1/**************************************************************************
2 *
3 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
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 TUNGSTEN GRAPHICS 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 <keith@tungstengraphics.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
41
42struct unfilled_stage {
43   struct draw_stage stage;
44
45   /** [0] = front face, [1] = back face.
46    * legal values:  PIPE_POLYGON_MODE_FILL, PIPE_POLYGON_MODE_LINE,
47    * and PIPE_POLYGON_MODE_POINT,
48    */
49   unsigned mode[2];
50};
51
52
53static INLINE struct unfilled_stage *unfilled_stage( struct draw_stage *stage )
54{
55   return (struct unfilled_stage *)stage;
56}
57
58
59
60static void point( struct draw_stage *stage,
61		   struct vertex_header *v0 )
62{
63   struct prim_header tmp;
64   tmp.v[0] = v0;
65   stage->next->point( stage->next, &tmp );
66}
67
68static void line( struct draw_stage *stage,
69		  struct vertex_header *v0,
70		  struct vertex_header *v1 )
71{
72   struct prim_header tmp;
73   tmp.v[0] = v0;
74   tmp.v[1] = v1;
75   stage->next->line( stage->next, &tmp );
76}
77
78
79static void points( struct draw_stage *stage,
80		    struct prim_header *header )
81{
82   struct vertex_header *v0 = header->v[0];
83   struct vertex_header *v1 = header->v[1];
84   struct vertex_header *v2 = header->v[2];
85
86   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) point( stage, v0 );
87   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) point( stage, v1 );
88   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) point( stage, v2 );
89}
90
91
92static void lines( struct draw_stage *stage,
93		   struct prim_header *header )
94{
95   struct vertex_header *v0 = header->v[0];
96   struct vertex_header *v1 = header->v[1];
97   struct vertex_header *v2 = header->v[2];
98
99   if (header->flags & DRAW_PIPE_RESET_STIPPLE)
100      stage->next->reset_stipple_counter( stage->next );
101
102   if ((header->flags & DRAW_PIPE_EDGE_FLAG_2) && v2->edgeflag) line( stage, v2, v0 );
103   if ((header->flags & DRAW_PIPE_EDGE_FLAG_0) && v0->edgeflag) line( stage, v0, v1 );
104   if ((header->flags & DRAW_PIPE_EDGE_FLAG_1) && v1->edgeflag) line( stage, v1, v2 );
105}
106
107
108/** For debugging */
109static void
110print_header_flags(unsigned flags)
111{
112   debug_printf("header->flags = ");
113   if (flags & DRAW_PIPE_RESET_STIPPLE)
114      debug_printf("RESET_STIPPLE ");
115   if (flags & DRAW_PIPE_EDGE_FLAG_0)
116      debug_printf("EDGE_FLAG_0 ");
117   if (flags & DRAW_PIPE_EDGE_FLAG_1)
118      debug_printf("EDGE_FLAG_1 ");
119   if (flags & DRAW_PIPE_EDGE_FLAG_2)
120      debug_printf("EDGE_FLAG_2 ");
121   debug_printf("\n");
122}
123
124
125/* Unfilled tri:
126 *
127 * Note edgeflags in the vertex struct is not sufficient as we will
128 * need to manipulate them when decomposing primitives.
129 *
130 * We currently keep the vertex edgeflag and primitive edgeflag mask
131 * separate until the last possible moment.
132 */
133static void unfilled_tri( struct draw_stage *stage,
134			  struct prim_header *header )
135{
136   struct unfilled_stage *unfilled = unfilled_stage(stage);
137   unsigned cw = header->det >= 0.0;
138   unsigned mode = unfilled->mode[cw];
139
140   if (0)
141      print_header_flags(header->flags);
142
143   switch (mode) {
144   case PIPE_POLYGON_MODE_FILL:
145      stage->next->tri( stage->next, header );
146      break;
147   case PIPE_POLYGON_MODE_LINE:
148      lines( stage, header );
149      break;
150   case PIPE_POLYGON_MODE_POINT:
151      points( stage, header );
152      break;
153   default:
154      assert(0);
155   }
156}
157
158
159static void unfilled_first_tri( struct draw_stage *stage,
160				struct prim_header *header )
161{
162   struct unfilled_stage *unfilled = unfilled_stage(stage);
163   const struct pipe_rasterizer_state *rast = stage->draw->rasterizer;
164
165   unfilled->mode[0] = rast->front_ccw ? rast->fill_front : rast->fill_back;
166   unfilled->mode[1] = rast->front_ccw ? rast->fill_back : rast->fill_front;
167
168   stage->tri = unfilled_tri;
169   stage->tri( stage, header );
170}
171
172
173
174static void unfilled_flush( struct draw_stage *stage,
175			    unsigned flags )
176{
177   stage->next->flush( stage->next, flags );
178
179   stage->tri = unfilled_first_tri;
180}
181
182
183static void unfilled_reset_stipple_counter( struct draw_stage *stage )
184{
185   stage->next->reset_stipple_counter( stage->next );
186}
187
188
189static void unfilled_destroy( struct draw_stage *stage )
190{
191   draw_free_temp_verts( stage );
192   FREE( stage );
193}
194
195
196/**
197 * Create unfilled triangle stage.
198 */
199struct draw_stage *draw_unfilled_stage( struct draw_context *draw )
200{
201   struct unfilled_stage *unfilled = CALLOC_STRUCT(unfilled_stage);
202   if (unfilled == NULL)
203      goto fail;
204
205   unfilled->stage.draw = draw;
206   unfilled->stage.name = "unfilled";
207   unfilled->stage.next = NULL;
208   unfilled->stage.tmp = NULL;
209   unfilled->stage.point = draw_pipe_passthrough_point;
210   unfilled->stage.line = draw_pipe_passthrough_line;
211   unfilled->stage.tri = unfilled_first_tri;
212   unfilled->stage.flush = unfilled_flush;
213   unfilled->stage.reset_stipple_counter = unfilled_reset_stipple_counter;
214   unfilled->stage.destroy = unfilled_destroy;
215
216   if (!draw_alloc_temp_verts( &unfilled->stage, 0 ))
217      goto fail;
218
219   return &unfilled->stage;
220
221 fail:
222   if (unfilled)
223      unfilled->stage.destroy( &unfilled->stage );
224
225   return NULL;
226}
227