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    uint32_t dw1 = brw->meta_in_progress ? 0 : GEN6_CLIP_STATISTICS_ENABLE;
  40    uint32_t dw2 = 0;
  41
  42    /* _NEW_BUFFERS */
  43    struct gl_framebuffer *fb = ctx->DrawBuffer;
  44
  45    /* CACHE_NEW_WM_PROG */
  46    if (brw->wm.prog_data->barycentric_interp_modes &
  47        BRW_WM_NONPERSPECTIVE_BARYCENTRIC_BITS) {
  48       dw2 |= GEN6_CLIP_NON_PERSPECTIVE_BARYCENTRIC_ENABLE;
  49    }
  50
  51    if (!ctx->Transform.DepthClamp)
  52       dw2 |= GEN6_CLIP_Z_TEST;
  53
  54    /* _NEW_LIGHT */
  55    if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
  56       dw2 |=
  57          (0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  58          (1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  59          (0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  60    } else {
  61       dw2 |=
  62          (2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
  63          (2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
  64          (1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
  65    }
  66
  67    /* _NEW_TRANSFORM */
  68    dw2 |= (ctx->Transform.ClipPlanesEnabled <<
  69            GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT);
  70
  71    if (ctx->Viewport.X == 0 &&
  72        ctx->Viewport.Y == 0 &&
  73        ctx->Viewport.Width == fb->Width &&
  74        ctx->Viewport.Height == fb->Height) {
  75       dw2 |= GEN6_CLIP_GB_TEST;
  76    }
  77
  78    /* BRW_NEW_RASTERIZER_DISCARD */
  79    if (ctx->RasterDiscard) {
  80       dw2 |= GEN6_CLIP_MODE_REJECT_ALL;
  81       perf_debug("Rasterizer discard is currently implemented via the clipper; "
  82                  "having the GS not write primitives would likely be faster.");
  83    }
  84
  85    BEGIN_BATCH(4);
  86    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
  87    OUT_BATCH(dw1);
  88    OUT_BATCH(GEN6_CLIP_ENABLE |
  89              GEN6_CLIP_API_OGL |
  90              GEN6_CLIP_MODE_NORMAL |
  91              GEN6_CLIP_XY_TEST |
  92              dw2);
  93    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
  94              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
  95              GEN6_CLIP_FORCE_ZERO_RTAINDEX);
  96    ADVANCE_BATCH();
  97 }
  98
  99 const struct brw_tracked_state gen6_clip_state = {
 100    .dirty = {
 101       .mesa  = _NEW_TRANSFORM | _NEW_LIGHT | _NEW_BUFFERS,
 102       .brw   = BRW_NEW_CONTEXT |
 103                BRW_NEW_META_IN_PROGRESS |
 104                BRW_NEW_RASTERIZER_DISCARD,
 105       .cache = CACHE_NEW_WM_PROG
 106    },
 107    .emit = upload_clip_state,
 108 };