Distorted Android

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// 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/>.                            //

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package org.distorted.library;

import java.util.LinkedList;

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/**

 * Keep all objects created in a static LinkedList. The point: we need to be able to mark

 * Objects for deletion, and delete all marked Objects later at a convenient time (that's

 * because we can only delete from a thread that holds the OpenGL context so here we provide a

 * framework where one is able to mark for deletion at any time and actual deletion takes place

 * on the next render).

*/

abstract class DistortedSurface

  {

  static final int FAILED_TO_CREATE = -1;

  static final int NOT_CREATED_YET  = -2;

  static final int DONT_CREATE      = -3;

  private static boolean mToDo = false;

  private static LinkedList<DistortedSurface> mDoneList = new LinkedList<>();

  private static LinkedList<DistortedSurface> mToDoList = new LinkedList<>();

  private boolean mMarked;

  int[] mColorH = new int[1];

  int mSizeX, mSizeY;  // in screen space

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

  abstract void create();

  abstract void delete();

  abstract void recreate();

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// must be called form a thread holding OpenGL Context

  static synchronized void toDo()

    {

    if( mToDo )

      {

      DistortedSurface surface;

      int num = mToDoList.size();

      for(int i=0; i<num; i++)

        {

        surface = mToDoList.removeFirst();

        if(surface.mMarked)

          {

          surface.delete();

          surface.mMarked = false;

          }

        else

          {

          surface.create();

          mDoneList.add(surface);

          }

        }

      mToDo = false;

      }

    }

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

  static synchronized void onDestroy()

    {

    DistortedSurface surface;

    int num = mDoneList.size();

    for(int i=0; i<num; i++)

      {

      surface = mDoneList.removeFirst();

      if( !surface.mMarked )

        {

        surface.recreate();

        mToDoList.add(surface);

        }

      }

    mToDo = true;

    }

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

  synchronized void moveToToDo()

    {

    if ( mDoneList.remove(this) )

      {

      mToDoList.add(this);

      mToDo = true;

      }

    }

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

  DistortedSurface(int width, int height, int color)

    {

    mSizeX    = width ;

    mSizeY    = height;

    mColorH[0]= color;

    mMarked   = false;

    if( color!=DONT_CREATE )

      {

      mToDoList.add(this);

      mToDo = true;

      }

    }

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

// PUBLIC API

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

/**

 * Mark the underlying OpenGL object for deletion. Actual deletion will take place on the next render.

 */

  public void markForDeletion()

    {

    if( !mMarked )

      {

      mToDo   = true;

      mMarked = true;

      mDoneList.remove(this);

      mToDoList.add(this);

      }

    }

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

/**

 * Return unique ID of the Surface.

 */

  public long getID()

    {

    return mColorH[0];

    }

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

/**

 * Returns the height of the Surface.

 *

 * @return height of the object, in pixels.

 */

  public int getWidth()

    {

    return mSizeX;

    }

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

/**

 * Returns the width of the Surface.

 *

 * @return width of the Object, in pixels.

 */

  public int getHeight()

    {

    return mSizeY;

    }

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

/**

 * Returns the depth of the Surface.

 * <p>

 * Admittedly quite a strange method. Why do we need to pass a Mesh to it? Because one cannot determine

 * 'depth' of a Surface (bitmap really!) when rendered based only on the texture itself, that depends

 * on the Mesh it is rendered with.

 *

 * @return depth of the Object, in pixels.

 */

  public int getDepth(MeshObject mesh)

    {

    return mesh==null ? 0 : (int)(mSizeX*mesh.zFactor);

    }

  }