1 /**************************************************************************
2 *
3 * Copyright 2008 VMware, Inc.
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * 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, sub license, 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 portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28
29 #ifndef U_PRIM_H
30 #define U_PRIM_H
31
32
33 #include "pipe/p_defines.h"
34 #include "util/u_debug.h"
35
36 #ifdef __cplusplus
37 extern "C" {
38 #endif
39
40 struct u_prim_vertex_count {
41 unsigned min;
42 unsigned incr;
43 };
44
45 /**
46 * Decompose a primitive that is a loop, a strip, or a fan. Return the
47 * original primitive if it is already decomposed.
48 */
49 static inline enum pipe_prim_type
u_decomposed_prim(enum pipe_prim_type prim)50 u_decomposed_prim(enum pipe_prim_type prim)
51 {
52 switch (prim) {
53 case PIPE_PRIM_LINE_LOOP:
54 case PIPE_PRIM_LINE_STRIP:
55 return PIPE_PRIM_LINES;
56 case PIPE_PRIM_TRIANGLE_STRIP:
57 case PIPE_PRIM_TRIANGLE_FAN:
58 return PIPE_PRIM_TRIANGLES;
59 case PIPE_PRIM_QUAD_STRIP:
60 return PIPE_PRIM_QUADS;
61 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
62 return PIPE_PRIM_LINES_ADJACENCY;
63 case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
64 return PIPE_PRIM_TRIANGLES_ADJACENCY;
65 default:
66 return prim;
67 }
68 }
69
70 /**
71 * Reduce a primitive to one of PIPE_PRIM_POINTS, PIPE_PRIM_LINES, and
72 * PIPE_PRIM_TRIANGLES.
73 */
74 static inline enum pipe_prim_type
u_reduced_prim(enum pipe_prim_type prim)75 u_reduced_prim(enum pipe_prim_type prim)
76 {
77 switch (prim) {
78 case PIPE_PRIM_POINTS:
79 return PIPE_PRIM_POINTS;
80 case PIPE_PRIM_LINES:
81 case PIPE_PRIM_LINE_LOOP:
82 case PIPE_PRIM_LINE_STRIP:
83 case PIPE_PRIM_LINES_ADJACENCY:
84 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
85 return PIPE_PRIM_LINES;
86 default:
87 return PIPE_PRIM_TRIANGLES;
88 }
89 }
90
91 /**
92 * Re-assemble a primitive to remove its adjacency.
93 */
94 static inline enum pipe_prim_type
u_assembled_prim(enum pipe_prim_type prim)95 u_assembled_prim(enum pipe_prim_type prim)
96 {
97 switch (prim) {
98 case PIPE_PRIM_LINES_ADJACENCY:
99 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
100 return PIPE_PRIM_LINES;
101 case PIPE_PRIM_TRIANGLES_ADJACENCY:
102 case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
103 return PIPE_PRIM_TRIANGLES;
104 default:
105 return prim;
106 }
107 }
108
109 /**
110 * Return the vertex count information for a primitive.
111 *
112 * Note that if this function is called directly or indirectly anywhere in a
113 * source file, it will increase the size of the binary slightly more than
114 * expected because of the use of a table.
115 */
116 static inline const struct u_prim_vertex_count *
u_prim_vertex_count(enum pipe_prim_type prim)117 u_prim_vertex_count(enum pipe_prim_type prim)
118 {
119 static const struct u_prim_vertex_count prim_table[PIPE_PRIM_MAX] = {
120 { 1, 1 }, /* PIPE_PRIM_POINTS */
121 { 2, 2 }, /* PIPE_PRIM_LINES */
122 { 2, 1 }, /* PIPE_PRIM_LINE_LOOP */
123 { 2, 1 }, /* PIPE_PRIM_LINE_STRIP */
124 { 3, 3 }, /* PIPE_PRIM_TRIANGLES */
125 { 3, 1 }, /* PIPE_PRIM_TRIANGLE_STRIP */
126 { 3, 1 }, /* PIPE_PRIM_TRIANGLE_FAN */
127 { 4, 4 }, /* PIPE_PRIM_QUADS */
128 { 4, 2 }, /* PIPE_PRIM_QUAD_STRIP */
129 { 3, 1 }, /* PIPE_PRIM_POLYGON */
130 { 4, 4 }, /* PIPE_PRIM_LINES_ADJACENCY */
131 { 4, 1 }, /* PIPE_PRIM_LINE_STRIP_ADJACENCY */
132 { 6, 6 }, /* PIPE_PRIM_TRIANGLES_ADJACENCY */
133 { 6, 2 }, /* PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY */
134 };
135
136 return (likely(prim < PIPE_PRIM_MAX)) ? &prim_table[prim] : NULL;
137 }
138
139 /**
140 * Given a vertex count, return the number of primitives.
141 * For polygons, return the number of triangles.
142 */
143 static inline unsigned
u_prims_for_vertices(enum pipe_prim_type prim,unsigned num)144 u_prims_for_vertices(enum pipe_prim_type prim, unsigned num)
145 {
146 const struct u_prim_vertex_count *info = u_prim_vertex_count(prim);
147
148 assert(info);
149 assert(info->incr != 0);
150
151 if (num < info->min)
152 return 0;
153
154 return 1 + ((num - info->min) / info->incr);
155 }
156
157 static inline boolean
u_validate_pipe_prim(enum pipe_prim_type pipe_prim,unsigned nr)158 u_validate_pipe_prim(enum pipe_prim_type pipe_prim, unsigned nr)
159 {
160 const struct u_prim_vertex_count *count = u_prim_vertex_count(pipe_prim);
161
162 return (count && nr >= count->min);
163 }
164
165
166 static inline boolean
u_trim_pipe_prim(enum pipe_prim_type pipe_prim,unsigned * nr)167 u_trim_pipe_prim(enum pipe_prim_type pipe_prim, unsigned *nr)
168 {
169 const struct u_prim_vertex_count *count = u_prim_vertex_count(pipe_prim);
170
171 if (count && *nr >= count->min) {
172 if (count->incr > 1)
173 *nr -= (*nr % count->incr);
174 return TRUE;
175 }
176 else {
177 *nr = 0;
178 return FALSE;
179 }
180 }
181
182 static inline unsigned
u_vertices_per_prim(enum pipe_prim_type primitive)183 u_vertices_per_prim(enum pipe_prim_type primitive)
184 {
185 switch(primitive) {
186 case PIPE_PRIM_POINTS:
187 return 1;
188 case PIPE_PRIM_LINES:
189 case PIPE_PRIM_LINE_LOOP:
190 case PIPE_PRIM_LINE_STRIP:
191 return 2;
192 case PIPE_PRIM_TRIANGLES:
193 case PIPE_PRIM_TRIANGLE_STRIP:
194 case PIPE_PRIM_TRIANGLE_FAN:
195 return 3;
196 case PIPE_PRIM_LINES_ADJACENCY:
197 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
198 return 4;
199 case PIPE_PRIM_TRIANGLES_ADJACENCY:
200 case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
201 return 6;
202
203 /* following primitives should never be used
204 * with geometry shaders abd their size is
205 * undefined */
206 case PIPE_PRIM_POLYGON:
207 case PIPE_PRIM_QUADS:
208 case PIPE_PRIM_QUAD_STRIP:
209 default:
210 debug_printf("Unrecognized geometry shader primitive");
211 return 3;
212 }
213 }
214
215 /**
216 * Returns the number of decomposed primitives for the given
217 * vertex count.
218 * Parts of the pipline are invoked once for each triangle in
219 * triangle strip, triangle fans and triangles and once
220 * for each line in line strip, line loop, lines. Also
221 * statistics depend on knowing the exact number of decomposed
222 * primitives for a set of vertices.
223 */
224 static inline unsigned
u_decomposed_prims_for_vertices(enum pipe_prim_type primitive,int vertices)225 u_decomposed_prims_for_vertices(enum pipe_prim_type primitive, int vertices)
226 {
227 switch (primitive) {
228 case PIPE_PRIM_POINTS:
229 return vertices;
230 case PIPE_PRIM_LINES:
231 return vertices / 2;
232 case PIPE_PRIM_LINE_LOOP:
233 return (vertices >= 2) ? vertices : 0;
234 case PIPE_PRIM_LINE_STRIP:
235 return (vertices >= 2) ? vertices - 1 : 0;
236 case PIPE_PRIM_TRIANGLES:
237 return vertices / 3;
238 case PIPE_PRIM_TRIANGLE_STRIP:
239 return (vertices >= 3) ? vertices - 2 : 0;
240 case PIPE_PRIM_TRIANGLE_FAN:
241 return (vertices >= 3) ? vertices - 2 : 0;
242 case PIPE_PRIM_LINES_ADJACENCY:
243 return vertices / 4;
244 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
245 return (vertices >= 4) ? vertices - 3 : 0;
246 case PIPE_PRIM_TRIANGLES_ADJACENCY:
247 return vertices / 6;
248 case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
249 return (vertices >= 6) ? 1 + (vertices - 6) / 2 : 0;
250 case PIPE_PRIM_QUADS:
251 return vertices / 4;
252 case PIPE_PRIM_QUAD_STRIP:
253 return (vertices >= 4) ? (vertices - 2) / 2 : 0;
254 /* Polygons can't be decomposed
255 * because the number of their vertices isn't known so
256 * for them and whatever else we don't recognize just
257 * return 1 if the number of vertices is greater than
258 * or equal to 3 and zero otherwise */
259 case PIPE_PRIM_POLYGON:
260 default:
261 debug_printf("Invalid decomposition primitive!\n");
262 return (vertices >= 3) ? 1 : 0;
263 }
264 }
265
266 /**
267 * Returns the number of reduced/tessellated primitives for the given vertex
268 * count. Each quad is treated as two triangles. Polygons are treated as
269 * triangle fans.
270 */
271 static inline unsigned
u_reduced_prims_for_vertices(enum pipe_prim_type primitive,int vertices)272 u_reduced_prims_for_vertices(enum pipe_prim_type primitive, int vertices)
273 {
274 switch (primitive) {
275 case PIPE_PRIM_QUADS:
276 case PIPE_PRIM_QUAD_STRIP:
277 return u_decomposed_prims_for_vertices(primitive, vertices) * 2;
278 case PIPE_PRIM_POLYGON:
279 primitive = PIPE_PRIM_TRIANGLE_FAN;
280 /* fall through */
281 default:
282 return u_decomposed_prims_for_vertices(primitive, vertices);
283 }
284 }
285
286 const char *u_prim_name(enum pipe_prim_type pipe_prim);
287
288
289 #ifdef __cplusplus
290 }
291 #endif
292
293
294 #endif
295