Distorted Android

        <activity android:name=".wind.WindActivity"/>

import org.distorted.examples.wind.WindActivity;

   {

      final Map<String, Object> item = new HashMap<>();

      item.put(ITEM_IMAGE, R.drawable.icon_example_wind);

      item.put(ITEM_TITLE, (i+1)+". "+getText(R.string.example_wind));

      item.put(ITEM_SUBTITLE, getText(R.string.example_wind_subtitle));

      data.add(item);

      activityMapping.put(i++, WindActivity.class);

   }

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

// 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.examples.wind;

import android.app.Activity;

import android.opengl.GLSurfaceView;

import android.os.Bundle;

import android.widget.SeekBar;

import android.widget.SeekBar.OnSeekBarChangeListener;

import android.widget.TextView;

import org.distorted.examples.R;

import org.distorted.library.Distorted;

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

public class WindActivity extends Activity implements OnSeekBarChangeListener

{

    private TextView windText;

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

    @Override

    protected void onCreate(Bundle icicle) 

      {

      super.onCreate(icicle);

      setContentView(R.layout.windlayout);

      SeekBar bar = (SeekBar)findViewById(R.id.windSeek);

      bar.setOnSeekBarChangeListener(this);

      windText = (TextView)findViewById(R.id.windText);

      bar.setProgress(50);

      windText.setText("Wind: 50");

      }

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

    @Override

    protected void onPause() 

      {

      GLSurfaceView view = (GLSurfaceView) this.findViewById(R.id.windSurfaceView);

      view.onPause();

      super.onPause();

      }

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

    @Override

    protected void onResume() 

      {

      super.onResume();

      GLSurfaceView view = (GLSurfaceView) this.findViewById(R.id.windSurfaceView);

      view.onResume();

      }

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

    @Override

    protected void onDestroy() 

      {

      Distorted.onDestroy();  

      super.onDestroy();

      }

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

    public void onProgressChanged(SeekBar bar, int progress, boolean fromUser) 

      {

      switch (bar.getId()) 

        {

        case R.id.windSeek:WindSurfaceView view = (WindSurfaceView) this.findViewById(R.id.windSurfaceView);

                           view.getRenderer().setWind(progress);

                           windText.setText("Wind: "+progress);

                           break;

        }

      }

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

    public void onStartTrackingTouch(SeekBar bar) { }

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

    public void onStopTrackingTouch(SeekBar bar)  { }

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

}

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

// 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.examples.wind;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.opengl.GLES20;

import android.opengl.GLSurfaceView;

import org.distorted.examples.R;

import org.distorted.library.Distorted;

import org.distorted.library.DistortedCubes;

import org.distorted.library.DistortedObject;

import org.distorted.library.EffectTypes;

import org.distorted.library.type.DynamicQuat;

import org.distorted.library.type.Static3D;

import org.distorted.library.type.Static4D;

import java.io.IOException;

import java.io.InputStream;

import javax.microedition.khronos.egl.EGLConfig;

import javax.microedition.khronos.opengles.GL10;

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

class WindRenderer implements GLSurfaceView.Renderer

{

   private GLSurfaceView mView;

   private DistortedObject mObject;

   private DynamicQuat mQuatInt1, mQuatInt2;

   private int mWind;

   private int mObjWidth, mObjHeight;

   Static4D mQuat1, mQuat2;

   int mScreenMin;

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

   WindRenderer(GLSurfaceView view)

      { 

      mView = view;

      mObject = new DistortedCubes(50,30,10,false);

      mObjWidth = mObject.getWidth();

      mObjHeight= mObject.getHeight();

      mQuat1 = new Static4D(           0,         0,           0,          1);  // unity quaternion

      mQuat2 = new Static4D(-0.25189602f,0.3546389f,0.009657208f,0.90038127f);  // something semi-random that looks good

      mQuatInt1 = new DynamicQuat(0,0.5f);

      mQuatInt2 = new DynamicQuat(0,0.5f);

      mQuatInt1.add(mQuat1);

      mQuatInt2.add(mQuat2);

      }

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

   void setWind(int wind)

      {

      mWind = wind;

      }

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

   public void onDrawFrame(GL10 glUnused) 

      {

      GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

      GLES20.glClear( GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);

      mObject.draw(System.currentTimeMillis());

      }

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

   public void onSurfaceChanged(GL10 glUnused, int width, int height) 

      {

      mScreenMin = width<height ? width:height;

      mObject.abortEffects(EffectTypes.MATRIX);

      float factor;

      if( width*mObjHeight > height*mObjWidth ) // screen is more 'horizontal' than the Object

        {

        factor = (0.8f*height)/mObjHeight;

        }

      else

        {

        factor = (0.8f*width)/mObjWidth;

        }

      mObject.move( new Static3D( (width-factor*mObjWidth)/2 , (height-factor*mObjHeight)/2 , 0) );

      mObject.scale(factor);

      Static3D center = new Static3D(mObjWidth/2,mObjHeight/2, 0);

      mObject.quaternion(mQuatInt1, center);

      mObject.quaternion(mQuatInt2, center);

      Distorted.onSurfaceChanged(width, height);

      }

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

   public void onSurfaceCreated(GL10 glUnused, EGLConfig config) 

      {  

      InputStream is = mView.getContext().getResources().openRawResource(R.raw.iceland);

      Bitmap bitmap;

      try

        {

        bitmap = BitmapFactory.decodeStream(is);

        }

      finally

        {

        try

          {

          is.close();

          }

        catch(IOException e) { }

        }

      mObject.setBitmap(bitmap);

      try

        {

        Distorted.onSurfaceCreated(mView.getContext());

        }

      catch(Exception ex)

        {

        android.util.Log.e("Wind", ex.getMessage() );

        }

      }

}

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

// 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.examples.wind;

import android.content.Context;

import android.opengl.GLSurfaceView;

import android.os.Build;

import android.util.AttributeSet;

import android.view.MotionEvent;

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

class WindSurfaceView extends GLSurfaceView

{

    private int mX, mY;

    private WindRenderer mRenderer;

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

    public WindSurfaceView(Context c, AttributeSet attrs)

      {

      super(c, attrs);

      mX = -1;

      mY = -1;

      if(!isInEditMode())

        {

        setEGLContextClientVersion(2);

        if( Build.FINGERPRINT.startsWith("generic") )

          { 

          setEGLConfigChooser(8, 8, 8, 8, 16, 0);   

          }

        mRenderer = new WindRenderer(this);

        setRenderer(mRenderer);

        }

      }

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

    public WindRenderer getRenderer()

      {

      return mRenderer;

      }

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

    @Override public boolean onTouchEvent(MotionEvent event)

      {

      int action = event.getAction();

      int x = (int)event.getX();

      int y = (int)event.getY();

      switch(action)

         {

         case MotionEvent.ACTION_DOWN: mX = x;

                                       mY = y;

                                       break;

         case MotionEvent.ACTION_MOVE: if( mX>=0 && mY>= 0 )

                                         {

                                         float px = mY-y;

                                         float py = mX-x;

                                         float pz = 0;

                                         float plen = (float)Math.sqrt(px*px + py*py + pz*pz);

                                         if( plen>0 )

                                           {

                                           px /= plen;

                                           py /= plen;

                                           pz /= plen;

                                           float cosA = (float)Math.cos(plen*3.14f/mRenderer.mScreenMin);

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

                                           mRenderer.mQuat1.set(px*sinA, py*sinA, pz*sinA, cosA);

                                           }

                                         }

                                       break;

         case MotionEvent.ACTION_UP  : mX = -1;

                                       mY = -1;

                                       float qx = mRenderer.mQuat1.getX();

                                       float qy = mRenderer.mQuat1.getY();

                                       float qz = mRenderer.mQuat1.getZ();

                                       float qw = mRenderer.mQuat1.getW();

                                       float rx = mRenderer.mQuat2.getX();

                                       float ry = mRenderer.mQuat2.getY();

                                       float rz = mRenderer.mQuat2.getZ();

                                       float rw = mRenderer.mQuat2.getW();

                                       // This is quaternion multiplication. (tx.ty.tz.tw)

                                       // is now equal to (qx,qy,qz,qw)*(rx,ry,rz,rw)

                                       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;

                                       // The point of this is so that there are always

                                       // exactly 2 quaternions: Quat1 representing the rotation

                                       // accumulating only since the last screen touch, and Quat2

                                       // which remembers the combined effect of all previous

                                       // swipes.

                                       // We cannot be accumulating an ever-growing list of quaternions

                                       // and add a new one every time user swipes the screen - there

                                       // is a limited number of slots in the EffectQueueMatrix!

                                       mRenderer.mQuat1.set(0f, 0f, 0f, 1f);

                                       mRenderer.mQuat2.set(tx, ty, tz, tw);

                                       break;

         }

      return true;

      }

}

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

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="fill_parent"

    android:layout_height="fill_parent"

    android:orientation="vertical" >

    <org.distorted.examples.wind.WindSurfaceView

        android:id="@+id/windSurfaceView"

        android:layout_width="fill_parent"

        android:layout_height="0dp"

        android:layout_weight="1" />

    <LinearLayout

        android:id="@+id/linearLayout1"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:gravity="center|fill_horizontal"

        android:orientation="horizontal"

        android:paddingBottom="10dp"

        android:paddingTop="10dp" >

        <TextView

            android:id="@+id/windText"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_weight="1"

            android:paddingLeft="15dp"

            android:textAppearance="?android:attr/textAppearanceMedium" />

        <SeekBar

            android:id="@+id/windSeek"

            android:layout_width="106dp"

            android:layout_height="wrap_content"

            android:layout_weight="0.94"

            android:paddingLeft="15dp"

            android:paddingRight="10dp" />

    </LinearLayout>

</LinearLayout>

    <string name="example_wind">Variable wind</string>

    <string name="example_wind_subtitle">A couple of effects put together to create an effect of a waving flag.</string>