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    /* _NEW_BUFFERS */
  43    bool render_to_fbo = brw->intel.ctx.DrawBuffer->Name != 0;
  44
  45    if (brw_fprog_uses_noperspective(fprog)) {
  46       nonperspective_barycentric_enable_flag =
  47          GEN6_CLIP_NON_PERSPECTIVE_BARYCENTRIC_ENABLE;
  48    }
  49
  50    dw1 |= GEN7_CLIP_EARLY_CULL;
  51
  52    /* _NEW_POLYGON */
  53    if ((ctx->Polygon.FrontFace == GL_CCW) ^ render_to_fbo)
  54       dw1 |= GEN7_CLIP_WINDING_CCW;
  55
  56    if (ctx->Polygon.CullFlag) {
  57       switch (ctx->Polygon.CullFaceMode) {
  58       case GL_FRONT:
  59          dw1 |= GEN7_CLIP_CULLMODE_FRONT;
  60          break;
  61       case GL_BACK:
  62          dw1 |= GEN7_CLIP_CULLMODE_BACK;
  63          break;
  64       case GL_FRONT_AND_BACK:
  65          dw1 |= GEN7_CLIP_CULLMODE_BOTH;
  66          break;
  67       default:
  68          assert(!"Should not get here: invalid CullFlag");
  69          break;
  70       }
  71    } else {
  72       dw1 |= GEN7_CLIP_CULLMODE_NONE;
  73    }
  74
  75    /* _NEW_TRANSFORM */
  76    if (!ctx->Transform.DepthClamp)
  77       depth_clamp = GEN6_CLIP_Z_TEST;
  78
  79    /* _NEW_LIGHT */
  80    if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
  81       provoking =
  82          (0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  83          (1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  84          (0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  85    } else {
  86       provoking =
  87          (2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  88          (2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  89          (1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  90    }
  91
  92    /* _NEW_TRANSFORM */
  93    userclip = ctx->Transform.ClipPlanesEnabled;
  94
  95    BEGIN_BATCH(4);
  96    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
  97    OUT_BATCH(dw1);
  98    OUT_BATCH(GEN6_CLIP_ENABLE |
  99              GEN6_CLIP_API_OGL |
 100              GEN6_CLIP_MODE_NORMAL |
 101              nonperspective_barycentric_enable_flag |
 102              GEN6_CLIP_XY_TEST |
 103              userclip << GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT |
 104              depth_clamp |
 105              provoking);
 106    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
 107              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
 108              GEN6_CLIP_FORCE_ZERO_RTAINDEX);
 109    ADVANCE_BATCH();
 110 }
 111
 112 const struct brw_tracked_state gen7_clip_state = {
 113    .dirty = {
 114       .mesa  = (_NEW_BUFFERS |
 115                 _NEW_POLYGON |
 116                 _NEW_LIGHT |
 117                 _NEW_TRANSFORM),
 118       .brw   = (BRW_NEW_CONTEXT |
 119                 BRW_NEW_FRAGMENT_PROGRAM),
 120       .cache = 0
 121    },
 122    .emit = upload_clip_state,
 123 };