// rotatepoint.h
//
// Copyright (C) 2003, 2004 Jason Bevins
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2.1 of the License, or (at
// your option) any later version.
//
// This library 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 Lesser General Public
// License (COPYING.txt) for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this library; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// The developer's email is jlbezigvins@gmzigail.com (for great email, take
// off every 'zig'.)
//
module noise.mod.rotatepoint;

private {
  import noise.mod.modulebase;
  import noise.mathconsts;
}

/// @addtogroup libnoise
/// @{

/// @addtogroup modules
/// @{

/// @addtogroup transformermodules
/// @{

/// Default @a x rotation angle for the module::RotatePoint noise
/// module.
const double DEFAULT_ROTATE_X = 0.0;

/// Default @a y rotation angle for the module::RotatePoint noise
/// module.
const double DEFAULT_ROTATE_Y = 0.0;

/// Default @a z rotation angle for the module::RotatePoint noise
/// module.
const double DEFAULT_ROTATE_Z = 0.0;

/// Noise module that rotates the input value around the origin before
/// returning the output value from a source module.
///
/// @image html modulerotatepoint.png
///
/// The GetValue() method rotates the coordinates of the input value
/// around the origin before returning the output value from the source
/// module.  To set the rotation angles, call the SetAngles() method.  To
/// set the rotation angle around the individual @a x, @a y, or @a z axes,
/// call the SetXAngle(), SetYAngle() or SetZAngle() methods,
/// respectively.
///
/// The coordinate system of the input value is assumed to be
/// "left-handed" (@a x increases to the right, @a y increases upward,
/// and @a z increases inward.)
///
/// This noise module requires one source module.
class RotatePoint : Mod
{

  public:

    /// Constructor.
    ///
    /// The default rotation angle around the @a x axis, in degrees, is
    /// set to module::DEFAULT_ROTATE_X.
    ///
    /// The default rotation angle around the @a y axis, in degrees, is
    /// set to module::DEFAULT_ROTATE_Y.
    ///
    /// The default rotation angle around the @a z axis, in degrees, is
    /// set to module::DEFAULT_ROTATE_Z.
    this()
    {
        super(this.GetSourceModCount());
        SetAngles (DEFAULT_ROTATE_X, DEFAULT_ROTATE_Y, DEFAULT_ROTATE_Z);
    }

    override int GetSourceModCount () const
    {
      return 1;
    }

    override double GetValue (double x, double y, double z) const
    {
      assert (m_pSourceMod[0] !is null);

      double nx = (m_x1Matrix * x) + (m_y1Matrix * y) + (m_z1Matrix * z);
      double ny = (m_x2Matrix * x) + (m_y2Matrix * y) + (m_z2Matrix * z);
      double nz = (m_x3Matrix * x) + (m_y3Matrix * y) + (m_z3Matrix * z);
      return m_pSourceMod[0].GetValue (nx, ny, nz);
    }

    /// Returns the rotation angle around the @a x axis to apply to the
    /// input value.
    ///
    /// @returns The rotation angle around the @a x axis, in degrees.
    double GetXAngle () const
    {
      return m_xAngle;
    }

    /// Returns the rotation angle around the @a y axis to apply to the
    /// input value.
    ///
    /// @returns The rotation angle around the @a y axis, in degrees.
    double GetYAngle () const
    {
      return m_yAngle;
    }

    /// Returns the rotation angle around the @a z axis to apply to the
    /// input value.
    ///
    /// @returns The rotation angle around the @a z axis, in degrees.
    double GetZAngle () const
    {
      return m_zAngle;
    }

    /// Sets the rotation angles around all three axes to apply to the
    /// input value.
    ///
    /// @param xAngle The rotation angle around the @a x axis, in degrees.
    /// @param yAngle The rotation angle around the @a y axis, in degrees.
    /// @param zAngle The rotation angle around the @a z axis, in degrees.
    ///
    /// The GetValue() method rotates the coordinates of the input value
    /// around the origin before returning the output value from the
    /// source module.
    void SetAngles (double xAngle, double yAngle, double zAngle)
    {
      double xCos, yCos, zCos, xSin, ySin, zSin;
      xCos = cos (xAngle * DEG_TO_RAD);
      yCos = cos (yAngle * DEG_TO_RAD);
      zCos = cos (zAngle * DEG_TO_RAD);
      xSin = sin (xAngle * DEG_TO_RAD);
      ySin = sin (yAngle * DEG_TO_RAD);
      zSin = sin (zAngle * DEG_TO_RAD);

      m_x1Matrix = ySin * xSin * zSin + yCos * zCos;
      m_y1Matrix = xCos * zSin;
      m_z1Matrix = ySin * zCos - yCos * xSin * zSin;
      m_x2Matrix = ySin * xSin * zCos - yCos * zSin;
      m_y2Matrix = xCos * zCos;
      m_z2Matrix = -yCos * xSin * zCos - ySin * zSin;
      m_x3Matrix = -ySin * xCos;
      m_y3Matrix = xSin;
      m_z3Matrix = yCos * xCos;

      m_xAngle = xAngle;
      m_yAngle = yAngle;
      m_zAngle = zAngle;
    }

    /// Sets the rotation angle around the @a x axis to apply to the input
    /// value.
    ///
    /// @param xAngle The rotation angle around the @a x axis, in degrees.
    ///
    /// The GetValue() method rotates the coordinates of the input value
    /// around the origin before returning the output value from the
    /// source module.
    void SetXAngle (double xAngle)
    {
      SetAngles (xAngle, m_yAngle, m_zAngle);
    }

    /// Sets the rotation angle around the @a y axis to apply to the input
    /// value.
    ///
    /// @param yAngle The rotation angle around the @a y axis, in degrees.
    ///
    /// The GetValue() method rotates the coordinates of the input value
    /// around the origin before returning the output value from the
    /// source module.
    void SetYAngle (double yAngle)
    {
      SetAngles (m_xAngle, yAngle, m_zAngle);
    }

    /// Sets the rotation angle around the @a z axis to apply to the input
    /// value.
    ///
    /// @param zAngle The rotation angle around the @a z axis, in degrees.
    ///
    /// The GetValue() method rotates the coordinates of the input value
    /// around the origin before returning the output value from the
    /// source module.
    void SetZAngle (double zAngle)
    {
      SetAngles (m_xAngle, m_yAngle, zAngle);
    }

  protected:

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_x1Matrix;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_x2Matrix;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_x3Matrix;

    /// @a x rotation angle applied to the input value, in degrees.
    double m_xAngle;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_y1Matrix;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_y2Matrix;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_y3Matrix;

    /// @a y rotation angle applied to the input value, in degrees.
    double m_yAngle;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_z1Matrix;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_z2Matrix;

    /// An entry within the 3x3 rotation matrix used for rotating the
    /// input value.
    double m_z3Matrix;

    /// @a z rotation angle applied to the input value, in degrees.
    double m_zAngle;

};

/// @}

/// @}

/// @}