src/mesa/state_tracker/st_atom_alphatest.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   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 TUNGSTEN GRAPHICS 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   * Authors:
  30   *   Keith Whitwell <keith@tungstengraphics.com>
  31   *   Brian Paul
  32   */
  33
  34
  35 #include "st_context.h"
  36 #include "st_cache.h"
  37 #include "st_atom.h"
  38 #include "pipe/p_context.h"
  39 #include "pipe/p_defines.h"
  40
  41
  42 /**
  43  * Convert GLenum stencil func tokens to pipe tokens.
  44  */
  45 static GLuint
  46 gl_alpha_func_to_sp(GLenum func)
  47 {
  48    /* Same values, just biased */
  49    assert(PIPE_FUNC_NEVER == GL_NEVER - GL_NEVER);
  50    assert(PIPE_FUNC_LESS == GL_LESS - GL_NEVER);
  51    assert(PIPE_FUNC_EQUAL == GL_EQUAL - GL_NEVER);
  52    assert(PIPE_FUNC_LEQUAL == GL_LEQUAL - GL_NEVER);
  53    assert(PIPE_FUNC_GREATER == GL_GREATER - GL_NEVER);
  54    assert(PIPE_FUNC_NOTEQUAL == GL_NOTEQUAL - GL_NEVER);
  55    assert(PIPE_FUNC_GEQUAL == GL_GEQUAL - GL_NEVER);
  56    assert(PIPE_FUNC_ALWAYS == GL_ALWAYS - GL_NEVER);
  57    assert(func >= GL_NEVER);
  58    assert(func <= GL_ALWAYS);
  59    return func - GL_NEVER;
  60 }
  61
  62
  63 static void
  64 update_alpha_test( struct st_context *st )
  65 {
  66    struct pipe_alpha_test_state alpha;
  67    const struct cso_alpha_test *cso;
  68
  69    memset(&alpha, 0, sizeof(alpha));
  70
  71    if (st->ctx->Color.AlphaEnabled) {
  72       alpha.enabled = 1;
  73       alpha.func = gl_alpha_func_to_sp(st->ctx->Color.AlphaFunc);
  74       alpha.ref = st->ctx->Color.AlphaRef;
  75    }
  76    cso = st_cached_alpha_test_state(st, &alpha);
  77    if (st->state.alpha_test != cso) {
  78       /* state has changed */
  79       st->state.alpha_test = cso;
  80       st->pipe->bind_alpha_test_state(st->pipe, cso->data); /* bind new state */
  81    }
  82 }
  83
  84
  85 const struct st_tracked_state st_update_alpha_test = {
  86    .name = "st_update_alpha_test",
  87    .dirty = {
  88       .mesa = (_NEW_COLOR),
  89       .st  = 0,
  90    },
  91    .update = update_alpha_test
  92 };