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/* Authors:  Keith Whitwell <keith@tungstengraphics.com>
29 */
30
31#include "util/u_math.h"
32#include "util/u_memory.h"
33
34#include "pipe/p_shader_tokens.h"
35#include "draw_vs.h"
36#include "draw_pipe.h"
37
38
39/** subclass of draw_stage */
40struct flat_stage
41{
42   struct draw_stage stage;
43
44   uint num_color_attribs;
45   uint color_attribs[2];  /* front/back primary colors */
46
47   uint num_spec_attribs;
48   uint spec_attribs[2];  /* front/back secondary colors */
49};
50
51#define COPY_3FV( DST, SRC )         \
52do {                                \
53   (DST)[0] = (SRC)[0];             \
54   (DST)[1] = (SRC)[1];             \
55   (DST)[2] = (SRC)[2];             \
56} while (0)
57
58
59static INLINE struct flat_stage *
60flat_stage(struct draw_stage *stage)
61{
62   return (struct flat_stage *) stage;
63}
64
65
66/** Copy all the color attributes from 'src' vertex to 'dst' vertex */
67static INLINE void copy_colors( struct draw_stage *stage,
68                                struct vertex_header *dst,
69                                const struct vertex_header *src )
70{
71   const struct flat_stage *flat = flat_stage(stage);
72   uint i;
73
74   for (i = 0; i < flat->num_color_attribs; i++) {
75      const uint attr = flat->color_attribs[i];
76      COPY_4FV(dst->data[attr], src->data[attr]);
77   }
78
79   for (i = 0; i < flat->num_spec_attribs; i++) {
80      const uint attr = flat->spec_attribs[i];
81      COPY_3FV(dst->data[attr], src->data[attr]);
82   }
83}
84
85
86/** Copy all the color attributes from src vertex to dst0 & dst1 vertices */
87static INLINE void copy_colors2( struct draw_stage *stage,
88                                 struct vertex_header *dst0,
89                                 struct vertex_header *dst1,
90                                 const struct vertex_header *src )
91{
92   const struct flat_stage *flat = flat_stage(stage);
93   uint i;
94   for (i = 0; i < flat->num_color_attribs; i++) {
95      const uint attr = flat->color_attribs[i];
96      COPY_4FV(dst0->data[attr], src->data[attr]);
97      COPY_4FV(dst1->data[attr], src->data[attr]);
98   }
99
100   for (i = 0; i < flat->num_spec_attribs; i++) {
101      const uint attr = flat->spec_attribs[i];
102      COPY_3FV(dst0->data[attr], src->data[attr]);
103      COPY_3FV(dst1->data[attr], src->data[attr]);
104   }
105}
106
107
108/**
109 * Flatshade tri.  Required for clipping and when unfilled tris are
110 * active, otherwise handled by hardware.
111 */
112static void flatshade_tri_0( struct draw_stage *stage,
113                             struct prim_header *header )
114{
115   struct prim_header tmp;
116
117   tmp.det = header->det;
118   tmp.flags = header->flags;
119   tmp.pad = header->pad;
120   tmp.v[0] = header->v[0];
121   tmp.v[1] = dup_vert(stage, header->v[1], 0);
122   tmp.v[2] = dup_vert(stage, header->v[2], 1);
123
124   copy_colors2(stage, tmp.v[1], tmp.v[2], tmp.v[0]);
125
126   stage->next->tri( stage->next, &tmp );
127}
128
129
130static void flatshade_tri_2( struct draw_stage *stage,
131                             struct prim_header *header )
132{
133   struct prim_header tmp;
134
135   tmp.det = header->det;
136   tmp.flags = header->flags;
137   tmp.pad = header->pad;
138   tmp.v[0] = dup_vert(stage, header->v[0], 0);
139   tmp.v[1] = dup_vert(stage, header->v[1], 1);
140   tmp.v[2] = header->v[2];
141
142   copy_colors2(stage, tmp.v[0], tmp.v[1], tmp.v[2]);
143
144   stage->next->tri( stage->next, &tmp );
145}
146
147
148
149
150
151/**
152 * Flatshade line.  Required for clipping.
153 */
154static void flatshade_line_0( struct draw_stage *stage,
155                              struct prim_header *header )
156{
157   struct prim_header tmp;
158
159   tmp.v[0] = header->v[0];
160   tmp.v[1] = dup_vert(stage, header->v[1], 0);
161
162   copy_colors(stage, tmp.v[1], tmp.v[0]);
163
164   stage->next->line( stage->next, &tmp );
165}
166
167static void flatshade_line_1( struct draw_stage *stage,
168                              struct prim_header *header )
169{
170   struct prim_header tmp;
171
172   tmp.v[0] = dup_vert(stage, header->v[0], 0);
173   tmp.v[1] = header->v[1];
174
175   copy_colors(stage, tmp.v[0], tmp.v[1]);
176
177   stage->next->line( stage->next, &tmp );
178}
179
180
181
182
183static void flatshade_init_state( struct draw_stage *stage )
184{
185   struct flat_stage *flat = flat_stage(stage);
186   const struct draw_vertex_shader *vs = stage->draw->vs.vertex_shader;
187   uint i;
188
189   /* Find which vertex shader outputs are colors, make a list */
190   flat->num_color_attribs = 0;
191   flat->num_spec_attribs = 0;
192   for (i = 0; i < vs->info.num_outputs; i++) {
193      if (vs->info.output_semantic_name[i] == TGSI_SEMANTIC_COLOR ||
194          vs->info.output_semantic_name[i] == TGSI_SEMANTIC_BCOLOR) {
195         if (vs->info.output_semantic_index[i] == 0)
196            flat->color_attribs[flat->num_color_attribs++] = i;
197         else
198            flat->spec_attribs[flat->num_spec_attribs++] = i;
199      }
200   }
201
202   /* Choose flatshade routine according to provoking vertex:
203    */
204   if (stage->draw->rasterizer->flatshade_first) {
205      stage->line = flatshade_line_0;
206      stage->tri = flatshade_tri_0;
207   }
208   else {
209      stage->line = flatshade_line_1;
210      stage->tri = flatshade_tri_2;
211   }
212}
213
214static void flatshade_first_tri( struct draw_stage *stage,
215				 struct prim_header *header )
216{
217   flatshade_init_state( stage );
218   stage->tri( stage, header );
219}
220
221static void flatshade_first_line( struct draw_stage *stage,
222				  struct prim_header *header )
223{
224   flatshade_init_state( stage );
225   stage->line( stage, header );
226}
227
228
229static void flatshade_flush( struct draw_stage *stage,
230			     unsigned flags )
231{
232   stage->tri = flatshade_first_tri;
233   stage->line = flatshade_first_line;
234   stage->next->flush( stage->next, flags );
235}
236
237
238static void flatshade_reset_stipple_counter( struct draw_stage *stage )
239{
240   stage->next->reset_stipple_counter( stage->next );
241}
242
243
244static void flatshade_destroy( struct draw_stage *stage )
245{
246   draw_free_temp_verts( stage );
247   FREE( stage );
248}
249
250
251/**
252 * Create flatshading drawing stage.
253 */
254struct draw_stage *draw_flatshade_stage( struct draw_context *draw )
255{
256   struct flat_stage *flatshade = CALLOC_STRUCT(flat_stage);
257   if (flatshade == NULL)
258      goto fail;
259
260   flatshade->stage.draw = draw;
261   flatshade->stage.name = "flatshade";
262   flatshade->stage.next = NULL;
263   flatshade->stage.point = draw_pipe_passthrough_point;
264   flatshade->stage.line = flatshade_first_line;
265   flatshade->stage.tri = flatshade_first_tri;
266   flatshade->stage.flush = flatshade_flush;
267   flatshade->stage.reset_stipple_counter = flatshade_reset_stipple_counter;
268   flatshade->stage.destroy = flatshade_destroy;
269
270   if (!draw_alloc_temp_verts( &flatshade->stage, 2 ))
271      goto fail;
272
273   return &flatshade->stage;
274
275 fail:
276   if (flatshade)
277      flatshade->stage.destroy( &flatshade->stage );
278
279   return NULL;
280}
281
282
283