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
  22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  **************************************************************************/
  27
  28
  29 #include "st_context.h"
  30 #include "pipe/p_context.h"
  31 #include "st_atom.h"
  32
  33 #include "cso_cache/cso_context.h"
  34
  35
  36 /* Second state atom for user clip planes:
  37  */
  38 static void update_sample_mask( struct st_context *st )
  39 {
  40    unsigned sample_mask = 0xffffffff;
  41    unsigned sample_count = 1;
  42    struct pipe_framebuffer_state *framebuffer = &st->state.framebuffer;
  43
  44    /* dependency here on bound surface (or rather, sample count) is worrying */
  45    if (framebuffer->zsbuf)
  46       sample_count = framebuffer->zsbuf->texture->nr_samples;
  47    else if (framebuffer->cbufs[0])
  48       sample_count = framebuffer->cbufs[0]->texture->nr_samples;
  49
  50    if (st->ctx->Multisample.Enabled && sample_count > 1) {
  51    /* unlike in gallium/d3d10 the mask is only active if msaa is enabled */
  52       if (st->ctx->Multisample.SampleCoverage) {
  53          unsigned nr_bits;
  54          nr_bits = (unsigned)
  55             (st->ctx->Multisample.SampleCoverageValue * (float)sample_count);
  56          /* there's lot of ways how to do this. We just use first few bits,
  57             since we have no knowledge of sample positions here. When
  58             app-supplied mask though is used too might need to be smarter.
  59             Also, there's a interface restriction here in theory it is
  60             encouraged this mask not be the same at each pixel. */
  61          sample_mask = (1 << nr_bits) - 1;
  62          if (st->ctx->Multisample.SampleCoverageInvert)
  63             sample_mask = ~sample_mask;
  64       }
  65       if (st->ctx->Multisample.SampleMask)
  66          sample_mask &= st->ctx->Multisample.SampleMaskValue;
  67    }
  68
  69    /* mask off unused bits or don't care? */
  70
  71    if (sample_mask != st->state.sample_mask) {
  72       st->state.sample_mask = sample_mask;
  73       cso_set_sample_mask(st->cso_context, sample_mask);
  74    }
  75 }
  76
  77
  78 const struct st_tracked_state st_update_msaa = {
  79    "st_update_msaa",                                    /* name */
  80    {                                                    /* dirty */
  81       (_NEW_MULTISAMPLE | _NEW_BUFFERS),                /* mesa */
  82       ST_NEW_FRAMEBUFFER,                               /* st */
  83    },
  84    update_sample_mask                                   /* update */
  85 };