src/mesa/main/api_validate.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.1
   4  *
   5  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the "Software"),
   9  * to deal in the Software without restriction, including without limitation
  10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  11  * and/or sell copies of the Software, and to permit persons to whom the
  12  * Software is furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included
  15  * in all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 #include <stdbool.h>
  26 #include "glheader.h"
  27 #include "api_validate.h"
  28 #include "bufferobj.h"
  29 #include "context.h"
  30 #include "imports.h"
  31 #include "mfeatures.h"
  32 #include "mtypes.h"
  33 #include "enums.h"
  34 #include "vbo/vbo.h"
  35 #include "transformfeedback.h"
  36 #include <stdbool.h>
  37
  38
  39 /**
  40  * \return  number of bytes in array [count] of type.
  41  */
  42 static GLsizei
  43 index_bytes(GLenum type, GLsizei count)
  44 {
  45    if (type == GL_UNSIGNED_INT) {
  46       return count * sizeof(GLuint);
  47    }
  48    else if (type == GL_UNSIGNED_BYTE) {
  49       return count * sizeof(GLubyte);
  50    }
  51    else {
  52       ASSERT(type == GL_UNSIGNED_SHORT);
  53       return count * sizeof(GLushort);
  54    }
  55 }
  56
  57
  58 /**
  59  * Find the max index in the given element/index buffer
  60  */
  61 GLuint
  62 _mesa_max_buffer_index(struct gl_context *ctx, GLuint count, GLenum type,
  63                        const void *indices,
  64                        struct gl_buffer_object *elementBuf)
  65 {
  66    const GLubyte *map = NULL;
  67    GLuint max = 0;
  68    GLuint i;
  69
  70    if (_mesa_is_bufferobj(elementBuf)) {
  71       /* elements are in a user-defined buffer object.  need to map it */
  72       map = ctx->Driver.MapBufferRange(ctx, 0, elementBuf->Size,
  73                                        GL_MAP_READ_BIT, elementBuf);
  74       /* Actual address is the sum of pointers */
  75       indices = (const GLvoid *) ADD_POINTERS(map, (const GLubyte *) indices);
  76    }
  77
  78    if (type == GL_UNSIGNED_INT) {
  79       for (i = 0; i < count; i++)
  80          if (((GLuint *) indices)[i] > max)
  81             max = ((GLuint *) indices)[i];
  82    }
  83    else if (type == GL_UNSIGNED_SHORT) {
  84       for (i = 0; i < count; i++)
  85          if (((GLushort *) indices)[i] > max)
  86             max = ((GLushort *) indices)[i];
  87    }
  88    else {
  89       ASSERT(type == GL_UNSIGNED_BYTE);
  90       for (i = 0; i < count; i++)
  91          if (((GLubyte *) indices)[i] > max)
  92             max = ((GLubyte *) indices)[i];
  93    }
  94
  95    if (map) {
  96       ctx->Driver.UnmapBuffer(ctx, elementBuf);
  97    }
  98
  99    return max;
 100 }
 101
 102
 103 /**
 104  * Check if OK to draw arrays/elements.
 105  */
 106 static GLboolean
 107 check_valid_to_render(struct gl_context *ctx, const char *function)
 108 {
 109    if (!_mesa_valid_to_render(ctx, function)) {
 110       return GL_FALSE;
 111    }
 112
 113    switch (ctx->API) {
 114    case API_OPENGLES2:
 115       /* For ES2, we can draw if any vertex array is enabled (and we
 116        * should always have a vertex program/shader). */
 117       if (ctx->Array.ArrayObj->_Enabled == 0x0 || !ctx->VertexProgram._Current)
 118          return GL_FALSE;
 119       break;
 120
 121    case API_OPENGLES:
 122       /* For OpenGL ES, only draw if we have vertex positions
 123        */
 124       if (!ctx->Array.ArrayObj->VertexAttrib[VERT_ATTRIB_POS].Enabled)
 125          return GL_FALSE;
 126       break;
 127
 128    case API_OPENGL_COMPAT:
 129    case API_OPENGL_CORE:
 130       {
 131          const struct gl_shader_program *vsProg =
 132             ctx->Shader.CurrentVertexProgram;
 133          GLboolean haveVertexShader = (vsProg && vsProg->LinkStatus);
 134          GLboolean haveVertexProgram = ctx->VertexProgram._Enabled;
 135          if (haveVertexShader || haveVertexProgram) {
 136             /* Draw regardless of whether or not we have any vertex arrays.
 137              * (Ex: could draw a point using a constant vertex pos)
 138              */
 139             return GL_TRUE;
 140          }
 141          else {
 142             /* Draw if we have vertex positions (GL_VERTEX_ARRAY or generic
 143              * array [0]).
 144              */
 145             return (ctx->Array.ArrayObj->VertexAttrib[VERT_ATTRIB_POS].Enabled ||
 146                     ctx->Array.ArrayObj->VertexAttrib[VERT_ATTRIB_GENERIC0].Enabled);
 147          }
 148       }
 149       break;
 150
 151    default:
 152       assert(!"Invalid API value in check_valid_to_render()");
 153    }
 154
 155    return GL_TRUE;
 156 }
 157
 158
 159 /**
 160  * Do bounds checking on array element indexes.  Check that the vertices
 161  * pointed to by the indices don't lie outside buffer object bounds.
 162  * \return GL_TRUE if OK, GL_FALSE if any indexed vertex goes is out of bounds
 163  */
 164 static GLboolean
 165 check_index_bounds(struct gl_context *ctx, GLsizei count, GLenum type,
 166                    const GLvoid *indices, GLint basevertex)
 167 {
 168    struct _mesa_prim prim;
 169    struct _mesa_index_buffer ib;
 170    GLuint min, max;
 171
 172    /* Only the X Server needs to do this -- otherwise, accessing outside
 173     * array/BO bounds allows application termination.
 174     */
 175    if (!ctx->Const.CheckArrayBounds)
 176       return GL_TRUE;
 177
 178    memset(&prim, 0, sizeof(prim));
 179    prim.count = count;
 180
 181    memset(&ib, 0, sizeof(ib));
 182    ib.type = type;
 183    ib.ptr = indices;
 184    ib.obj = ctx->Array.ArrayObj->ElementArrayBufferObj;
 185
 186    vbo_get_minmax_indices(ctx, &prim, &ib, &min, &max, 1);
 187
 188    if ((int)(min + basevertex) < 0 ||
 189        max + basevertex >= ctx->Array.ArrayObj->_MaxElement) {
 190       /* the max element is out of bounds of one or more enabled arrays */
 191       _mesa_warning(ctx, "glDrawElements() index=%u is out of bounds (max=%u)",
 192                     max, ctx->Array.ArrayObj->_MaxElement);
 193       return GL_FALSE;
 194    }
 195
 196    return GL_TRUE;
 197 }
 198
 199
 200 /**
 201  * Is 'mode' a valid value for glBegin(), glDrawArrays(), glDrawElements(),
 202  * etc?  The set of legal values depends on whether geometry shaders/programs
 203  * are supported.
 204  */
 205 GLboolean
 206 _mesa_valid_prim_mode(struct gl_context *ctx, GLenum mode, const char *name)
 207 {
 208    bool valid_enum;
 209
 210    switch (mode) {
 211    case GL_POINTS:
 212    case GL_LINES:
 213    case GL_LINE_LOOP:
 214    case GL_LINE_STRIP:
 215    case GL_TRIANGLES:
 216    case GL_TRIANGLE_STRIP:
 217    case GL_TRIANGLE_FAN:
 218       valid_enum = true;
 219       break;
 220    case GL_QUADS:
 221    case GL_QUAD_STRIP:
 222    case GL_POLYGON:
 223       valid_enum = (ctx->API == API_OPENGL_COMPAT);
 224       break;
 225    case GL_LINES_ADJACENCY:
 226    case GL_LINE_STRIP_ADJACENCY:
 227    case GL_TRIANGLES_ADJACENCY:
 228    case GL_TRIANGLE_STRIP_ADJACENCY:
 229       valid_enum = _mesa_is_desktop_gl(ctx)
 230          && ctx->Extensions.ARB_geometry_shader4;
 231       break;
 232    default:
 233       valid_enum = false;
 234       break;
 235    }
 236
 237    if (!valid_enum) {
 238       _mesa_error(ctx, GL_INVALID_ENUM, "%s(mode=%x)", name, mode);
 239       return GL_FALSE;
 240    }
 241
 242    /* From the GL_EXT_transform_feedback spec:
 243     *
 244     *     "The error INVALID_OPERATION is generated if Begin, or any command
 245     *      that performs an explicit Begin, is called when:
 246     *
 247     *      * a geometry shader is not active and <mode> does not match the
 248     *        allowed begin modes for the current transform feedback state as
 249     *        given by table X.1.
 250     *
 251     *      * a geometry shader is active and the output primitive type of the
 252     *        geometry shader does not match the allowed begin modes for the
 253     *        current transform feedback state as given by table X.1.
 254     *
 255     */
 256    if (_mesa_is_xfb_active_and_unpaused(ctx)) {
 257       GLboolean pass = GL_TRUE;
 258
 259       switch (mode) {
 260       case GL_POINTS:
 261          pass = ctx->TransformFeedback.Mode == GL_POINTS;
 262          break;
 263       case GL_LINES:
 264       case GL_LINE_STRIP:
 265       case GL_LINE_LOOP:
 266          pass = ctx->TransformFeedback.Mode == GL_LINES;
 267          break;
 268       default:
 269          pass = ctx->TransformFeedback.Mode == GL_TRIANGLES;
 270          break;
 271       }
 272       if (!pass) {
 273          _mesa_error(ctx, GL_INVALID_OPERATION,
 274                      "%s(mode=%s vs transform feedback %s)",
 275                      name,
 276                      _mesa_lookup_prim_by_nr(mode),
 277                      _mesa_lookup_prim_by_nr(ctx->TransformFeedback.Mode));
 278          return GL_FALSE;
 279       }
 280    }
 281
 282    return GL_TRUE;
 283 }
 284
 285 /**
 286  * Verify that the element type is valid.
 287  *
 288  * Generates \c GL_INVALID_ENUM and returns \c false if it is not.
 289  */
 290 static bool
 291 valid_elements_type(struct gl_context *ctx, GLenum type, const char *name)
 292 {
 293    switch (type) {
 294    case GL_UNSIGNED_BYTE:
 295    case GL_UNSIGNED_SHORT:
 296    case GL_UNSIGNED_INT:
 297       return true;
 298
 299    default:
 300       _mesa_error(ctx, GL_INVALID_ENUM, "%s(type = %s)", name,
 301                   _mesa_lookup_enum_by_nr(type));
 302       return false;
 303    }
 304 }
 305
 306 /**
 307  * Error checking for glDrawElements().  Includes parameter checking
 308  * and VBO bounds checking.
 309  * \return GL_TRUE if OK to render, GL_FALSE if error found
 310  */
 311 GLboolean
 312 _mesa_validate_DrawElements(struct gl_context *ctx,
 313                             GLenum mode, GLsizei count, GLenum type,
 314                             const GLvoid *indices, GLint basevertex)
 315 {
 316    FLUSH_CURRENT(ctx, 0);
 317
 318    /* From the GLES3 specification, section 2.14.2 (Transform Feedback
 319     * Primitive Capture):
 320     *
 321     *   The error INVALID_OPERATION is also generated by DrawElements,
 322     *   DrawElementsInstanced, and DrawRangeElements while transform feedback
 323     *   is active and not paused, regardless of mode.
 324     */
 325    if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx)) {
 326       _mesa_error(ctx, GL_INVALID_OPERATION,
 327                   "glDrawElements(transform feedback active)");
 328       return GL_FALSE;
 329    }
 330
 331    if (count <= 0) {
 332       if (count < 0)
 333          _mesa_error(ctx, GL_INVALID_VALUE, "glDrawElements(count)" );
 334       return GL_FALSE;
 335    }
 336
 337    if (!_mesa_valid_prim_mode(ctx, mode, "glDrawElements")) {
 338       return GL_FALSE;
 339    }
 340
 341    if (!valid_elements_type(ctx, type, "glDrawElements"))
 342       return GL_FALSE;
 343
 344    if (!check_valid_to_render(ctx, "glDrawElements"))
 345       return GL_FALSE;
 346
 347    /* Vertex buffer object tests */
 348    if (_mesa_is_bufferobj(ctx->Array.ArrayObj->ElementArrayBufferObj)) {
 349       /* use indices in the buffer object */
 350       /* make sure count doesn't go outside buffer bounds */
 351       if (index_bytes(type, count) > ctx->Array.ArrayObj->ElementArrayBufferObj->Size) {
 352          _mesa_warning(ctx, "glDrawElements index out of buffer bounds");
 353          return GL_FALSE;
 354       }
 355    }
 356    else {
 357       /* not using a VBO */
 358       if (!indices)
 359          return GL_FALSE;
 360    }
 361
 362    if (!check_index_bounds(ctx, count, type, indices, basevertex))
 363       return GL_FALSE;
 364
 365    return GL_TRUE;
 366 }
 367
 368
 369 /**
 370  * Error checking for glMultiDrawElements().  Includes parameter checking
 371  * and VBO bounds checking.
 372  * \return GL_TRUE if OK to render, GL_FALSE if error found
 373  */
 374 GLboolean
 375 _mesa_validate_MultiDrawElements(struct gl_context *ctx,
 376                                  GLenum mode, const GLsizei *count,
 377                                  GLenum type, const GLvoid * const *indices,
 378                                  GLuint primcount, const GLint *basevertex)
 379 {
 380    unsigned i;
 381
 382    FLUSH_CURRENT(ctx, 0);
 383
 384    for (i = 0; i < primcount; i++) {
 385       if (count[i] <= 0) {
 386          if (count[i] < 0)
 387             _mesa_error(ctx, GL_INVALID_VALUE,
 388                         "glMultiDrawElements(count)" );
 389          return GL_FALSE;
 390       }
 391    }
 392
 393    if (!_mesa_valid_prim_mode(ctx, mode, "glMultiDrawElements")) {
 394       return GL_FALSE;
 395    }
 396
 397    if (!valid_elements_type(ctx, type, "glMultiDrawElements"))
 398       return GL_FALSE;
 399
 400    if (!check_valid_to_render(ctx, "glMultiDrawElements"))
 401       return GL_FALSE;
 402
 403    /* Vertex buffer object tests */
 404    if (_mesa_is_bufferobj(ctx->Array.ArrayObj->ElementArrayBufferObj)) {
 405       /* use indices in the buffer object */
 406       /* make sure count doesn't go outside buffer bounds */
 407       for (i = 0; i < primcount; i++) {
 408          if (index_bytes(type, count[i]) >
 409              ctx->Array.ArrayObj->ElementArrayBufferObj->Size) {
 410             _mesa_warning(ctx,
 411                           "glMultiDrawElements index out of buffer bounds");
 412             return GL_FALSE;
 413          }
 414       }
 415    }
 416    else {
 417       /* not using a VBO */
 418       for (i = 0; i < primcount; i++) {
 419          if (!indices[i])
 420             return GL_FALSE;
 421       }
 422    }
 423
 424    for (i = 0; i < primcount; i++) {
 425       if (!check_index_bounds(ctx, count[i], type, indices[i],
 426                               basevertex ? basevertex[i] : 0))
 427          return GL_FALSE;
 428    }
 429
 430    return GL_TRUE;
 431 }
 432
 433
 434 /**
 435  * Error checking for glDrawRangeElements().  Includes parameter checking
 436  * and VBO bounds checking.
 437  * \return GL_TRUE if OK to render, GL_FALSE if error found
 438  */
 439 GLboolean
 440 _mesa_validate_DrawRangeElements(struct gl_context *ctx, GLenum mode,
 441                                  GLuint start, GLuint end,
 442                                  GLsizei count, GLenum type,
 443                                  const GLvoid *indices, GLint basevertex)
 444 {
 445    FLUSH_CURRENT(ctx, 0);
 446
 447    /* From the GLES3 specification, section 2.14.2 (Transform Feedback
 448     * Primitive Capture):
 449     *
 450     *   The error INVALID_OPERATION is also generated by DrawElements,
 451     *   DrawElementsInstanced, and DrawRangeElements while transform feedback
 452     *   is active and not paused, regardless of mode.
 453     */
 454    if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx)) {
 455       _mesa_error(ctx, GL_INVALID_OPERATION,
 456                   "glDrawElements(transform feedback active)");
 457       return GL_FALSE;
 458    }
 459
 460    if (count <= 0) {
 461       if (count < 0)
 462          _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(count)" );
 463       return GL_FALSE;
 464    }
 465
 466    if (!_mesa_valid_prim_mode(ctx, mode, "glDrawRangeElements")) {
 467       return GL_FALSE;
 468    }
 469
 470    if (end < start) {
 471       _mesa_error(ctx, GL_INVALID_VALUE, "glDrawRangeElements(end<start)");
 472       return GL_FALSE;
 473    }
 474
 475    if (!valid_elements_type(ctx, type, "glDrawRangeElements"))
 476       return GL_FALSE;
 477
 478    if (!check_valid_to_render(ctx, "glDrawRangeElements"))
 479       return GL_FALSE;
 480
 481    /* Vertex buffer object tests */
 482    if (_mesa_is_bufferobj(ctx->Array.ArrayObj->ElementArrayBufferObj)) {
 483       /* use indices in the buffer object */
 484       /* make sure count doesn't go outside buffer bounds */
 485       if (index_bytes(type, count) > ctx->Array.ArrayObj->ElementArrayBufferObj->Size) {
 486          _mesa_warning(ctx, "glDrawRangeElements index out of buffer bounds");
 487          return GL_FALSE;
 488       }
 489    }
 490    else {
 491       /* not using a VBO */
 492       if (!indices)
 493          return GL_FALSE;
 494    }
 495
 496    if (!check_index_bounds(ctx, count, type, indices, basevertex))
 497       return GL_FALSE;
 498
 499    return GL_TRUE;
 500 }
 501
 502
 503 /**
 504  * Called from the tnl module to error check the function parameters and
 505  * verify that we really can draw something.
 506  * \return GL_TRUE if OK to render, GL_FALSE if error found
 507  */
 508 GLboolean
 509 _mesa_validate_DrawArrays(struct gl_context *ctx,
 510                           GLenum mode, GLint start, GLsizei count)
 511 {
 512    struct gl_transform_feedback_object *xfb_obj
 513       = ctx->TransformFeedback.CurrentObject;
 514    FLUSH_CURRENT(ctx, 0);
 515
 516    if (count <= 0) {
 517       if (count < 0)
 518          _mesa_error(ctx, GL_INVALID_VALUE, "glDrawArrays(count)" );
 519       return GL_FALSE;
 520    }
 521
 522    if (!_mesa_valid_prim_mode(ctx, mode, "glDrawArrays")) {
 523       return GL_FALSE;
 524    }
 525
 526    if (!check_valid_to_render(ctx, "glDrawArrays"))
 527       return GL_FALSE;
 528
 529    if (ctx->Const.CheckArrayBounds) {
 530       if (start + count > (GLint) ctx->Array.ArrayObj->_MaxElement)
 531          return GL_FALSE;
 532    }
 533
 534    /* From the GLES3 specification, section 2.14.2 (Transform Feedback
 535     * Primitive Capture):
 536     *
 537     *   The error INVALID_OPERATION is generated by DrawArrays and
 538     *   DrawArraysInstanced if recording the vertices of a primitive to the
 539     *   buffer objects being used for transform feedback purposes would result
 540     *   in either exceeding the limits of any buffer object’s size, or in
 541     *   exceeding the end position offset + size − 1, as set by
 542     *   BindBufferRange.
 543     *
 544     * This is in contrast to the behaviour of desktop GL, where the extra
 545     * primitives are silently dropped from the transform feedback buffer.
 546     */
 547    if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx)) {
 548       size_t prim_count = vbo_count_tessellated_primitives(mode, count, 1);
 549       if (xfb_obj->GlesRemainingPrims < prim_count) {
 550          _mesa_error(ctx, GL_INVALID_OPERATION,
 551                      "glDrawArrays(exceeds transform feedback size)");
 552          return GL_FALSE;
 553       }
 554       xfb_obj->GlesRemainingPrims -= prim_count;
 555    }
 556
 557    return GL_TRUE;
 558 }
 559
 560
 561 GLboolean
 562 _mesa_validate_DrawArraysInstanced(struct gl_context *ctx, GLenum mode, GLint first,
 563                                    GLsizei count, GLsizei numInstances)
 564 {
 565    struct gl_transform_feedback_object *xfb_obj
 566       = ctx->TransformFeedback.CurrentObject;
 567    FLUSH_CURRENT(ctx, 0);
 568
 569    if (count <= 0) {
 570       if (count < 0)
 571          _mesa_error(ctx, GL_INVALID_VALUE,
 572                      "glDrawArraysInstanced(count=%d)", count);
 573       return GL_FALSE;
 574    }
 575
 576    if (first < 0) {
 577       _mesa_error(ctx, GL_INVALID_VALUE,
 578                   "glDrawArraysInstanced(start=%d)", first);
 579       return GL_FALSE;
 580    }
 581
 582    if (!_mesa_valid_prim_mode(ctx, mode, "glDrawArraysInstanced")) {
 583       return GL_FALSE;
 584    }
 585
 586    if (numInstances <= 0) {
 587       if (numInstances < 0)
 588          _mesa_error(ctx, GL_INVALID_VALUE,
 589                      "glDrawArraysInstanced(numInstances=%d)", numInstances);
 590       return GL_FALSE;
 591    }
 592
 593    if (!check_valid_to_render(ctx, "glDrawArraysInstanced(invalid to render)"))
 594       return GL_FALSE;
 595
 596    if (ctx->Const.CheckArrayBounds) {
 597       if (first + count > (GLint) ctx->Array.ArrayObj->_MaxElement)
 598          return GL_FALSE;
 599    }
 600
 601    /* From the GLES3 specification, section 2.14.2 (Transform Feedback
 602     * Primitive Capture):
 603     *
 604     *   The error INVALID_OPERATION is generated by DrawArrays and
 605     *   DrawArraysInstanced if recording the vertices of a primitive to the
 606     *   buffer objects being used for transform feedback purposes would result
 607     *   in either exceeding the limits of any buffer object’s size, or in
 608     *   exceeding the end position offset + size − 1, as set by
 609     *   BindBufferRange.
 610     *
 611     * This is in contrast to the behaviour of desktop GL, where the extra
 612     * primitives are silently dropped from the transform feedback buffer.
 613     */
 614    if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx)) {
 615       size_t prim_count
 616          = vbo_count_tessellated_primitives(mode, count, numInstances);
 617       if (xfb_obj->GlesRemainingPrims < prim_count) {
 618          _mesa_error(ctx, GL_INVALID_OPERATION,
 619                      "glDrawArraysInstanced(exceeds transform feedback size)");
 620          return GL_FALSE;
 621       }
 622       xfb_obj->GlesRemainingPrims -= prim_count;
 623    }
 624
 625    return GL_TRUE;
 626 }
 627
 628
 629 GLboolean
 630 _mesa_validate_DrawElementsInstanced(struct gl_context *ctx,
 631                                      GLenum mode, GLsizei count, GLenum type,
 632                                      const GLvoid *indices, GLsizei numInstances,
 633                                      GLint basevertex)
 634 {
 635    FLUSH_CURRENT(ctx, 0);
 636
 637    /* From the GLES3 specification, section 2.14.2 (Transform Feedback
 638     * Primitive Capture):
 639     *
 640     *   The error INVALID_OPERATION is also generated by DrawElements,
 641     *   DrawElementsInstanced, and DrawRangeElements while transform feedback
 642     *   is active and not paused, regardless of mode.
 643     */
 644    if (_mesa_is_gles3(ctx) && _mesa_is_xfb_active_and_unpaused(ctx)) {
 645       _mesa_error(ctx, GL_INVALID_OPERATION,
 646                   "glDrawElements(transform feedback active)");
 647       return GL_FALSE;
 648    }
 649
 650    if (count <= 0) {
 651       if (count < 0)
 652          _mesa_error(ctx, GL_INVALID_VALUE,
 653                      "glDrawElementsInstanced(count=%d)", count);
 654       return GL_FALSE;
 655    }
 656
 657    if (!_mesa_valid_prim_mode(ctx, mode, "glDrawElementsInstanced")) {
 658       return GL_FALSE;
 659    }
 660
 661    if (!valid_elements_type(ctx, type, "glDrawElementsInstanced"))
 662       return GL_FALSE;
 663
 664    if (numInstances <= 0) {
 665       if (numInstances < 0)
 666          _mesa_error(ctx, GL_INVALID_VALUE,
 667                      "glDrawElementsInstanced(numInstances=%d)", numInstances);
 668       return GL_FALSE;
 669    }
 670
 671    if (!check_valid_to_render(ctx, "glDrawElementsInstanced"))
 672       return GL_FALSE;
 673
 674    /* Vertex buffer object tests */
 675    if (_mesa_is_bufferobj(ctx->Array.ArrayObj->ElementArrayBufferObj)) {
 676       /* use indices in the buffer object */
 677       /* make sure count doesn't go outside buffer bounds */
 678       if (index_bytes(type, count) > ctx->Array.ArrayObj->ElementArrayBufferObj->Size) {
 679          _mesa_warning(ctx,
 680                        "glDrawElementsInstanced index out of buffer bounds");
 681          return GL_FALSE;
 682       }
 683    }
 684    else {
 685       /* not using a VBO */
 686       if (!indices)
 687          return GL_FALSE;
 688    }
 689
 690    if (!check_index_bounds(ctx, count, type, indices, basevertex))
 691       return GL_FALSE;
 692
 693    return GL_TRUE;
 694 }
 695
 696
 697 GLboolean
 698 _mesa_validate_DrawTransformFeedback(struct gl_context *ctx,
 699                                      GLenum mode,
 700                                      struct gl_transform_feedback_object *obj,
 701                                      GLuint stream,
 702                                      GLsizei numInstances)
 703 {
 704    FLUSH_CURRENT(ctx, 0);
 705
 706    if (!_mesa_valid_prim_mode(ctx, mode, "glDrawTransformFeedback*(mode)")) {
 707       return GL_FALSE;
 708    }
 709
 710    if (!obj) {
 711       _mesa_error(ctx, GL_INVALID_VALUE, "glDrawTransformFeedback*(name)");
 712       return GL_FALSE;
 713    }
 714
 715    if (!obj->EndedAnytime) {
 716       _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawTransformFeedback*");
 717       return GL_FALSE;
 718    }
 719
 720    if (stream >= ctx->Const.MaxVertexStreams) {
 721       _mesa_error(ctx, GL_INVALID_VALUE,
 722                   "glDrawTransformFeedbackStream*(index>=MaxVertexStream)");
 723       return GL_FALSE;
 724    }
 725
 726    if (numInstances <= 0) {
 727       if (numInstances < 0)
 728          _mesa_error(ctx, GL_INVALID_VALUE,
 729                      "glDrawTransformFeedback*Instanced(numInstances=%d)",
 730                      numInstances);
 731       return GL_FALSE;
 732    }
 733
 734    if (!check_valid_to_render(ctx, "glDrawTransformFeedback*")) {
 735       return GL_FALSE;
 736    }
 737
 738    return GL_TRUE;
 739 }