/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * gimpoperationnormalmode-sse2.c
 * Copyright (C) 2013 Daniel Sabo
 *
 * This program 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 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <gegl-plugin.h>

#include "operations-types.h"

#include "gimpoperationnormalmode.h"

#if COMPILE_SSE2_INTRINISICS
/* SSE2 */
#include <emmintrin.h>

gboolean
gimp_operation_normal_mode_process_pixels_sse2 (gfloat              *in,
                                                gfloat              *aux,
                                                gfloat              *mask,
                                                gfloat              *out,
                                                gfloat               opacity,
                                                glong                samples,
                                                const GeglRectangle *roi,
                                                gint                 level)
{
  /* check alignment */
  if ((((uintptr_t)in) | ((uintptr_t)aux) | ((uintptr_t)out)) & 0x0F)
    {
      return gimp_operation_normal_mode_process_pixels_core (in, aux, mask, out,
                                                             opacity, samples,
                                                             roi, level);
    }
  else
    {
      const __v4sf *v_in  = (const __v4sf*) in;
      const __v4sf *v_aux = (const __v4sf*) aux;
            __v4sf *v_out = (      __v4sf*) out;

      const __v4sf one = _mm_set1_ps (1.0f);
      const __v4sf v_opacity = _mm_set1_ps (opacity);

      while (samples--)
        {
          __v4sf rgba_in, rgba_aux, alpha;

          rgba_in  = *v_in++;
          rgba_aux = *v_aux++;

          /* expand alpha */
          alpha = (__v4sf)_mm_shuffle_epi32 ((__m128i)rgba_aux,
                                             _MM_SHUFFLE (3, 3, 3, 3));

          if (mask)
            {
              __v4sf mask_alpha;

              /* multiply aux's alpha by the mask */
              mask_alpha = _mm_set1_ps (*mask++);
              alpha = alpha * mask_alpha;
            }

          alpha = alpha * v_opacity;

          if (_mm_ucomigt_ss (alpha, _mm_setzero_ps ()))
            {
              __v4sf dst_alpha, a_term, out_pixel, out_alpha, out_pixel_rbaa;

              /* expand alpha */
              dst_alpha = (__v4sf)_mm_shuffle_epi32 ((__m128i)rgba_in,
                                                     _MM_SHUFFLE (3, 3, 3, 3));

              /* a_term = dst_a * (1.0 - src_a) */
              a_term = dst_alpha * (one - alpha);

              /* out(color) = src * src_a + dst * a_term */
              out_pixel = rgba_aux * alpha + rgba_in * a_term;

              /* out(alpha) = 1.0 * src_a + 1.0 * a_term */
              out_alpha = alpha + a_term;

              /* un-premultiply */
              out_pixel = out_pixel / out_alpha;

              /* swap in the real alpha */
              out_pixel_rbaa = _mm_shuffle_ps (out_pixel, out_alpha, _MM_SHUFFLE (3, 3, 2, 0));
              out_pixel = _mm_shuffle_ps (out_pixel, out_pixel_rbaa, _MM_SHUFFLE (2, 1, 1, 0));

              *v_out++ = out_pixel;
            }
          else
            {
              *v_out++ = rgba_in;
            }
        }
    }

  return TRUE;
}
#endif /* COMPILE_SSE2_INTRINISICS */
