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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  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/varray.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 #include "st_program.h"
  51
  52 #include "pipe/p_context.h"
  53 #include "pipe/p_defines.h"
  54
  55 #include "draw/draw_context.h"
  56 #include "draw/draw_pipe.h"
  57
  58
  59 /**
  60  * This is actually used for both feedback and selection.
  61  */
  62 struct feedback_stage
  63 {
  64    struct draw_stage stage;   /**< Base class */
  65    struct gl_context *ctx;            /**< Rendering context */
  66    GLboolean reset_stipple_counter;
  67 };
  68
  69
  70 /**********************************************************************
  71  * GL Feedback functions
  72  **********************************************************************/
  73
  74 static inline struct feedback_stage *
  75 feedback_stage( struct draw_stage *stage )
  76 {
  77    return (struct feedback_stage *)stage;
  78 }
  79
  80
  81 static void
  82 feedback_vertex(struct gl_context *ctx, const struct draw_context *draw,
  83                 const struct vertex_header *v)
  84 {
  85    const struct st_context *st = st_context(ctx);
  86    GLfloat win[4];
  87    const GLfloat *color, *texcoord;
  88    GLuint slot;
  89
  90    win[0] = v->data[0][0];
  91    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
  92       win[1] = ctx->DrawBuffer->Height - v->data[0][1];
  93    else
  94       win[1] = v->data[0][1];
  95    win[2] = v->data[0][2];
  96    win[3] = 1.0F / v->data[0][3];
  97
  98    /* XXX
  99     * When we compute vertex layout, save info about position of the
 100     * color and texcoord attribs to use here.
 101     */
 102
 103    slot = st->vp->result_to_output[VARYING_SLOT_COL0];
 104    if (slot != ~0U)
 105       color = v->data[slot];
 106    else
 107       color = ctx->Current.Attrib[VERT_ATTRIB_COLOR0];
 108
 109    slot = st->vp->result_to_output[VARYING_SLOT_TEX0];
 110    if (slot != ~0U)
 111       texcoord = v->data[slot];
 112    else
 113       texcoord = ctx->Current.Attrib[VERT_ATTRIB_TEX0];
 114
 115    _mesa_feedback_vertex(ctx, win, color, texcoord);
 116 }
 117
 118
 119 static void
 120 feedback_tri( struct draw_stage *stage, struct prim_header *prim )
 121 {
 122    struct feedback_stage *fs = feedback_stage(stage);
 123    struct draw_context *draw = stage->draw;
 124    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POLYGON_TOKEN);
 125    _mesa_feedback_token(fs->ctx, (GLfloat) 3); /* three vertices */
 126    feedback_vertex(fs->ctx, draw, prim->v[0]);
 127    feedback_vertex(fs->ctx, draw, prim->v[1]);
 128    feedback_vertex(fs->ctx, draw, prim->v[2]);
 129 }
 130
 131
 132 static void
 133 feedback_line( struct draw_stage *stage, struct prim_header *prim )
 134 {
 135    struct feedback_stage *fs = feedback_stage(stage);
 136    struct draw_context *draw = stage->draw;
 137    if (fs->reset_stipple_counter) {
 138       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_RESET_TOKEN);
 139       fs->reset_stipple_counter = GL_FALSE;
 140    }
 141    else {
 142       _mesa_feedback_token(fs->ctx, (GLfloat) GL_LINE_TOKEN);
 143    }
 144    feedback_vertex(fs->ctx, draw, prim->v[0]);
 145    feedback_vertex(fs->ctx, draw, prim->v[1]);
 146 }
 147
 148
 149 static void
 150 feedback_point( struct draw_stage *stage, struct prim_header *prim )
 151 {
 152    struct feedback_stage *fs = feedback_stage(stage);
 153    struct draw_context *draw = stage->draw;
 154    _mesa_feedback_token(fs->ctx, (GLfloat) GL_POINT_TOKEN);
 155    feedback_vertex(fs->ctx, draw, prim->v[0]);
 156 }
 157
 158
 159 static void
 160 feedback_flush( struct draw_stage *stage, unsigned flags )
 161 {
 162    /* no-op */
 163 }
 164
 165
 166 static void
 167 feedback_reset_stipple_counter( struct draw_stage *stage )
 168 {
 169    struct feedback_stage *fs = feedback_stage(stage);
 170    fs->reset_stipple_counter = GL_TRUE;
 171 }
 172
 173
 174 static void
 175 feedback_destroy( struct draw_stage *stage )
 176 {
 177    /* no-op */
 178 }
 179
 180 /**
 181  * Create GL feedback drawing stage.
 182  */
 183 static struct draw_stage *
 184 draw_glfeedback_stage(struct gl_context *ctx, struct draw_context *draw)
 185 {
 186    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 187
 188    fs->stage.draw = draw;
 189    fs->stage.next = NULL;
 190    fs->stage.point = feedback_point;
 191    fs->stage.line = feedback_line;
 192    fs->stage.tri = feedback_tri;
 193    fs->stage.flush = feedback_flush;
 194    fs->stage.reset_stipple_counter = feedback_reset_stipple_counter;
 195    fs->stage.destroy = feedback_destroy;
 196    fs->ctx = ctx;
 197
 198    return &fs->stage;
 199 }
 200
 201
 202
 203 /**********************************************************************
 204  * GL Selection functions
 205  **********************************************************************/
 206
 207 static void
 208 select_tri( struct draw_stage *stage, struct prim_header *prim )
 209 {
 210    struct feedback_stage *fs = feedback_stage(stage);
 211    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 212    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 213    _mesa_update_hitflag( fs->ctx, prim->v[2]->data[0][2] );
 214 }
 215
 216 static void
 217 select_line( struct draw_stage *stage, struct prim_header *prim )
 218 {
 219    struct feedback_stage *fs = feedback_stage(stage);
 220    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 221    _mesa_update_hitflag( fs->ctx, prim->v[1]->data[0][2] );
 222 }
 223
 224
 225 static void
 226 select_point( struct draw_stage *stage, struct prim_header *prim )
 227 {
 228    struct feedback_stage *fs = feedback_stage(stage);
 229    _mesa_update_hitflag( fs->ctx, prim->v[0]->data[0][2] );
 230 }
 231
 232
 233 static void
 234 select_flush( struct draw_stage *stage, unsigned flags )
 235 {
 236    /* no-op */
 237 }
 238
 239
 240 static void
 241 select_reset_stipple_counter( struct draw_stage *stage )
 242 {
 243    /* no-op */
 244 }
 245
 246 static void
 247 select_destroy( struct draw_stage *stage )
 248 {
 249    /* no-op */
 250 }
 251
 252
 253 /**
 254  * Create GL selection mode drawing stage.
 255  */
 256 static struct draw_stage *
 257 draw_glselect_stage(struct gl_context *ctx, struct draw_context *draw)
 258 {
 259    struct feedback_stage *fs = ST_CALLOC_STRUCT(feedback_stage);
 260
 261    fs->stage.draw = draw;
 262    fs->stage.next = NULL;
 263    fs->stage.point = select_point;
 264    fs->stage.line = select_line;
 265    fs->stage.tri = select_tri;
 266    fs->stage.flush = select_flush;
 267    fs->stage.reset_stipple_counter = select_reset_stipple_counter;
 268    fs->stage.destroy = select_destroy;
 269    fs->ctx = ctx;
 270
 271    return &fs->stage;
 272 }
 273
 274
 275 static void
 276 st_RenderMode(struct gl_context *ctx, GLenum newMode )
 277 {
 278    struct st_context *st = st_context(ctx);
 279    struct draw_context *draw = st_get_draw_context(st);
 280
 281    if (!st->draw)
 282       return;
 283
 284    if (newMode == GL_RENDER) {
 285       /* restore normal VBO draw function */
 286       st_init_draw_functions(&ctx->Driver);
 287    }
 288    else if (newMode == GL_SELECT) {
 289       if (!st->selection_stage)
 290          st->selection_stage = draw_glselect_stage(ctx, draw);
 291       draw_set_rasterize_stage(draw, st->selection_stage);
 292       /* Plug in new vbo draw function */
 293       ctx->Driver.Draw = st_feedback_draw_vbo;
 294    }
 295    else {
 296       struct gl_program *vp = st->ctx->VertexProgram._Current;
 297
 298       if (!st->feedback_stage)
 299          st->feedback_stage = draw_glfeedback_stage(ctx, draw);
 300       draw_set_rasterize_stage(draw, st->feedback_stage);
 301       /* Plug in new vbo draw function */
 302       ctx->Driver.Draw = st_feedback_draw_vbo;
 303       /* need to generate/use a vertex program that emits pos/color/tex */
 304       if (vp)
 305          st->dirty |= ST_NEW_VERTEX_PROGRAM(st, st_vertex_program(vp));
 306    }
 307 }
 308
 309
 310
 311 void st_init_feedback_functions(struct dd_function_table *functions)
 312 {
 313    functions->RenderMode = st_RenderMode;
 314 }