DOWN: mX = x;

                                       mY = y;

                                       Static4D touchPoint1 = new Static4D(x, y, 0, 0);

                                       Static4D rotatedTouchPoint1= rotateVectorByInvertedQuat(touchPoint1, mQuatAccumulated);

                                       Static4D rotatedCamera= rotateVectorByInvertedQuat(CAMERA_POINT, mQuatAccumulated);

                                       if( mMovement.faceTouched(rotatedTouchPoint1, rotatedCamera) )

                                         {

                                         mDragging           = false;

                                         mBeginningRotation  = mRenderer.canRotate();

                                         mContinuingRotation = false;

                                         }

                                       else

                                         {

                                         mDragging           = mRenderer.canDrag();

                                         mBeginningRotation  = false;

                                         mContinuingRotation = false;

                                         }

                                       break;

         case MotionEvent.ACTION_MOVE: if( mDragging )

                                         {

                                         mTempCurrent.set(quatFromDrag(mX-x,y-mY));

                                         mRenderer.setQuatCurrentOnNextRender();

                                         if( (mX-x)*(mX-x) + (mY-y)*(mY-y) > 1.0f/(DIRECTION_SENSITIVITY*DIRECTION_SENSITIVITY) )

                                           {

                                           mX = x;

                                           mY = y;

                                           mTempAccumulated.set(quatMultiply(mQuatCurrent, mQuatAccumulated));

                                           mTempCurrent.set(0f, 0f, 0f, 1f);

                                           mRenderer.setQuatCurrentOnNextRender();

                                           mRenderer.setQuatAccumulatedOnNextRender();

                                           }

                                         }

                                       if( mBeginningRotation )

                                         {

                                         if( (mX-x)*(mX-x)+(mY-y)*(mY-y) > 1.0f/(ROTATION_SENSITIVITY*ROTATION_SENSITIVITY) )

                                           {

                                           Static4D touchPoint2 = new Static4D(x, y, 0, 0);

                                           Static4D rotatedTouchPoint2= rotateVectorByInvertedQuat(touchPoint2, mQuatAccumulated);

                                           Static2D rot = mMovement.newRotation(rotatedTouchPoint2);

                                           RubikCube cube = mRenderer.getCube();

                                           cube.addNewRotation( (int)rot.get0(), (int)(cube.getSize()*rot.get1()) );

                                           mBeginningRotation = false;

                                           mContinuingRotation= true;

                                           }

                                         }

                                       else if( mContinuingRotation )

                                         {

                                         Static4D touchPoint3 = new Static4D(x, y, 0, 0);

                                         Static4D rotatedTouchPoint3= rotateVectorByInvertedQuat(touchPoint3, mQuatAccumulated);

                                         float angle = mMovement.continueRotation(rotatedTouchPoint3);

                                         mRenderer.getCube().continueRotation(SWIPING_SENSITIVITY*angle);

                                         }

                                       break;

         case MotionEvent.ACTION_UP  : if( mDragging )

                                         {

                                         mTempAccumulated.set(quatMultiply(mQuatCurrent, mQuatAccumulated));

                                         mTempCurrent.set(0f, 0f, 0f, 1f);

                                         mRenderer.setQuatCurrentOnNextRender();

                                         mRenderer.setQuatAccumulatedOnNextRender();

                                         }

                                       if( mContinuingRotation )

                                         {

                                         mRenderer.finishRotation();

                                         }

                                       break;

         }

      return true;

      }

}