Distorted Android

package org.distorted.examples.cubes;

import org.distorted.examples.R;

import android.content.Context;

import android.opengl.GLSurfaceView;

import android.os.Build;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.widget.Toast;

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

class CubesSurfaceView extends GLSurfaceView 

{

    int mX, mY;

    CubesRenderer mRenderer;

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

    public CubesSurfaceView(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 CubesRenderer(this);

        setRenderer(mRenderer);

        Toast.makeText(c, R.string.example_cubes_toast , Toast.LENGTH_SHORT).show();   

        }

      }

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

    @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();

                                       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;

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

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

                                       break;

         }

      return true;

      }

}