src/mesa/state_tracker/st_atom_msaa.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2010 VMware, Inc.
   4  * All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
   8  * "Software"), to deal in the Software without restriction, including
   9  * without limitation the rights to use, copy, modify, merge, publish,
  10  * distribute, sub license, and/or sell copies of the Software, and to
  11  * permit persons to whom the Software is furnished to do so, subject to
  12  * the following conditions:
  13  *
  14  * The above copyright notice and this permission notice (including the
  15  * next paragraph) shall be included in all copies or substantial portions
  16  * of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  21  * IN NO EVENT SHALL THE AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR
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  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "st_context.h"
  30 #include "pipe/p_screen.h"
  31 #include "pipe/p_context.h"
  32 #include "st_atom.h"
  33 #include "st_program.h"
  34
  35 #include "cso_cache/cso_context.h"
  36 #include "main/framebuffer.h"
  37
  38
  39 /* Update the sample mask for MSAA.
  40  */
  41 void
  42 st_update_sample_mask(struct st_context *st)
  43 {
  44    unsigned sample_mask = 0xffffffff;
  45    unsigned sample_count = st->state.fb_num_samples;
  46
  47    if (_mesa_is_multisample_enabled(st->ctx) && sample_count > 1) {
  48       /* unlike in gallium/d3d10 the mask is only active if msaa is enabled */
  49       if (st->ctx->Multisample.SampleCoverage) {
  50          unsigned nr_bits = (unsigned)
  51             (st->ctx->Multisample.SampleCoverageValue * (float) sample_count);
  52          /* there's lot of ways how to do this. We just use first few bits,
  53           * since we have no knowledge of sample positions here. When
  54           * app-supplied mask though is used too might need to be smarter.
  55           * Also, there's an interface restriction here in theory it is
  56           * encouraged this mask not be the same at each pixel.
  57           */
  58          sample_mask = (1 << nr_bits) - 1;
  59          if (st->ctx->Multisample.SampleCoverageInvert)
  60             sample_mask = ~sample_mask;
  61       }
  62       if (st->ctx->Multisample.SampleMask)
  63          sample_mask &= st->ctx->Multisample.SampleMaskValue;
  64    }
  65
  66    cso_set_sample_mask(st->cso_context, sample_mask);
  67 }
  68
  69
  70 void
  71 st_update_sample_shading(struct st_context *st)
  72 {
  73    if (!st->fp)
  74       return;
  75
  76    if (!st->ctx->Extensions.ARB_sample_shading)
  77       return;
  78
  79    cso_set_min_samples(st->cso_context,
  80          _mesa_get_min_invocations_per_fragment(st->ctx, &st->fp->Base, false));
  81 }