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
  39    /* _NEW_BUFFERS */
  40    GLboolean render_to_fbo = brw->intel.ctx.DrawBuffer->Name != 0;
  41
  42    /* BRW_NEW_VERTEX_PROGRAM */
  43    struct brw_vertex_program *vp =
  44       (struct brw_vertex_program *)brw->vertex_program;
  45
  46    dw1 |= GEN7_CLIP_EARLY_CULL;
  47
  48    /* _NEW_POLYGON */
  49    if ((ctx->Polygon.FrontFace == GL_CCW) ^ render_to_fbo)
  50       dw1 |= GEN7_CLIP_WINDING_CCW;
  51
  52    if (ctx->Polygon.CullFlag) {
  53       switch (ctx->Polygon.CullFaceMode) {
  54       case GL_FRONT:
  55          dw1 |= GEN7_CLIP_CULLMODE_FRONT;
  56          break;
  57       case GL_BACK:
  58          dw1 |= GEN7_CLIP_CULLMODE_BACK;
  59          break;
  60       case GL_FRONT_AND_BACK:
  61          dw1 |= GEN7_CLIP_CULLMODE_BOTH;
  62          break;
  63       default:
  64          assert(!"Should not get here: invalid CullFlag");
  65          break;
  66       }
  67    } else {
  68       dw1 |= GEN7_CLIP_CULLMODE_NONE;
  69    }
  70
  71    /* _NEW_TRANSFORM */
  72    if (!ctx->Transform.DepthClamp)
  73       depth_clamp = GEN6_CLIP_Z_TEST;
  74
  75    /* _NEW_LIGHT */
  76    if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
  77       provoking =
  78          (0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  79          (1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  80          (0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  81    } else {
  82       provoking =
  83          (2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  84          (2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  85          (1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  86    }
  87
  88    /* _NEW_TRANSFORM */
  89    userclip = brw_compute_userclip_flags(vp->program.UsesClipDistance,
  90                                          ctx->Transform.ClipPlanesEnabled);
  91
  92    BEGIN_BATCH(4);
  93    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
  94    OUT_BATCH(dw1);
  95    OUT_BATCH(GEN6_CLIP_ENABLE |
  96              GEN6_CLIP_API_OGL |
  97              GEN6_CLIP_MODE_NORMAL |
  98              GEN6_CLIP_XY_TEST |
  99              userclip << GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT |
 100              depth_clamp |
 101              provoking);
 102    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
 103              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
 104              GEN6_CLIP_FORCE_ZERO_RTAINDEX);
 105    ADVANCE_BATCH();
 106 }
 107
 108 const struct brw_tracked_state gen7_clip_state = {
 109    .dirty = {
 110       .mesa  = (_NEW_BUFFERS |
 111                 _NEW_POLYGON |
 112                 _NEW_LIGHT |
 113                 _NEW_TRANSFORM),
 114       .brw   = BRW_NEW_CONTEXT | BRW_NEW_VERTEX_PROGRAM,
 115       .cache = 0
 116    },
 117    .emit = upload_clip_state,
 118 };