/**************************************************************************
 * 
 * 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 "util/u_framebuffer.h"


/* Update the sample mask for MSAA.
 */
static void update_sample_mask( struct st_context *st )
{
   unsigned sample_mask = 0xffffffff;
   struct pipe_framebuffer_state *framebuffer = &st->state.framebuffer;
   /* dependency here on bound surface (or rather, sample count) is worrying */
   unsigned sample_count = util_framebuffer_get_num_samples(framebuffer);

   if (st->ctx->Multisample.Enabled && sample_count > 1) {
      /* unlike in gallium/d3d10 the mask is only active if msaa is enabled */
      if (st->ctx->Multisample.SampleCoverage) {
         unsigned nr_bits;
         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;
   }

   /* mask off unused bits or don't care? */

   if (sample_mask != st->state.sample_mask) {
      st->state.sample_mask = sample_mask;
      cso_set_sample_mask(st->cso_context, sample_mask);
   }
}

static void 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, false));
}

const struct st_tracked_state st_update_msaa = {
   update_sample_mask					/* update */
};

const struct st_tracked_state st_update_sample_shading = {
   update_sample_shading				/* update */
};