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
  30 static void
  31 upload_clip_state(struct brw_context *brw)
  32 {
  33    struct intel_context *intel = &brw->intel;
  34    struct gl_context *ctx = &intel->ctx;
  35    uint32_t depth_clamp = 0;
  36    uint32_t provoking, userclip;
  37    uint32_t dw1 = GEN6_CLIP_STATISTICS_ENABLE;
  38    uint32_t nonperspective_barycentric_enable_flag = 0;
  39    /* BRW_NEW_FRAGMENT_PROGRAM */
  40    const struct gl_fragment_program *fprog = brw->fragment_program;
  41
  42    if (brw->hiz.op) {
  43       /* HiZ operations emit a rectangle primitive, which requires clipping to
  44        * be disabled. From page 10 of the Sandy Bridge PRM Volume 2 Part 1
  45        * Section 1.3 3D Primitives Overview:
  46        *    RECTLIST:
  47        *    Either the CLIP unit should be DISABLED, or the CLIP unit's Clip
  48        *    Mode should be set to a value other than CLIPMODE_NORMAL.
  49        */
  50       BEGIN_BATCH(4);
  51       OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
  52       OUT_BATCH(0);
  53       OUT_BATCH(0);
  54       OUT_BATCH(0);
  55       ADVANCE_BATCH();
  56       return;
  57    }
  58
  59    /* _NEW_BUFFERS */
  60    bool render_to_fbo = brw->intel.ctx.DrawBuffer->Name != 0;
  61
  62    if (brw_fprog_uses_noperspective(fprog)) {
  63       nonperspective_barycentric_enable_flag =
  64          GEN6_CLIP_NON_PERSPECTIVE_BARYCENTRIC_ENABLE;
  65    }
  66
  67    dw1 |= GEN7_CLIP_EARLY_CULL;
  68
  69    /* _NEW_POLYGON */
  70    if ((ctx->Polygon.FrontFace == GL_CCW) ^ render_to_fbo)
  71       dw1 |= GEN7_CLIP_WINDING_CCW;
  72
  73    if (ctx->Polygon.CullFlag) {
  74       switch (ctx->Polygon.CullFaceMode) {
  75       case GL_FRONT:
  76          dw1 |= GEN7_CLIP_CULLMODE_FRONT;
  77          break;
  78       case GL_BACK:
  79          dw1 |= GEN7_CLIP_CULLMODE_BACK;
  80          break;
  81       case GL_FRONT_AND_BACK:
  82          dw1 |= GEN7_CLIP_CULLMODE_BOTH;
  83          break;
  84       default:
  85          assert(!"Should not get here: invalid CullFlag");
  86          break;
  87       }
  88    } else {
  89       dw1 |= GEN7_CLIP_CULLMODE_NONE;
  90    }
  91
  92    /* _NEW_TRANSFORM */
  93    if (!ctx->Transform.DepthClamp)
  94       depth_clamp = GEN6_CLIP_Z_TEST;
  95
  96    /* _NEW_LIGHT */
  97    if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
  98       provoking =
  99          (0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
 100          (1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
 101          (0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
 102    } else {
 103       provoking =
 104          (2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
 105          (2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
 106          (1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
 107    }
 108
 109    /* _NEW_TRANSFORM */
 110    userclip = ctx->Transform.ClipPlanesEnabled;
 111
 112    BEGIN_BATCH(4);
 113    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
 114    OUT_BATCH(dw1);
 115    OUT_BATCH(GEN6_CLIP_ENABLE |
 116              GEN6_CLIP_API_OGL |
 117              GEN6_CLIP_MODE_NORMAL |
 118              nonperspective_barycentric_enable_flag |
 119              GEN6_CLIP_XY_TEST |
 120              userclip << GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT |
 121              depth_clamp |
 122              provoking);
 123    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
 124              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
 125              GEN6_CLIP_FORCE_ZERO_RTAINDEX);
 126    ADVANCE_BATCH();
 127 }
 128
 129 const struct brw_tracked_state gen7_clip_state = {
 130    .dirty = {
 131       .mesa  = (_NEW_BUFFERS |
 132                 _NEW_POLYGON |
 133                 _NEW_LIGHT |
 134                 _NEW_TRANSFORM),
 135       .brw   = (BRW_NEW_CONTEXT |
 136                 BRW_NEW_FRAGMENT_PROGRAM |
 137                 BRW_NEW_HIZ),
 138       .cache = 0
 139    },
 140    .emit = upload_clip_state,
 141 };