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 attributes 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    assert(index < ARRAY_SIZE(vao->VertexAttrib));
 237    struct gl_array_attributes *array = &vao->VertexAttrib[index];
 238    assert(index < ARRAY_SIZE(vao->BufferBinding));
 239    struct gl_vertex_buffer_binding *binding = &vao->BufferBinding[index];
 240
 241    array->Size = size;
 242    array->Type = type;
 243    array->Format = GL_RGBA; /* only significant for GL_EXT_vertex_array_bgra */
 244    array->Stride = 0;
 245    array->Ptr = NULL;
 246    array->RelativeOffset = 0;
 247    array->Enabled = GL_FALSE;
 248    array->Normalized = GL_FALSE;
 249    array->Integer = GL_FALSE;
 250    array->Doubles = GL_FALSE;
 251    array->_ElementSize = size * _mesa_sizeof_type(type);
 252    ASSERT_BITFIELD_SIZE(struct gl_array_attributes, BufferBindingIndex,
 253                         VERT_ATTRIB_MAX - 1);
 254    array->BufferBindingIndex = index;
 255
 256    binding->Offset = 0;
 257    binding->Stride = array->_ElementSize;
 258    binding->BufferObj = NULL;
 259    binding->_BoundArrays = BITFIELD_BIT(index);
 260
 261    /* Vertex array buffers */
 262    _mesa_reference_buffer_object(ctx, &binding->BufferObj,
 263                                  ctx->Shared->NullBufferObj);
 264 }
 265
 266
 267 /**
 268  * Initialize a gl_vertex_array_object's arrays.
 269  */
 270 void
 271 _mesa_initialize_vao(struct gl_context *ctx,
 272                      struct gl_vertex_array_object *vao,
 273                      GLuint name)
 274 {
 275    GLuint i;
 276
 277    vao->Name = name;
 278
 279    vao->RefCount = 1;
 280
 281    /* Init the individual arrays */
 282    for (i = 0; i < ARRAY_SIZE(vao->VertexAttrib); i++) {
 283       switch (i) {
 284       case VERT_ATTRIB_NORMAL:
 285          init_array(ctx, vao, VERT_ATTRIB_NORMAL, 3, GL_FLOAT);
 286          break;
 287       case VERT_ATTRIB_COLOR1:
 288          init_array(ctx, vao, VERT_ATTRIB_COLOR1, 3, GL_FLOAT);
 289          break;
 290       case VERT_ATTRIB_FOG:
 291          init_array(ctx, vao, VERT_ATTRIB_FOG, 1, GL_FLOAT);
 292          break;
 293       case VERT_ATTRIB_COLOR_INDEX:
 294          init_array(ctx, vao, VERT_ATTRIB_COLOR_INDEX, 1, GL_FLOAT);
 295          break;
 296       case VERT_ATTRIB_EDGEFLAG:
 297          init_array(ctx, vao, VERT_ATTRIB_EDGEFLAG, 1, GL_BOOL);
 298          break;
 299       case VERT_ATTRIB_POINT_SIZE:
 300          init_array(ctx, vao, VERT_ATTRIB_POINT_SIZE, 1, GL_FLOAT);
 301          break;
 302       default:
 303          init_array(ctx, vao, i, 4, GL_FLOAT);
 304          break;
 305       }
 306    }
 307
 308    _mesa_reference_buffer_object(ctx, &vao->IndexBufferObj,
 309                                  ctx->Shared->NullBufferObj);
 310 }
 311
 312
 313 /**
 314  * Updates the derived gl_vertex_arrays when a gl_array_attributes
 315  * or a gl_vertex_buffer_binding has changed.
 316  */
 317 void
 318 _mesa_update_vao_derived_arrays(struct gl_context *ctx,
 319                                 struct gl_vertex_array_object *vao)
 320 {
 321    GLbitfield arrays = vao->NewArrays;
 322
 323    while (arrays) {
 324       const int attrib = u_bit_scan(&arrays);
 325       struct gl_vertex_array *client_array = &vao->_VertexAttrib[attrib];
 326       const struct gl_array_attributes *attrib_array =
 327          &vao->VertexAttrib[attrib];
 328       const struct gl_vertex_buffer_binding *buffer_binding =
 329          &vao->BufferBinding[attrib_array->BufferBindingIndex];
 330
 331       _mesa_update_vertex_array(ctx, client_array, attrib_array,
 332                                 buffer_binding);
 333    }
 334 }
 335
 336
 337 bool
 338 _mesa_all_varyings_in_vbos(const struct gl_vertex_array_object *vao)
 339 {
 340    /* Walk those enabled arrays that have the default vbo attached */
 341    GLbitfield mask = vao->_Enabled & ~vao->VertexAttribBufferMask;
 342
 343    while (mask) {
 344       /* Do not use u_bit_scan64 as we can walk multiple
 345        * attrib arrays at once
 346        */
 347       const int i = ffs(mask) - 1;
 348       const struct gl_array_attributes *attrib_array =
 349          &vao->VertexAttrib[i];
 350       const struct gl_vertex_buffer_binding *buffer_binding =
 351          &vao->BufferBinding[attrib_array->BufferBindingIndex];
 352
 353       /* Only enabled arrays shall appear in the _Enabled bitmask */
 354       assert(attrib_array->Enabled);
 355       /* We have already masked out vao->VertexAttribBufferMask  */
 356       assert(!_mesa_is_bufferobj(buffer_binding->BufferObj));
 357
 358       /* Bail out once we find the first non vbo with a non zero stride */
 359       if (buffer_binding->Stride != 0)
 360          return false;
 361
 362       /* Note that we cannot use the xor variant since the _BoundArray mask
 363        * may contain array attributes that are bound but not enabled.
 364        */
 365       mask &= ~buffer_binding->_BoundArrays;
 366    }
 367
 368    return true;
 369 }
 370
 371 bool
 372 _mesa_all_buffers_are_unmapped(const struct gl_vertex_array_object *vao)
 373 {
 374    /* Walk the enabled arrays that have a vbo attached */
 375    GLbitfield mask = vao->_Enabled & vao->VertexAttribBufferMask;
 376
 377    while (mask) {
 378       const int i = ffs(mask) - 1;
 379       const struct gl_array_attributes *attrib_array =
 380          &vao->VertexAttrib[i];
 381       const struct gl_vertex_buffer_binding *buffer_binding =
 382          &vao->BufferBinding[attrib_array->BufferBindingIndex];
 383
 384       /* Only enabled arrays shall appear in the _Enabled bitmask */
 385       assert(attrib_array->Enabled);
 386       /* We have already masked with vao->VertexAttribBufferMask  */
 387       assert(_mesa_is_bufferobj(buffer_binding->BufferObj));
 388
 389       /* Bail out once we find the first disallowed mapping */
 390       if (_mesa_check_disallowed_mapping(buffer_binding->BufferObj))
 391          return false;
 392
 393       /* We have handled everything that is bound to this buffer_binding. */
 394       mask &= ~buffer_binding->_BoundArrays;
 395    }
 396
 397    return true;
 398 }
 399
 400 /**********************************************************************/
 401 /* API Functions                                                      */
 402 /**********************************************************************/
 403
 404
 405 /**
 406  * ARB version of glBindVertexArray()
 407  */
 408 static ALWAYS_INLINE void
 409 bind_vertex_array(struct gl_context *ctx, GLuint id, bool no_error)
 410 {
 411    struct gl_vertex_array_object *const oldObj = ctx->Array.VAO;
 412    struct gl_vertex_array_object *newObj = NULL;
 413
 414    assert(oldObj != NULL);
 415
 416    if (oldObj->Name == id)
 417       return;   /* rebinding the same array object- no change */
 418
 419    /*
 420     * Get pointer to new array object (newObj)
 421     */
 422    if (id == 0) {
 423       /* The spec says there is no array object named 0, but we use
 424        * one internally because it simplifies things.
 425        */
 426       newObj = ctx->Array.DefaultVAO;
 427    }
 428    else {
 429       /* non-default array object */
 430       newObj = _mesa_lookup_vao(ctx, id);
 431       if (!no_error && !newObj) {
 432          _mesa_error(ctx, GL_INVALID_OPERATION,
 433                      "glBindVertexArray(non-gen name)");
 434          return;
 435       }
 436
 437       newObj->EverBound = GL_TRUE;
 438    }
 439
 440    /* The _DrawArrays pointer is pointing at the VAO being unbound and
 441     * that VAO may be in the process of being deleted. If it's not going
 442     * to be deleted, this will have no effect, because the pointer needs
 443     * to be updated by the VBO module anyway.
 444     *
 445     * Before the VBO module can update the pointer, we have to set it
 446     * to NULL for drivers not to set up arrays which are not bound,
 447     * or to prevent a crash if the VAO being unbound is going to be
 448     * deleted.
 449     */
 450    _mesa_set_drawing_arrays(ctx, NULL);
 451
 452    ctx->NewState |= _NEW_ARRAY;
 453    _mesa_reference_vao(ctx, &ctx->Array.VAO, newObj);
 454 }
 455
 456
 457 void GLAPIENTRY
 458 _mesa_BindVertexArray_no_error(GLuint id)
 459 {
 460    GET_CURRENT_CONTEXT(ctx);
 461    bind_vertex_array(ctx, id, true);
 462 }
 463
 464
 465 void GLAPIENTRY
 466 _mesa_BindVertexArray(GLuint id)
 467 {
 468    GET_CURRENT_CONTEXT(ctx);
 469    bind_vertex_array(ctx, id, false);
 470 }
 471
 472
 473 /**
 474  * Delete a set of array objects.
 475  *
 476  * \param n      Number of array objects to delete.
 477  * \param ids    Array of \c n array object IDs.
 478  */
 479 static void
 480 delete_vertex_arrays(struct gl_context *ctx, GLsizei n, const GLuint *ids)
 481 {
 482    GLsizei i;
 483
 484    for (i = 0; i < n; i++) {
 485       struct gl_vertex_array_object *obj = _mesa_lookup_vao(ctx, ids[i]);
 486
 487       if (obj) {
 488          assert(obj->Name == ids[i]);
 489
 490          /* If the array object is currently bound, the spec says "the binding
 491           * for that object reverts to zero and the default vertex array
 492           * becomes current."
 493           */
 494          if (obj == ctx->Array.VAO)
 495             _mesa_BindVertexArray_no_error(0);
 496
 497          /* The ID is immediately freed for re-use */
 498          _mesa_HashRemoveLocked(ctx->Array.Objects, obj->Name);
 499
 500          if (ctx->Array.LastLookedUpVAO == obj)
 501             _mesa_reference_vao(ctx, &ctx->Array.LastLookedUpVAO, NULL);
 502
 503          /* Unreference the array object.
 504           * If refcount hits zero, the object will be deleted.
 505           */
 506          _mesa_reference_vao(ctx, &obj, NULL);
 507       }
 508    }
 509 }
 510
 511
 512 void GLAPIENTRY
 513 _mesa_DeleteVertexArrays_no_error(GLsizei n, const GLuint *ids)
 514 {
 515    GET_CURRENT_CONTEXT(ctx);
 516    delete_vertex_arrays(ctx, n, ids);
 517 }
 518
 519
 520 void GLAPIENTRY
 521 _mesa_DeleteVertexArrays(GLsizei n, const GLuint *ids)
 522 {
 523    GET_CURRENT_CONTEXT(ctx);
 524
 525    if (n < 0) {
 526       _mesa_error(ctx, GL_INVALID_VALUE, "glDeleteVertexArray(n)");
 527       return;
 528    }
 529
 530    delete_vertex_arrays(ctx, n, ids);
 531 }
 532
 533
 534 /**
 535  * Generate a set of unique array object IDs and store them in \c arrays.
 536  * Helper for _mesa_GenVertexArrays() and _mesa_CreateVertexArrays()
 537  * below.
 538  *
 539  * \param n       Number of IDs to generate.
 540  * \param arrays  Array of \c n locations to store the IDs.
 541  * \param create  Indicates that the objects should also be created.
 542  * \param func    The name of the GL entry point.
 543  */
 544 static void
 545 gen_vertex_arrays(struct gl_context *ctx, GLsizei n, GLuint *arrays,
 546                   bool create, const char *func)
 547 {
 548    GLuint first;
 549    GLint i;
 550
 551    if (!arrays)
 552       return;
 553
 554    first = _mesa_HashFindFreeKeyBlock(ctx->Array.Objects, n);
 555
 556    /* For the sake of simplicity we create the array objects in both
 557     * the Gen* and Create* cases.  The only difference is the value of
 558     * EverBound, which is set to true in the Create* case.
 559     */
 560    for (i = 0; i < n; i++) {
 561       struct gl_vertex_array_object *obj;
 562       GLuint name = first + i;
 563
 564       obj = _mesa_new_vao(ctx, name);
 565       if (!obj) {
 566          _mesa_error(ctx, GL_OUT_OF_MEMORY, "%s", func);
 567          return;
 568       }
 569       obj->EverBound = create;
 570       _mesa_HashInsertLocked(ctx->Array.Objects, obj->Name, obj);
 571       arrays[i] = first + i;
 572    }
 573 }
 574
 575
 576 static void
 577 gen_vertex_arrays_err(struct gl_context *ctx, GLsizei n, GLuint *arrays,
 578                       bool create, const char *func)
 579 {
 580    if (n < 0) {
 581       _mesa_error(ctx, GL_INVALID_VALUE, "%s(n < 0)", func);
 582       return;
 583    }
 584
 585    gen_vertex_arrays(ctx, n, arrays, create, func);
 586 }
 587
 588
 589 /**
 590  * ARB version of glGenVertexArrays()
 591  * All arrays will be required to live in VBOs.
 592  */
 593 void GLAPIENTRY
 594 _mesa_GenVertexArrays_no_error(GLsizei n, GLuint *arrays)
 595 {
 596    GET_CURRENT_CONTEXT(ctx);
 597    gen_vertex_arrays(ctx, n, arrays, false, "glGenVertexArrays");
 598 }
 599
 600
 601 void GLAPIENTRY
 602 _mesa_GenVertexArrays(GLsizei n, GLuint *arrays)
 603 {
 604    GET_CURRENT_CONTEXT(ctx);
 605    gen_vertex_arrays_err(ctx, n, arrays, false, "glGenVertexArrays");
 606 }
 607
 608
 609 /**
 610  * ARB_direct_state_access
 611  * Generates ID's and creates the array objects.
 612  */
 613 void GLAPIENTRY
 614 _mesa_CreateVertexArrays_no_error(GLsizei n, GLuint *arrays)
 615 {
 616    GET_CURRENT_CONTEXT(ctx);
 617    gen_vertex_arrays(ctx, n, arrays, true, "glCreateVertexArrays");
 618 }
 619
 620
 621 void GLAPIENTRY
 622 _mesa_CreateVertexArrays(GLsizei n, GLuint *arrays)
 623 {
 624    GET_CURRENT_CONTEXT(ctx);
 625    gen_vertex_arrays_err(ctx, n, arrays, true, "glCreateVertexArrays");
 626 }
 627
 628
 629 /**
 630  * Determine if ID is the name of an array object.
 631  *
 632  * \param id  ID of the potential array object.
 633  * \return  \c GL_TRUE if \c id is the name of a array object,
 634  *          \c GL_FALSE otherwise.
 635  */
 636 GLboolean GLAPIENTRY
 637 _mesa_IsVertexArray( GLuint id )
 638 {
 639    struct gl_vertex_array_object * obj;
 640    GET_CURRENT_CONTEXT(ctx);
 641    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
 642
 643    obj = _mesa_lookup_vao(ctx, id);
 644
 645    return obj != NULL && obj->EverBound;
 646 }
 647
 648
 649 /**
 650  * Sets the element array buffer binding of a vertex array object.
 651  *
 652  * This is the ARB_direct_state_access equivalent of
 653  * glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffer).
 654  */
 655 static ALWAYS_INLINE void
 656 vertex_array_element_buffer(struct gl_context *ctx, GLuint vaobj, GLuint buffer,
 657                             bool no_error)
 658 {
 659    struct gl_vertex_array_object *vao;
 660    struct gl_buffer_object *bufObj;
 661
 662    ASSERT_OUTSIDE_BEGIN_END(ctx);
 663
 664    if (!no_error) {
 665       /* The GL_ARB_direct_state_access specification says:
 666        *
 667        *    "An INVALID_OPERATION error is generated by
 668        *     VertexArrayElementBuffer if <vaobj> is not [compatibility profile:
 669        *     zero or] the name of an existing vertex array object."
 670        */
 671       vao =_mesa_lookup_vao_err(ctx, vaobj, "glVertexArrayElementBuffer");
 672       if (!vao)
 673          return;
 674    } else {
 675       vao = _mesa_lookup_vao(ctx, vaobj);
 676    }
 677
 678    if (buffer != 0) {
 679       if (!no_error) {
 680          /* The GL_ARB_direct_state_access specification says:
 681           *
 682           *    "An INVALID_OPERATION error is generated if <buffer> is not zero
 683           *     or the name of an existing buffer object."
 684           */
 685          bufObj = _mesa_lookup_bufferobj_err(ctx, buffer,
 686                                              "glVertexArrayElementBuffer");
 687       } else {
 688          bufObj = _mesa_lookup_bufferobj(ctx, buffer);
 689       }
 690    } else {
 691       bufObj = ctx->Shared->NullBufferObj;
 692    }
 693
 694    if (bufObj)
 695       _mesa_reference_buffer_object(ctx, &vao->IndexBufferObj, bufObj);
 696 }
 697
 698
 699 void GLAPIENTRY
 700 _mesa_VertexArrayElementBuffer_no_error(GLuint vaobj, GLuint buffer)
 701 {
 702    GET_CURRENT_CONTEXT(ctx);
 703    vertex_array_element_buffer(ctx, vaobj, buffer, true);
 704 }
 705
 706
 707 void GLAPIENTRY
 708 _mesa_VertexArrayElementBuffer(GLuint vaobj, GLuint buffer)
 709 {
 710    GET_CURRENT_CONTEXT(ctx);
 711    vertex_array_element_buffer(ctx, vaobj, buffer, false);
 712 }
 713
 714
 715 void GLAPIENTRY
 716 _mesa_GetVertexArrayiv(GLuint vaobj, GLenum pname, GLint *param)
 717 {
 718    GET_CURRENT_CONTEXT(ctx);
 719    struct gl_vertex_array_object *vao;
 720
 721    ASSERT_OUTSIDE_BEGIN_END(ctx);
 722
 723    /* The GL_ARB_direct_state_access specification says:
 724     *
 725     *   "An INVALID_OPERATION error is generated if <vaobj> is not
 726     *    [compatibility profile: zero or] the name of an existing
 727     *    vertex array object."
 728     */
 729    vao =_mesa_lookup_vao_err(ctx, vaobj, "glGetVertexArrayiv");
 730    if (!vao)
 731       return;
 732
 733    /* The GL_ARB_direct_state_access specification says:
 734     *
 735     *   "An INVALID_ENUM error is generated if <pname> is not
 736     *    ELEMENT_ARRAY_BUFFER_BINDING."
 737     */
 738    if (pname != GL_ELEMENT_ARRAY_BUFFER_BINDING) {
 739       _mesa_error(ctx, GL_INVALID_ENUM,
 740                   "glGetVertexArrayiv(pname != "
 741                   "GL_ELEMENT_ARRAY_BUFFER_BINDING)");
 742       return;
 743    }
 744
 745    param[0] = vao->IndexBufferObj->Name;
 746 }