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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 : NULL;
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 : NULL;
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