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