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
36 #include "brw_context.h"
37 #include "brw_eu.h"
38
39 /* Initial 3 verts, plus at most 6 additional verts from intersections
40 * with fixed planes, plus at most 8 additional verts from intersections
41 * with user clip planes
42 */
43 #define MAX_VERTS (3+6+8)
44
45 /* Note that if unfilled primitives are being emitted, we have to fix
46 * up polygon offset and flatshading at this point:
47 */
48 struct brw_clip_prog_key {
49 GLbitfield64 attrs;
50 bool contains_flat_varying;
51 bool contains_noperspective_varying;
52 const unsigned char *interp_mode;
53 GLuint primitive:4;
54 GLuint nr_userclip:4;
55 GLuint pv_first:1;
56 GLuint do_unfilled:1;
57 GLuint fill_cw:2; /* includes cull information */
58 GLuint fill_ccw:2; /* includes cull information */
59 GLuint offset_cw:1;
60 GLuint offset_ccw:1;
61 GLuint copy_bfc_cw:1;
62 GLuint copy_bfc_ccw:1;
63 GLuint clip_mode:3;
64
65 GLfloat offset_factor;
66 GLfloat offset_units;
67 GLfloat offset_clamp;
68 };
69
70
71 #define CLIP_LINE 0
72 #define CLIP_POINT 1
73 #define CLIP_FILL 2
74 #define CLIP_CULL 3
75
76
77 #define PRIM_MASK (0x1f)
78
79 struct brw_clip_compile {
80 struct brw_codegen func;
81 struct brw_clip_prog_key key;
82 struct brw_clip_prog_data prog_data;
83
84 struct {
85 struct brw_reg R0;
86 struct brw_reg vertex[MAX_VERTS];
87
88 struct brw_reg t;
89 struct brw_reg t0, t1;
90 struct brw_reg dp0, dp1;
91
92 struct brw_reg dpPrev;
93 struct brw_reg dp;
94 struct brw_reg loopcount;
95 struct brw_reg nr_verts;
96 struct brw_reg planemask;
97
98 struct brw_reg inlist;
99 struct brw_reg outlist;
100 struct brw_reg freelist;
101
102 struct brw_reg dir;
103 struct brw_reg tmp0, tmp1;
104 struct brw_reg offset;
105
106 struct brw_reg fixed_planes;
107 struct brw_reg plane_equation;
108
109 struct brw_reg ff_sync;
110
111 /* Bitmask indicating which coordinate attribute should be used for
112 * comparison to each clipping plane. A 0 indicates that VARYING_SLOT_POS
113 * should be used, because it's one of the fixed +/- x/y/z planes that
114 * constitute the bounds of the view volume. A 1 indicates that
115 * VARYING_SLOT_CLIP_VERTEX should be used (if available) since it's a user-
116 * defined clipping plane.
117 */
118 struct brw_reg vertex_src_mask;
119
120 /* Offset into the vertex of the current plane's clipdistance value */
121 struct brw_reg clipdistance_offset;
122 } reg;
123
124 /* Number of registers storing VUE data */
125 GLuint nr_regs;
126
127 GLuint first_tmp;
128 GLuint last_tmp;
129
130 bool need_direction;
131
132 struct brw_vue_map vue_map;
133 };
134
135 /**
136 * True if the given varying is one of the outputs of the vertex shader.
137 */
brw_clip_have_varying(struct brw_clip_compile * c,GLuint varying)138 static inline bool brw_clip_have_varying(struct brw_clip_compile *c,
139 GLuint varying)
140 {
141 return (c->key.attrs & BITFIELD64_BIT(varying)) ? 1 : 0;
142 }
143
144 /* Points are only culled, so no need for a clip routine, however it
145 * works out easier to have a dummy one.
146 */
147 void brw_emit_unfilled_clip( struct brw_clip_compile *c );
148 void brw_emit_tri_clip( struct brw_clip_compile *c );
149 void brw_emit_line_clip( struct brw_clip_compile *c );
150 void brw_emit_point_clip( struct brw_clip_compile *c );
151
152 /* brw_clip_tri.c, for use by the unfilled clip routine:
153 */
154 void brw_clip_tri_init_vertices( struct brw_clip_compile *c );
155 void brw_clip_tri_flat_shade( struct brw_clip_compile *c );
156 void brw_clip_tri( struct brw_clip_compile *c );
157 void brw_clip_tri_emit_polygon( struct brw_clip_compile *c );
158 void brw_clip_tri_alloc_regs( struct brw_clip_compile *c,
159 GLuint nr_verts );
160
161
162 /* Utils:
163 */
164
165 void brw_clip_interp_vertex( struct brw_clip_compile *c,
166 struct brw_indirect dest_ptr,
167 struct brw_indirect v0_ptr, /* from */
168 struct brw_indirect v1_ptr, /* to */
169 struct brw_reg t0,
170 bool force_edgeflag );
171
172 void brw_clip_init_planes( struct brw_clip_compile *c );
173
174 void brw_clip_emit_vue(struct brw_clip_compile *c,
175 struct brw_indirect vert,
176 enum brw_urb_write_flags flags,
177 GLuint header);
178
179 void brw_clip_kill_thread(struct brw_clip_compile *c);
180
181 struct brw_reg brw_clip_plane_stride( struct brw_clip_compile *c );
182 struct brw_reg brw_clip_plane0_address( struct brw_clip_compile *c );
183
184 void brw_clip_copy_flatshaded_attributes( struct brw_clip_compile *c,
185 GLuint to, GLuint from );
186
187 void brw_clip_init_clipmask( struct brw_clip_compile *c );
188
189 struct brw_reg get_tmp( struct brw_clip_compile *c );
190
191 void brw_clip_project_position(struct brw_clip_compile *c,
192 struct brw_reg pos );
193 void brw_clip_ff_sync(struct brw_clip_compile *c);
194 void brw_clip_init_ff_sync(struct brw_clip_compile *c);
195 #endif
196