src/mesa/drivers/dri/i965/gen6_clip_state.c

   1 /*
   2  * Copyright © 2009 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  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27
  28 #include "brw_context.h"
  29 #include "brw_state.h"
  30 #include "brw_defines.h"
  31 #include "brw_util.h"
  32 #include "intel_batchbuffer.h"
  33 #include "main/fbobject.h"
  34
  35 static void
  36 upload_clip_state(struct brw_context *brw)
  37 {
  38    struct gl_context *ctx = &brw->ctx;
  39    /* BRW_NEW_META_IN_PROGRESS */
  40    uint32_t dw1 = brw->meta_in_progress ? 0 : GEN6_CLIP_STATISTICS_ENABLE;
  41    uint32_t dw2 = 0;
  42
  43    /* _NEW_BUFFERS */
  44    struct gl_framebuffer *fb = ctx->DrawBuffer;
  45
  46    /* CACHE_NEW_WM_PROG */
  47    if (brw->wm.prog_data->barycentric_interp_modes &
  48        BRW_WM_NONPERSPECTIVE_BARYCENTRIC_BITS) {
  49       dw2 |= GEN6_CLIP_NON_PERSPECTIVE_BARYCENTRIC_ENABLE;
  50    }
  51
  52    if (brw->gen >= 7)
  53       dw1 |= GEN7_CLIP_EARLY_CULL;
  54
  55    if (brw->gen == 7) {
  56       /* _NEW_POLYGON */
  57       if ((ctx->Polygon.FrontFace == GL_CCW) ^ _mesa_is_user_fbo(fb))
  58          dw1 |= GEN7_CLIP_WINDING_CCW;
  59
  60       if (ctx->Polygon.CullFlag) {
  61          switch (ctx->Polygon.CullFaceMode) {
  62          case GL_FRONT:
  63             dw1 |= GEN7_CLIP_CULLMODE_FRONT;
  64             break;
  65          case GL_BACK:
  66             dw1 |= GEN7_CLIP_CULLMODE_BACK;
  67             break;
  68          case GL_FRONT_AND_BACK:
  69             dw1 |= GEN7_CLIP_CULLMODE_BOTH;
  70             break;
  71          default:
  72             assert(!"Should not get here: invalid CullFlag");
  73             break;
  74          }
  75       } else {
  76          dw1 |= GEN7_CLIP_CULLMODE_NONE;
  77       }
  78    }
  79
  80    if (brw->gen < 8 && !ctx->Transform.DepthClamp)
  81       dw2 |= GEN6_CLIP_Z_TEST;
  82
  83    /* _NEW_LIGHT */
  84    if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
  85       dw2 |=
  86          (0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  87          (1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  88          (0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  89    } else {
  90       dw2 |=
  91          (2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  92          (2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  93          (1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  94    }
  95
  96    /* _NEW_TRANSFORM */
  97    dw2 |= (ctx->Transform.ClipPlanesEnabled <<
  98            GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT);
  99
 100    dw2 |= GEN6_CLIP_GB_TEST;
 101    for (unsigned i = 0; i < ctx->Const.MaxViewports; i++) {
 102       if (ctx->ViewportArray[i].X != 0 ||
 103           ctx->ViewportArray[i].Y != 0 ||
 104           ctx->ViewportArray[i].Width != (float) fb->Width ||
 105           ctx->ViewportArray[i].Height != (float) fb->Height) {
 106          dw2 &= ~GEN6_CLIP_GB_TEST;
 107          if (brw->gen >= 8) {
 108             perf_debug("Disabling GB clipping due to lack of Gen8 viewport "
 109                        "clipping setup code.  This should be fixed.");
 110          }
 111          break;
 112       }
 113    }
 114
 115    /* BRW_NEW_RASTERIZER_DISCARD */
 116    if (ctx->RasterDiscard) {
 117       dw2 |= GEN6_CLIP_MODE_REJECT_ALL;
 118       perf_debug("Rasterizer discard is currently implemented via the clipper; "
 119                  "%s be faster.", brw->gen >= 7 ? "using the SOL unit may" :
 120                  "having the GS not write primitives would likely");
 121    }
 122
 123    BEGIN_BATCH(4);
 124    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
 125    OUT_BATCH(dw1);
 126    OUT_BATCH(GEN6_CLIP_ENABLE |
 127              GEN6_CLIP_API_OGL |
 128              GEN6_CLIP_MODE_NORMAL |
 129              GEN6_CLIP_XY_TEST |
 130              dw2);
 131    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
 132              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
 133              (fb->MaxNumLayers > 0 ? 0 : GEN6_CLIP_FORCE_ZERO_RTAINDEX) |
 134              ((ctx->Const.MaxViewports - 1) & GEN6_CLIP_MAX_VP_INDEX_MASK));
 135    ADVANCE_BATCH();
 136 }
 137
 138 const struct brw_tracked_state gen6_clip_state = {
 139    .dirty = {
 140       .mesa  = _NEW_TRANSFORM | _NEW_LIGHT | _NEW_BUFFERS,
 141       .brw   = BRW_NEW_CONTEXT |
 142                BRW_NEW_META_IN_PROGRESS |
 143                BRW_NEW_RASTERIZER_DISCARD,
 144       .cache = CACHE_NEW_WM_PROG
 145    },
 146    .emit = upload_clip_state,
 147 };
 148
 149 const struct brw_tracked_state gen7_clip_state = {
 150    .dirty = {
 151       .mesa  = _NEW_BUFFERS | _NEW_LIGHT | _NEW_POLYGON | _NEW_TRANSFORM,
 152       .brw   = BRW_NEW_CONTEXT |
 153                BRW_NEW_META_IN_PROGRESS |
 154                BRW_NEW_RASTERIZER_DISCARD,
 155       .cache = CACHE_NEW_WM_PROG
 156    },
 157    .emit = upload_clip_state,
 158 };