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 * GL_SELECT and GL_FEEDBACK render modes.
30 * Basically, we use a private instance of the 'draw' module for doing
31 * selection/feedback.  It would be nice to use the transform_feedback
32 * hardware feature, but it's defined as happening pre-clip and we want
33 * post-clipped primitives.  Also, there's concerns about the efficiency
34 * of using the hardware for this anyway.
35 *
36 * Authors:
37 *   Brian Paul
38 */
39
40#include "main/imports.h"
41#include "main/context.h"
42#include "main/feedback.h"
43#include "main/mfeatures.h"
44
45#include "vbo/vbo.h"
46
47#include "st_context.h"
48#include "st_draw.h"
49#include "st_cb_feedback.h"
50
51#include "pipe/p_context.h"
52#include "pipe/p_defines.h"
53
54#include "draw/draw_context.h"
55#include "draw/draw_pipe.h"
56
57
58#if FEATURE_feedback
59
60/**
61 * This is actually used for both feedback and selection.
62 */
63struct feedback_stage
64{
65   struct draw_stage stage;   /**< Base class */
66   struct gl_context *ctx;            /**< Rendering context */
67   GLboolean reset_stipple_counter;
68};
69
70
71/**********************************************************************
72 * GL Feedback functions
73 **********************************************************************/
74
75static INLINE struct feedback_stage *
76feedback_stage( struct draw_stage *stage )
77{
78   return (struct feedback_stage *)stage;
79}
80
81
82static void
83feedback_vertex(struct gl_context *ctx, const struct draw_context *draw,
84                const struct vertex_header *v)
85{
86   const struct st_context *st = st_context(ctx);
87   GLfloat win[4];
88   const GLfloat *color, *texcoord;
89   GLuint slot;
90
91   /* Recall that Y=0=Top of window for Gallium wincoords */
92   win[0] = v->data[0][0];
93   win[1] = ctx->DrawBuffer->Height - v->data[0][1];
94   win[2] = v->data[0][2];
95   win[3] = 1.0F / v->data[0][3];
96
97   /* XXX
98    * When we compute vertex layout, save info about position of the
99    * color and texcoord attribs to use here.
100    */
101
102   slot = st->vertex_result_to_slot[VERT_RESULT_COL0];
103   if (slot != ~0U)
104      color = v->data[slot];
105   else
106      color = ctx->Current.Attrib[VERT_ATTRIB_COLOR0];
107
108   slot = st->vertex_result_to_slot[VERT_RESULT_TEX0];
109   if (slot != ~0U)
110      texcoord = v->data[slot];
111   else
112      texcoord = ctx->Current.Attrib[VERT_ATTRIB_TEX0];
113
114   _mesa_feedback_vertex(ctx, win, color, texcoord);
115}
116
117
118static void
119feedback_tri( struct draw_stage *stage, struct prim_header *prim )
120{
121   struct feedback_stage *fs = feedback_stage(stage);
122   struct draw_context *draw = stage->draw;
123   _mesa_feedback_token(fs->ctx, (GLfloat) GL_POLYGON_TOKEN);
124   _mesa_feedback_token(fs->ctx, (GLfloat) 3); /* three vertices */
125   feedback_vertex(fs->ctx, draw, prim->v[0]);
126   feedback_vertex(fs->ctx, draw, prim->v[1]);
127   feedback_vertex(fs->ctx, draw, prim->v[2]);
128}
129
130
131static void
132feedback_line( struct draw_stage *stage, struct prim_header *prim )
133{
134   struct feedback_stage *fs = feedback_stage(stage);
135   struct draw_context *draw = stage->draw;
136   if (fs->reset_stipple_counter) {
137      _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_RESET_TOKEN);
138      fs->reset_stipple_counter = GL_FALSE;
139   }
140   else {
141      _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_TOKEN);
142   }
143   feedback_vertex(fs->ctx, draw, prim->v[0]);
144   feedback_vertex(fs->ctx, draw, prim->v[1]);
145}
146
147
148static void
149feedback_point( struct draw_stage *stage, struct prim_header *prim )
150{
151   struct feedback_stage *fs = feedback_stage(stage);
152   struct draw_context *draw = stage->draw;
153   _mesa_feedback_token(fs->ctx, (GLfloat) GL_POINT_TOKEN);
154   feedback_vertex(fs->ctx, draw, prim->v[0]);
155}
156
157
158static void
159feedback_flush( struct draw_stage *stage, unsigned flags )
160{
161   /* no-op */
162}
163
164
165static void
166feedback_reset_stipple_counter( struct draw_stage *stage )
167{
168   struct feedback_stage *fs = feedback_stage(stage);
169   fs->reset_stipple_counter = GL_TRUE;
170}
171
172
173static void
174feedback_destroy( struct draw_stage *stage )
175{
176   /* no-op */
177}
178
179/**
180 * Create GL feedback drawing stage.
181 */
182static struct draw_stage *
183draw_glfeedback_stage(struct gl_context *ctx, struct draw_context *draw)
184{
185   struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
186
187   fs->stage.draw = draw;
188   fs->stage.next = NULL;
189   fs->stage.point = feedback_point;
190   fs->stage.line = feedback_line;
191   fs->stage.tri = feedback_tri;
192   fs->stage.flush = feedback_flush;
193   fs->stage.reset_stipple_counter = feedback_reset_stipple_counter;
194   fs->stage.destroy = feedback_destroy;
195   fs->ctx = ctx;
196
197   return &fs->stage;
198}
199
200
201
202/**********************************************************************
203 * GL Selection functions
204 **********************************************************************/
205
206static void
207select_tri( struct draw_stage *stage, struct prim_header *prim )
208{
209   struct feedback_stage *fs = feedback_stage(stage);
210   _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
211   _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
212   _mesa_update_hitflag( fs->ctx, prim->v[2]->data[0][2] );
213}
214
215static void
216select_line( struct draw_stage *stage, struct prim_header *prim )
217{
218   struct feedback_stage *fs = feedback_stage(stage);
219   _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
220   _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
221}
222
223
224static void
225select_point( struct draw_stage *stage, struct prim_header *prim )
226{
227   struct feedback_stage *fs = feedback_stage(stage);
228   _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
229}
230
231
232static void
233select_flush( struct draw_stage *stage, unsigned flags )
234{
235   /* no-op */
236}
237
238
239static void
240select_reset_stipple_counter( struct draw_stage *stage )
241{
242   /* no-op */
243}
244
245static void
246select_destroy( struct draw_stage *stage )
247{
248   /* no-op */
249}
250
251
252/**
253 * Create GL selection mode drawing stage.
254 */
255static struct draw_stage *
256draw_glselect_stage(struct gl_context *ctx, struct draw_context *draw)
257{
258   struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
259
260   fs->stage.draw = draw;
261   fs->stage.next = NULL;
262   fs->stage.point = select_point;
263   fs->stage.line = select_line;
264   fs->stage.tri = select_tri;
265   fs->stage.flush = select_flush;
266   fs->stage.reset_stipple_counter = select_reset_stipple_counter;
267   fs->stage.destroy = select_destroy;
268   fs->ctx = ctx;
269
270   return &fs->stage;
271}
272
273
274static void
275st_RenderMode(struct gl_context *ctx, GLenum newMode )
276{
277   struct st_context *st = st_context(ctx);
278   struct draw_context *draw = st->draw;
279
280   if (newMode == GL_RENDER) {
281      /* restore normal VBO draw function */
282      vbo_set_draw_func(ctx, st_draw_vbo);
283   }
284   else if (newMode == GL_SELECT) {
285      if (!st->selection_stage)
286         st->selection_stage = draw_glselect_stage(ctx, draw);
287      draw_set_rasterize_stage(draw, st->selection_stage);
288      /* Plug in new vbo draw function */
289      vbo_set_draw_func(ctx, st_feedback_draw_vbo);
290   }
291   else {
292      if (!st->feedback_stage)
293         st->feedback_stage = draw_glfeedback_stage(ctx, draw);
294      draw_set_rasterize_stage(draw, st->feedback_stage);
295      /* Plug in new vbo draw function */
296      vbo_set_draw_func(ctx, st_feedback_draw_vbo);
297      /* need to generate/use a vertex program that emits pos/color/tex */
298      st->dirty.st |= ST_NEW_VERTEX_PROGRAM;
299   }
300}
301
302
303
304void st_init_feedback_functions(struct dd_function_table *functions)
305{
306   functions->RenderMode = st_RenderMode;
307}
308
309#endif /* FEATURE_feedback */
310