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 * Authors:
26 * Keith Whitwell <keithw@vmware.com>
27 * Chia-I Wu <olv@lunarg.com>
28 */
29
30 /* these macros are optional */
31 #ifndef LOCAL_VARS
32 #define LOCAL_VARS
33 #endif
34 #ifndef FUNC_ENTER
35 #define FUNC_ENTER do {} while (0)
36 #endif
37 #ifndef FUNC_EXIT
38 #define FUNC_EXIT do {} while (0)
39 #endif
40 #ifndef LINE_ADJ
41 #define LINE_ADJ(flags, a0, i0, i1, a1) LINE(flags, i0, i1)
42 #endif
43 #ifndef TRIANGLE_ADJ
44 #define TRIANGLE_ADJ(flags, i0, a0, i1, a1, i2, a2) TRIANGLE(flags, i0, i1, i2)
45 #endif
46
47 static void
FUNC(FUNC_VARS)48 FUNC(FUNC_VARS)
49 {
50 unsigned idx[6], i;
51 ushort flags;
52 LOCAL_VARS
53
54 FUNC_ENTER;
55
56 /* prim, prim_flags, count, and last_vertex_last should have been defined */
57 if (0) {
58 debug_printf("%s: prim 0x%x, prim_flags 0x%x, count %d, last_vertex_last %d\n",
59 __FUNCTION__, prim, prim_flags, count, last_vertex_last);
60 }
61
62 switch (prim) {
63 case PIPE_PRIM_POINTS:
64 for (i = 0; i < count; i++) {
65 idx[0] = GET_ELT(i);
66 POINT(idx[0]);
67 }
68 break;
69
70 case PIPE_PRIM_LINES:
71 flags = DRAW_PIPE_RESET_STIPPLE;
72 for (i = 0; i + 1 < count; i += 2) {
73 idx[0] = GET_ELT(i);
74 idx[1] = GET_ELT(i + 1);
75 LINE(flags, idx[0], idx[1]);
76 }
77 break;
78
79 case PIPE_PRIM_LINE_LOOP:
80 case PIPE_PRIM_LINE_STRIP:
81 if (count >= 2) {
82 flags = (prim_flags & DRAW_SPLIT_BEFORE) ? 0 : DRAW_PIPE_RESET_STIPPLE;
83 idx[1] = GET_ELT(0);
84 idx[2] = idx[1];
85
86 for (i = 1; i < count; i++, flags = 0) {
87 idx[0] = idx[1];
88 idx[1] = GET_ELT(i);
89 LINE(flags, idx[0], idx[1]);
90 }
91 /* close the loop */
92 if (prim == PIPE_PRIM_LINE_LOOP && !prim_flags)
93 LINE(flags, idx[1], idx[2]);
94 }
95 break;
96
97 case PIPE_PRIM_TRIANGLES:
98 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
99 for (i = 0; i + 2 < count; i += 3) {
100 idx[0] = GET_ELT(i);
101 idx[1] = GET_ELT(i + 1);
102 idx[2] = GET_ELT(i + 2);
103 TRIANGLE(flags, idx[0], idx[1], idx[2]);
104 }
105 break;
106
107 case PIPE_PRIM_TRIANGLE_STRIP:
108 if (count >= 3) {
109 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
110 idx[1] = GET_ELT(0);
111 idx[2] = GET_ELT(1);
112
113 if (last_vertex_last) {
114 for (i = 0; i + 2 < count; i++) {
115 idx[0] = idx[1];
116 idx[1] = idx[2];
117 idx[2] = GET_ELT(i + 2);
118 /* always emit idx[2] last */
119 if (i & 1)
120 TRIANGLE(flags, idx[1], idx[0], idx[2]);
121 else
122 TRIANGLE(flags, idx[0], idx[1], idx[2]);
123 }
124 }
125 else {
126 for (i = 0; i + 2 < count; i++) {
127 idx[0] = idx[1];
128 idx[1] = idx[2];
129 idx[2] = GET_ELT(i + 2);
130 /* always emit idx[0] first */
131 if (i & 1)
132 TRIANGLE(flags, idx[0], idx[2], idx[1]);
133 else
134 TRIANGLE(flags, idx[0], idx[1], idx[2]);
135 }
136 }
137 }
138 break;
139
140 case PIPE_PRIM_TRIANGLE_FAN:
141 if (count >= 3) {
142 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
143 idx[0] = GET_ELT(0);
144 idx[2] = GET_ELT(1);
145
146 /* idx[0] is neither the first nor the last vertex */
147 if (last_vertex_last) {
148 for (i = 0; i + 2 < count; i++) {
149 idx[1] = idx[2];
150 idx[2] = GET_ELT(i + 2);
151 /* always emit idx[2] last */
152 TRIANGLE(flags, idx[0], idx[1], idx[2]);
153 }
154 }
155 else {
156 for (i = 0; i + 2 < count; i++) {
157 idx[1] = idx[2];
158 idx[2] = GET_ELT(i + 2);
159 /* always emit idx[1] first */
160 TRIANGLE(flags, idx[1], idx[2], idx[0]);
161 }
162 }
163 }
164 break;
165
166 case PIPE_PRIM_QUADS:
167 if (last_vertex_last) {
168 for (i = 0; i + 3 < count; i += 4) {
169 idx[0] = GET_ELT(i);
170 idx[1] = GET_ELT(i + 1);
171 idx[2] = GET_ELT(i + 2);
172 idx[3] = GET_ELT(i + 3);
173
174 flags = DRAW_PIPE_RESET_STIPPLE |
175 DRAW_PIPE_EDGE_FLAG_0 |
176 DRAW_PIPE_EDGE_FLAG_2;
177 /* always emit idx[3] last */
178 TRIANGLE(flags, idx[0], idx[1], idx[3]);
179
180 flags = DRAW_PIPE_EDGE_FLAG_0 |
181 DRAW_PIPE_EDGE_FLAG_1;
182 TRIANGLE(flags, idx[1], idx[2], idx[3]);
183 }
184 }
185 else {
186 for (i = 0; i + 3 < count; i += 4) {
187 idx[0] = GET_ELT(i);
188 idx[1] = GET_ELT(i + 1);
189 idx[2] = GET_ELT(i + 2);
190 idx[3] = GET_ELT(i + 3);
191
192 flags = DRAW_PIPE_RESET_STIPPLE |
193 DRAW_PIPE_EDGE_FLAG_0 |
194 DRAW_PIPE_EDGE_FLAG_1;
195 /* always emit idx[3] / idx[0] first */
196 if (quads_flatshade_last)
197 TRIANGLE(flags, idx[3], idx[0], idx[1]);
198 else
199 TRIANGLE(flags, idx[0], idx[1], idx[2]);
200
201 flags = DRAW_PIPE_EDGE_FLAG_1 |
202 DRAW_PIPE_EDGE_FLAG_2;
203 if (quads_flatshade_last)
204 TRIANGLE(flags, idx[3], idx[1], idx[2]);
205 else
206 TRIANGLE(flags, idx[0], idx[2], idx[3]);
207 }
208 }
209 break;
210
211 case PIPE_PRIM_QUAD_STRIP:
212 if (count >= 4) {
213 idx[2] = GET_ELT(0);
214 idx[3] = GET_ELT(1);
215
216 if (last_vertex_last) {
217 for (i = 0; i + 3 < count; i += 2) {
218 idx[0] = idx[2];
219 idx[1] = idx[3];
220 idx[2] = GET_ELT(i + 2);
221 idx[3] = GET_ELT(i + 3);
222
223 /* always emit idx[3] last */
224 flags = DRAW_PIPE_RESET_STIPPLE |
225 DRAW_PIPE_EDGE_FLAG_0 |
226 DRAW_PIPE_EDGE_FLAG_2;
227 TRIANGLE(flags, idx[2], idx[0], idx[3]);
228
229 flags = DRAW_PIPE_EDGE_FLAG_0 |
230 DRAW_PIPE_EDGE_FLAG_1;
231 TRIANGLE(flags, idx[0], idx[1], idx[3]);
232 }
233 }
234 else {
235 for (i = 0; i + 3 < count; i += 2) {
236 idx[0] = idx[2];
237 idx[1] = idx[3];
238 idx[2] = GET_ELT(i + 2);
239 idx[3] = GET_ELT(i + 3);
240
241 flags = DRAW_PIPE_RESET_STIPPLE |
242 DRAW_PIPE_EDGE_FLAG_0 |
243 DRAW_PIPE_EDGE_FLAG_1;
244 /* always emit idx[3] / idx[0 first */
245 if (quads_flatshade_last)
246 TRIANGLE(flags, idx[3], idx[2], idx[0]);
247 else
248 TRIANGLE(flags, idx[0], idx[3], idx[2]);
249
250 flags = DRAW_PIPE_EDGE_FLAG_1 |
251 DRAW_PIPE_EDGE_FLAG_2;
252 if (quads_flatshade_last)
253 TRIANGLE(flags, idx[3], idx[0], idx[1]);
254 else
255 TRIANGLE(flags, idx[0], idx[1], idx[3]);
256 }
257 }
258 }
259 break;
260
261 case PIPE_PRIM_POLYGON:
262 if (count >= 3) {
263 ushort edge_next, edge_finish;
264
265 if (last_vertex_last) {
266 flags = (DRAW_PIPE_RESET_STIPPLE |
267 DRAW_PIPE_EDGE_FLAG_0);
268 if (!(prim_flags & DRAW_SPLIT_BEFORE))
269 flags |= DRAW_PIPE_EDGE_FLAG_2;
270
271 edge_next = DRAW_PIPE_EDGE_FLAG_0;
272 edge_finish =
273 (prim_flags & DRAW_SPLIT_AFTER) ? 0 : DRAW_PIPE_EDGE_FLAG_1;
274 }
275 else {
276 flags = (DRAW_PIPE_RESET_STIPPLE |
277 DRAW_PIPE_EDGE_FLAG_1);
278 if (!(prim_flags & DRAW_SPLIT_BEFORE))
279 flags |= DRAW_PIPE_EDGE_FLAG_0;
280
281 edge_next = DRAW_PIPE_EDGE_FLAG_1;
282 edge_finish =
283 (prim_flags & DRAW_SPLIT_AFTER) ? 0 : DRAW_PIPE_EDGE_FLAG_2;
284 }
285
286 idx[0] = GET_ELT(0);
287 idx[2] = GET_ELT(1);
288
289 for (i = 0; i + 2 < count; i++, flags = edge_next) {
290 idx[1] = idx[2];
291 idx[2] = GET_ELT(i + 2);
292
293 if (i + 3 == count)
294 flags |= edge_finish;
295
296 /* idx[0] is both the first and the last vertex */
297 if (last_vertex_last)
298 TRIANGLE(flags, idx[1], idx[2], idx[0]);
299 else
300 TRIANGLE(flags, idx[0], idx[1], idx[2]);
301 }
302 }
303 break;
304
305 case PIPE_PRIM_LINES_ADJACENCY:
306 flags = DRAW_PIPE_RESET_STIPPLE;
307 for (i = 0; i + 3 < count; i += 4) {
308 idx[0] = GET_ELT(i);
309 idx[1] = GET_ELT(i + 1);
310 idx[2] = GET_ELT(i + 2);
311 idx[3] = GET_ELT(i + 3);
312 LINE_ADJ(flags, idx[0], idx[1], idx[2], idx[3]);
313 }
314 break;
315
316 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
317 if (count >= 4) {
318 flags = (prim_flags & DRAW_SPLIT_BEFORE) ? 0 : DRAW_PIPE_RESET_STIPPLE;
319 idx[1] = GET_ELT(0);
320 idx[2] = GET_ELT(1);
321 idx[3] = GET_ELT(2);
322
323 for (i = 1; i + 2 < count; i++, flags = 0) {
324 idx[0] = idx[1];
325 idx[1] = idx[2];
326 idx[2] = idx[3];
327 idx[3] = GET_ELT(i + 2);
328 LINE_ADJ(flags, idx[0], idx[1], idx[2], idx[3]);
329 }
330 }
331 break;
332
333 case PIPE_PRIM_TRIANGLES_ADJACENCY:
334 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
335 for (i = 0; i + 5 < count; i += 6) {
336 idx[0] = GET_ELT(i);
337 idx[1] = GET_ELT(i + 1);
338 idx[2] = GET_ELT(i + 2);
339 idx[3] = GET_ELT(i + 3);
340 idx[4] = GET_ELT(i + 4);
341 idx[5] = GET_ELT(i + 5);
342 TRIANGLE_ADJ(flags, idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
343 }
344 break;
345
346 case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
347 if (count >= 6) {
348 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
349 idx[0] = GET_ELT(1);
350 idx[2] = GET_ELT(0);
351 idx[4] = GET_ELT(2);
352 idx[3] = GET_ELT(4);
353
354 /*
355 * The vertices of the i-th triangle are stored in
356 * idx[0,2,4] = { 2*i, 2*i+2, 2*i+4 };
357 *
358 * The adjacent vertices are stored in
359 * idx[1,3,5] = { 2*i-2, 2*i+6, 2*i+3 }.
360 *
361 * However, there are two exceptions:
362 *
363 * For the first triangle, idx[1] = 1;
364 * For the last triangle, idx[3] = 2*i+5.
365 */
366 if (last_vertex_last) {
367 for (i = 0; i + 5 < count; i += 2) {
368 idx[1] = idx[0];
369
370 idx[0] = idx[2];
371 idx[2] = idx[4];
372 idx[4] = idx[3];
373
374 idx[3] = GET_ELT(i + ((i + 7 < count) ? 6 : 5));
375 idx[5] = GET_ELT(i + 3);
376
377 /*
378 * alternate the first two vertices (idx[0] and idx[2]) and the
379 * corresponding adjacent vertices (idx[3] and idx[5]) to have
380 * the correct orientation
381 */
382 if (i & 2) {
383 TRIANGLE_ADJ(flags,
384 idx[2], idx[1], idx[0], idx[5], idx[4], idx[3]);
385 }
386 else {
387 TRIANGLE_ADJ(flags,
388 idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
389 }
390 }
391 }
392 else {
393 for (i = 0; i + 5 < count; i += 2) {
394 idx[1] = idx[0];
395
396 idx[0] = idx[2];
397 idx[2] = idx[4];
398 idx[4] = idx[3];
399
400 idx[3] = GET_ELT(i + ((i + 7 < count) ? 6 : 5));
401 idx[5] = GET_ELT(i + 3);
402
403 /*
404 * alternate the last two vertices (idx[2] and idx[4]) and the
405 * corresponding adjacent vertices (idx[1] and idx[5]) to have
406 * the correct orientation
407 */
408 if (i & 2) {
409 TRIANGLE_ADJ(flags,
410 idx[0], idx[5], idx[4], idx[3], idx[2], idx[1]);
411 }
412 else {
413 TRIANGLE_ADJ(flags,
414 idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
415 }
416 }
417 }
418 }
419 break;
420
421 default:
422 assert(0);
423 break;
424 }
425
426 FUNC_EXIT;
427 }
428
429 #undef LOCAL_VARS
430 #undef FUNC_ENTER
431 #undef FUNC_EXIT
432 #undef LINE_ADJ
433 #undef TRIANGLE_ADJ
434
435 #undef FUNC
436 #undef FUNC_VARS
437 #undef GET_ELT
438 #undef POINT
439 #undef LINE
440 #undef TRIANGLE
441