opencl/posterize.cl


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/* This file is an image processing operation for GEGL
 *
 * GEGL 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 3 of the License, or (at your option) any later version.
 *
 * GEGL 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 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright 2013 Carlos Zubieta <czubieta.dev@gmail.com>
 */

__kernel void cl_posterize(__global const float4 *in,
                           __global       float4 *out,
                                          float  levels)
{
  int gid     = get_global_id(0);
  float4 in_v = in[gid];

  in_v.xyz  = trunc(in_v.xyz * levels + (float3)(0.5f)) / levels;
  out[gid]  = in_v;
}