/**************************************************************************
 *
 * Copyright 2010 VMware, Inc.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 **************************************************************************/


#include "st_context.h"
#include "pipe/p_screen.h"
#include "pipe/p_context.h"
#include "st_atom.h"
#include "st_program.h"

#include "cso_cache/cso_context.h"
#include "main/framebuffer.h"


/* Update the sample mask for MSAA.
 */
void
st_update_sample_mask(struct st_context *st)
{
   unsigned sample_mask = 0xffffffff;
   unsigned sample_count = st->state.fb_num_samples;

   if (_mesa_is_multisample_enabled(st->ctx) && sample_count > 1) {
      /* unlike in gallium/d3d10 the mask is only active if msaa is enabled */
      if (st->ctx->Multisample.SampleCoverage) {
         unsigned nr_bits = (unsigned)
            (st->ctx->Multisample.SampleCoverageValue * (float) sample_count);
         /* there's lot of ways how to do this. We just use first few bits,
          * since we have no knowledge of sample positions here. When
          * app-supplied mask though is used too might need to be smarter.
          * Also, there's an interface restriction here in theory it is
          * encouraged this mask not be the same at each pixel.
          */
         sample_mask = (1 << nr_bits) - 1;
         if (st->ctx->Multisample.SampleCoverageInvert)
            sample_mask = ~sample_mask;
      }
      if (st->ctx->Multisample.SampleMask)
         sample_mask &= st->ctx->Multisample.SampleMaskValue;
   }

   cso_set_sample_mask(st->cso_context, sample_mask);
}


void
st_update_sample_shading(struct st_context *st)
{
   if (!st->fp)
      return;

   if (!st->ctx->Extensions.ARB_sample_shading)
      return;

   cso_set_min_samples(st->cso_context,
         _mesa_get_min_invocations_per_fragment(st->ctx, &st->fp->Base));
}