Distorted Android

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

// Copyright 2019 Leszek Koltunski                                                               //

//                                                                                               //

// This file is part of DistortedLibrary.                                                               //

//                                                                                               //

// DistortedLibrary 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.                                                           //

//                                                                                               //

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

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

package org.distorted.examples.rubik;

import android.opengl.GLSurfaceView;

import org.distorted.library.effect.VertexEffectSink;

import org.distorted.library.main.DistortedLibrary;

import org.distorted.library.main.DistortedScreen;

import org.distorted.library.message.EffectListener;

import org.distorted.library.message.EffectMessage;

import org.distorted.library.type.Static3D;

import javax.microedition.khronos.egl.EGLConfig;

import javax.microedition.khronos.opengles.GL10;

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

class RubikRenderer implements GLSurfaceView.Renderer, EffectListener

{

    private static final float CUBE_SCREEN_RATIO = 0.5f;

    private static final float CAMERA_DISTANCE   = 0.6f;  // 0.6 of the length of max(scrHeight,scrWidth)

    private static final int MIN_CUBE_SIZE = 1;

    private static final int MAX_CUBE_SIZE = 6;

    private RubikSurfaceView mView;

    private DistortedScreen mScreen;

    private Static3D mMove, mScale;

    private int mNextCubeSize;

    private boolean mChangeCubeSizeNow;

    private int mNumCube;

    private RubikCube mCube;

    private int mScreenWidth, mScreenHeight;

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

    RubikRenderer(RubikSurfaceView v)

      {

      mView = v;

      mScreen = new DistortedScreen();

      mScreenWidth = mScreenHeight = 0;

      mMove  = new Static3D(0,0,0);

      mScale = new Static3D(1,1,1);

      mNextCubeSize= MIN_CUBE_SIZE;

      mChangeCubeSizeNow = false;

      mNumCube = 0;

      }

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

// change the cube size here, 'after the next render' as not to cause artifacts.

    public void onDrawFrame(GL10 glUnused) 

      {

      mScreen.render( System.currentTimeMillis() );

      if( mChangeCubeSizeNow )

        {

        mChangeCubeSizeNow = false;

        createNextCube();

        }

      }

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

// EffectListener. The library sends a message to us when it's time to create a new cube.

   public void effectMessage(final EffectMessage em, final long effectID, final long objectID)

     {

     switch(em)

        {

        case EFFECT_FINISHED: mNextCubeSize++;

                              if( mNextCubeSize> MAX_CUBE_SIZE ) mNextCubeSize = MIN_CUBE_SIZE;

                              mChangeCubeSizeNow = true;

                              break;

        }

     }

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

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

     {

     float cameraDistance = CAMERA_DISTANCE*(width>height ? width:height);

     float fovInDegrees   = computeFOV(cameraDistance,height);

     mScreen.setProjection( fovInDegrees, 0.1f);

     mScreen.resize(width, height);

     recomputeScaleFactor(width,height);

     mScreenHeight = height;

     mScreenWidth  = width;

     }

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

   public void onSurfaceCreated(GL10 glUnused, EGLConfig config)

     {

     createNextCube();

     VertexEffectSink.enable();

     try

       {

       DistortedLibrary.onCreate(mView.getContext());

       }

     catch(Exception ex)

       {

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

       }

     }

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

   private void createNextCube()

     {

     if( mCube!=null ) mCube.releaseResources();

     mCube = new RubikCube(mNextCubeSize, mMove, mScale);

     mCube.createTexture();

     if( mScreenWidth!=0 ) recomputeScaleFactor(mScreenWidth,mScreenHeight);

     mScreen.detachAll();

     mCube.attachToScreen(mScreen);

     mCube.addRotation(this);

     RubikActivity act = mView.getRubikActivity();

     act.setText(++mNumCube);

     }

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

   private float computeFOV(float cameraDistance, int screenHeight)

     {

     double halfFOVInRadians = Math.atan( screenHeight/(2*cameraDistance) );

     return (float)(2*halfFOVInRadians*(180/Math.PI));

     }

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

   private void recomputeScaleFactor(int screenWidth, int screenHeight)

     {

     float cubeSizeInScreenSpace = CUBE_SCREEN_RATIO*(screenWidth>screenHeight ? screenHeight:screenWidth);

     float texSize = mCube.getTextureSize();

     float scaleFactor = cubeSizeInScreenSpace/(texSize*mCube.getSize());

     mMove.set( (screenWidth-scaleFactor*texSize)/2 , (screenHeight-scaleFactor*texSize)/2 , -scaleFactor*texSize/2 );

     mScale.set(scaleFactor,scaleFactor,scaleFactor);

     }

}