1 /*
2  Copyright (C) Intel Corp.  2006.  All Rights Reserved.
3  Intel funded Tungsten Graphics (http://www.tungstengraphics.com) 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 <keith@tungstengraphics.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 #define MAX_VERTS (3+6+6)
40 
41 /* Note that if unfilled primitives are being emitted, we have to fix
42  * up polygon offset and flatshading at this point:
43  */
44 struct brw_clip_prog_key {
45    GLbitfield64 attrs;
46    GLuint primitive:4;
47    GLuint nr_userclip:4;
48    GLuint do_flat_shading:1;
49    GLuint pv_first:1;
50    GLuint do_unfilled:1;
51    GLuint fill_cw:2;		/* includes cull information */
52    GLuint fill_ccw:2;		/* includes cull information */
53    GLuint offset_cw:1;
54    GLuint offset_ccw:1;
55    GLuint copy_bfc_cw:1;
56    GLuint copy_bfc_ccw:1;
57    GLuint clip_mode:3;
58 
59    GLfloat offset_factor;
60    GLfloat offset_units;
61 };
62 
63 
64 #define CLIP_LINE   0
65 #define CLIP_POINT  1
66 #define CLIP_FILL   2
67 #define CLIP_CULL   3
68 
69 
70 #define PRIM_MASK  (0x1f)
71 
72 struct brw_clip_compile {
73    struct brw_compile func;
74    struct brw_clip_prog_key key;
75    struct brw_clip_prog_data prog_data;
76 
77    struct {
78       struct brw_reg R0;
79       struct brw_reg vertex[MAX_VERTS];
80 
81       struct brw_reg t;
82       struct brw_reg t0, t1;
83       struct brw_reg dp0, dp1;
84 
85       struct brw_reg dpPrev;
86       struct brw_reg dp;
87       struct brw_reg loopcount;
88       struct brw_reg nr_verts;
89       struct brw_reg planemask;
90 
91       struct brw_reg inlist;
92       struct brw_reg outlist;
93       struct brw_reg freelist;
94 
95       struct brw_reg dir;
96       struct brw_reg tmp0, tmp1;
97       struct brw_reg offset;
98 
99       struct brw_reg fixed_planes;
100       struct brw_reg plane_equation;
101 
102       struct brw_reg ff_sync;
103    } reg;
104 
105    /* Number of registers storing VUE data */
106    GLuint nr_regs;
107 
108    GLuint first_tmp;
109    GLuint last_tmp;
110 
111    bool need_direction;
112 
113    struct brw_vue_map vue_map;
114 };
115 
116 #define ATTR_SIZE  (4*4)
117 
118 /**
119  * True if the given vert_result is one of the outputs of the vertex shader.
120  */
brw_clip_have_vert_result(struct brw_clip_compile * c,GLuint vert_result)121 static inline bool brw_clip_have_vert_result(struct brw_clip_compile *c,
122                                              GLuint vert_result)
123 {
124    return (c->key.attrs & BITFIELD64_BIT(vert_result)) ? 1 : 0;
125 }
126 
127 /* Points are only culled, so no need for a clip routine, however it
128  * works out easier to have a dummy one.
129  */
130 void brw_emit_unfilled_clip( struct brw_clip_compile *c );
131 void brw_emit_tri_clip( struct brw_clip_compile *c );
132 void brw_emit_line_clip( struct brw_clip_compile *c );
133 void brw_emit_point_clip( struct brw_clip_compile *c );
134 
135 /* brw_clip_tri.c, for use by the unfilled clip routine:
136  */
137 void brw_clip_tri_init_vertices( struct brw_clip_compile *c );
138 void brw_clip_tri_flat_shade( struct brw_clip_compile *c );
139 void brw_clip_tri( struct brw_clip_compile *c );
140 void brw_clip_tri_emit_polygon( struct brw_clip_compile *c );
141 void brw_clip_tri_alloc_regs( struct brw_clip_compile *c,
142 			      GLuint nr_verts );
143 
144 
145 /* Utils:
146  */
147 
148 void brw_clip_interp_vertex( struct brw_clip_compile *c,
149 			     struct brw_indirect dest_ptr,
150 			     struct brw_indirect v0_ptr, /* from */
151 			     struct brw_indirect v1_ptr, /* to */
152 			     struct brw_reg t0,
153 			     bool force_edgeflag );
154 
155 void brw_clip_init_planes( struct brw_clip_compile *c );
156 
157 void brw_clip_emit_vue(struct brw_clip_compile *c,
158 		       struct brw_indirect vert,
159 		       bool allocate,
160 		       bool eot,
161 		       GLuint header);
162 
163 void brw_clip_kill_thread(struct brw_clip_compile *c);
164 
165 struct brw_reg brw_clip_plane_stride( struct brw_clip_compile *c );
166 struct brw_reg brw_clip_plane0_address( struct brw_clip_compile *c );
167 
168 void brw_clip_copy_colors( struct brw_clip_compile *c,
169 			   GLuint to, GLuint from );
170 
171 void brw_clip_init_clipmask( struct brw_clip_compile *c );
172 
173 struct brw_reg get_tmp( struct brw_clip_compile *c );
174 
175 void brw_clip_project_position(struct brw_clip_compile *c,
176              struct brw_reg pos );
177 void brw_clip_ff_sync(struct brw_clip_compile *c);
178 void brw_clip_init_ff_sync(struct brw_clip_compile *c);
179 #endif
180