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.mesh;

import android.opengl.GLES31;

import org.distorted.library.main.Distorted;

import org.distorted.library.main.DistortedBuffer;

import org.distorted.library.program.DistortedProgram;

import java.nio.ByteBuffer;

import java.nio.ByteOrder;

import java.nio.FloatBuffer;

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

/**

 * Abstract class which represents a Mesh, i.e. an array of vertices (rendered as a TRIANGLE_STRIP)

 * <p>

 * If you want to render to a particular shape, extend from here, construct a float array

 * containing per-vertex attributes, and call back setData().

 */

public abstract class MeshBase

   {

   // sizes of attributes of an individual vertex.

   private static final int POS_DATA_SIZE= 3; // vertex coordinates: x,y,z

   private static final int NOR_DATA_SIZE= 3; // normal vector: x,y,z

   private static final int INF_DATA_SIZE= 3; // 'inflate' vector: x,y,z

   private static final int TEX_DATA_SIZE= 2; // texture coordinates

   static final int POS_ATTRIB   = 0;

   static final int NOR_ATTRIB   = POS_DATA_SIZE;

   static final int INF_ATTRIB   = POS_DATA_SIZE + NOR_DATA_SIZE;

   static final int TEX_ATTRIB   = POS_DATA_SIZE + NOR_DATA_SIZE + INF_DATA_SIZE;

   static final int VERT_ATTRIBS = POS_DATA_SIZE + NOR_DATA_SIZE + INF_DATA_SIZE + TEX_DATA_SIZE;  // number of attributes of a 'normal' vertex

   static final int TRAN_ATTRIBS = POS_DATA_SIZE + POS_DATA_SIZE;                                  // number of attributes of a transform feedback vertex

   private static final int BYTES_PER_FLOAT = 4;

   private static final int OFFSET_POS = POS_ATTRIB*BYTES_PER_FLOAT;

   private static final int OFFSET_NOR = NOR_ATTRIB*BYTES_PER_FLOAT;

   private static final int OFFSET_INF = INF_ATTRIB*BYTES_PER_FLOAT;

   private static final int OFFSET_TEX = TEX_ATTRIB*BYTES_PER_FLOAT;

   private static final int TRAN_SIZE  = TRAN_ATTRIBS*BYTES_PER_FLOAT;

   private static final int VERT_SIZE  = VERT_ATTRIBS*BYTES_PER_FLOAT;

   private boolean mShowNormals;       // when rendering this mesh, draw normal vectors?

   private DistortedBuffer mVBO, mTFO; // main vertex buffer and transform feedback buffer

   private final float zFactor;        // strange workaround for the fact that we need to somehow store the 'depth'

                                       // of the Mesh. Used in DistortedEffects. See DistortedTexture.getDepth().

   private int mNumVertices;

   private FloatBuffer mVertAttribs;   // packed: PosX,PosY,PosZ, NorX,NorY,NorZ, InfX,InfY,InfZ, TexS,TexT

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

   MeshBase(float factor)

     {

     zFactor      = factor;

     mShowNormals = false;

     mVBO = new DistortedBuffer(GLES31.GL_ARRAY_BUFFER             , GLES31.GL_STATIC_READ);

     mTFO = new DistortedBuffer(GLES31.GL_TRANSFORM_FEEDBACK_BUFFER, GLES31.GL_STATIC_READ);

     }

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

// when a derived class is done computing its mesh, it has to call this method.

   void setAttribs(float[] vertexAttribs)

     {

     mNumVertices = vertexAttribs.length/VERT_ATTRIBS;

     mVertAttribs = ByteBuffer.allocateDirect(mNumVertices*VERT_SIZE).order(ByteOrder.nativeOrder()).asFloatBuffer();

     mVertAttribs.put(vertexAttribs).position(0);

     mVBO.setData(mNumVertices*VERT_SIZE, mVertAttribs);

     mTFO.setData(mNumVertices*TRAN_SIZE, null        );

     }

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

/**

 * Not part of public API, do not document (public only because has to be used from the main package)

 *

 * @y.exclude

 */

   public int getTFO()

     {

     return mTFO.mIndex[0];

     }

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

/**

 * Not part of public API, do not document (public only because has to be used from the main package)

 *

 * @y.exclude

 */

   public int getNumVertices()

     {

     return mNumVertices;

     }

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

/**

 * Not part of public API, do not document (public only because has to be used from the main package)

 *

 * @y.exclude

 */

   public float getZFactor()

     {

     return zFactor;

     }

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

/**

 * Not part of public API, do not document (public only because has to be used from the main package)

 *

 * @y.exclude

 */

   public void bindVertexAttribs(DistortedProgram program)

     {

     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, mVBO.mIndex[0] );

     GLES31.glVertexAttribPointer(program.mAttribute[0], POS_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_POS);

     GLES31.glVertexAttribPointer(program.mAttribute[1], NOR_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_NOR);

     GLES31.glVertexAttribPointer(program.mAttribute[2], INF_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_INF);

     GLES31.glVertexAttribPointer(program.mAttribute[3], TEX_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_TEX);

     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, 0);

     }

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

/**

 * Not part of public API, do not document (public only because has to be used from the main package)

 *

 * @y.exclude

 */

   public void bindTransformAttribs(DistortedProgram program)

     {

     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, mTFO.mIndex[0] );

     GLES31.glVertexAttribPointer(program.mAttribute[0], POS_DATA_SIZE, GLES31.GL_FLOAT, false, 0, 0);

     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, 0);

     }

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

// PUBLIC API

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

/**

 * When rendering this Mesh, do we want to render the Normal vectors as well?

 * <p>

 * Will work only on OpenGL ES >= 3.0 devices.

 *

 * @param show Controls if we render the Normal vectors or not.

 */

   public void setShowNormals(boolean show)

     {

     mShowNormals = (Distorted.GLSL >= 300 && show);

     }

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

/**

 * When rendering this mesh, should we also draw the normal vectors?

 *

 * @return <i>true</i> if we do render normal vectors

 */

   public boolean getShowNormals()

     {

     return mShowNormals;

     }

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

/**

 * Release all internal resources.

 */

   public void markForDeletion()

     {

     mVertAttribs.clear();

     mVBO.markForDeletion();

     mTFO.markForDeletion();

     }

   }