1/*
2 Copyright (C) Intel Corp.  2006.  All Rights Reserved.
3 Intel funded Tungsten Graphics to
4 develop this 3D driver.
5
6 Permission is hereby granted, free of charge, to any person obtaining
7 a copy of this software and associated documentation files (the
8 "Software"), to deal in the Software without restriction, including
9 without limitation the rights to use, copy, modify, merge, publish,
10 distribute, sublicense, and/or sell copies of the Software, and to
11 permit persons to whom the Software is furnished to do so, subject to
12 the following conditions:
13
14 The above copyright notice and this permission notice (including the
15 next paragraph) shall be included in all copies or substantial
16 portions of the Software.
17
18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21 IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25
26 **********************************************************************/
27 /*
28  * Authors:
29  *   Keith Whitwell <keithw@vmware.com>
30  */
31
32#ifndef BRW_CLIP_H
33#define BRW_CLIP_H
34
35#include "brw_compiler.h"
36#include "brw_eu.h"
37
38/* Initial 3 verts, plus at most 6 additional verts from intersections
39 * with fixed planes, plus at most 8 additional verts from intersections
40 * with user clip planes
41 */
42#define MAX_VERTS (3+6+8)
43
44#define PRIM_MASK  (0x1f)
45
46struct brw_clip_compile {
47   struct brw_codegen func;
48   struct brw_clip_prog_key key;
49   struct brw_clip_prog_data prog_data;
50
51   struct {
52      struct brw_reg R0;
53      struct brw_reg vertex[MAX_VERTS];
54
55      struct brw_reg t;
56      struct brw_reg t0, t1;
57      struct brw_reg dp0, dp1;
58
59      struct brw_reg dpPrev;
60      struct brw_reg dp;
61      struct brw_reg loopcount;
62      struct brw_reg nr_verts;
63      struct brw_reg planemask;
64
65      struct brw_reg inlist;
66      struct brw_reg outlist;
67      struct brw_reg freelist;
68
69      struct brw_reg dir;
70      struct brw_reg tmp0, tmp1;
71      struct brw_reg offset;
72
73      struct brw_reg fixed_planes;
74      struct brw_reg plane_equation;
75
76      struct brw_reg ff_sync;
77
78      /* Bitmask indicating which coordinate attribute should be used for
79       * comparison to each clipping plane. A 0 indicates that VARYING_SLOT_POS
80       * should be used, because it's one of the fixed +/- x/y/z planes that
81       * constitute the bounds of the view volume. A 1 indicates that
82       * VARYING_SLOT_CLIP_VERTEX should be used (if available) since it's a user-
83       * defined clipping plane.
84       */
85      struct brw_reg vertex_src_mask;
86
87      /* Offset into the vertex of the current plane's clipdistance value */
88      struct brw_reg clipdistance_offset;
89   } reg;
90
91   /* Number of registers storing VUE data */
92   GLuint nr_regs;
93
94   GLuint first_tmp;
95   GLuint last_tmp;
96
97   bool need_direction;
98
99   struct brw_vue_map vue_map;
100};
101
102/**
103 * True if the given varying is one of the outputs of the vertex shader.
104 */
105static inline bool brw_clip_have_varying(struct brw_clip_compile *c,
106                                         GLuint varying)
107{
108   return (c->key.attrs & BITFIELD64_BIT(varying)) ? 1 : 0;
109}
110
111/* Points are only culled, so no need for a clip routine, however it
112 * works out easier to have a dummy one.
113 */
114void brw_emit_unfilled_clip( struct brw_clip_compile *c );
115void brw_emit_tri_clip( struct brw_clip_compile *c );
116void brw_emit_line_clip( struct brw_clip_compile *c );
117void brw_emit_point_clip( struct brw_clip_compile *c );
118
119/* brw_clip_tri.c, for use by the unfilled clip routine:
120 */
121void brw_clip_tri_init_vertices( struct brw_clip_compile *c );
122void brw_clip_tri_flat_shade( struct brw_clip_compile *c );
123void brw_clip_tri( struct brw_clip_compile *c );
124void brw_clip_tri_emit_polygon( struct brw_clip_compile *c );
125void brw_clip_tri_alloc_regs( struct brw_clip_compile *c,
126			      GLuint nr_verts );
127
128
129/* Utils:
130 */
131
132void brw_clip_interp_vertex( struct brw_clip_compile *c,
133			     struct brw_indirect dest_ptr,
134			     struct brw_indirect v0_ptr, /* from */
135			     struct brw_indirect v1_ptr, /* to */
136			     struct brw_reg t0,
137			     bool force_edgeflag );
138
139void brw_clip_init_planes( struct brw_clip_compile *c );
140
141void brw_clip_emit_vue(struct brw_clip_compile *c,
142		       struct brw_indirect vert,
143                       enum brw_urb_write_flags flags,
144		       GLuint header);
145
146void brw_clip_kill_thread(struct brw_clip_compile *c);
147
148struct brw_reg brw_clip_plane_stride( struct brw_clip_compile *c );
149struct brw_reg brw_clip_plane0_address( struct brw_clip_compile *c );
150
151void brw_clip_copy_flatshaded_attributes( struct brw_clip_compile *c,
152                                          GLuint to, GLuint from );
153
154void brw_clip_init_clipmask( struct brw_clip_compile *c );
155
156struct brw_reg get_tmp( struct brw_clip_compile *c );
157
158void brw_clip_project_position(struct brw_clip_compile *c,
159             struct brw_reg pos );
160void brw_clip_ff_sync(struct brw_clip_compile *c);
161void brw_clip_init_ff_sync(struct brw_clip_compile *c);
162
163#endif
164