1 /**************************************************************************
2 *
3 * Copyright 2007 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 * \brief Drawing stage for handling glPolygonMode(line/point).
30 * Convert triangles to points or lines as needed.
31 */
32
33 /* Authors: Keith Whitwell <[email protected]>
34 */
35
36 #include "util/u_memory.h"
37 #include "pipe/p_defines.h"
38 #include "draw_private.h"
39 #include "draw_pipe.h"
40 #include "draw_fs.h"
41
42
43 struct unfilled_stage {
44 struct draw_stage stage;
45
46 /** [0] = front face, [1] = back face.
47 * legal values: PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE,
48 * and PIPE_POLYGON_MODE_POINT,
49 */
50 unsigned mode[2];
51
52 int face_slot;
53 };
54
55
56 static inline struct
unfilled_stage(struct draw_stage * stage)57 unfilled_stage *unfilled_stage(struct draw_stage *stage)
58 {
59 return (struct unfilled_stage *) stage;
60 }
61
62
63 static void
inject_front_face_info(struct draw_stage * stage,struct prim_header * header)64 inject_front_face_info(struct draw_stage *stage,
65 struct prim_header *header)
66 {
67 struct unfilled_stage *unfilled = unfilled_stage(stage);
68 bool is_front_face = (
69 (stage->draw->rasterizer->front_ccw && header->det < 0.0f) ||
70 (!stage->draw->rasterizer->front_ccw && header->det > 0.0f));
71 int slot = unfilled->face_slot;
72
73 /* In case the backend doesn't care about it */
74 if (slot < 0) {
75 return;
76 }
77
78 for (unsigned i = 0; i < 3; ++i) {
79 struct vertex_header *v = header->v[i];
80 v->data[slot][0] = is_front_face;
81 v->data[slot][1] = is_front_face;
82 v->data[slot][2] = is_front_face;
83 v->data[slot][3] = is_front_face;
84 v->vertex_id = UNDEFINED_VERTEX_ID;
85 }
86 }
87
88
89 static void
point(struct draw_stage * stage,struct prim_header * header,struct vertex_header * v0)90 point(struct draw_stage *stage,
91 struct prim_header *header,
92 struct vertex_header *v0)
93 {
94 struct prim_header tmp;
95 tmp.det = header->det;
96 tmp.flags = 0;
97 tmp.v[0] = v0;
98 stage->next->point(stage->next, &tmp);
99 }
100
101
102 static void
line(struct draw_stage * stage,struct prim_header * header,struct vertex_header * v0,struct vertex_header * v1)103 line(struct draw_stage *stage,
104 struct prim_header *header,
105 struct vertex_header *v0,
106 struct vertex_header *v1)
107 {
108 struct prim_header tmp;
109 tmp.det = header->det;
110 tmp.flags = 0;
111 tmp.v[0] = v0;
112 tmp.v[1] = v1;
113 stage->next->line(stage->next, &tmp);
114 }
115
116
117 static void
points(struct draw_stage * stage,struct prim_header * header)118 points(struct draw_stage *stage,
119 struct prim_header *header)
120 {
121 struct vertex_header *v0 = header->v[0];
122 struct vertex_header *v1 = header->v[1];
123 struct vertex_header *v2 = header->v[2];
124
125 inject_front_face_info(stage, header);
126
127 if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag)
128 point(stage, header, v0);
129 if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag)
130 point(stage, header, v1);
131 if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag)
132 point(stage, header, v2);
133 }
134
135
136 static void
lines(struct draw_stage * stage,struct prim_header * header)137 lines(struct draw_stage *stage,
138 struct prim_header *header)
139 {
140 struct vertex_header *v0 = header->v[0];
141 struct vertex_header *v1 = header->v[1];
142 struct vertex_header *v2 = header->v[2];
143
144 if (header->flags & DRAW_PIPE_RESET_STIPPLE)
145 /*
146 * XXX could revisit this. The only stage which cares is the line
147 * stipple stage. Could just emit correct reset flags here and not
148 * bother about all the calling through reset_stipple_counter
149 * stages. Though technically it is necessary if line stipple is
150 * handled by the driver, but this is not actually hooked up when
151 * using vbuf (vbuf stage reset_stipple_counter does nothing).
152 */
153 stage->next->reset_stipple_counter(stage->next);
154
155 inject_front_face_info(stage, header);
156
157 if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag)
158 line(stage, header, v2, v0);
159 if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag)
160 line(stage, header, v0, v1);
161 if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag)
162 line(stage, header, v1, v2);
163 }
164
165
166 /** For debugging */
167 static void
print_header_flags(unsigned flags)168 print_header_flags(unsigned flags)
169 {
170 debug_printf("header->flags = ");
171 if (flags & DRAW_PIPE_RESET_STIPPLE)
172 debug_printf("RESET_STIPPLE ");
173 if (flags & DRAW_PIPE_EDGE_FLAG_0)
174 debug_printf("EDGE_FLAG_0 ");
175 if (flags & DRAW_PIPE_EDGE_FLAG_1)
176 debug_printf("EDGE_FLAG_1 ");
177 if (flags & DRAW_PIPE_EDGE_FLAG_2)
178 debug_printf("EDGE_FLAG_2 ");
179 debug_printf("\n");
180 }
181
182
183 /* Unfilled tri:
184 *
185 * Note edgeflags in the vertex struct is not sufficient as we will
186 * need to manipulate them when decomposing primitives.
187 *
188 * We currently keep the vertex edgeflag and primitive edgeflag mask
189 * separate until the last possible moment.
190 */
191 static void
unfilled_tri(struct draw_stage * stage,struct prim_header * header)192 unfilled_tri(struct draw_stage *stage,
193 struct prim_header *header)
194 {
195 struct unfilled_stage *unfilled = unfilled_stage(stage);
196 unsigned cw = header->det >= 0.0;
197 unsigned mode = unfilled->mode[cw];
198
199 if (0)
200 print_header_flags(header->flags);
201
202 switch (mode) {
203 case PIPE_POLYGON_MODE_FILL:
204 stage->next->tri(stage->next, header);
205 break;
206 case PIPE_POLYGON_MODE_LINE:
207 lines(stage, header);
208 break;
209 case PIPE_POLYGON_MODE_POINT:
210 points(stage, header);
211 break;
212 default:
213 assert(0);
214 }
215 }
216
217
218 static void
unfilled_first_tri(struct draw_stage * stage,struct prim_header * header)219 unfilled_first_tri(struct draw_stage *stage,
220 struct prim_header *header)
221 {
222 struct unfilled_stage *unfilled = unfilled_stage(stage);
223 const struct pipe_rasterizer_state *rast = stage->draw->rasterizer;
224
225 unfilled->mode[0] = rast->front_ccw ? rast->fill_front : rast->fill_back;
226 unfilled->mode[1] = rast->front_ccw ? rast->fill_back : rast->fill_front;
227
228 stage->tri = unfilled_tri;
229 stage->tri(stage, header);
230 }
231
232
233 static void
unfilled_flush(struct draw_stage * stage,unsigned flags)234 unfilled_flush(struct draw_stage *stage,
235 unsigned flags)
236 {
237 stage->next->flush(stage->next, flags);
238
239 stage->tri = unfilled_first_tri;
240 }
241
242
243 static void
unfilled_reset_stipple_counter(struct draw_stage * stage)244 unfilled_reset_stipple_counter(struct draw_stage *stage)
245 {
246 stage->next->reset_stipple_counter(stage->next);
247 }
248
249
250 static void
unfilled_destroy(struct draw_stage * stage)251 unfilled_destroy(struct draw_stage *stage)
252 {
253 draw_free_temp_verts(stage);
254 FREE(stage);
255 }
256
257
258 /*
259 * Try to allocate an output slot which we can use
260 * to preserve the front face information.
261 */
262 void
draw_unfilled_prepare_outputs(struct draw_context * draw,struct draw_stage * stage)263 draw_unfilled_prepare_outputs(struct draw_context *draw,
264 struct draw_stage *stage)
265 {
266 struct unfilled_stage *unfilled = unfilled_stage(stage);
267 const struct pipe_rasterizer_state *rast = draw ? draw->rasterizer : NULL;
268 bool is_unfilled = (rast &&
269 (rast->fill_front != PIPE_POLYGON_MODE_FILL ||
270 rast->fill_back != PIPE_POLYGON_MODE_FILL));
271 const struct draw_fragment_shader *fs = draw ? draw->fs.fragment_shader : NULL;
272
273 if (is_unfilled && fs && fs->info.uses_frontface) {
274 unfilled->face_slot = draw_alloc_extra_vertex_attrib(
275 stage->draw, TGSI_SEMANTIC_FACE, 0);
276 } else {
277 unfilled->face_slot = -1;
278 }
279 }
280
281
282 /**
283 * Create unfilled triangle stage.
284 */
285 struct draw_stage *
draw_unfilled_stage(struct draw_context * draw)286 draw_unfilled_stage(struct draw_context *draw)
287 {
288 struct unfilled_stage *unfilled = CALLOC_STRUCT(unfilled_stage);
289 if (!unfilled)
290 goto fail;
291
292 unfilled->stage.draw = draw;
293 unfilled->stage.name = "unfilled";
294 unfilled->stage.next = NULL;
295 unfilled->stage.tmp = NULL;
296 unfilled->stage.point = draw_pipe_passthrough_point;
297 unfilled->stage.line = draw_pipe_passthrough_line;
298 unfilled->stage.tri = unfilled_first_tri;
299 unfilled->stage.flush = unfilled_flush;
300 unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;
301 unfilled->stage.destroy = unfilled_destroy;
302
303 unfilled->face_slot = -1;
304
305 if (!draw_alloc_temp_verts(&unfilled->stage, 0))
306 goto fail;
307
308 return &unfilled->stage;
309
310 fail:
311 if (unfilled)
312 unfilled->stage.destroy(&unfilled->stage);
313
314 return NULL;
315 }
316