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  * 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 
44 #include "vbo/vbo.h"
45 
46 #include "st_context.h"
47 #include "st_draw.h"
48 #include "st_cb_feedback.h"
49 #include "st_program.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 /**
59  * This is actually used for both feedback and selection.
60  */
61 struct feedback_stage
62 {
63    struct draw_stage stage;   /**< Base class */
64    struct gl_context *ctx;            /**< Rendering context */
65    GLboolean reset_stipple_counter;
66 };
67 
68 
69 /**********************************************************************
70  * GL Feedback functions
71  **********************************************************************/
72 
73 static inline struct feedback_stage *
feedback_stage(struct draw_stage * stage)74 feedback_stage( struct draw_stage *stage )
75 {
76    return (struct feedback_stage *)stage;
77 }
78 
79 
80 static void
feedback_vertex(struct gl_context * ctx,const struct draw_context * draw,const struct vertex_header * v)81 feedback_vertex(struct gl_context *ctx, const struct draw_context *draw,
82                 const struct vertex_header *v)
83 {
84    const struct st_context *st = st_context(ctx);
85    GLfloat win[4];
86    const GLfloat *color, *texcoord;
87    GLuint slot;
88 
89    win[0] = v->data[0][0];
90    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
91       win[1] = ctx->DrawBuffer->Height - v->data[0][1];
92    else
93       win[1] = 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[VARYING_SLOT_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[VARYING_SLOT_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_get_draw_context(st);
279 
280    if (!st->draw)
281       return;
282 
283    if (newMode == GL_RENDER) {
284       /* restore normal VBO draw function */
285       vbo_set_draw_func(ctx, st_draw_vbo);
286    }
287    else if (newMode == GL_SELECT) {
288       if (!st->selection_stage)
289          st->selection_stage = draw_glselect_stage(ctx, draw);
290       draw_set_rasterize_stage(draw, st->selection_stage);
291       /* Plug in new vbo draw function */
292       vbo_set_draw_func(ctx, st_feedback_draw_vbo);
293    }
294    else {
295       struct gl_program *vp = st->ctx->VertexProgram._Current;
296 
297       if (!st->feedback_stage)
298          st->feedback_stage = draw_glfeedback_stage(ctx, draw);
299       draw_set_rasterize_stage(draw, st->feedback_stage);
300       /* Plug in new vbo draw function */
301       vbo_set_draw_func(ctx, st_feedback_draw_vbo);
302       /* need to generate/use a vertex program that emits pos/color/tex */
303       if (vp)
304          st->dirty |= ST_NEW_VERTEX_PROGRAM(st, st_vertex_program(vp));
305    }
306 }
307 
308 
309 
st_init_feedback_functions(struct dd_function_table * functions)310 void st_init_feedback_functions(struct dd_function_table *functions)
311 {
312    functions->RenderMode = st_RenderMode;
313 }
314