1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright 2008 VMware, Inc.
5 * Copyright (C) 2010 LunarG Inc.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
24 */
25
26 static void
FUNC(FUNC_VARS)27 FUNC(FUNC_VARS)
28 {
29 unsigned first, incr;
30 LOCAL_VARS
31
32 /*
33 * prim, start, count, and max_count_{simple,loop,fan} should have been
34 * defined
35 */
36 if (0) {
37 debug_printf("%s: prim 0x%x, start %d, count %d, max_count_simple %d, "
38 "max_count_loop %d, max_count_fan %d\n",
39 __FUNCTION__, prim, start, count, max_count_simple,
40 max_count_loop, max_count_fan);
41 }
42
43 if (prim == PIPE_PRIM_PATCHES) {
44 first = vsplit->draw->pt.vertices_per_patch;
45 incr = vsplit->draw->pt.vertices_per_patch;
46 } else
47 draw_pt_split_prim(prim, &first, &incr);
48 /* sanitize primitive length */
49 count = draw_pt_trim_count(count, first, incr);
50 if (count < first)
51 return;
52
53 /* try flushing the entire primitive */
54 if (PRIMITIVE(start, count))
55 return;
56
57 /* must be able to at least flush two complete primitives */
58 assert(max_count_simple >= first + incr &&
59 max_count_loop >= first + incr &&
60 max_count_fan >= first + incr);
61
62 /* no splitting required */
63 if (count <= max_count_simple) {
64 SEGMENT_SIMPLE(0x0, start, count);
65 }
66 else {
67 const unsigned rollback = first - incr;
68 unsigned flags = DRAW_SPLIT_AFTER, seg_start = 0, seg_max;
69
70 /*
71 * Both count and seg_max below are explicitly trimmed. Because
72 *
73 * seg_start = N * (seg_max - rollback) = N' * incr,
74 *
75 * we have
76 *
77 * remaining = count - seg_start = first + N'' * incr.
78 *
79 * That is, remaining is implicitly trimmed.
80 */
81 switch (prim) {
82 case PIPE_PRIM_PATCHES:
83 case PIPE_PRIM_POINTS:
84 case PIPE_PRIM_LINES:
85 case PIPE_PRIM_LINE_STRIP:
86 case PIPE_PRIM_TRIANGLES:
87 case PIPE_PRIM_TRIANGLE_STRIP:
88 case PIPE_PRIM_QUADS:
89 case PIPE_PRIM_QUAD_STRIP:
90 case PIPE_PRIM_LINES_ADJACENCY:
91 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
92 case PIPE_PRIM_TRIANGLES_ADJACENCY:
93 case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
94 seg_max =
95 draw_pt_trim_count(MIN2(max_count_simple, count), first, incr);
96 if (prim == PIPE_PRIM_TRIANGLE_STRIP ||
97 prim == PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY) {
98 /* make sure we flush even number of triangles at a time */
99 if (seg_max < count && !(((seg_max - first) / incr) & 1))
100 seg_max -= incr;
101 }
102
103 do {
104 const unsigned remaining = count - seg_start;
105
106 if (remaining > seg_max) {
107 SEGMENT_SIMPLE(flags, start + seg_start, seg_max);
108 seg_start += seg_max - rollback;
109
110 flags |= DRAW_SPLIT_BEFORE;
111 }
112 else {
113 flags &= ~DRAW_SPLIT_AFTER;
114
115 SEGMENT_SIMPLE(flags, start + seg_start, remaining);
116 seg_start += remaining;
117 }
118 } while (seg_start < count);
119 break;
120
121 case PIPE_PRIM_LINE_LOOP:
122 seg_max =
123 draw_pt_trim_count(MIN2(max_count_loop, count), first, incr);
124
125 do {
126 const unsigned remaining = count - seg_start;
127
128 if (remaining > seg_max) {
129 SEGMENT_LOOP(flags, start + seg_start, seg_max, start);
130 seg_start += seg_max - rollback;
131
132 flags |= DRAW_SPLIT_BEFORE;
133 }
134 else {
135 flags &= ~DRAW_SPLIT_AFTER;
136
137 SEGMENT_LOOP(flags, start + seg_start, remaining, start);
138 seg_start += remaining;
139 }
140 } while (seg_start < count);
141 break;
142
143 case PIPE_PRIM_TRIANGLE_FAN:
144 case PIPE_PRIM_POLYGON:
145 seg_max =
146 draw_pt_trim_count(MIN2(max_count_fan, count), first, incr);
147
148 do {
149 const unsigned remaining = count - seg_start;
150
151 if (remaining > seg_max) {
152 SEGMENT_FAN(flags, start + seg_start, seg_max, start);
153 seg_start += seg_max - rollback;
154
155 flags |= DRAW_SPLIT_BEFORE;
156 }
157 else {
158 flags &= ~DRAW_SPLIT_AFTER;
159
160 SEGMENT_FAN(flags, start + seg_start, remaining, start);
161 seg_start += remaining;
162 }
163 } while (seg_start < count);
164 break;
165
166 default:
167 assert(0);
168 break;
169 }
170 }
171 }
172
173 #undef FUNC
174 #undef FUNC_VARS
175 #undef LOCAL_VARS
176
177 #undef PRIMITIVE
178 #undef SEGMENT_SIMPLE
179 #undef SEGMENT_LOOP
180 #undef SEGMENT_FAN
181