Distorted Android

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

// 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.library;

import android.opengl.GLES30;

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

/**

 * Class which represents a OpenGL Framebuffer object.

 * <p>

 * User is able to create offscreen FBOs and both a) render to them b) use their COLOR0 attachment as

 * an input texture.

 */

public class DistortedFramebuffer extends DistortedOutputSurface implements DistortedInputSurface

  {

  private int[] mDepthH = new int[1];

  private int[] mFBOH   = new int[1];

  private boolean mDepthEnabled;

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

// Must be called from a thread holding OpenGL Context

// Watch out - this has the side-effect of binding a Texture and a Framebuffer!

  public void create()

    {

    if( mColorH[0]==NOT_CREATED_YET )

      {

      GLES30.glGenTextures(1, mColorH, 0);

      GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, mColorH[0]);

      GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_S, GLES30.GL_REPEAT);

      GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_T, GLES30.GL_REPEAT);

      GLES30.glTexParameterf(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MIN_FILTER, GLES30.GL_NEAREST);

      GLES30.glTexParameterf(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MAG_FILTER, GLES30.GL_LINEAR);

      GLES30.glTexImage2D(GLES30.GL_TEXTURE_2D, 0, GLES30.GL_RGBA, mSizeX, mSizeY, 0, GLES30.GL_RGBA, GLES30.GL_UNSIGNED_BYTE, null);

      GLES30.glGenFramebuffers(1, mFBOH, 0);

      GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, mFBOH[0]);

      GLES30.glFramebufferTexture2D(GLES30.GL_FRAMEBUFFER, GLES30.GL_COLOR_ATTACHMENT0, GLES30.GL_TEXTURE_2D, mColorH[0], 0);

      checkStatus("color");

      }

    if( mDepthEnabled && mDepthH[0]==NOT_CREATED_YET ) // we need to create a new DEPTH attachment

      {

      GLES30.glGenTextures(1, mDepthH, 0);

      GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, mDepthH[0]);

      GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_S, GLES30.GL_REPEAT);

      GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_WRAP_T, GLES30.GL_REPEAT);

      GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MIN_FILTER, GLES30.GL_NEAREST);

      GLES30.glTexParameteri(GLES30.GL_TEXTURE_2D, GLES30.GL_TEXTURE_MAG_FILTER, GLES30.GL_NEAREST);

      GLES30.glTexImage2D(GLES30.GL_TEXTURE_2D, 0, GLES30.GL_DEPTH_COMPONENT, mSizeX, mSizeY, 0, GLES30.GL_DEPTH_COMPONENT, GLES30.GL_UNSIGNED_SHORT, null);

      GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, mFBOH[0]);

      GLES30.glFramebufferTexture2D(GLES30.GL_FRAMEBUFFER, GLES30.GL_DEPTH_ATTACHMENT, GLES30.GL_TEXTURE_2D, mDepthH[0], 0);

      checkStatus("depth");

      }

    if( !mDepthEnabled && mDepthH[0]!=NOT_CREATED_YET ) // we need to detach and destroy the DEPTH attachment.

      {

      GLES30.glDeleteTextures(1, mDepthH, 0);

      mDepthH[0]=NOT_CREATED_YET;

      }

    }

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

  private boolean checkStatus(String message)

    {

    int status = GLES30.glCheckFramebufferStatus(GLES30.GL_FRAMEBUFFER);

    if(status != GLES30.GL_FRAMEBUFFER_COMPLETE)

      {

      android.util.Log.e("DistortedFramebuffer", "FRAMEBUFFER INCOMPLETE, "+message+" error="+status);

      GLES30.glDeleteTextures(1, mColorH, 0);

      GLES30.glDeleteTextures(1, mDepthH, 0);

      GLES30.glDeleteFramebuffers(1, mFBOH, 0);

      mFBOH[0]   = 0;

      mColorH[0] = FAILED_TO_CREATE;

      mDepthH[0] = FAILED_TO_CREATE;

      return false;

      }

    return true;

    }

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

// Must be called from a thread holding OpenGL Context

  void delete()

    {

    if( mColorH[0]>=0 )

      {

      if( mDepthH[0]>=0 )

        {

        GLES30.glDeleteTextures(1, mDepthH, 0);

        mDepthH[0]=NOT_CREATED_YET;

        }

      GLES30.glDeleteTextures(1, mColorH, 0);

      mColorH[0] = NOT_CREATED_YET;

      GLES30.glDeleteFramebuffers(1, mFBOH, 0);

      mFBOH[0] = 0;

      }

    }

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

// called from onDestroy(); mark OpenGL assets as 'not created'

  void destroy()

    {

    if( mColorH[0]!=DONT_CREATE ) mColorH[0] = NOT_CREATED_YET;

    if( mDepthEnabled           ) mDepthH[0] = NOT_CREATED_YET;

    }

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

// if new size fits into the size of the underlying Texture, just change the projection without

// reallocating the Texture. Otherwise, we need to reallocate.

//

// Must be called from a thread holding the OpenGL context.

  void resizeFast(int width, int height)

    {

    if( mWidth!=width || mHeight!=height )

      {

      mWidth = width;

      mHeight= height;

      createProjection();

      if( width> mSizeX || height> mSizeY)

        {

        mSizeX = width;

        mSizeY = height;

        delete();

        }

      }

    create();

    }

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

// PUBLIC API

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

/**

 * Create a new offscreen Framebuffer.

 *

 * @param width Width of the COLOR attachment.

 * @param height Height of the COLOR attachment.

 * @param depthEnabled Add DEPTH attachment?

 */

  @SuppressWarnings("unused")

  public DistortedFramebuffer(int width, int height, boolean depthEnabled)

    {

    super(width,height,NOT_CREATED_YET);

    mDepthEnabled= depthEnabled;

    mFBOH[0]     = NOT_CREATED_YET;

    mDepthH[0]   = NOT_CREATED_YET;

    }

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

/**

 * Create a new offscreen Framebuffer.

 *

 * @param width Width of the COLOR attachment.

 * @param height Height of the COLOR attachment.

 */

  @SuppressWarnings("unused")

  public DistortedFramebuffer(int width, int height)

    {

    super(width,height,NOT_CREATED_YET);

    mDepthEnabled= false;

    mFBOH[0]     = NOT_CREATED_YET;

    mDepthH[0]   = NOT_CREATED_YET;

    }

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

/**

 * Bind the underlying rectangle of pixels as a OpenGL Texture.

 *

 * @returns <code>true</code> if successful.

 */

  public boolean setAsInput()

    {

    if( mColorH[0]>0 )

      {

      GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, mColorH[0]);

      return true;

      }

    return false;

    }

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

/**

 * Bind this Surface as a Framebuffer we can render to.

 */

  public void setAsOutput()

    {

    GLES30.glBindFramebuffer(GLES30.GL_FRAMEBUFFER, mFBOH[0]);

    if( mDepthH[0]!=NOT_CREATED_YET )

      {

      GLES30.glEnable(GLES30.GL_DEPTH_TEST);

      GLES30.glDepthMask(true);

      }

    else

      {

      GLES30.glDisable(GLES30.GL_DEPTH_TEST);

      GLES30.glDepthMask(false);

      }

    }

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

/**

 * Create a new DEPTH buffer and attach it or (param=false) detach an existing DEPTh attachment and destroy it.

 *

 * @param enable <bold>true</bold> if we want to attach a new DEPTH buffer to the FBO.<br>

 *               <bold>false</bold> if we want to detach the DEPTH attachment.

 */

  public void enableDepthAttachment(boolean enable)

    {

    mDepthEnabled = enable;

    }

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

/**

 * Return the ID of the Texture (COLOR attachment 0) that's backing this FBO.

 * <p>

 * Catch: this will only work if the library has had time to actually create the texture. Remember

 * that the texture gets created only on first render, thus creating a Texture object and immediately

 * calling this method will return an invalid (negative) result.

 *

 * @return If there was not a single render between creation of the Object and calling this method on

 *         it, return a negative value. Otherwise, return ID of COLOR attachment 0.

 */

  public int getTextureID()

    {

    return mColorH[0];

    }

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

/**

 * Return true if the FBO contains a DEPTH attachment.

 *

 * @return <bold>true</bold> if the FBO contains a DEPTH attachment.

 */

  public boolean hasDepth()

    {

    return mDepthEnabled;

    }

  }