src/mesa/state_tracker/st_cb_feedback.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 VMware, Inc.
   4  * All Rights Reserved.
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   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the
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  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
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  21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
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  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    struct gl_context *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(struct gl_context *ctx, const struct draw_context *draw,
  81                 const struct vertex_header *v)
  82 {
  83    const struct st_context *st = st_context(ctx);
  84    GLfloat win[4];
  85    const GLfloat *color, *texcoord;
  86    GLuint slot;
  87
  88    win[0] = v->data[0][0];
  89    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
  90       win[1] = ctx->DrawBuffer->Height - v->data[0][1];
  91    else
  92       win[1] = v->data[0][1];
  93    win[2] = v->data[0][2];
  94    win[3] = 1.0F / v->data[0][3];
  95
  96    /* XXX
  97     * When we compute vertex layout, save info about position of the
  98     * color and texcoord attribs to use here.
  99     */
 100
 101    slot = st->vertex_result_to_slot[VARYING_SLOT_COL0];
 102    if (slot != ~0U)
 103       color = v->data[slot];
 104    else
 105       color = ctx->Current.Attrib[VERT_ATTRIB_COLOR0];
 106
 107    slot = st->vertex_result_to_slot[VARYING_SLOT_TEX0];
 108    if (slot != ~0U)
 109       texcoord = v->data[slot];
 110    else
 111       texcoord = ctx->Current.Attrib[VERT_ATTRIB_TEX0];
 112
 113    _mesa_feedback_vertex(ctx, win, color, texcoord);
 114 }
 115
 116
 117 static void
 118 feedback_tri( struct draw_stage *stage, struct prim_header *prim )
 119 {
 120    struct feedback_stage *fs = feedback_stage(stage);
 121    struct draw_context *draw = stage->draw;
 122    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POLYGON_TOKEN);
 123    _mesa_feedback_token(fs->ctx, (GLfloat) 3); /* three vertices */
 124    feedback_vertex(fs->ctx, draw, prim->v[0]);
 125    feedback_vertex(fs->ctx, draw, prim->v[1]);
 126    feedback_vertex(fs->ctx, draw, prim->v[2]);
 127 }
 128
 129
 130 static void
 131 feedback_line( struct draw_stage *stage, struct prim_header *prim )
 132 {
 133    struct feedback_stage *fs = feedback_stage(stage);
 134    struct draw_context *draw = stage->draw;
 135    if (fs->reset_stipple_counter) {
 136       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_RESET_TOKEN);
 137       fs->reset_stipple_counter = GL_FALSE;
 138    }
 139    else {
 140       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_TOKEN);
 141    }
 142    feedback_vertex(fs->ctx, draw, prim->v[0]);
 143    feedback_vertex(fs->ctx, draw, prim->v[1]);
 144 }
 145
 146
 147 static void
 148 feedback_point( struct draw_stage *stage, struct prim_header *prim )
 149 {
 150    struct feedback_stage *fs = feedback_stage(stage);
 151    struct draw_context *draw = stage->draw;
 152    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POINT_TOKEN);
 153    feedback_vertex(fs->ctx, draw, prim->v[0]);
 154 }
 155
 156
 157 static void
 158 feedback_flush( struct draw_stage *stage, unsigned flags )
 159 {
 160    /* no-op */
 161 }
 162
 163
 164 static void
 165 feedback_reset_stipple_counter( struct draw_stage *stage )
 166 {
 167    struct feedback_stage *fs = feedback_stage(stage);
 168    fs->reset_stipple_counter = GL_TRUE;
 169 }
 170
 171
 172 static void
 173 feedback_destroy( struct draw_stage *stage )
 174 {
 175    /* no-op */
 176 }
 177
 178 /**
 179  * Create GL feedback drawing stage.
 180  */
 181 static struct draw_stage *
 182 draw_glfeedback_stage(struct gl_context *ctx, struct draw_context *draw)
 183 {
 184    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 185
 186    fs->stage.draw = draw;
 187    fs->stage.next = NULL;
 188    fs->stage.point = feedback_point;
 189    fs->stage.line = feedback_line;
 190    fs->stage.tri = feedback_tri;
 191    fs->stage.flush = feedback_flush;
 192    fs->stage.reset_stipple_counter = feedback_reset_stipple_counter;
 193    fs->stage.destroy = feedback_destroy;
 194    fs->ctx = ctx;
 195
 196    return &fs->stage;
 197 }
 198
 199
 200
 201 /**********************************************************************
 202  * GL Selection functions
 203  **********************************************************************/
 204
 205 static void
 206 select_tri( struct draw_stage *stage, struct prim_header *prim )
 207 {
 208    struct feedback_stage *fs = feedback_stage(stage);
 209    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 210    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 211    _mesa_update_hitflag( fs->ctx, prim->v[2]->data[0][2] );
 212 }
 213
 214 static void
 215 select_line( struct draw_stage *stage, struct prim_header *prim )
 216 {
 217    struct feedback_stage *fs = feedback_stage(stage);
 218    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 219    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 220 }
 221
 222
 223 static void
 224 select_point( struct draw_stage *stage, struct prim_header *prim )
 225 {
 226    struct feedback_stage *fs = feedback_stage(stage);
 227    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 228 }
 229
 230
 231 static void
 232 select_flush( struct draw_stage *stage, unsigned flags )
 233 {
 234    /* no-op */
 235 }
 236
 237
 238 static void
 239 select_reset_stipple_counter( struct draw_stage *stage )
 240 {
 241    /* no-op */
 242 }
 243
 244 static void
 245 select_destroy( struct draw_stage *stage )
 246 {
 247    /* no-op */
 248 }
 249
 250
 251 /**
 252  * Create GL selection mode drawing stage.
 253  */
 254 static struct draw_stage *
 255 draw_glselect_stage(struct gl_context *ctx, struct draw_context *draw)
 256 {
 257    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 258
 259    fs->stage.draw = draw;
 260    fs->stage.next = NULL;
 261    fs->stage.point = select_point;
 262    fs->stage.line = select_line;
 263    fs->stage.tri = select_tri;
 264    fs->stage.flush = select_flush;
 265    fs->stage.reset_stipple_counter = select_reset_stipple_counter;
 266    fs->stage.destroy = select_destroy;
 267    fs->ctx = ctx;
 268
 269    return &fs->stage;
 270 }
 271
 272
 273 static void
 274 st_RenderMode(struct gl_context *ctx, GLenum newMode )
 275 {
 276    struct st_context *st = st_context(ctx);
 277    struct draw_context *draw = st->draw;
 278
 279    if (newMode == GL_RENDER) {
 280       /* restore normal VBO draw function */
 281       vbo_set_draw_func(ctx, st_draw_vbo);
 282    }
 283    else if (newMode == GL_SELECT) {
 284       if (!st->selection_stage)
 285          st->selection_stage = draw_glselect_stage(ctx, draw);
 286       draw_set_rasterize_stage(draw, st->selection_stage);
 287       /* Plug in new vbo draw function */
 288       vbo_set_draw_func(ctx, st_feedback_draw_vbo);
 289    }
 290    else {
 291       if (!st->feedback_stage)
 292          st->feedback_stage = draw_glfeedback_stage(ctx, draw);
 293       draw_set_rasterize_stage(draw, st->feedback_stage);
 294       /* Plug in new vbo draw function */
 295       vbo_set_draw_func(ctx, st_feedback_draw_vbo);
 296       /* need to generate/use a vertex program that emits pos/color/tex */
 297       st->dirty.st |= ST_NEW_VERTEX_PROGRAM;
 298    }
 299 }
 300
 301
 302
 303 void st_init_feedback_functions(struct dd_function_table *functions)
 304 {
 305    functions->RenderMode = st_RenderMode;
 306 }