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/>.                            //

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

package org.distorted.library.main;

import android.graphics.Bitmap;

import android.graphics.Canvas;

import android.graphics.Matrix;

import android.graphics.Paint;

import android.opengl.GLES30;

import android.opengl.GLUtils;

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

/**

 * Class which represents a OpenGL Texture object.

 * <p>

 * Create a Texture of arbitrary size and feed some pixels to it via the setTexture() method.

 */

public class DistortedTexture extends InternalSurface

  {

  private Bitmap mBmp;

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// We have to flip vertically every single Bitmap that we get fed with.

//

// Reason: textures read from files are the only objects in OpenGL which have their origins at the

// upper-left corner. Everywhere else the origin is in the lower-left corner. Thus we have to flip.

// The alternative solution, namely inverting the y-coordinate of the TexCoord does not really work-

// i.e. it works only in case of rendering directly to the screen, but if we render to an FBO and

// then take the FBO and render to screen, (DistortedNode does so!) things get inverted as textures

// created from FBO have their origins in the lower-left... Mindfuck!

  private static Bitmap flipBitmap(Bitmap src)

    {

    Matrix matrix = new Matrix();

    matrix.preScale(1.0f,-1.0f);

    return Bitmap.createBitmap(src,0,0,src.getWidth(),src.getHeight(), matrix,true);

    }

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

// must be called from a thread holding OpenGL Context

  void create()

    {

    if( mBmp!=null )

      {

      if( mColorCreated==NOT_CREATED_YET )

        {

        mColorCreated = CREATED;

        GLES30.glGenTextures(1, mColorH, 0);

        }

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

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

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

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

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

      GLUtils.texImage2D(GLES30.GL_TEXTURE_2D, 0, flipBitmap(mBmp), 0);

      GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, 0);

      mBmp = null;

      }

    }

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

// must be called from a thread holding OpenGL Context

  void delete()

    {

    if( mColorH[0]>0 )

      {

      GLES30.glDeleteTextures(1, mColorH, 0);

      mColorH[0] = 0;

      mColorCreated = NOT_CREATED_YET;

      }

    }

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

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

  void recreate()

    {

    if( mColorCreated!=DONT_CREATE )

      {

      mColorCreated = NOT_CREATED_YET;

      mColorH[0] = 0;

      }

    }

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

// create SYSTEM or TREE textures (those are just like normal Textures, just hold information

// that they were autocreated only for the Library's internal purposes (SYSTEM) or for using

// inside a Tree of DistortedNodes (TREE)

// SYSTEM surfaces do not get removed in onDestroy().

  public DistortedTexture(int type)

    {

    super(NOT_CREATED_YET,1,1,type);

    mBmp= null;

    }

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// PUBLIC API

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

/**

 * Create an empty texture.

 */

  public DistortedTexture()

    {

    this(TYPE_USER);

    }

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/**

 * Sets the underlying android.graphics.Bitmap object.

 * <p>

 * You can only recycle() the passed Bitmap once the OpenGL context gets created (i.e. after call

 * to GLSurfaceView.onSurfaceCreated) because only after this point can the Library upload it to the GPU!

 *

 * @param bmp The android.graphics.Bitmap object to apply effects to and display.

 */

  public void setTexture(Bitmap bmp)

    {

    mBmp= bmp;

    markForCreation();

    }

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

/**

 * Paints the Texture with solid color.

 *

 * @param argb The color to paint the Texture with.

 */

  public void setColorARGB(int argb)

    {

    Paint paint = new Paint();

    paint.setColor(argb);

    paint.setStyle(Paint.Style.FILL);

    mBmp = Bitmap.createBitmap(1,1, Bitmap.Config.ARGB_8888);

    Canvas canvas = new Canvas(mBmp);

    canvas.drawRect(0,0,1,1,paint);

    markForCreation();

    }

  }