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 #include "main/fbobject.h"
30 
31 static void
upload_clip_state(struct brw_context * brw)32 upload_clip_state(struct brw_context *brw)
33 {
34    struct intel_context *intel = &brw->intel;
35    struct gl_context *ctx = &intel->ctx;
36    uint32_t depth_clamp = 0;
37    uint32_t provoking, userclip;
38    uint32_t dw1 = GEN6_CLIP_STATISTICS_ENABLE;
39    uint32_t nonperspective_barycentric_enable_flag = 0;
40 
41    /* _NEW_BUFFERS */
42    bool render_to_fbo = _mesa_is_user_fbo(brw->intel.ctx.DrawBuffer);
43 
44    /* CACHE_NEW_WM_PROG */
45    if (brw->wm.prog_data->barycentric_interp_modes &
46        BRW_WM_NONPERSPECTIVE_BARYCENTRIC_BITS) {
47       nonperspective_barycentric_enable_flag =
48          GEN6_CLIP_NON_PERSPECTIVE_BARYCENTRIC_ENABLE;
49    }
50 
51    dw1 |= GEN7_CLIP_EARLY_CULL;
52 
53    /* _NEW_POLYGON */
54    if ((ctx->Polygon.FrontFace == GL_CCW) ^ render_to_fbo)
55       dw1 |= GEN7_CLIP_WINDING_CCW;
56 
57    if (ctx->Polygon.CullFlag) {
58       switch (ctx->Polygon.CullFaceMode) {
59       case GL_FRONT:
60 	 dw1 |= GEN7_CLIP_CULLMODE_FRONT;
61 	 break;
62       case GL_BACK:
63 	 dw1 |= GEN7_CLIP_CULLMODE_BACK;
64 	 break;
65       case GL_FRONT_AND_BACK:
66 	 dw1 |= GEN7_CLIP_CULLMODE_BOTH;
67 	 break;
68       default:
69 	 assert(!"Should not get here: invalid CullFlag");
70 	 break;
71       }
72    } else {
73       dw1 |= GEN7_CLIP_CULLMODE_NONE;
74    }
75 
76    /* _NEW_TRANSFORM */
77    if (!ctx->Transform.DepthClamp)
78       depth_clamp = GEN6_CLIP_Z_TEST;
79 
80    /* _NEW_LIGHT */
81    if (ctx->Light.ProvokingVertex == GL_FIRST_VERTEX_CONVENTION) {
82       provoking =
83 	 (0 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
84 	 (1 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
85 	 (0 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
86    } else {
87       provoking =
88 	 (2 << GEN6_CLIP_TRI_PROVOKE_SHIFT) |
89 	 (2 << GEN6_CLIP_TRIFAN_PROVOKE_SHIFT) |
90 	 (1 << GEN6_CLIP_LINE_PROVOKE_SHIFT);
91    }
92 
93    /* _NEW_TRANSFORM */
94    userclip = ctx->Transform.ClipPlanesEnabled;
95 
96    BEGIN_BATCH(4);
97    OUT_BATCH(_3DSTATE_CLIP << 16 | (4 - 2));
98    OUT_BATCH(dw1);
99    OUT_BATCH(GEN6_CLIP_ENABLE |
100 	     GEN6_CLIP_API_OGL |
101 	     GEN6_CLIP_MODE_NORMAL |
102              nonperspective_barycentric_enable_flag |
103 	     GEN6_CLIP_XY_TEST |
104 	     userclip << GEN6_USER_CLIP_CLIP_DISTANCES_SHIFT |
105 	     depth_clamp |
106 	     provoking);
107    OUT_BATCH(U_FIXED(0.125, 3) << GEN6_CLIP_MIN_POINT_WIDTH_SHIFT |
108              U_FIXED(255.875, 3) << GEN6_CLIP_MAX_POINT_WIDTH_SHIFT |
109              GEN6_CLIP_FORCE_ZERO_RTAINDEX);
110    ADVANCE_BATCH();
111 }
112 
113 const struct brw_tracked_state gen7_clip_state = {
114    .dirty = {
115       .mesa  = (_NEW_BUFFERS |
116                 _NEW_POLYGON |
117                 _NEW_LIGHT |
118                 _NEW_TRANSFORM),
119       .brw   = BRW_NEW_CONTEXT,
120       .cache = CACHE_NEW_WM_PROG
121    },
122    .emit = upload_clip_state,
123 };
124