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 */
63 struct 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
75 static INLINE struct feedback_stage *
feedback_stage(struct draw_stage * stage)76 feedback_stage( struct draw_stage *stage )
77 {
78 return (struct feedback_stage *)stage;
79 }
80
81
82 static void
feedback_vertex(struct gl_context * ctx,const struct draw_context * draw,const struct vertex_header * v)83 feedback_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
118 static void
feedback_tri(struct draw_stage * stage,struct prim_header * prim)119 feedback_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
131 static void
feedback_line(struct draw_stage * stage,struct prim_header * prim)132 feedback_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
148 static void
feedback_point(struct draw_stage * stage,struct prim_header * prim)149 feedback_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
158 static void
feedback_flush(struct draw_stage * stage,unsigned flags)159 feedback_flush( struct draw_stage *stage, unsigned flags )
160 {
161 /* no-op */
162 }
163
164
165 static void
feedback_reset_stipple_counter(struct draw_stage * stage)166 feedback_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
173 static void
feedback_destroy(struct draw_stage * stage)174 feedback_destroy( struct draw_stage *stage )
175 {
176 /* no-op */
177 }
178
179 /**
180 * Create GL feedback drawing stage.
181 */
182 static struct draw_stage *
draw_glfeedback_stage(struct gl_context * ctx,struct draw_context * draw)183 draw_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
206 static void
select_tri(struct draw_stage * stage,struct prim_header * prim)207 select_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
215 static void
select_line(struct draw_stage * stage,struct prim_header * prim)216 select_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
224 static void
select_point(struct draw_stage * stage,struct prim_header * prim)225 select_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
232 static void
select_flush(struct draw_stage * stage,unsigned flags)233 select_flush( struct draw_stage *stage, unsigned flags )
234 {
235 /* no-op */
236 }
237
238
239 static void
select_reset_stipple_counter(struct draw_stage * stage)240 select_reset_stipple_counter( struct draw_stage *stage )
241 {
242 /* no-op */
243 }
244
245 static void
select_destroy(struct draw_stage * stage)246 select_destroy( struct draw_stage *stage )
247 {
248 /* no-op */
249 }
250
251
252 /**
253 * Create GL selection mode drawing stage.
254 */
255 static struct draw_stage *
draw_glselect_stage(struct gl_context * ctx,struct draw_context * draw)256 draw_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
274 static void
st_RenderMode(struct gl_context * ctx,GLenum newMode)275 st_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
st_init_feedback_functions(struct dd_function_table * functions)304 void st_init_feedback_functions(struct dd_function_table *functions)
305 {
306 functions->RenderMode = st_RenderMode;
307 }
308
309 #endif /* FEATURE_feedback */
310