src/mesa/main/arrayobj.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
   5  * (C) Copyright IBM Corporation 2006
   6  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included
  16  * in all copies or substantial portions 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 MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  22  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  23  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  * OTHER DEALINGS IN THE SOFTWARE.
  25  */
  26
  27
  28 /**
  29  * \file arrayobj.c
  30  *
  31  * Implementation of Vertex Array Objects (VAOs), from OpenGL 3.1+ /
  32  * the GL_ARB_vertex_array_object extension.
  33  *
  34  * \todo
  35  * The code in this file borrows a lot from bufferobj.c.  There's a certain
  36  * amount of cruft left over from that origin that may be unnecessary.
  37  *
  38  * \author Ian Romanick <idr@us.ibm.com>
  39  * \author Brian Paul
  40  */
  41
  42
  43 #include "glheader.h"
  44 #include "hash.h"
  45 #include "image.h"
  46 #include "imports.h"
  47 #include "context.h"
  48 #include "bufferobj.h"
  49 #include "arrayobj.h"
  50 #include "macros.h"
  51 #include "mtypes.h"
  52 #include "varray.h"
  53 #include "main/dispatch.h"
  54 #include "util/bitscan.h"
  55
  56
  57 /**
  58  * Look up the array object for the given ID.
  59  *
  60  * \returns
  61  * Either a pointer to the array object with the specified ID or \c NULL for
  62  * a non-existent ID.  The spec defines ID 0 as being technically
  63  * non-existent.
  64  */
  65
  66 struct gl_vertex_array_object *
  67 _mesa_lookup_vao(struct gl_context *ctx, GLuint id)
  68 {
  69    if (id == 0) {
  70       return NULL;
  71    } else {
  72       struct gl_vertex_array_object *vao;
  73
  74       if (ctx->Array.LastLookedUpVAO &&
  75           ctx->Array.LastLookedUpVAO->Name == id) {
  76          vao = ctx->Array.LastLookedUpVAO;
  77       } else {
  78          vao = (struct gl_vertex_array_object *)
  79             _mesa_HashLookupLocked(ctx->Array.Objects, id);
  80
  81          _mesa_reference_vao(ctx, &ctx->Array.LastLookedUpVAO, vao);
  82       }
  83
  84       return vao;
  85    }
  86 }
  87
  88
  89 /**
  90  * Looks up the array object for the given ID.
  91  *
  92  * Unlike _mesa_lookup_vao, this function generates a GL_INVALID_OPERATION
  93  * error if the array object does not exist. It also returns the default
  94  * array object when ctx is a compatibility profile context and id is zero.
  95  */
  96 struct gl_vertex_array_object *
  97 _mesa_lookup_vao_err(struct gl_context *ctx, GLuint id, const char *caller)
  98 {
  99    /* The ARB_direct_state_access specification says:
 100     *
 101     *    "<vaobj> is [compatibility profile:
 102     *     zero, indicating the default vertex array object, or]
 103     *     the name of the vertex array object."
 104     */
 105    if (id == 0) {
 106       if (ctx->API == API_OPENGL_CORE) {
 107          _mesa_error(ctx, GL_INVALID_OPERATION,
 108                      "%s(zero is not valid vaobj name in a core profile "
 109                      "context)", caller);
 110          return NULL;
 111       }
 112
 113       return ctx->Array.DefaultVAO;
 114    } else {
 115       struct gl_vertex_array_object *vao;
 116
 117       if (ctx->Array.LastLookedUpVAO &&
 118           ctx->Array.LastLookedUpVAO->Name == id) {
 119          vao = ctx->Array.LastLookedUpVAO;
 120       } else {
 121          vao = (struct gl_vertex_array_object *)
 122             _mesa_HashLookupLocked(ctx->Array.Objects, id);
 123
 124          /* The ARB_direct_state_access specification says:
 125           *
 126           *    "An INVALID_OPERATION error is generated if <vaobj> is not
 127           *     [compatibility profile: zero or] the name of an existing
 128           *     vertex array object."
 129           */
 130          if (!vao || !vao->EverBound) {
 131             _mesa_error(ctx, GL_INVALID_OPERATION,
 132                         "%s(non-existent vaobj=%u)", caller, id);
 133             return NULL;
 134          }
 135
 136          _mesa_reference_vao(ctx, &ctx->Array.LastLookedUpVAO, vao);
 137       }
 138
 139       return vao;
 140    }
 141 }
 142
 143
 144 /**
 145  * For all the vertex binding points in the array object, unbind any pointers
 146  * to any buffer objects (VBOs).
 147  * This is done just prior to array object destruction.
 148  */
 149 static void
 150 unbind_array_object_vbos(struct gl_context *ctx, struct gl_vertex_array_object *obj)
 151 {
 152    GLuint i;
 153
 154    for (i = 0; i < ARRAY_SIZE(obj->BufferBinding); i++)
 155       _mesa_reference_buffer_object(ctx, &obj->BufferBinding[i].BufferObj, NULL);
 156
 157    for (i = 0; i < ARRAY_SIZE(obj->_VertexAttrib); i++)
 158       _mesa_reference_buffer_object(ctx, &obj->_VertexAttrib[i].BufferObj, NULL);
 159 }
 160
 161
 162 /**
 163  * Allocate and initialize a new vertex array object.
 164  */
 165 struct gl_vertex_array_object *
 166 _mesa_new_vao(struct gl_context *ctx, GLuint name)
 167 {
 168    struct gl_vertex_array_object *obj = CALLOC_STRUCT(gl_vertex_array_object);
 169    if (obj)
 170       _mesa_initialize_vao(ctx, obj, name);
 171    return obj;
 172 }
 173
 174
 175 /**
 176  * Delete an array object.
 177  */
 178 void
 179 _mesa_delete_vao(struct gl_context *ctx, struct gl_vertex_array_object *obj)
 180 {
 181    unbind_array_object_vbos(ctx, obj);
 182    _mesa_reference_buffer_object(ctx, &obj->IndexBufferObj, NULL);
 183    free(obj->Label);
 184    free(obj);
 185 }
 186
 187
 188 /**
 189  * Set ptr to vao w/ reference counting.
 190  * Note: this should only be called from the _mesa_reference_vao()
 191  * inline function.
 192  */
 193 void
 194 _mesa_reference_vao_(struct gl_context *ctx,
 195                      struct gl_vertex_array_object **ptr,
 196                      struct gl_vertex_array_object *vao)
 197 {
 198    assert(*ptr != vao);
 199
 200    if (*ptr) {
 201       /* Unreference the old array object */
 202       struct gl_vertex_array_object *oldObj = *ptr;
 203
 204       assert(oldObj->RefCount > 0);
 205       oldObj->RefCount--;
 206
 207       if (oldObj->RefCount == 0)
 208          _mesa_delete_vao(ctx, oldObj);
 209
 210       *ptr = NULL;
 211    }
 212    assert(!*ptr);
 213
 214    if (vao) {
 215       /* reference new array object */
 216       assert(vao->RefCount > 0);
 217
 218       vao->RefCount++;
 219       *ptr = vao;
 220    }
 221 }
 222
 223
 224 /**
 225  * Initialize attribtes of a vertex array within a vertex array object.
 226  * \param vao  the container vertex array object
 227  * \param index  which array in the VAO to initialize
 228  * \param size  number of components (1, 2, 3 or 4) per attribute
 229  * \param type  datatype of the attribute (GL_FLOAT, GL_INT, etc).
 230  */
 231 static void
 232 init_array(struct gl_context *ctx,
 233            struct gl_vertex_array_object *vao,
 234            GLuint index, GLint size, GLint type)
 235 {
 236    struct gl_array_attributes *array = &vao->VertexAttrib[index];
 237    struct gl_vertex_buffer_binding *binding = &vao->BufferBinding[index];
 238
 239    array->Size = size;
 240    array->Type = type;
 241    array->Format = GL_RGBA; /* only significant for GL_EXT_vertex_array_bgra */
 242    array->Stride = 0;
 243    array->Ptr = NULL;
 244    array->RelativeOffset = 0;
 245    array->Enabled = GL_FALSE;
 246    array->Normalized = GL_FALSE;
 247    array->Integer = GL_FALSE;
 248    array->Doubles = GL_FALSE;
 249    array->_ElementSize = size * _mesa_sizeof_type(type);
 250    array->BufferBindingIndex = index;
 251
 252    binding->Offset = 0;
 253    binding->Stride = array->_ElementSize;
 254    binding->BufferObj = NULL;
 255    binding->_BoundArrays = BITFIELD_BIT(index);
 256
 257    /* Vertex array buffers */
 258    _mesa_reference_buffer_object(ctx, &binding->BufferObj,
 259                                  ctx->Shared->NullBufferObj);
 260 }
 261
 262
 263 /**
 264  * Initialize a gl_vertex_array_object's arrays.
 265  */
 266 void
 267 _mesa_initialize_vao(struct gl_context *ctx,
 268                      struct gl_vertex_array_object *vao,
 269                      GLuint name)
 270 {
 271    GLuint i;
 272
 273    vao->Name = name;
 274
 275    vao->RefCount = 1;
 276
 277    /* Init the individual arrays */
 278    for (i = 0; i < ARRAY_SIZE(vao->VertexAttrib); i++) {
 279       switch (i) {
 280       case VERT_ATTRIB_NORMAL:
 281          init_array(ctx, vao, VERT_ATTRIB_NORMAL, 3, GL_FLOAT);
 282          break;
 283       case VERT_ATTRIB_COLOR1:
 284          init_array(ctx, vao, VERT_ATTRIB_COLOR1, 3, GL_FLOAT);
 285          break;
 286       case VERT_ATTRIB_FOG:
 287          init_array(ctx, vao, VERT_ATTRIB_FOG, 1, GL_FLOAT);
 288          break;
 289       case VERT_ATTRIB_COLOR_INDEX:
 290          init_array(ctx, vao, VERT_ATTRIB_COLOR_INDEX, 1, GL_FLOAT);
 291          break;
 292       case VERT_ATTRIB_EDGEFLAG:
 293          init_array(ctx, vao, VERT_ATTRIB_EDGEFLAG, 1, GL_BOOL);
 294          break;
 295       case VERT_ATTRIB_POINT_SIZE:
 296          init_array(ctx, vao, VERT_ATTRIB_POINT_SIZE, 1, GL_FLOAT);
 297          break;
 298       default:
 299          init_array(ctx, vao, i, 4, GL_FLOAT);
 300          break;
 301       }
 302    }
 303
 304    _mesa_reference_buffer_object(ctx, &vao->IndexBufferObj,
 305                                  ctx->Shared->NullBufferObj);
 306 }
 307
 308
 309 /**
 310  * Updates the derived gl_vertex_arrays when a gl_vertex_attrib_array
 311  * or a gl_vertex_buffer_binding has changed.
 312  */
 313 void
 314 _mesa_update_vao_client_arrays(struct gl_context *ctx,
 315                                struct gl_vertex_array_object *vao)
 316 {
 317    GLbitfield arrays = vao->NewArrays;
 318
 319    while (arrays) {
 320       const int attrib = u_bit_scan(&arrays);
 321       struct gl_vertex_array *client_array = &vao->_VertexAttrib[attrib];
 322       const struct gl_array_attributes *attrib_array =
 323          &vao->VertexAttrib[attrib];
 324       const struct gl_vertex_buffer_binding *buffer_binding =
 325          &vao->BufferBinding[attrib_array->BufferBindingIndex];
 326
 327       _mesa_update_client_array(ctx, client_array, attrib_array,
 328                                 buffer_binding);
 329    }
 330 }
 331
 332
 333 bool
 334 _mesa_all_varyings_in_vbos(const struct gl_vertex_array_object *vao)
 335 {
 336    /* Walk those enabled arrays that have the default vbo attached */
 337    GLbitfield mask = vao->_Enabled & ~vao->VertexAttribBufferMask;
 338
 339    while (mask) {
 340       /* Do not use u_bit_scan64 as we can walk multiple
 341        * attrib arrays at once
 342        */
 343       const int i = ffs(mask) - 1;
 344       const struct gl_array_attributes *attrib_array =
 345          &vao->VertexAttrib[i];
 346       const struct gl_vertex_buffer_binding *buffer_binding =
 347          &vao->BufferBinding[attrib_array->BufferBindingIndex];
 348
 349       /* Only enabled arrays shall appear in the _Enabled bitmask */
 350       assert(attrib_array->Enabled);
 351       /* We have already masked out vao->VertexAttribBufferMask  */
 352       assert(!_mesa_is_bufferobj(buffer_binding->BufferObj));
 353
 354       /* Bail out once we find the first non vbo with a non zero stride */
 355       if (buffer_binding->Stride != 0)
 356          return false;
 357
 358       /* Note that we cannot use the xor variant since the _BoundArray mask
 359        * may contain array attributes that are bound but not enabled.
 360        */
 361       mask &= ~buffer_binding->_BoundArrays;
 362    }
 363
 364    return true;
 365 }
 366
 367 bool
 368 _mesa_all_buffers_are_unmapped(const struct gl_vertex_array_object *vao)
 369 {
 370    /* Walk the enabled arrays that have a vbo attached */
 371    GLbitfield mask = vao->_Enabled & vao->VertexAttribBufferMask;
 372
 373    while (mask) {
 374       const int i = ffs(mask) - 1;
 375       const struct gl_array_attributes *attrib_array =
 376          &vao->VertexAttrib[i];
 377       const struct gl_vertex_buffer_binding *buffer_binding =
 378          &vao->BufferBinding[attrib_array->BufferBindingIndex];
 379
 380       /* Only enabled arrays shall appear in the _Enabled bitmask */
 381       assert(attrib_array->Enabled);
 382       /* We have already masked with vao->VertexAttribBufferMask  */
 383       assert(_mesa_is_bufferobj(buffer_binding->BufferObj));
 384
 385       /* Bail out once we find the first disallowed mapping */
 386       if (_mesa_check_disallowed_mapping(buffer_binding->BufferObj))
 387          return false;
 388
 389       /* We have handled everything that is bound to this buffer_binding. */
 390       mask &= ~buffer_binding->_BoundArrays;
 391    }
 392
 393    return true;
 394 }
 395
 396 /**********************************************************************/
 397 /* API Functions                                                      */
 398 /**********************************************************************/
 399
 400
 401 /**
 402  * ARB version of glBindVertexArray()
 403  */
 404 static ALWAYS_INLINE void
 405 bind_vertex_array(struct gl_context *ctx, GLuint id, bool no_error)
 406 {
 407    struct gl_vertex_array_object *const oldObj = ctx->Array.VAO;
 408    struct gl_vertex_array_object *newObj = NULL;
 409
 410    assert(oldObj != NULL);
 411
 412    if (oldObj->Name == id)
 413       return;   /* rebinding the same array object- no change */
 414
 415    /*
 416     * Get pointer to new array object (newObj)
 417     */
 418    if (id == 0) {
 419       /* The spec says there is no array object named 0, but we use
 420        * one internally because it simplifies things.
 421        */
 422       newObj = ctx->Array.DefaultVAO;
 423    }
 424    else {
 425       /* non-default array object */
 426       newObj = _mesa_lookup_vao(ctx, id);
 427       if (!no_error && !newObj) {
 428          _mesa_error(ctx, GL_INVALID_OPERATION,
 429                      "glBindVertexArray(non-gen name)");
 430          return;
 431       }
 432
 433       newObj->EverBound = GL_TRUE;
 434    }
 435
 436    if (ctx->Array.DrawMethod == DRAW_ARRAYS) {
 437       /* The _DrawArrays pointer is pointing at the VAO being unbound and
 438        * that VAO may be in the process of being deleted. If it's not going
 439        * to be deleted, this will have no effect, because the pointer needs
 440        * to be updated by the VBO module anyway.
 441        *
 442        * Before the VBO module can update the pointer, we have to set it
 443        * to NULL for drivers not to set up arrays which are not bound,
 444        * or to prevent a crash if the VAO being unbound is going to be
 445        * deleted.
 446        */
 447       ctx->Array._DrawArrays = NULL;
 448       ctx->Array.DrawMethod = DRAW_NONE;
 449    }
 450
 451    ctx->NewState |= _NEW_ARRAY;
 452    _mesa_reference_vao(ctx, &ctx->Array.VAO, newObj);
 453 }
 454
 455
 456 void GLAPIENTRY
 457 _mesa_BindVertexArray_no_error(GLuint id)
 458 {
 459    GET_CURRENT_CONTEXT(ctx);
 460    bind_vertex_array(ctx, id, true);
 461 }
 462
 463
 464 void GLAPIENTRY
 465 _mesa_BindVertexArray(GLuint id)
 466 {
 467    GET_CURRENT_CONTEXT(ctx);
 468    bind_vertex_array(ctx, id, false);
 469 }
 470
 471
 472 /**
 473  * Delete a set of array objects.
 474  *
 475  * \param n      Number of array objects to delete.
 476  * \param ids    Array of \c n array object IDs.
 477  */
 478 static void
 479 delete_vertex_arrays(struct gl_context *ctx, GLsizei n, const GLuint *ids)
 480 {
 481    GLsizei i;
 482
 483    for (i = 0; i < n; i++) {
 484       struct gl_vertex_array_object *obj = _mesa_lookup_vao(ctx, ids[i]);
 485
 486       if (obj) {
 487          assert(obj->Name == ids[i]);
 488
 489          /* If the array object is currently bound, the spec says "the binding
 490           * for that object reverts to zero and the default vertex array
 491           * becomes current."
 492           */
 493          if (obj == ctx->Array.VAO)
 494             _mesa_BindVertexArray_no_error(0);
 495
 496          /* The ID is immediately freed for re-use */
 497          _mesa_HashRemoveLocked(ctx->Array.Objects, obj->Name);
 498
 499          if (ctx->Array.LastLookedUpVAO == obj)
 500             _mesa_reference_vao(ctx, &ctx->Array.LastLookedUpVAO, NULL);
 501
 502          /* Unreference the array object.
 503           * If refcount hits zero, the object will be deleted.
 504           */
 505          _mesa_reference_vao(ctx, &obj, NULL);
 506       }
 507    }
 508 }
 509
 510
 511 void GLAPIENTRY
 512 _mesa_DeleteVertexArrays_no_error(GLsizei n, const GLuint *ids)
 513 {
 514    GET_CURRENT_CONTEXT(ctx);
 515    delete_vertex_arrays(ctx, n, ids);
 516 }
 517
 518
 519 void GLAPIENTRY
 520 _mesa_DeleteVertexArrays(GLsizei n, const GLuint *ids)
 521 {
 522    GET_CURRENT_CONTEXT(ctx);
 523
 524    if (n < 0) {
 525       _mesa_error(ctx, GL_INVALID_VALUE, "glDeleteVertexArray(n)");
 526       return;
 527    }
 528
 529    delete_vertex_arrays(ctx, n, ids);
 530 }
 531
 532
 533 /**
 534  * Generate a set of unique array object IDs and store them in \c arrays.
 535  * Helper for _mesa_GenVertexArrays() and _mesa_CreateVertexArrays()
 536  * below.
 537  *
 538  * \param n       Number of IDs to generate.
 539  * \param arrays  Array of \c n locations to store the IDs.
 540  * \param create  Indicates that the objects should also be created.
 541  * \param func    The name of the GL entry point.
 542  */
 543 static void
 544 gen_vertex_arrays(struct gl_context *ctx, GLsizei n, GLuint *arrays,
 545                   bool create, const char *func)
 546 {
 547    GLuint first;
 548    GLint i;
 549
 550    if (!arrays)
 551       return;
 552
 553    first = _mesa_HashFindFreeKeyBlock(ctx->Array.Objects, n);
 554
 555    /* For the sake of simplicity we create the array objects in both
 556     * the Gen* and Create* cases.  The only difference is the value of
 557     * EverBound, which is set to true in the Create* case.
 558     */
 559    for (i = 0; i < n; i++) {
 560       struct gl_vertex_array_object *obj;
 561       GLuint name = first + i;
 562
 563       obj = _mesa_new_vao(ctx, name);
 564       if (!obj) {
 565          _mesa_error(ctx, GL_OUT_OF_MEMORY, "%s", func);
 566          return;
 567       }
 568       obj->EverBound = create;
 569       _mesa_HashInsertLocked(ctx->Array.Objects, obj->Name, obj);
 570       arrays[i] = first + i;
 571    }
 572 }
 573
 574
 575 static void
 576 gen_vertex_arrays_err(struct gl_context *ctx, GLsizei n, GLuint *arrays,
 577                       bool create, const char *func)
 578 {
 579    if (n < 0) {
 580       _mesa_error(ctx, GL_INVALID_VALUE, "%s(n < 0)", func);
 581       return;
 582    }
 583
 584    gen_vertex_arrays(ctx, n, arrays, create, func);
 585 }
 586
 587
 588 /**
 589  * ARB version of glGenVertexArrays()
 590  * All arrays will be required to live in VBOs.
 591  */
 592 void GLAPIENTRY
 593 _mesa_GenVertexArrays_no_error(GLsizei n, GLuint *arrays)
 594 {
 595    GET_CURRENT_CONTEXT(ctx);
 596    gen_vertex_arrays(ctx, n, arrays, false, "glGenVertexArrays");
 597 }
 598
 599
 600 void GLAPIENTRY
 601 _mesa_GenVertexArrays(GLsizei n, GLuint *arrays)
 602 {
 603    GET_CURRENT_CONTEXT(ctx);
 604    gen_vertex_arrays_err(ctx, n, arrays, false, "glGenVertexArrays");
 605 }
 606
 607
 608 /**
 609  * ARB_direct_state_access
 610  * Generates ID's and creates the array objects.
 611  */
 612 void GLAPIENTRY
 613 _mesa_CreateVertexArrays_no_error(GLsizei n, GLuint *arrays)
 614 {
 615    GET_CURRENT_CONTEXT(ctx);
 616    gen_vertex_arrays(ctx, n, arrays, true, "glCreateVertexArrays");
 617 }
 618
 619
 620 void GLAPIENTRY
 621 _mesa_CreateVertexArrays(GLsizei n, GLuint *arrays)
 622 {
 623    GET_CURRENT_CONTEXT(ctx);
 624    gen_vertex_arrays_err(ctx, n, arrays, true, "glCreateVertexArrays");
 625 }
 626
 627
 628 /**
 629  * Determine if ID is the name of an array object.
 630  *
 631  * \param id  ID of the potential array object.
 632  * \return  \c GL_TRUE if \c id is the name of a array object,
 633  *          \c GL_FALSE otherwise.
 634  */
 635 GLboolean GLAPIENTRY
 636 _mesa_IsVertexArray( GLuint id )
 637 {
 638    struct gl_vertex_array_object * obj;
 639    GET_CURRENT_CONTEXT(ctx);
 640    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
 641
 642    obj = _mesa_lookup_vao(ctx, id);
 643
 644    return obj != NULL && obj->EverBound;
 645 }
 646
 647
 648 /**
 649  * Sets the element array buffer binding of a vertex array object.
 650  *
 651  * This is the ARB_direct_state_access equivalent of
 652  * glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffer).
 653  */
 654 static ALWAYS_INLINE void
 655 vertex_array_element_buffer(struct gl_context *ctx, GLuint vaobj, GLuint buffer,
 656                             bool no_error)
 657 {
 658    struct gl_vertex_array_object *vao;
 659    struct gl_buffer_object *bufObj;
 660
 661    ASSERT_OUTSIDE_BEGIN_END(ctx);
 662
 663    if (!no_error) {
 664       /* The GL_ARB_direct_state_access specification says:
 665        *
 666        *    "An INVALID_OPERATION error is generated by
 667        *     VertexArrayElementBuffer if <vaobj> is not [compatibility profile:
 668        *     zero or] the name of an existing vertex array object."
 669        */
 670       vao =_mesa_lookup_vao_err(ctx, vaobj, "glVertexArrayElementBuffer");
 671       if (!vao)
 672          return;
 673    } else {
 674       vao = _mesa_lookup_vao(ctx, vaobj);
 675    }
 676
 677    if (buffer != 0) {
 678       if (!no_error) {
 679          /* The GL_ARB_direct_state_access specification says:
 680           *
 681           *    "An INVALID_OPERATION error is generated if <buffer> is not zero
 682           *     or the name of an existing buffer object."
 683           */
 684          bufObj = _mesa_lookup_bufferobj_err(ctx, buffer,
 685                                              "glVertexArrayElementBuffer");
 686       } else {
 687          bufObj = _mesa_lookup_bufferobj(ctx, buffer);
 688       }
 689    } else {
 690       bufObj = ctx->Shared->NullBufferObj;
 691    }
 692
 693    if (bufObj)
 694       _mesa_reference_buffer_object(ctx, &vao->IndexBufferObj, bufObj);
 695 }
 696
 697
 698 void GLAPIENTRY
 699 _mesa_VertexArrayElementBuffer_no_error(GLuint vaobj, GLuint buffer)
 700 {
 701    GET_CURRENT_CONTEXT(ctx);
 702    vertex_array_element_buffer(ctx, vaobj, buffer, true);
 703 }
 704
 705
 706 void GLAPIENTRY
 707 _mesa_VertexArrayElementBuffer(GLuint vaobj, GLuint buffer)
 708 {
 709    GET_CURRENT_CONTEXT(ctx);
 710    vertex_array_element_buffer(ctx, vaobj, buffer, false);
 711 }
 712
 713
 714 void GLAPIENTRY
 715 _mesa_GetVertexArrayiv(GLuint vaobj, GLenum pname, GLint *param)
 716 {
 717    GET_CURRENT_CONTEXT(ctx);
 718    struct gl_vertex_array_object *vao;
 719
 720    ASSERT_OUTSIDE_BEGIN_END(ctx);
 721
 722    /* The GL_ARB_direct_state_access specification says:
 723     *
 724     *   "An INVALID_OPERATION error is generated if <vaobj> is not
 725     *    [compatibility profile: zero or] the name of an existing
 726     *    vertex array object."
 727     */
 728    vao =_mesa_lookup_vao_err(ctx, vaobj, "glGetVertexArrayiv");
 729    if (!vao)
 730       return;
 731
 732    /* The GL_ARB_direct_state_access specification says:
 733     *
 734     *   "An INVALID_ENUM error is generated if <pname> is not
 735     *    ELEMENT_ARRAY_BUFFER_BINDING."
 736     */
 737    if (pname != GL_ELEMENT_ARRAY_BUFFER_BINDING) {
 738       _mesa_error(ctx, GL_INVALID_ENUM,
 739                   "glGetVertexArrayiv(pname != "
 740                   "GL_ELEMENT_ARRAY_BUFFER_BINDING)");
 741       return;
 742    }
 743
 744    param[0] = vao->IndexBufferObj->Name;
 745 }