1 /*
2 * Mesa 3-D graphics library
3 * Version: 7.9
4 *
5 * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.
6 * Copyright (C) 2010 LunarG Inc.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
23 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
24 * DEALINGS IN THE SOFTWARE.
25 *
26 * Authors:
27 * Keith Whitwell <keith@tungstengraphics.com>
28 * Chia-I Wu <olv@lunarg.com>
29 */
30
31 /* these macros are optional */
32 #ifndef LOCAL_VARS
33 #define LOCAL_VARS
34 #endif
35 #ifndef FUNC_ENTER
36 #define FUNC_ENTER do {} while (0)
37 #endif
38 #ifndef FUNC_EXIT
39 #define FUNC_EXIT do {} while (0)
40 #endif
41 #ifndef LINE_ADJ
42 #define LINE_ADJ(flags, a0, i0, i1, a1) LINE(flags, i0, i1)
43 #endif
44 #ifndef TRIANGLE_ADJ
45 #define TRIANGLE_ADJ(flags, i0, a0, i1, a1, i2, a2) TRIANGLE(flags, i0, i1, i2)
46 #endif
47
48 static void
FUNC(FUNC_VARS)49 FUNC(FUNC_VARS)
50 {
51 unsigned idx[6], i;
52 ushort flags;
53 LOCAL_VARS
54
55 FUNC_ENTER;
56
57 /* prim, prim_flags, count, and last_vertex_last should have been defined */
58 if (0) {
59 debug_printf("%s: prim 0x%x, prim_flags 0x%x, count %d, last_vertex_last %d\n",
60 __FUNCTION__, prim, prim_flags, count, last_vertex_last);
61 }
62
63 switch (prim) {
64 case PIPE_PRIM_POINTS:
65 for (i = 0; i < count; i++) {
66 idx[0] = GET_ELT(i);
67 POINT(idx[0]);
68 }
69 break;
70
71 case PIPE_PRIM_LINES:
72 flags = DRAW_PIPE_RESET_STIPPLE;
73 for (i = 0; i + 1 < count; i += 2) {
74 idx[0] = GET_ELT(i);
75 idx[1] = GET_ELT(i + 1);
76 LINE(flags, idx[0], idx[1]);
77 }
78 break;
79
80 case PIPE_PRIM_LINE_LOOP:
81 case PIPE_PRIM_LINE_STRIP:
82 if (count >= 2) {
83 flags = (prim_flags & DRAW_SPLIT_BEFORE) ? 0 : DRAW_PIPE_RESET_STIPPLE;
84 idx[1] = GET_ELT(0);
85 idx[2] = idx[1];
86
87 for (i = 1; i < count; i++, flags = 0) {
88 idx[0] = idx[1];
89 idx[1] = GET_ELT(i);
90 LINE(flags, idx[0], idx[1]);
91 }
92 /* close the loop */
93 if (prim == PIPE_PRIM_LINE_LOOP && !prim_flags)
94 LINE(flags, idx[1], idx[2]);
95 }
96 break;
97
98 case PIPE_PRIM_TRIANGLES:
99 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
100 for (i = 0; i + 2 < count; i += 3) {
101 idx[0] = GET_ELT(i);
102 idx[1] = GET_ELT(i + 1);
103 idx[2] = GET_ELT(i + 2);
104 TRIANGLE(flags, idx[0], idx[1], idx[2]);
105 }
106 break;
107
108 case PIPE_PRIM_TRIANGLE_STRIP:
109 if (count >= 3) {
110 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
111 idx[1] = GET_ELT(0);
112 idx[2] = GET_ELT(1);
113
114 if (last_vertex_last) {
115 for (i = 0; i + 2 < count; i++) {
116 idx[0] = idx[1];
117 idx[1] = idx[2];
118 idx[2] = GET_ELT(i + 2);
119 /* always emit idx[2] last */
120 if (i & 1)
121 TRIANGLE(flags, idx[1], idx[0], idx[2]);
122 else
123 TRIANGLE(flags, idx[0], idx[1], idx[2]);
124 }
125 }
126 else {
127 for (i = 0; i + 2 < count; i++) {
128 idx[0] = idx[1];
129 idx[1] = idx[2];
130 idx[2] = GET_ELT(i + 2);
131 /* always emit idx[0] first */
132 if (i & 1)
133 TRIANGLE(flags, idx[0], idx[2], idx[1]);
134 else
135 TRIANGLE(flags, idx[0], idx[1], idx[2]);
136 }
137 }
138 }
139 break;
140
141 case PIPE_PRIM_TRIANGLE_FAN:
142 if (count >= 3) {
143 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
144 idx[0] = GET_ELT(0);
145 idx[2] = GET_ELT(1);
146
147 /* idx[0] is neither the first nor the last vertex */
148 if (last_vertex_last) {
149 for (i = 0; i + 2 < count; i++) {
150 idx[1] = idx[2];
151 idx[2] = GET_ELT(i + 2);
152 /* always emit idx[2] last */
153 TRIANGLE(flags, idx[0], idx[1], idx[2]);
154 }
155 }
156 else {
157 for (i = 0; i + 2 < count; i++) {
158 idx[1] = idx[2];
159 idx[2] = GET_ELT(i + 2);
160 /* always emit idx[1] first */
161 TRIANGLE(flags, idx[1], idx[2], idx[0]);
162 }
163 }
164 }
165 break;
166
167 case PIPE_PRIM_QUADS:
168 if (last_vertex_last) {
169 for (i = 0; i + 3 < count; i += 4) {
170 idx[0] = GET_ELT(i);
171 idx[1] = GET_ELT(i + 1);
172 idx[2] = GET_ELT(i + 2);
173 idx[3] = GET_ELT(i + 3);
174
175 flags = DRAW_PIPE_RESET_STIPPLE |
176 DRAW_PIPE_EDGE_FLAG_0 |
177 DRAW_PIPE_EDGE_FLAG_2;
178 /* always emit idx[3] last */
179 TRIANGLE(flags, idx[0], idx[1], idx[3]);
180
181 flags = DRAW_PIPE_EDGE_FLAG_0 |
182 DRAW_PIPE_EDGE_FLAG_1;
183 TRIANGLE(flags, idx[1], idx[2], idx[3]);
184 }
185 }
186 else {
187 for (i = 0; i + 3 < count; i += 4) {
188 idx[0] = GET_ELT(i);
189 idx[1] = GET_ELT(i + 1);
190 idx[2] = GET_ELT(i + 2);
191 idx[3] = GET_ELT(i + 3);
192
193 flags = DRAW_PIPE_RESET_STIPPLE |
194 DRAW_PIPE_EDGE_FLAG_0 |
195 DRAW_PIPE_EDGE_FLAG_1;
196 /* always emit idx[3] / idx[0] first */
197 if (quads_flatshade_last)
198 TRIANGLE(flags, idx[3], idx[0], idx[1]);
199 else
200 TRIANGLE(flags, idx[0], idx[1], idx[2]);
201
202 flags = DRAW_PIPE_EDGE_FLAG_1 |
203 DRAW_PIPE_EDGE_FLAG_2;
204 if (quads_flatshade_last)
205 TRIANGLE(flags, idx[3], idx[1], idx[2]);
206 else
207 TRIANGLE(flags, idx[0], idx[2], idx[3]);
208 }
209 }
210 break;
211
212 case PIPE_PRIM_QUAD_STRIP:
213 if (count >= 4) {
214 idx[2] = GET_ELT(0);
215 idx[3] = GET_ELT(1);
216
217 if (last_vertex_last) {
218 for (i = 0; i + 3 < count; i += 2) {
219 idx[0] = idx[2];
220 idx[1] = idx[3];
221 idx[2] = GET_ELT(i + 2);
222 idx[3] = GET_ELT(i + 3);
223
224 /* always emit idx[3] last */
225 flags = DRAW_PIPE_RESET_STIPPLE |
226 DRAW_PIPE_EDGE_FLAG_0 |
227 DRAW_PIPE_EDGE_FLAG_2;
228 TRIANGLE(flags, idx[2], idx[0], idx[3]);
229
230 flags = DRAW_PIPE_EDGE_FLAG_0 |
231 DRAW_PIPE_EDGE_FLAG_1;
232 TRIANGLE(flags, idx[0], idx[1], idx[3]);
233 }
234 }
235 else {
236 for (i = 0; i + 3 < count; i += 2) {
237 idx[0] = idx[2];
238 idx[1] = idx[3];
239 idx[2] = GET_ELT(i + 2);
240 idx[3] = GET_ELT(i + 3);
241
242 flags = DRAW_PIPE_RESET_STIPPLE |
243 DRAW_PIPE_EDGE_FLAG_0 |
244 DRAW_PIPE_EDGE_FLAG_1;
245 /* always emit idx[3] / idx[0 first */
246 if (quads_flatshade_last)
247 TRIANGLE(flags, idx[3], idx[2], idx[0]);
248 else
249 TRIANGLE(flags, idx[0], idx[3], idx[2]);
250
251 flags = DRAW_PIPE_EDGE_FLAG_1 |
252 DRAW_PIPE_EDGE_FLAG_2;
253 if (quads_flatshade_last)
254 TRIANGLE(flags, idx[3], idx[0], idx[1]);
255 else
256 TRIANGLE(flags, idx[0], idx[1], idx[3]);
257 }
258 }
259 }
260 break;
261
262 case PIPE_PRIM_POLYGON:
263 if (count >= 3) {
264 ushort edge_next, edge_finish;
265
266 if (last_vertex_last) {
267 flags = (DRAW_PIPE_RESET_STIPPLE |
268 DRAW_PIPE_EDGE_FLAG_0);
269 if (!(prim_flags & DRAW_SPLIT_BEFORE))
270 flags |= DRAW_PIPE_EDGE_FLAG_2;
271
272 edge_next = DRAW_PIPE_EDGE_FLAG_0;
273 edge_finish =
274 (prim_flags & DRAW_SPLIT_AFTER) ? 0 : DRAW_PIPE_EDGE_FLAG_1;
275 }
276 else {
277 flags = (DRAW_PIPE_RESET_STIPPLE |
278 DRAW_PIPE_EDGE_FLAG_1);
279 if (!(prim_flags & DRAW_SPLIT_BEFORE))
280 flags |= DRAW_PIPE_EDGE_FLAG_0;
281
282 edge_next = DRAW_PIPE_EDGE_FLAG_1;
283 edge_finish =
284 (prim_flags & DRAW_SPLIT_AFTER) ? 0 : DRAW_PIPE_EDGE_FLAG_2;
285 }
286
287 idx[0] = GET_ELT(0);
288 idx[2] = GET_ELT(1);
289
290 for (i = 0; i + 2 < count; i++, flags = edge_next) {
291 idx[1] = idx[2];
292 idx[2] = GET_ELT(i + 2);
293
294 if (i + 3 == count)
295 flags |= edge_finish;
296
297 /* idx[0] is both the first and the last vertex */
298 if (last_vertex_last)
299 TRIANGLE(flags, idx[1], idx[2], idx[0]);
300 else
301 TRIANGLE(flags, idx[0], idx[1], idx[2]);
302 }
303 }
304 break;
305
306 case PIPE_PRIM_LINES_ADJACENCY:
307 flags = DRAW_PIPE_RESET_STIPPLE;
308 for (i = 0; i + 3 < count; i += 4) {
309 idx[0] = GET_ELT(i);
310 idx[1] = GET_ELT(i + 1);
311 idx[2] = GET_ELT(i + 2);
312 idx[3] = GET_ELT(i + 3);
313 LINE_ADJ(flags, idx[0], idx[1], idx[2], idx[3]);
314 }
315 break;
316
317 case PIPE_PRIM_LINE_STRIP_ADJACENCY:
318 if (count >= 4) {
319 flags = (prim_flags & DRAW_SPLIT_BEFORE) ? 0 : DRAW_PIPE_RESET_STIPPLE;
320 idx[1] = GET_ELT(0);
321 idx[2] = GET_ELT(1);
322 idx[3] = GET_ELT(2);
323
324 for (i = 1; i + 2 < count; i++, flags = 0) {
325 idx[0] = idx[1];
326 idx[1] = idx[2];
327 idx[2] = idx[3];
328 idx[3] = GET_ELT(i + 2);
329 LINE_ADJ(flags, idx[0], idx[1], idx[2], idx[3]);
330 }
331 }
332 break;
333
334 case PIPE_PRIM_TRIANGLES_ADJACENCY:
335 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
336 for (i = 0; i + 5 < count; i += 6) {
337 idx[0] = GET_ELT(i);
338 idx[1] = GET_ELT(i + 1);
339 idx[2] = GET_ELT(i + 2);
340 idx[3] = GET_ELT(i + 3);
341 idx[4] = GET_ELT(i + 4);
342 idx[5] = GET_ELT(i + 5);
343 TRIANGLE_ADJ(flags, idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
344 }
345 break;
346
347 case PIPE_PRIM_TRIANGLE_STRIP_ADJACENCY:
348 if (count >= 6) {
349 flags = DRAW_PIPE_RESET_STIPPLE | DRAW_PIPE_EDGE_FLAG_ALL;
350 idx[0] = GET_ELT(1);
351 idx[2] = GET_ELT(0);
352 idx[4] = GET_ELT(2);
353 idx[3] = GET_ELT(4);
354
355 /*
356 * The vertices of the i-th triangle are stored in
357 * idx[0,2,4] = { 2*i, 2*i+2, 2*i+4 };
358 *
359 * The adjacent vertices are stored in
360 * idx[1,3,5] = { 2*i-2, 2*i+6, 2*i+3 }.
361 *
362 * However, there are two exceptions:
363 *
364 * For the first triangle, idx[1] = 1;
365 * For the last triangle, idx[3] = 2*i+5.
366 */
367 if (last_vertex_last) {
368 for (i = 0; i + 5 < count; i += 2) {
369 idx[1] = idx[0];
370
371 idx[0] = idx[2];
372 idx[2] = idx[4];
373 idx[4] = idx[3];
374
375 idx[3] = GET_ELT(i + ((i + 7 < count) ? 6 : 5));
376 idx[5] = GET_ELT(i + 3);
377
378 /*
379 * alternate the first two vertices (idx[0] and idx[2]) and the
380 * corresponding adjacent vertices (idx[3] and idx[5]) to have
381 * the correct orientation
382 */
383 if (i & 2) {
384 TRIANGLE_ADJ(flags,
385 idx[2], idx[1], idx[0], idx[5], idx[4], idx[3]);
386 }
387 else {
388 TRIANGLE_ADJ(flags,
389 idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
390 }
391 }
392 }
393 else {
394 for (i = 0; i + 5 < count; i += 2) {
395 idx[1] = idx[0];
396
397 idx[0] = idx[2];
398 idx[2] = idx[4];
399 idx[4] = idx[3];
400
401 idx[3] = GET_ELT(i + ((i + 7 < count) ? 6 : 5));
402 idx[5] = GET_ELT(i + 3);
403
404 /*
405 * alternate the last two vertices (idx[2] and idx[4]) and the
406 * corresponding adjacent vertices (idx[1] and idx[5]) to have
407 * the correct orientation
408 */
409 if (i & 2) {
410 TRIANGLE_ADJ(flags,
411 idx[0], idx[5], idx[4], idx[3], idx[2], idx[1]);
412 }
413 else {
414 TRIANGLE_ADJ(flags,
415 idx[0], idx[1], idx[2], idx[3], idx[4], idx[5]);
416 }
417 }
418 }
419 }
420 break;
421
422 default:
423 assert(0);
424 break;
425 }
426
427 FUNC_EXIT;
428 }
429
430 #undef LOCAL_VARS
431 #undef FUNC_ENTER
432 #undef FUNC_EXIT
433 #undef LINE_ADJ
434 #undef TRIANGLE_ADJ
435
436 #undef FUNC
437 #undef FUNC_VARS
438 #undef GET_ELT
439 #undef POINT
440 #undef LINE
441 #undef TRIANGLE
442