src/mesa/state_tracker/st_cb_feedback.c

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