src/mesa/drivers/dri/i965/gen7_clip_state.c

   1 /*
   2  * Copyright © 2011 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  */
  23
  24 #include "brw_context.h"
  25 #include "brw_state.h"
  26 #include "brw_defines.h"
  27 #include "brw_util.h"
  28 #include "intel_batchbuffer.h"
  29 #include "main/fbobject.h"
  30
  31 static void
  32 upload_clip_state(struct brw_context *brw)
  33 {
  34    struct intel_context *intel = &brw->intel;
  35    struct gl_context *ctx = &intel->ctx;
  36    uint32_t depth_clamp = 0;
  37    uint32_t provoking, userclip;
  38    uint32_t dw1 = GEN6_CLIP_STATISTICS_ENABLE;
  39    uint32_t nonperspective_barycentric_enable_flag = 0;
  40
  41    /* _NEW_BUFFERS */
  42    bool render_to_fbo = _mesa_is_user_fbo(brw->intel.ctx.DrawBuffer);
  43
  44    /* CACHE_NEW_WM_PROG */
  45    if (brw->wm.prog_data->barycentric_interp_modes &
  46        BRW_WM_NONPERSPECTIVE_BARYCENTRIC_BITS) {
  47       nonperspective_barycentric_enable_flag =
  48          GEN6_CLIP_NON_PERSPECTIVE_BARYCENTRIC_ENABLE;
  49    }
  50
  51    dw1 |= GEN7_CLIP_EARLY_CULL;
  52
  53    /* _NEW_POLYGON */
  54    if ((ctx->Polygon.FrontFace == GL_CCW) ^ render_to_fbo)
  55       dw1 |= GEN7_CLIP_WINDING_CCW;
  56
  57    if (ctx->Polygon.CullFlag) {
  58       switch (ctx->Polygon.CullFaceMode) {
  59       case GL_FRONT:
  60          dw1 |= GEN7_CLIP_CULLMODE_FRONT;
  61          break;
  62       case GL_BACK:
  63          dw1 |= GEN7_CLIP_CULLMODE_BACK;
  64          break;
  65       case GL_FRONT_AND_BACK:
  66          dw1 |= GEN7_CLIP_CULLMODE_BOTH;
  67          break;
  68       default:
  69          assert(!"Should not get here: invalid CullFlag");
  70          break;
  71       }
  72    } else {
  73       dw1 |= GEN7_CLIP_CULLMODE_NONE;
  74    }
  75
  76    /* _NEW_TRANSFORM */
  77    if (!ctx->Transform.DepthClamp)
  78       depth_clamp = GEN6_CLIP_Z_TEST;
  79
  80    /* _NEW_LIGHT */
  81    if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
  82       provoking =
  83          (0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  84          (1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  85          (0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  86    } else {
  87       provoking =
  88          (2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  89          (2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  90          (1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  91    }
  92
  93    /* _NEW_TRANSFORM */
  94    userclip = ctx->Transform.ClipPlanesEnabled;
  95
  96    BEGIN_BATCH(4);
  97    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
  98    OUT_BATCH(dw1);
  99    OUT_BATCH(GEN6_CLIP_ENABLE |
 100              GEN6_CLIP_API_OGL |
 101              GEN6_CLIP_MODE_NORMAL |
 102              nonperspective_barycentric_enable_flag |
 103              GEN6_CLIP_XY_TEST |
 104              GEN6_CLIP_GB_TEST |
 105              userclip << GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT |
 106              depth_clamp |
 107              provoking);
 108    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
 109              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
 110              GEN6_CLIP_FORCE_ZERO_RTAINDEX);
 111    ADVANCE_BATCH();
 112 }
 113
 114 const struct brw_tracked_state gen7_clip_state = {
 115    .dirty = {
 116       .mesa  = (_NEW_BUFFERS |
 117                 _NEW_POLYGON |
 118                 _NEW_LIGHT |
 119                 _NEW_TRANSFORM),
 120       .brw   = BRW_NEW_CONTEXT,
 121       .cache = CACHE_NEW_WM_PROG
 122    },
 123    .emit = upload_clip_state,
 124 };