src/mesa/main/transformfeedback.c

   1 /*
   2  * Mesa 3-D graphics library
   3  *
   4  * Copyright (C) 2010  VMware, Inc.  All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  22  * OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25
  26 /*
  27  * Transform feedback support.
  28  *
  29  * Authors:
  30  *   Brian Paul
  31  */
  32
  33
  34 #include "buffers.h"
  35 #include "context.h"
  36 #include "hash.h"
  37 #include "macros.h"
  38 #include "mtypes.h"
  39 #include "transformfeedback.h"
  40 #include "shaderapi.h"
  41 #include "shaderobj.h"
  42 #include "main/dispatch.h"
  43
  44 #include "program/prog_parameter.h"
  45
  46 struct using_program_tuple
  47 {
  48    struct gl_program *prog;
  49    bool found;
  50 };
  51
  52 static void
  53 active_xfb_object_references_program(GLuint key, void *data, void *user_data)
  54 {
  55    struct using_program_tuple *callback_data = user_data;
  56    struct gl_transform_feedback_object *obj = data;
  57    if (obj->Active && obj->program == callback_data->prog)
  58       callback_data->found = true;
  59 }
  60
  61 /**
  62  * Return true if any active transform feedback object is using a program.
  63  */
  64 bool
  65 _mesa_transform_feedback_is_using_program(struct gl_context *ctx,
  66                                           struct gl_shader_program *shProg)
  67 {
  68    if (!shProg->last_vert_prog)
  69       return false;
  70
  71    struct using_program_tuple callback_data;
  72    callback_data.found = false;
  73    callback_data.prog = shProg->last_vert_prog;
  74
  75    _mesa_HashWalkLocked(ctx->TransformFeedback.Objects,
  76                         active_xfb_object_references_program, &callback_data);
  77
  78    /* Also check DefaultObject, as it's not in the Objects hash table. */
  79    active_xfb_object_references_program(0, ctx->TransformFeedback.DefaultObject,
  80                                         &callback_data);
  81
  82    return callback_data.found;
  83 }
  84
  85 /**
  86  * Do reference counting of transform feedback buffers.
  87  */
  88 static void
  89 reference_transform_feedback_object(struct gl_transform_feedback_object **ptr,
  90                                     struct gl_transform_feedback_object *obj)
  91 {
  92    if (*ptr == obj)
  93       return;
  94
  95    if (*ptr) {
  96       /* Unreference the old object */
  97       struct gl_transform_feedback_object *oldObj = *ptr;
  98
  99       assert(oldObj->RefCount > 0);
 100       oldObj->RefCount--;
 101
 102       if (oldObj->RefCount == 0) {
 103          GET_CURRENT_CONTEXT(ctx);
 104          if (ctx)
 105             ctx->Driver.DeleteTransformFeedback(ctx, oldObj);
 106       }
 107
 108       *ptr = NULL;
 109    }
 110    assert(!*ptr);
 111
 112    if (obj) {
 113       assert(obj->RefCount > 0);
 114
 115       /* reference new object */
 116       obj->RefCount++;
 117       obj->EverBound = GL_TRUE;
 118       *ptr = obj;
 119    }
 120 }
 121
 122
 123 /**
 124  * Check that all the buffer objects currently bound for transform
 125  * feedback actually exist.  Raise a GL_INVALID_OPERATION error if
 126  * any buffers are missing.
 127  * \return GL_TRUE for success, GL_FALSE if error
 128  */
 129 GLboolean
 130 _mesa_validate_transform_feedback_buffers(struct gl_context *ctx)
 131 {
 132    /* XXX to do */
 133    return GL_TRUE;
 134 }
 135
 136
 137
 138 /**
 139  * Per-context init for transform feedback.
 140  */
 141 void
 142 _mesa_init_transform_feedback(struct gl_context *ctx)
 143 {
 144    /* core mesa expects this, even a dummy one, to be available */
 145    assert(ctx->Driver.NewTransformFeedback);
 146
 147    ctx->TransformFeedback.DefaultObject =
 148       ctx->Driver.NewTransformFeedback(ctx, 0);
 149
 150    assert(ctx->TransformFeedback.DefaultObject->RefCount == 1);
 151
 152    reference_transform_feedback_object(&ctx->TransformFeedback.CurrentObject,
 153                                        ctx->TransformFeedback.DefaultObject);
 154
 155    assert(ctx->TransformFeedback.DefaultObject->RefCount == 2);
 156
 157    ctx->TransformFeedback.Objects = _mesa_NewHashTable();
 158
 159    _mesa_reference_buffer_object(ctx,
 160                                  &ctx->TransformFeedback.CurrentBuffer,
 161                                  ctx->Shared->NullBufferObj);
 162 }
 163
 164
 165
 166 /**
 167  * Callback for _mesa_HashDeleteAll().
 168  */
 169 static void
 170 delete_cb(GLuint key, void *data, void *userData)
 171 {
 172    struct gl_context *ctx = (struct gl_context *) userData;
 173    struct gl_transform_feedback_object *obj =
 174       (struct gl_transform_feedback_object *) data;
 175
 176    ctx->Driver.DeleteTransformFeedback(ctx, obj);
 177 }
 178
 179
 180 /**
 181  * Per-context free/clean-up for transform feedback.
 182  */
 183 void
 184 _mesa_free_transform_feedback(struct gl_context *ctx)
 185 {
 186    /* core mesa expects this, even a dummy one, to be available */
 187    assert(ctx->Driver.NewTransformFeedback);
 188
 189    _mesa_reference_buffer_object(ctx,
 190                                  &ctx->TransformFeedback.CurrentBuffer,
 191                                  NULL);
 192
 193    /* Delete all feedback objects */
 194    _mesa_HashDeleteAll(ctx->TransformFeedback.Objects, delete_cb, ctx);
 195    _mesa_DeleteHashTable(ctx->TransformFeedback.Objects);
 196
 197    /* Delete the default feedback object */
 198    assert(ctx->Driver.DeleteTransformFeedback);
 199    ctx->Driver.DeleteTransformFeedback(ctx,
 200                                        ctx->TransformFeedback.DefaultObject);
 201
 202    ctx->TransformFeedback.CurrentObject = NULL;
 203 }
 204
 205
 206 /** Initialize the fields of a gl_transform_feedback_object. */
 207 void
 208 _mesa_init_transform_feedback_object(struct gl_transform_feedback_object *obj,
 209                                      GLuint name)
 210 {
 211    if (!obj)
 212       return;
 213
 214    obj->Name = name;
 215    obj->RefCount = 1;
 216    obj->EverBound = GL_FALSE;
 217 }
 218
 219
 220 /** Default fallback for ctx->Driver.NewTransformFeedback() */
 221 static struct gl_transform_feedback_object *
 222 new_transform_feedback(struct gl_context *ctx, GLuint name)
 223 {
 224    struct gl_transform_feedback_object *obj;
 225    obj = CALLOC_STRUCT(gl_transform_feedback_object);
 226    _mesa_init_transform_feedback_object(obj, name);
 227    return obj;
 228 }
 229
 230 /** Default fallback for ctx->Driver.DeleteTransformFeedback() */
 231 static void
 232 delete_transform_feedback(struct gl_context *ctx,
 233                           struct gl_transform_feedback_object *obj)
 234 {
 235    GLuint i;
 236
 237    for (i = 0; i < ARRAY_SIZE(obj->Buffers); i++) {
 238       _mesa_reference_buffer_object(ctx, &obj->Buffers[i], NULL);
 239    }
 240
 241    free(obj->Label);
 242    free(obj);
 243 }
 244
 245
 246 /** Default fallback for ctx->Driver.BeginTransformFeedback() */
 247 static void
 248 begin_transform_feedback(struct gl_context *ctx, GLenum mode,
 249                          struct gl_transform_feedback_object *obj)
 250 {
 251    /* nop */
 252 }
 253
 254 /** Default fallback for ctx->Driver.EndTransformFeedback() */
 255 static void
 256 end_transform_feedback(struct gl_context *ctx,
 257                        struct gl_transform_feedback_object *obj)
 258 {
 259    /* nop */
 260 }
 261
 262 /** Default fallback for ctx->Driver.PauseTransformFeedback() */
 263 static void
 264 pause_transform_feedback(struct gl_context *ctx,
 265                          struct gl_transform_feedback_object *obj)
 266 {
 267    /* nop */
 268 }
 269
 270 /** Default fallback for ctx->Driver.ResumeTransformFeedback() */
 271 static void
 272 resume_transform_feedback(struct gl_context *ctx,
 273                           struct gl_transform_feedback_object *obj)
 274 {
 275    /* nop */
 276 }
 277
 278
 279 /**
 280  * Plug in default device driver functions for transform feedback.
 281  * Most drivers will override some/all of these.
 282  */
 283 void
 284 _mesa_init_transform_feedback_functions(struct dd_function_table *driver)
 285 {
 286    driver->NewTransformFeedback = new_transform_feedback;
 287    driver->DeleteTransformFeedback = delete_transform_feedback;
 288    driver->BeginTransformFeedback = begin_transform_feedback;
 289    driver->EndTransformFeedback = end_transform_feedback;
 290    driver->PauseTransformFeedback = pause_transform_feedback;
 291    driver->ResumeTransformFeedback = resume_transform_feedback;
 292 }
 293
 294
 295 /**
 296  * Fill in the correct Size value for each buffer in \c obj.
 297  *
 298  * From the GL 4.3 spec, section 6.1.1 ("Binding Buffer Objects to Indexed
 299  * Targets"):
 300  *
 301  *   BindBufferBase binds the entire buffer, even when the size of the buffer
 302  *   is changed after the binding is established. It is equivalent to calling
 303  *   BindBufferRange with offset zero, while size is determined by the size of
 304  *   the bound buffer at the time the binding is used.
 305  *
 306  *   Regardless of the size specified with BindBufferRange, or indirectly with
 307  *   BindBufferBase, the GL will never read or write beyond the end of a bound
 308  *   buffer. In some cases this constraint may result in visibly different
 309  *   behavior when a buffer overflow would otherwise result, such as described
 310  *   for transform feedback operations in section 13.2.2.
 311  */
 312 static void
 313 compute_transform_feedback_buffer_sizes(
 314       struct gl_transform_feedback_object *obj)
 315 {
 316    unsigned i = 0;
 317    for (i = 0; i < MAX_FEEDBACK_BUFFERS; ++i) {
 318       GLintptr offset = obj->Offset[i];
 319       GLsizeiptr buffer_size
 320          = obj->Buffers[i] == NULL ? 0 : obj->Buffers[i]->Size;
 321       GLsizeiptr available_space
 322          = buffer_size <= offset ? 0 : buffer_size - offset;
 323       GLsizeiptr computed_size;
 324       if (obj->RequestedSize[i] == 0) {
 325          /* No size was specified at the time the buffer was bound, so allow
 326           * writing to all available space in the buffer.
 327           */
 328          computed_size = available_space;
 329       } else {
 330          /* A size was specified at the time the buffer was bound, however
 331           * it's possible that the buffer has shrunk since then.  So only
 332           * allow writing to the minimum of the specified size and the space
 333           * available.
 334           */
 335          computed_size = MIN2(available_space, obj->RequestedSize[i]);
 336       }
 337
 338       /* Legal sizes must be multiples of four, so round down if necessary. */
 339       obj->Size[i] = computed_size & ~0x3;
 340    }
 341 }
 342
 343
 344 /**
 345  * Compute the maximum number of vertices that can be written to the currently
 346  * enabled transform feedback buffers without overflowing any of them.
 347  */
 348 unsigned
 349 _mesa_compute_max_transform_feedback_vertices(struct gl_context *ctx,
 350       const struct gl_transform_feedback_object *obj,
 351       const struct gl_transform_feedback_info *info)
 352 {
 353    unsigned max_index = 0xffffffff;
 354    unsigned i;
 355
 356    for (i = 0; i < ctx->Const.MaxTransformFeedbackBuffers; i++) {
 357       if ((info->ActiveBuffers >> i) & 1) {
 358          unsigned stride = info->Buffers[i].Stride;
 359          unsigned max_for_this_buffer;
 360
 361          /* Skip any inactive buffers, which have a stride of 0. */
 362          if (stride == 0)
 363             continue;
 364
 365          max_for_this_buffer = obj->Size[i] / (4 * stride);
 366          max_index = MIN2(max_index, max_for_this_buffer);
 367       }
 368    }
 369
 370    return max_index;
 371 }
 372
 373
 374 /**
 375  ** Begin API functions
 376  **/
 377
 378
 379 /**
 380  * Figure out which stage of the pipeline is the source of transform feedback
 381  * data given the current context state, and return its gl_program.
 382  *
 383  * If no active program can generate transform feedback data (i.e. no vertex
 384  * shader is active), returns NULL.
 385  */
 386 static struct gl_program *
 387 get_xfb_source(struct gl_context *ctx)
 388 {
 389    int i;
 390    for (i = MESA_SHADER_GEOMETRY; i >= MESA_SHADER_VERTEX; i--) {
 391       if (ctx->_Shader->CurrentProgram[i] != NULL)
 392          return ctx->_Shader->CurrentProgram[i];
 393    }
 394    return NULL;
 395 }
 396
 397
 398 void GLAPIENTRY
 399 _mesa_BeginTransformFeedback(GLenum mode)
 400 {
 401    struct gl_transform_feedback_object *obj;
 402    struct gl_transform_feedback_info *info = NULL;
 403    GLuint i;
 404    unsigned vertices_per_prim;
 405    GET_CURRENT_CONTEXT(ctx);
 406
 407    obj = ctx->TransformFeedback.CurrentObject;
 408
 409    /* Figure out what pipeline stage is the source of data for transform
 410     * feedback.
 411     */
 412    struct gl_program *source = get_xfb_source(ctx);
 413    if (source == NULL) {
 414       _mesa_error(ctx, GL_INVALID_OPERATION,
 415                   "glBeginTransformFeedback(no program active)");
 416       return;
 417    }
 418
 419    info = source->sh.LinkedTransformFeedback;
 420
 421    if (info->NumOutputs == 0) {
 422       _mesa_error(ctx, GL_INVALID_OPERATION,
 423                   "glBeginTransformFeedback(no varyings to record)");
 424       return;
 425    }
 426
 427    switch (mode) {
 428    case GL_POINTS:
 429       vertices_per_prim = 1;
 430       break;
 431    case GL_LINES:
 432       vertices_per_prim = 2;
 433       break;
 434    case GL_TRIANGLES:
 435       vertices_per_prim = 3;
 436       break;
 437    default:
 438       _mesa_error(ctx, GL_INVALID_ENUM, "glBeginTransformFeedback(mode)");
 439       return;
 440    }
 441
 442    if (obj->Active) {
 443       _mesa_error(ctx, GL_INVALID_OPERATION,
 444                   "glBeginTransformFeedback(already active)");
 445       return;
 446    }
 447
 448    for (i = 0; i < ctx->Const.MaxTransformFeedbackBuffers; i++) {
 449       if ((info->ActiveBuffers >> i) & 1) {
 450          if (obj->BufferNames[i] == 0) {
 451             _mesa_error(ctx, GL_INVALID_OPERATION,
 452                         "glBeginTransformFeedback(binding point %d does not "
 453                         "have a buffer object bound)", i);
 454             return;
 455          }
 456       }
 457    }
 458
 459    FLUSH_VERTICES(ctx, 0);
 460    ctx->NewDriverState |= ctx->DriverFlags.NewTransformFeedback;
 461
 462    obj->Active = GL_TRUE;
 463    ctx->TransformFeedback.Mode = mode;
 464
 465    compute_transform_feedback_buffer_sizes(obj);
 466
 467    if (_mesa_is_gles3(ctx)) {
 468       /* In GLES3, we are required to track the usage of the transform
 469        * feedback buffer and report INVALID_OPERATION if a draw call tries to
 470        * exceed it.  So compute the maximum number of vertices that we can
 471        * write without overflowing any of the buffers currently being used for
 472        * feedback.
 473        */
 474       unsigned max_vertices
 475          = _mesa_compute_max_transform_feedback_vertices(ctx, obj, info);
 476       obj->GlesRemainingPrims = max_vertices / vertices_per_prim;
 477    }
 478
 479    if (obj->program != source) {
 480       ctx->NewDriverState |= ctx->DriverFlags.NewTransformFeedbackProg;
 481       obj->program = source;
 482    }
 483
 484    assert(ctx->Driver.BeginTransformFeedback);
 485    ctx->Driver.BeginTransformFeedback(ctx, mode, obj);
 486 }
 487
 488
 489 void GLAPIENTRY
 490 _mesa_EndTransformFeedback(void)
 491 {
 492    struct gl_transform_feedback_object *obj;
 493    GET_CURRENT_CONTEXT(ctx);
 494
 495    obj = ctx->TransformFeedback.CurrentObject;
 496
 497    if (!obj->Active) {
 498       _mesa_error(ctx, GL_INVALID_OPERATION,
 499                   "glEndTransformFeedback(not active)");
 500       return;
 501    }
 502
 503    FLUSH_VERTICES(ctx, 0);
 504    ctx->NewDriverState |= ctx->DriverFlags.NewTransformFeedback;
 505
 506    assert(ctx->Driver.EndTransformFeedback);
 507    ctx->Driver.EndTransformFeedback(ctx, obj);
 508
 509    ctx->TransformFeedback.CurrentObject->Active = GL_FALSE;
 510    ctx->TransformFeedback.CurrentObject->Paused = GL_FALSE;
 511    ctx->TransformFeedback.CurrentObject->EndedAnytime = GL_TRUE;
 512 }
 513
 514
 515 /**
 516  * Helper used by BindBufferRange() and BindBufferBase().
 517  */
 518 static void
 519 bind_buffer_range(struct gl_context *ctx,
 520                   struct gl_transform_feedback_object *obj,
 521                   GLuint index,
 522                   struct gl_buffer_object *bufObj,
 523                   GLintptr offset, GLsizeiptr size,
 524                   bool dsa)
 525 {
 526    /* Note: no need to FLUSH_VERTICES or flag NewTransformFeedback, because
 527     * transform feedback buffers can't be changed while transform feedback is
 528     * active.
 529     */
 530
 531    if (!dsa) {
 532       /* The general binding point */
 533       _mesa_reference_buffer_object(ctx,
 534                                     &ctx->TransformFeedback.CurrentBuffer,
 535                                     bufObj);
 536    }
 537
 538    /* The per-attribute binding point */
 539    _mesa_set_transform_feedback_binding(ctx, obj, index, bufObj, offset, size);
 540 }
 541
 542
 543 /**
 544  * Validate the buffer object to receive transform feedback results.  Plus,
 545  * validate the starting offset to place the results, and max size.
 546  * Called from the glBindBufferRange() and glTransformFeedbackBufferRange
 547  * functions.
 548  */
 549 bool
 550 _mesa_validate_buffer_range_xfb(struct gl_context *ctx,
 551                                 struct gl_transform_feedback_object *obj,
 552                                 GLuint index, struct gl_buffer_object *bufObj,
 553                                 GLintptr offset, GLsizeiptr size, bool dsa)
 554 {
 555    const char *gl_methd_name;
 556    if (dsa)
 557       gl_methd_name = "glTransformFeedbackBufferRange";
 558    else
 559       gl_methd_name = "glBindBufferRange";
 560
 561
 562    if (obj->Active) {
 563       _mesa_error(ctx, GL_INVALID_OPERATION, "%s(transform feedback active)",
 564                   gl_methd_name);
 565       return false;
 566    }
 567
 568    if (index >= ctx->Const.MaxTransformFeedbackBuffers) {
 569       /* OpenGL 4.5 core profile, 6.1, pdf page 82: "An INVALID_VALUE error is
 570        * generated if index is greater than or equal to the number of binding
 571        * points for transform feedback, as described in section 6.7.1."
 572        */
 573       _mesa_error(ctx, GL_INVALID_VALUE, "%s(index=%d out of bounds)",
 574                   gl_methd_name, index);
 575       return false;
 576    }
 577
 578    if (size & 0x3) {
 579       /* OpenGL 4.5 core profile, 6.7, pdf page 103: multiple of 4 */
 580       _mesa_error(ctx, GL_INVALID_VALUE, "%s(size=%d must be a multiple of "
 581                   "four)", gl_methd_name, (int) size);
 582       return false;
 583    }
 584
 585    if (offset & 0x3) {
 586       /* OpenGL 4.5 core profile, 6.7, pdf page 103: multiple of 4 */
 587       _mesa_error(ctx, GL_INVALID_VALUE, "%s(offset=%d must be a multiple "
 588                   "of four)", gl_methd_name, (int) offset);
 589       return false;
 590    }
 591
 592    if (offset < 0) {
 593       /* OpenGL 4.5 core profile, 6.1, pdf page 82: "An INVALID_VALUE error is
 594        * generated by BindBufferRange if offset is negative."
 595        *
 596        * OpenGL 4.5 core profile, 13.2, pdf page 445: "An INVALID_VALUE error
 597        * is generated by TransformFeedbackBufferRange if offset is negative."
 598        */
 599       _mesa_error(ctx, GL_INVALID_VALUE, "%s(offset=%d must be >= 0)",
 600                   gl_methd_name,
 601                   (int) offset);
 602       return false;
 603    }
 604
 605    if (size <= 0 && (dsa || bufObj != ctx->Shared->NullBufferObj)) {
 606       /* OpenGL 4.5 core profile, 6.1, pdf page 82: "An INVALID_VALUE error is
 607        * generated by BindBufferRange if buffer is non-zero and size is less
 608        * than or equal to zero."
 609        *
 610        * OpenGL 4.5 core profile, 13.2, pdf page 445: "An INVALID_VALUE error
 611        * is generated by TransformFeedbackBufferRange if size is less than or
 612        * equal to zero."
 613        */
 614       _mesa_error(ctx, GL_INVALID_VALUE, "%s(size=%d must be > 0)",
 615                   gl_methd_name, (int) size);
 616       return false;
 617    }
 618
 619    return true;
 620 }
 621
 622
 623 /**
 624  * Specify a buffer object to receive transform feedback results.
 625  * As above, but start at offset = 0.
 626  * Called from the glBindBufferBase() and glTransformFeedbackBufferBase()
 627  * functions.
 628  */
 629 void
 630 _mesa_bind_buffer_base_transform_feedback(struct gl_context *ctx,
 631                                           struct gl_transform_feedback_object *obj,
 632                                           GLuint index,
 633                                           struct gl_buffer_object *bufObj,
 634                                           bool dsa)
 635 {
 636    if (obj->Active) {
 637       _mesa_error(ctx, GL_INVALID_OPERATION,
 638                   "%s(transform feedback active)",
 639                   dsa ? "glTransformFeedbackBufferBase" : "glBindBufferBase");
 640       return;
 641    }
 642
 643    if (index >= ctx->Const.MaxTransformFeedbackBuffers) {
 644       _mesa_error(ctx, GL_INVALID_VALUE, "%s(index=%d out of bounds)",
 645                   dsa ? "glTransformFeedbackBufferBase" : "glBindBufferBase",
 646                   index);
 647       return;
 648    }
 649
 650    bind_buffer_range(ctx, obj, index, bufObj, 0, 0, dsa);
 651 }
 652
 653 /**
 654  * Wrapper around lookup_transform_feedback_object that throws
 655  * GL_INVALID_OPERATION if id is not in the hash table. After calling
 656  * _mesa_error, it returns NULL.
 657  */
 658 static struct gl_transform_feedback_object *
 659 lookup_transform_feedback_object_err(struct gl_context *ctx,
 660                                      GLuint xfb, const char* func)
 661 {
 662    struct gl_transform_feedback_object *obj;
 663
 664    obj = _mesa_lookup_transform_feedback_object(ctx, xfb);
 665    if (!obj) {
 666       _mesa_error(ctx, GL_INVALID_OPERATION,
 667                   "%s(xfb=%u: non-generated object name)", func, xfb);
 668    }
 669
 670    return obj;
 671 }
 672
 673 /**
 674  * Wrapper around _mesa_lookup_bufferobj that throws GL_INVALID_VALUE if id
 675  * is not in the hash table. Specialised version for the
 676  * transform-feedback-related functions. After calling _mesa_error, it
 677  * returns NULL.
 678  */
 679 static struct gl_buffer_object *
 680 lookup_transform_feedback_bufferobj_err(struct gl_context *ctx,
 681                                         GLuint buffer, const char* func)
 682 {
 683    struct gl_buffer_object *bufObj;
 684
 685    /* OpenGL 4.5 core profile, 13.2, pdf page 444: buffer must be zero or the
 686     * name of an existing buffer object.
 687     */
 688    if (buffer == 0) {
 689       bufObj = ctx->Shared->NullBufferObj;
 690    } else {
 691       bufObj = _mesa_lookup_bufferobj(ctx, buffer);
 692       if (!bufObj) {
 693          _mesa_error(ctx, GL_INVALID_VALUE, "%s(invalid buffer=%u)", func,
 694                      buffer);
 695       }
 696    }
 697
 698    return bufObj;
 699 }
 700
 701 void GLAPIENTRY
 702 _mesa_TransformFeedbackBufferBase(GLuint xfb, GLuint index, GLuint buffer)
 703 {
 704    GET_CURRENT_CONTEXT(ctx);
 705    struct gl_transform_feedback_object *obj;
 706    struct gl_buffer_object *bufObj;
 707
 708    obj = lookup_transform_feedback_object_err(ctx, xfb,
 709                                               "glTransformFeedbackBufferBase");
 710    if(!obj) {
 711       return;
 712    }
 713
 714    bufObj = lookup_transform_feedback_bufferobj_err(ctx, buffer,
 715                                               "glTransformFeedbackBufferBase");
 716    if(!bufObj) {
 717       return;
 718    }
 719
 720    _mesa_bind_buffer_base_transform_feedback(ctx, obj, index, bufObj, true);
 721 }
 722
 723 void GLAPIENTRY
 724 _mesa_TransformFeedbackBufferRange(GLuint xfb, GLuint index, GLuint buffer,
 725                                    GLintptr offset, GLsizeiptr size)
 726 {
 727    GET_CURRENT_CONTEXT(ctx);
 728    struct gl_transform_feedback_object *obj;
 729    struct gl_buffer_object *bufObj;
 730
 731    obj = lookup_transform_feedback_object_err(ctx, xfb,
 732                                               "glTransformFeedbackBufferRange");
 733    if(!obj) {
 734       return;
 735    }
 736
 737    bufObj = lookup_transform_feedback_bufferobj_err(ctx, buffer,
 738                                               "glTransformFeedbackBufferRange");
 739    if(!bufObj) {
 740       return;
 741    }
 742
 743    if (!_mesa_validate_buffer_range_xfb(ctx, obj, index, bufObj, offset,
 744                                         size, true))
 745       return;
 746
 747    /* The per-attribute binding point */
 748    _mesa_set_transform_feedback_binding(ctx, obj, index, bufObj, offset,
 749                                         size);
 750 }
 751
 752 /**
 753  * Specify a buffer object to receive transform feedback results, plus the
 754  * offset in the buffer to start placing results.
 755  * This function is part of GL_EXT_transform_feedback, but not GL3.
 756  */
 757 void GLAPIENTRY
 758 _mesa_BindBufferOffsetEXT(GLenum target, GLuint index, GLuint buffer,
 759                           GLintptr offset)
 760 {
 761    struct gl_transform_feedback_object *obj;
 762    struct gl_buffer_object *bufObj;
 763    GET_CURRENT_CONTEXT(ctx);
 764
 765    if (target != GL_TRANSFORM_FEEDBACK_BUFFER) {
 766       _mesa_error(ctx, GL_INVALID_ENUM, "glBindBufferOffsetEXT(target)");
 767       return;
 768    }
 769
 770    obj = ctx->TransformFeedback.CurrentObject;
 771
 772    if (obj->Active) {
 773       _mesa_error(ctx, GL_INVALID_OPERATION,
 774                   "glBindBufferOffsetEXT(transform feedback active)");
 775       return;
 776    }
 777
 778    if (index >= ctx->Const.MaxTransformFeedbackBuffers) {
 779       _mesa_error(ctx, GL_INVALID_VALUE,
 780                   "glBindBufferOffsetEXT(index=%d)", index);
 781       return;
 782    }
 783
 784    if (offset & 0x3) {
 785       /* must be multiple of four */
 786       _mesa_error(ctx, GL_INVALID_VALUE,
 787                   "glBindBufferOffsetEXT(offset=%d)", (int) offset);
 788       return;
 789    }
 790
 791    if (buffer == 0) {
 792       bufObj = ctx->Shared->NullBufferObj;
 793    } else {
 794       bufObj = _mesa_lookup_bufferobj(ctx, buffer);
 795    }
 796
 797    if (!bufObj) {
 798       _mesa_error(ctx, GL_INVALID_OPERATION,
 799                   "glBindBufferOffsetEXT(invalid buffer=%u)", buffer);
 800       return;
 801    }
 802
 803    _mesa_bind_buffer_range_xfb(ctx, obj, index, bufObj, offset, 0);
 804 }
 805
 806
 807 /**
 808  * This function specifies the transform feedback outputs to be written
 809  * to the feedback buffer(s), and in what order.
 810  */
 811 void GLAPIENTRY
 812 _mesa_TransformFeedbackVaryings(GLuint program, GLsizei count,
 813                                 const GLchar * const *varyings,
 814                                 GLenum bufferMode)
 815 {
 816    struct gl_shader_program *shProg;
 817    GLint i;
 818    GET_CURRENT_CONTEXT(ctx);
 819
 820    /* From the ARB_transform_feedback2 specification:
 821     * "The error INVALID_OPERATION is generated by TransformFeedbackVaryings
 822     *  if the current transform feedback object is active, even if paused."
 823     */
 824    if (ctx->TransformFeedback.CurrentObject->Active) {
 825       _mesa_error(ctx, GL_INVALID_OPERATION,
 826                "glTransformFeedbackVaryings(current object is active)");
 827       return;
 828    }
 829
 830    switch (bufferMode) {
 831    case GL_INTERLEAVED_ATTRIBS:
 832       break;
 833    case GL_SEPARATE_ATTRIBS:
 834       break;
 835    default:
 836       _mesa_error(ctx, GL_INVALID_ENUM,
 837                   "glTransformFeedbackVaryings(bufferMode)");
 838       return;
 839    }
 840
 841    if (count < 0 ||
 842        (bufferMode == GL_SEPARATE_ATTRIBS &&
 843         (GLuint) count > ctx->Const.MaxTransformFeedbackBuffers)) {
 844       _mesa_error(ctx, GL_INVALID_VALUE,
 845                   "glTransformFeedbackVaryings(count=%d)", count);
 846       return;
 847    }
 848
 849    shProg = _mesa_lookup_shader_program_err(ctx, program,
 850                                             "glTransformFeedbackVaryings");
 851    if (!shProg)
 852       return;
 853
 854    if (ctx->Extensions.ARB_transform_feedback3) {
 855       if (bufferMode == GL_INTERLEAVED_ATTRIBS) {
 856          unsigned buffers = 1;
 857
 858          for (i = 0; i < count; i++) {
 859             if (strcmp(varyings[i], "gl_NextBuffer") == 0)
 860                buffers++;
 861          }
 862
 863          if (buffers > ctx->Const.MaxTransformFeedbackBuffers) {
 864             _mesa_error(ctx, GL_INVALID_OPERATION,
 865                         "glTransformFeedbackVaryings(too many gl_NextBuffer "
 866                         "occurrences)");
 867             return;
 868          }
 869       } else {
 870          for (i = 0; i < count; i++) {
 871             if (strcmp(varyings[i], "gl_NextBuffer") == 0 ||
 872                 strcmp(varyings[i], "gl_SkipComponents1") == 0 ||
 873                 strcmp(varyings[i], "gl_SkipComponents2") == 0 ||
 874                 strcmp(varyings[i], "gl_SkipComponents3") == 0 ||
 875                 strcmp(varyings[i], "gl_SkipComponents4") == 0) {
 876                _mesa_error(ctx, GL_INVALID_OPERATION,
 877                            "glTransformFeedbackVaryings(SEPARATE_ATTRIBS,"
 878                            "varying=%s)",
 879                            varyings[i]);
 880                return;
 881             }
 882          }
 883       }
 884    }
 885
 886    /* free existing varyings, if any */
 887    for (i = 0; i < (GLint) shProg->TransformFeedback.NumVarying; i++) {
 888       free(shProg->TransformFeedback.VaryingNames[i]);
 889    }
 890    free(shProg->TransformFeedback.VaryingNames);
 891
 892    /* allocate new memory for varying names */
 893    shProg->TransformFeedback.VaryingNames =
 894       malloc(count * sizeof(GLchar *));
 895
 896    if (!shProg->TransformFeedback.VaryingNames) {
 897       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glTransformFeedbackVaryings()");
 898       return;
 899    }
 900
 901    /* Save the new names and the count */
 902    for (i = 0; i < count; i++) {
 903       shProg->TransformFeedback.VaryingNames[i] = strdup(varyings[i]);
 904    }
 905    shProg->TransformFeedback.NumVarying = count;
 906
 907    shProg->TransformFeedback.BufferMode = bufferMode;
 908
 909    /* No need to invoke FLUSH_VERTICES or flag NewTransformFeedback since
 910     * the varyings won't be used until shader link time.
 911     */
 912 }
 913
 914
 915 /**
 916  * Get info about the transform feedback outputs which are to be written
 917  * to the feedback buffer(s).
 918  */
 919 void GLAPIENTRY
 920 _mesa_GetTransformFeedbackVarying(GLuint program, GLuint index,
 921                                   GLsizei bufSize, GLsizei *length,
 922                                   GLsizei *size, GLenum *type, GLchar *name)
 923 {
 924    const struct gl_shader_program *shProg;
 925    struct gl_program_resource *res;
 926    GET_CURRENT_CONTEXT(ctx);
 927
 928    shProg = _mesa_lookup_shader_program_err(ctx, program,
 929                                             "glGetTransformFeedbackVarying");
 930    if (!shProg)
 931       return;
 932
 933    res = _mesa_program_resource_find_index((struct gl_shader_program *) shProg,
 934                                            GL_TRANSFORM_FEEDBACK_VARYING,
 935                                            index);
 936    if (!res) {
 937       _mesa_error(ctx, GL_INVALID_VALUE,
 938                   "glGetTransformFeedbackVarying(index=%u)", index);
 939       return;
 940    }
 941
 942    /* return the varying's name and length */
 943    _mesa_copy_string(name, bufSize, length, _mesa_program_resource_name(res));
 944
 945    /* return the datatype and value's size (in datatype units) */
 946    if (type)
 947       _mesa_program_resource_prop((struct gl_shader_program *) shProg,
 948                                   res, index, GL_TYPE, (GLint*) type,
 949                                   "glGetTransformFeedbackVarying");
 950    if (size)
 951       _mesa_program_resource_prop((struct gl_shader_program *) shProg,
 952                                   res, index, GL_ARRAY_SIZE, (GLint*) size,
 953                                   "glGetTransformFeedbackVarying");
 954 }
 955
 956
 957
 958 struct gl_transform_feedback_object *
 959 _mesa_lookup_transform_feedback_object(struct gl_context *ctx, GLuint name)
 960 {
 961    /* OpenGL 4.5 core profile, 13.2 pdf page 444: "xfb must be zero, indicating
 962     * the default transform feedback object, or the name of an existing
 963     * transform feedback object."
 964     */
 965    if (name == 0) {
 966       return ctx->TransformFeedback.DefaultObject;
 967    }
 968    else
 969       return (struct gl_transform_feedback_object *)
 970          _mesa_HashLookupLocked(ctx->TransformFeedback.Objects, name);
 971 }
 972
 973 static void
 974 create_transform_feedbacks(struct gl_context *ctx, GLsizei n, GLuint *ids,
 975                            bool dsa)
 976 {
 977    GLuint first;
 978    const char* func;
 979
 980    if (dsa)
 981       func = "glCreateTransformFeedbacks";
 982    else
 983       func = "glGenTransformFeedbacks";
 984
 985    if (n < 0) {
 986       _mesa_error(ctx, GL_INVALID_VALUE, "%s(n < 0)", func);
 987       return;
 988    }
 989
 990    if (!ids)
 991       return;
 992
 993    /* we don't need contiguous IDs, but this might be faster */
 994    first = _mesa_HashFindFreeKeyBlock(ctx->TransformFeedback.Objects, n);
 995    if (first) {
 996       GLsizei i;
 997       for (i = 0; i < n; i++) {
 998          struct gl_transform_feedback_object *obj
 999             = ctx->Driver.NewTransformFeedback(ctx, first + i);
1000          if (!obj) {
1001             _mesa_error(ctx, GL_OUT_OF_MEMORY, "%s", func);
1002             return;
1003          }
1004          ids[i] = first + i;
1005          _mesa_HashInsertLocked(ctx->TransformFeedback.Objects, first + i,
1006                                 obj);
1007          if (dsa) {
1008             /* this is normally done at bind time in the non-dsa case */
1009             obj->EverBound = GL_TRUE;
1010          }
1011       }
1012    }
1013    else {
1014       _mesa_error(ctx, GL_OUT_OF_MEMORY, "%s", func);
1015    }
1016 }
1017
1018 /**
1019  * Create new transform feedback objects.   Transform feedback objects
1020  * encapsulate the state related to transform feedback to allow quickly
1021  * switching state (and drawing the results, below).
1022  * Part of GL_ARB_transform_feedback2.
1023  */
1024 void GLAPIENTRY
1025 _mesa_GenTransformFeedbacks(GLsizei n, GLuint *names)
1026 {
1027    GET_CURRENT_CONTEXT(ctx);
1028
1029    /* GenTransformFeedbacks should just reserve the object names that a
1030     * subsequent call to BindTransformFeedback should actively create. For
1031     * the sake of simplicity, we reserve the names and create the objects
1032     * straight away.
1033     */
1034
1035    create_transform_feedbacks(ctx, n, names, false);
1036 }
1037
1038 /**
1039  * Create new transform feedback objects.   Transform feedback objects
1040  * encapsulate the state related to transform feedback to allow quickly
1041  * switching state (and drawing the results, below).
1042  * Part of GL_ARB_direct_state_access.
1043  */
1044 void GLAPIENTRY
1045 _mesa_CreateTransformFeedbacks(GLsizei n, GLuint *names)
1046 {
1047    GET_CURRENT_CONTEXT(ctx);
1048
1049    create_transform_feedbacks(ctx, n, names, true);
1050 }
1051
1052
1053 /**
1054  * Is the given ID a transform feedback object?
1055  * Part of GL_ARB_transform_feedback2.
1056  */
1057 GLboolean GLAPIENTRY
1058 _mesa_IsTransformFeedback(GLuint name)
1059 {
1060    struct gl_transform_feedback_object *obj;
1061    GET_CURRENT_CONTEXT(ctx);
1062
1063    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, GL_FALSE);
1064
1065    if (name == 0)
1066       return GL_FALSE;
1067
1068    obj = _mesa_lookup_transform_feedback_object(ctx, name);
1069    if (obj == NULL)
1070       return GL_FALSE;
1071
1072    return obj->EverBound;
1073 }
1074
1075
1076 /**
1077  * Bind the given transform feedback object.
1078  * Part of GL_ARB_transform_feedback2.
1079  */
1080 void GLAPIENTRY
1081 _mesa_BindTransformFeedback(GLenum target, GLuint name)
1082 {
1083    struct gl_transform_feedback_object *obj;
1084    GET_CURRENT_CONTEXT(ctx);
1085
1086    if (target != GL_TRANSFORM_FEEDBACK) {
1087       _mesa_error(ctx, GL_INVALID_ENUM, "glBindTransformFeedback(target)");
1088       return;
1089    }
1090
1091    if (_mesa_is_xfb_active_and_unpaused(ctx)) {
1092       _mesa_error(ctx, GL_INVALID_OPERATION,
1093               "glBindTransformFeedback(transform is active, or not paused)");
1094       return;
1095    }
1096
1097    obj = _mesa_lookup_transform_feedback_object(ctx, name);
1098    if (!obj) {
1099       _mesa_error(ctx, GL_INVALID_OPERATION,
1100                   "glBindTransformFeedback(name=%u)", name);
1101       return;
1102    }
1103
1104    reference_transform_feedback_object(&ctx->TransformFeedback.CurrentObject,
1105                                        obj);
1106 }
1107
1108
1109 /**
1110  * Delete the given transform feedback objects.
1111  * Part of GL_ARB_transform_feedback2.
1112  */
1113 void GLAPIENTRY
1114 _mesa_DeleteTransformFeedbacks(GLsizei n, const GLuint *names)
1115 {
1116    GLint i;
1117    GET_CURRENT_CONTEXT(ctx);
1118
1119    if (n < 0) {
1120       _mesa_error(ctx, GL_INVALID_VALUE, "glDeleteTransformFeedbacks(n < 0)");
1121       return;
1122    }
1123
1124    if (!names)
1125       return;
1126
1127    for (i = 0; i < n; i++) {
1128       if (names[i] > 0) {
1129          struct gl_transform_feedback_object *obj
1130             = _mesa_lookup_transform_feedback_object(ctx, names[i]);
1131          if (obj) {
1132             if (obj->Active) {
1133                _mesa_error(ctx, GL_INVALID_OPERATION,
1134                            "glDeleteTransformFeedbacks(object %u is active)",
1135                            names[i]);
1136                return;
1137             }
1138             _mesa_HashRemoveLocked(ctx->TransformFeedback.Objects, names[i]);
1139             /* unref, but object may not be deleted until later */
1140             if (obj == ctx->TransformFeedback.CurrentObject) {
1141                reference_transform_feedback_object(
1142                      &ctx->TransformFeedback.CurrentObject,
1143                      ctx->TransformFeedback.DefaultObject);
1144             }
1145             reference_transform_feedback_object(&obj, NULL);
1146          }
1147       }
1148    }
1149 }
1150
1151
1152 /**
1153  * Pause transform feedback.
1154  * Part of GL_ARB_transform_feedback2.
1155  */
1156 void GLAPIENTRY
1157 _mesa_PauseTransformFeedback(void)
1158 {
1159    struct gl_transform_feedback_object *obj;
1160    GET_CURRENT_CONTEXT(ctx);
1161
1162    obj = ctx->TransformFeedback.CurrentObject;
1163
1164    if (!_mesa_is_xfb_active_and_unpaused(ctx)) {
1165       _mesa_error(ctx, GL_INVALID_OPERATION,
1166            "glPauseTransformFeedback(feedback not active or already paused)");
1167       return;
1168    }
1169
1170    FLUSH_VERTICES(ctx, 0);
1171    ctx->NewDriverState |= ctx->DriverFlags.NewTransformFeedback;
1172
1173    assert(ctx->Driver.PauseTransformFeedback);
1174    ctx->Driver.PauseTransformFeedback(ctx, obj);
1175
1176    obj->Paused = GL_TRUE;
1177 }
1178
1179
1180 /**
1181  * Resume transform feedback.
1182  * Part of GL_ARB_transform_feedback2.
1183  */
1184 void GLAPIENTRY
1185 _mesa_ResumeTransformFeedback(void)
1186 {
1187    struct gl_transform_feedback_object *obj;
1188    GET_CURRENT_CONTEXT(ctx);
1189
1190    obj = ctx->TransformFeedback.CurrentObject;
1191
1192    if (!obj->Active || !obj->Paused) {
1193       _mesa_error(ctx, GL_INVALID_OPERATION,
1194                "glResumeTransformFeedback(feedback not active or not paused)");
1195       return;
1196    }
1197
1198    /* From the ARB_transform_feedback2 specification:
1199     * "The error INVALID_OPERATION is generated by ResumeTransformFeedback if
1200     *  the program object being used by the current transform feedback object
1201     *  is not active."
1202     */
1203    if (obj->program != get_xfb_source(ctx)) {
1204       _mesa_error(ctx, GL_INVALID_OPERATION,
1205                   "glResumeTransformFeedback(wrong program bound)");
1206       return;
1207    }
1208
1209    FLUSH_VERTICES(ctx, 0);
1210    ctx->NewDriverState |= ctx->DriverFlags.NewTransformFeedback;
1211
1212    obj->Paused = GL_FALSE;
1213
1214    assert(ctx->Driver.ResumeTransformFeedback);
1215    ctx->Driver.ResumeTransformFeedback(ctx, obj);
1216 }
1217
1218 extern void GLAPIENTRY
1219 _mesa_GetTransformFeedbackiv(GLuint xfb, GLenum pname, GLint *param)
1220 {
1221     struct gl_transform_feedback_object *obj;
1222     GET_CURRENT_CONTEXT(ctx);
1223
1224     obj = lookup_transform_feedback_object_err(ctx, xfb,
1225                                                "glGetTransformFeedbackiv");
1226     if(!obj) {
1227        return;
1228     }
1229
1230     switch(pname) {
1231     case GL_TRANSFORM_FEEDBACK_PAUSED:
1232        *param = obj->Paused;
1233        break;
1234     case GL_TRANSFORM_FEEDBACK_ACTIVE:
1235        *param = obj->Active;
1236        break;
1237     default:
1238        _mesa_error(ctx, GL_INVALID_ENUM,
1239                    "glGetTransformFeedbackiv(pname=%i)", pname);
1240     }
1241 }
1242
1243 extern void GLAPIENTRY
1244 _mesa_GetTransformFeedbacki_v(GLuint xfb, GLenum pname, GLuint index,
1245                               GLint *param)
1246 {
1247    struct gl_transform_feedback_object *obj;
1248    GET_CURRENT_CONTEXT(ctx);
1249
1250    obj = lookup_transform_feedback_object_err(ctx, xfb,
1251                                               "glGetTransformFeedbacki_v");
1252    if(!obj) {
1253       return;
1254    }
1255
1256    if (index >= ctx->Const.MaxTransformFeedbackBuffers) {
1257       _mesa_error(ctx, GL_INVALID_VALUE,
1258                   "glGetTransformFeedbacki_v(index=%i)", index);
1259       return;
1260    }
1261
1262    switch(pname) {
1263    case GL_TRANSFORM_FEEDBACK_BUFFER_BINDING:
1264       *param = obj->BufferNames[index];
1265       break;
1266    default:
1267       _mesa_error(ctx, GL_INVALID_ENUM,
1268                   "glGetTransformFeedbacki_v(pname=%i)", pname);
1269    }
1270 }
1271
1272 extern void GLAPIENTRY
1273 _mesa_GetTransformFeedbacki64_v(GLuint xfb, GLenum pname, GLuint index,
1274                                 GLint64 *param)
1275 {
1276    struct gl_transform_feedback_object *obj;
1277    GET_CURRENT_CONTEXT(ctx);
1278
1279    obj = lookup_transform_feedback_object_err(ctx, xfb,
1280                                               "glGetTransformFeedbacki64_v");
1281    if(!obj) {
1282       return;
1283    }
1284
1285    if (index >= ctx->Const.MaxTransformFeedbackBuffers) {
1286       _mesa_error(ctx, GL_INVALID_VALUE,
1287                   "glGetTransformFeedbacki64_v(index=%i)", index);
1288       return;
1289    }
1290
1291    compute_transform_feedback_buffer_sizes(obj);
1292    switch(pname) {
1293    case GL_TRANSFORM_FEEDBACK_BUFFER_START:
1294       *param = obj->Offset[index];
1295       break;
1296    case GL_TRANSFORM_FEEDBACK_BUFFER_SIZE:
1297       *param = obj->Size[index];
1298       break;
1299    default:
1300       _mesa_error(ctx, GL_INVALID_ENUM,
1301                   "glGetTransformFeedbacki64_v(pname=%i)", pname);
1302    }
1303 }