fastuidraw_anisotropic.frag.glsl.hpp

Go to the documentation of this file.

/*!
 * \file fastuidraw_anisotropic.frag.glsl.hpp
 * \brief file fastuidraw_anisotropic.frag.glsl.hpp
 *
 * Copyright 2018 by Intel.
 *
 * Contact: kevin.rogovin@gmail.com
 *
 * This Source Code Form is subject to the
 * terms of the Mozilla Public License, v. 2.0.
 * If a copy of the MPL was not distributed with
 * this file, You can obtain one at
 * http://mozilla.org/MPL/2.0/.
 *
 * \author Kevin Rogovin <kevin.rogovin@gmail.com>
 *
 */



/*!\addtogroup GLSLVertFragCode
 * @{
 */

/*!
 * \brief computes anisotropic coverage from a coverage value and its screen-space derivatives
 * \param d coverage value
 * \param dx derivative in x-direction of coverage value
 * \param dy derivative in y-direction of coverage value
 */
float
fastuidraw_anisotropic_coverage(float d, float dx, float dy)
{
  float mag_sq;
  mag_sq = (dx * dx + dy * dy);
  return clamp(0.5 + d * inversesqrt(mag_sq), 0.0, 1.0);
}
/*! @} */