Distorted Android

  VERTEX_ROTATE    ( EffectType.VERTEX  ,   new float[] {0.0f}           , 4, 0,     3    , VertexEffectRotate.class       ),

    float angle = uniforms[NUM_UNIFORMS*index  ];

    Matrix.rotateM( matrix, 0, angle, axisX, axisY, axisZ);

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

// Copyright 2020 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.effect;

import org.distorted.library.type.Data1D;

import org.distorted.library.type.Data3D;

import org.distorted.library.type.Data4D;

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

/**

 * Deform the Mesh by applying a 3D vector of force.

 */

public class VertexEffectRotate extends VertexEffect

  {

  private Data1D mAngle;

  private Data3D mAxis, mCenter;

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

/**

 * Only for use by the library itself.

 *

 * @y.exclude

 */

  public boolean compute(float[] uniforms, int index, long currentDuration, long step )

    {

    mCenter.get(uniforms,index+CENTER_OFFSET,currentDuration,step);

    mAxis.get(uniforms,index+1,currentDuration,step);

    float len = uniforms[index+1]*uniforms[index+1] + uniforms[index+2]*uniforms[index+2] + uniforms[index+3]*uniforms[index+3];

    len = (float)Math.sqrt(len);

    if( len!=0 )

      {

      uniforms[index+1] /= len;

      uniforms[index+2] /= len;

      uniforms[index+3] /= len;

      }

    return mAngle.get(uniforms,index,currentDuration,step);

    }

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

// PUBLIC API

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

/**

 * Have to call this before the shaders get compiled (i.e before DistortedLibrary.onCreate()) for the Effect to work.

 */

  public static void enable()

    {

    addEffect( EffectName.VERTEX_ROTATE,

               "float angle = vUniforms[effect].x*3.1415/360.0;\n"

             + "vec3 center = vUniforms[effect+1].yzw;         \n"

             + "float sinHalf = sin(angle);                    \n"

             + "float cosHalf = cos(angle);                    \n"

             + "float qx = vUniforms[effect].y * sinHalf;      \n"

             + "float qy = vUniforms[effect].z * sinHalf;      \n"

             + "float qz = vUniforms[effect].w * sinHalf;      \n"

             + "float qw = cosHalf;                            \n"

             + "v += center;                                   \n"

             + "float tx = qx - v.z*qy + v.y*qz + v.x*qw;      \n"

             + "float ty = qy + v.z*qx + v.y*qw - v.x*qz;      \n"

             + "float tz = qz + v.z*qw - v.y*qx + v.x*qy;      \n"

             + "float tw = qw - v.z*qz - v.y*qy - v.x*qx;      \n"

             + "v.x = qw*tx + qz*ty - qy*tz - qx*tw;           \n"

             + "v.y = qw*ty - qz*tx - qy*tw + qx*tz;           \n"

             + "v.z = qw*tz - qz*tw + qy*tx - qx*ty;           \n"

             + "v -= center;                                   \n"

             + "float nx =  - n.z*qy + n.y*qz + n.x*qw;        \n"

             + "float ny =  + n.z*qx + n.y*qw - n.x*qz;        \n"

             + "float nz =  + n.z*qw - n.y*qx + n.x*qy;        \n"

             + "float nw =  - n.z*qz - n.y*qy - n.x*qx;        \n"

             + "n.x = qw*nx + qz*ny - qy*nz - qx*nw;           \n"

             + "n.y = qw*ny - qz*nx - qy*nw + qx*nz;           \n"

             + "n.z = qw*nz - qz*nw + qy*nx - qx*ny;           \n"

             );

    }

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

/**

 * Rotate the Mesh by 'angle' degrees around the center, along an axis.

 *

 * @param angle  Angle that we want to rotate the Object to. Unit: degrees

 * @param axis   Axis of rotation

 * @param center Coordinates of the Point we are rotating around.

 */

  public VertexEffectRotate(Data1D angle, Data3D axis, Data3D center)

    {

    super(EffectName.VERTEX_ROTATE);

    mAngle = angle;

    mAxis = axis;

    mCenter = center;

    }

  }