src/mesa/state_tracker/st_sampler_view.c

   1 /*
   2  * Copyright 2016 VMware, Inc.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sub license, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the
  14  * next paragraph) shall be included in all copies or substantial portions
  15  * 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
  19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  20  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  21  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  22  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  23  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25
  26 #include "pipe/p_context.h"
  27 #include "util/u_format.h"
  28 #include "util/u_inlines.h"
  29
  30 #include "main/context.h"
  31 #include "main/macros.h"
  32 #include "main/mtypes.h"
  33 #include "main/teximage.h"
  34 #include "main/texobj.h"
  35 #include "program/prog_instruction.h"
  36
  37 #include "st_context.h"
  38 #include "st_sampler_view.h"
  39 #include "st_texture.h"
  40 #include "st_format.h"
  41 #include "st_cb_bufferobjects.h"
  42 #include "st_cb_texture.h"
  43
  44
  45 /**
  46  * Set the given view as the current context's view for the texture.
  47  *
  48  * Overwrites any pre-existing view of the context.
  49  *
  50  * Takes ownership of the view (i.e., stores the view without incrementing the
  51  * reference count).
  52  *
  53  * \return the view, or NULL on error. In case of error, the reference to the
  54  * view is released.
  55  */
  56 static struct pipe_sampler_view *
  57 st_texture_set_sampler_view(struct st_context *st,
  58                             struct st_texture_object *stObj,
  59                             struct pipe_sampler_view *view,
  60                             bool glsl130_or_later, bool srgb_skip_decode)
  61 {
  62    struct st_sampler_views *views;
  63    struct st_sampler_view *free = NULL;
  64    struct st_sampler_view *sv;
  65    GLuint i;
  66
  67    simple_mtx_lock(&stObj->validate_mutex);
  68    views = stObj->sampler_views;
  69
  70    for (i = 0; i < views->count; ++i) {
  71       sv = &views->views[i];
  72
  73       /* Is the array entry used ? */
  74       if (sv->view) {
  75          /* check if the context matches */
  76          if (sv->view->context == st->pipe) {
  77             pipe_sampler_view_release(st->pipe, &sv->view);
  78             goto found;
  79          }
  80       } else {
  81          /* Found a free slot, remember that */
  82          free = sv;
  83       }
  84    }
  85
  86    /* Couldn't find a slot for our context, create a new one */
  87    if (free) {
  88       sv = free;
  89    } else {
  90       if (views->count >= views->max) {
  91          /* Allocate a larger container. */
  92          unsigned new_max = 2 * views->max;
  93          unsigned new_size = sizeof(*views) + new_max * sizeof(views->views[0]);
  94
  95          if (new_max < views->max ||
  96              new_max > (UINT_MAX - sizeof(*views)) / sizeof(views->views[0])) {
  97             pipe_sampler_view_release(st->pipe, &view);
  98             goto out;
  99          }
 100
 101          struct st_sampler_views *new_views = malloc(new_size);
 102          if (!new_views) {
 103             pipe_sampler_view_release(st->pipe, &view);
 104             goto out;
 105          }
 106
 107          new_views->count = views->count;
 108          new_views->max = new_max;
 109          memcpy(&new_views->views[0], &views->views[0],
 110                views->count * sizeof(views->views[0]));
 111
 112          /* Initialize the pipe_sampler_view pointers to zero so that we don't
 113           * have to worry about racing against readers when incrementing
 114           * views->count.
 115           */
 116          memset(&new_views->views[views->count], 0,
 117                 (new_max - views->count) * sizeof(views->views[0]));
 118
 119          /* Use memory release semantics to ensure that concurrent readers will
 120           * get the correct contents of the new container.
 121           *
 122           * Also, the write should be atomic, but that's guaranteed anyway on
 123           * all supported platforms.
 124           */
 125          p_atomic_set(&stObj->sampler_views, new_views);
 126
 127          /* We keep the old container around until the texture object is
 128           * deleted, because another thread may still be reading from it. We
 129           * double the size of the container each time, so we end up with
 130           * at most twice the total memory allocation.
 131           */
 132          views->next = stObj->sampler_views_old;
 133          stObj->sampler_views_old = views;
 134
 135          views = new_views;
 136       }
 137
 138       sv = &views->views[views->count];
 139
 140       /* Since modification is guarded by the lock, only the write part of the
 141        * increment has to be atomic, and that's already guaranteed on all
 142        * supported platforms without using an atomic intrinsic.
 143        */
 144       views->count++;
 145    }
 146
 147 found:
 148    assert(sv->view == NULL);
 149
 150    sv->glsl130_or_later = glsl130_or_later;
 151    sv->srgb_skip_decode = srgb_skip_decode;
 152    sv->view = view;
 153
 154 out:
 155    simple_mtx_unlock(&stObj->validate_mutex);
 156    return view;
 157 }
 158
 159
 160 /**
 161  * Return the most-recently validated sampler view for the texture \p stObj
 162  * in the given context, if any.
 163  *
 164  * Performs no additional validation.
 165  */
 166 const struct st_sampler_view *
 167 st_texture_get_current_sampler_view(const struct st_context *st,
 168                                     const struct st_texture_object *stObj)
 169 {
 170    const struct st_sampler_views *views = p_atomic_read(&stObj->sampler_views);
 171
 172    for (unsigned i = 0; i < views->count; ++i) {
 173       const struct st_sampler_view *sv = &views->views[i];
 174       if (sv->view && sv->view->context == st->pipe)
 175          return sv;
 176    }
 177
 178    return NULL;
 179 }
 180
 181
 182 /**
 183  * For the given texture object, release any sampler views which belong
 184  * to the calling context.
 185  */
 186 void
 187 st_texture_release_sampler_view(struct st_context *st,
 188                                 struct st_texture_object *stObj)
 189 {
 190    GLuint i;
 191
 192    simple_mtx_lock(&stObj->validate_mutex);
 193    struct st_sampler_views *views = stObj->sampler_views;
 194    for (i = 0; i < views->count; ++i) {
 195       struct pipe_sampler_view **sv = &views->views[i].view;
 196
 197       if (*sv && (*sv)->context == st->pipe) {
 198          pipe_sampler_view_reference(sv, NULL);
 199          break;
 200       }
 201    }
 202    simple_mtx_unlock(&stObj->validate_mutex);
 203 }
 204
 205
 206 /**
 207  * Release all sampler views attached to the given texture object, regardless
 208  * of the context.
 209  */
 210 void
 211 st_texture_release_all_sampler_views(struct st_context *st,
 212                                      struct st_texture_object *stObj)
 213 {
 214    GLuint i;
 215
 216    /* TODO: This happens while a texture is deleted, because the Driver API
 217     * is asymmetric: the driver allocates the texture object memory, but
 218     * mesa/main frees it.
 219     */
 220    if (!stObj->sampler_views)
 221       return;
 222
 223    simple_mtx_lock(&stObj->validate_mutex);
 224    struct st_sampler_views *views = stObj->sampler_views;
 225    for (i = 0; i < views->count; ++i)
 226       pipe_sampler_view_release(st->pipe, &views->views[i].view);
 227    simple_mtx_unlock(&stObj->validate_mutex);
 228 }
 229
 230
 231 void
 232 st_texture_free_sampler_views(struct st_texture_object *stObj)
 233 {
 234    free(stObj->sampler_views);
 235    stObj->sampler_views = NULL;
 236
 237    while (stObj->sampler_views_old) {
 238       struct st_sampler_views *views = stObj->sampler_views_old;
 239       stObj->sampler_views_old = views->next;
 240       free(views);
 241    }
 242 }
 243
 244
 245 /**
 246  * Return swizzle1(swizzle2)
 247  */
 248 static unsigned
 249 swizzle_swizzle(unsigned swizzle1, unsigned swizzle2)
 250 {
 251    unsigned i, swz[4];
 252
 253    if (swizzle1 == SWIZZLE_XYZW) {
 254       /* identity swizzle, no change to swizzle2 */
 255       return swizzle2;
 256    }
 257
 258    for (i = 0; i < 4; i++) {
 259       unsigned s = GET_SWZ(swizzle1, i);
 260       switch (s) {
 261       case SWIZZLE_X:
 262       case SWIZZLE_Y:
 263       case SWIZZLE_Z:
 264       case SWIZZLE_W:
 265          swz[i] = GET_SWZ(swizzle2, s);
 266          break;
 267       case SWIZZLE_ZERO:
 268          swz[i] = SWIZZLE_ZERO;
 269          break;
 270       case SWIZZLE_ONE:
 271          swz[i] = SWIZZLE_ONE;
 272          break;
 273       default:
 274          assert(!"Bad swizzle term");
 275          swz[i] = SWIZZLE_X;
 276       }
 277    }
 278
 279    return MAKE_SWIZZLE4(swz[0], swz[1], swz[2], swz[3]);
 280 }
 281
 282
 283 /**
 284  * Given a user-specified texture base format, the actual gallium texture
 285  * format and the current GL_DEPTH_MODE, return a texture swizzle.
 286  *
 287  * Consider the case where the user requests a GL_RGB internal texture
 288  * format the driver actually uses an RGBA format.  The A component should
 289  * be ignored and sampling from the texture should always return (r,g,b,1).
 290  * But if we rendered to the texture we might have written A values != 1.
 291  * By sampling the texture with a ".xyz1" swizzle we'll get the expected A=1.
 292  * This function computes the texture swizzle needed to get the expected
 293  * values.
 294  *
 295  * In the case of depth textures, the GL_DEPTH_MODE state determines the
 296  * texture swizzle.
 297  *
 298  * This result must be composed with the user-specified swizzle to get
 299  * the final swizzle.
 300  */
 301 static unsigned
 302 compute_texture_format_swizzle(GLenum baseFormat, GLenum depthMode,
 303                                bool glsl130_or_later)
 304 {
 305    switch (baseFormat) {
 306    case GL_RGBA:
 307       return SWIZZLE_XYZW;
 308    case GL_RGB:
 309       return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ONE);
 310    case GL_RG:
 311       return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_ZERO, SWIZZLE_ONE);
 312    case GL_RED:
 313       return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_ZERO,
 314                            SWIZZLE_ZERO, SWIZZLE_ONE);
 315    case GL_ALPHA:
 316       return MAKE_SWIZZLE4(SWIZZLE_ZERO, SWIZZLE_ZERO,
 317                            SWIZZLE_ZERO, SWIZZLE_W);
 318    case GL_LUMINANCE:
 319       return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_X, SWIZZLE_X, SWIZZLE_ONE);
 320    case GL_LUMINANCE_ALPHA:
 321       return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_X, SWIZZLE_X, SWIZZLE_W);
 322    case GL_INTENSITY:
 323       return SWIZZLE_XXXX;
 324    case GL_STENCIL_INDEX:
 325    case GL_DEPTH_STENCIL:
 326    case GL_DEPTH_COMPONENT:
 327       /* Now examine the depth mode */
 328       switch (depthMode) {
 329       case GL_LUMINANCE:
 330          return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_X, SWIZZLE_X, SWIZZLE_ONE);
 331       case GL_INTENSITY:
 332          return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_X, SWIZZLE_X, SWIZZLE_X);
 333       case GL_ALPHA:
 334          /* The texture(sampler*Shadow) functions from GLSL 1.30 ignore
 335           * the depth mode and return float, while older shadow* functions
 336           * and ARB_fp instructions return vec4 according to the depth mode.
 337           *
 338           * The problem with the GLSL 1.30 functions is that GL_ALPHA forces
 339           * them to return 0, breaking them completely.
 340           *
 341           * A proper fix would increase code complexity and that's not worth
 342           * it for a rarely used feature such as the GL_ALPHA depth mode
 343           * in GL3. Therefore, change GL_ALPHA to GL_INTENSITY for all
 344           * shaders that use GLSL 1.30 or later.
 345           *
 346           * BTW, it's required that sampler views are updated when
 347           * shaders change (check_sampler_swizzle takes care of that).
 348           */
 349          if (glsl130_or_later)
 350             return SWIZZLE_XXXX;
 351          else
 352             return MAKE_SWIZZLE4(SWIZZLE_ZERO, SWIZZLE_ZERO,
 353                                  SWIZZLE_ZERO, SWIZZLE_X);
 354       case GL_RED:
 355          return MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_ZERO,
 356                               SWIZZLE_ZERO, SWIZZLE_ONE);
 357       default:
 358          assert(!"Unexpected depthMode");
 359          return SWIZZLE_XYZW;
 360       }
 361    default:
 362       assert(!"Unexpected baseFormat");
 363       return SWIZZLE_XYZW;
 364    }
 365 }
 366
 367
 368 static unsigned
 369 get_texture_format_swizzle(const struct st_context *st,
 370                            const struct st_texture_object *stObj,
 371                            bool glsl130_or_later)
 372 {
 373    GLenum baseFormat = _mesa_base_tex_image(&stObj->base)->_BaseFormat;
 374    unsigned tex_swizzle;
 375    GLenum depth_mode = stObj->base.DepthMode;
 376
 377    /* In ES 3.0, DEPTH_TEXTURE_MODE is expected to be GL_RED for textures
 378     * with depth component data specified with a sized internal format.
 379     */
 380    if (_mesa_is_gles3(st->ctx) &&
 381        (baseFormat == GL_DEPTH_COMPONENT ||
 382         baseFormat == GL_DEPTH_STENCIL ||
 383         baseFormat == GL_STENCIL_INDEX)) {
 384       const struct gl_texture_image *firstImage =
 385          _mesa_base_tex_image(&stObj->base);
 386       if (firstImage->InternalFormat != GL_DEPTH_COMPONENT &&
 387           firstImage->InternalFormat != GL_DEPTH_STENCIL &&
 388           firstImage->InternalFormat != GL_STENCIL_INDEX)
 389          depth_mode = GL_RED;
 390    }
 391    tex_swizzle = compute_texture_format_swizzle(baseFormat,
 392                                                 depth_mode,
 393                                                 glsl130_or_later);
 394
 395    /* Combine the texture format swizzle with user's swizzle */
 396    return swizzle_swizzle(stObj->base._Swizzle, tex_swizzle);
 397 }
 398
 399
 400 /**
 401  * Return TRUE if the texture's sampler view swizzle is not equal to
 402  * the texture's swizzle.
 403  *
 404  * \param stObj  the st texture object,
 405  */
 406 MAYBE_UNUSED static boolean
 407 check_sampler_swizzle(const struct st_context *st,
 408                       const struct st_texture_object *stObj,
 409                       const struct pipe_sampler_view *sv,
 410                       bool glsl130_or_later)
 411 {
 412    unsigned swizzle = get_texture_format_swizzle(st, stObj, glsl130_or_later);
 413
 414    return ((sv->swizzle_r != GET_SWZ(swizzle, 0)) ||
 415            (sv->swizzle_g != GET_SWZ(swizzle, 1)) ||
 416            (sv->swizzle_b != GET_SWZ(swizzle, 2)) ||
 417            (sv->swizzle_a != GET_SWZ(swizzle, 3)));
 418 }
 419
 420
 421 static unsigned
 422 last_level(const struct st_texture_object *stObj)
 423 {
 424    unsigned ret = MIN2(stObj->base.MinLevel + stObj->base._MaxLevel,
 425                        stObj->pt->last_level);
 426    if (stObj->base.Immutable)
 427       ret = MIN2(ret, stObj->base.MinLevel + stObj->base.NumLevels - 1);
 428    return ret;
 429 }
 430
 431
 432 static unsigned
 433 last_layer(const struct st_texture_object *stObj)
 434 {
 435    if (stObj->base.Immutable && stObj->pt->array_size > 1)
 436       return MIN2(stObj->base.MinLayer + stObj->base.NumLayers - 1,
 437                   stObj->pt->array_size - 1);
 438    return stObj->pt->array_size - 1;
 439 }
 440
 441
 442 /**
 443  * Determine the format for the texture sampler view.
 444  */
 445 static enum pipe_format
 446 get_sampler_view_format(struct st_context *st,
 447                         const struct st_texture_object *stObj,
 448                         bool srgb_skip_decode)
 449 {
 450    enum pipe_format format;
 451
 452    GLenum baseFormat = _mesa_base_tex_image(&stObj->base)->_BaseFormat;
 453    format = stObj->surface_based ? stObj->surface_format : stObj->pt->format;
 454
 455    if (baseFormat == GL_DEPTH_COMPONENT ||
 456        baseFormat == GL_DEPTH_STENCIL ||
 457        baseFormat == GL_STENCIL_INDEX) {
 458       if (stObj->base.StencilSampling || baseFormat == GL_STENCIL_INDEX)
 459          format = util_format_stencil_only(format);
 460
 461       return format;
 462    }
 463
 464    /* If sRGB decoding is off, use the linear format */
 465    if (srgb_skip_decode)
 466       format = util_format_linear(format);
 467
 468    /* Use R8_UNORM for video formats */
 469    switch (format) {
 470    case PIPE_FORMAT_NV12:
 471    case PIPE_FORMAT_IYUV:
 472       format = PIPE_FORMAT_R8_UNORM;
 473       break;
 474    default:
 475       break;
 476    }
 477    return format;
 478 }
 479
 480
 481 static struct pipe_sampler_view *
 482 st_create_texture_sampler_view_from_stobj(struct st_context *st,
 483                                           struct st_texture_object *stObj,
 484                                           enum pipe_format format,
 485                                           bool glsl130_or_later)
 486 {
 487    /* There is no need to clear this structure (consider CPU overhead). */
 488    struct pipe_sampler_view templ;
 489    unsigned swizzle = get_texture_format_swizzle(st, stObj, glsl130_or_later);
 490
 491    templ.format = format;
 492
 493    if (stObj->level_override) {
 494       templ.u.tex.first_level = templ.u.tex.last_level = stObj->level_override;
 495    } else {
 496       templ.u.tex.first_level = stObj->base.MinLevel + stObj->base.BaseLevel;
 497       templ.u.tex.last_level = last_level(stObj);
 498    }
 499    if (stObj->layer_override) {
 500       templ.u.tex.first_layer = templ.u.tex.last_layer = stObj->layer_override;
 501    } else {
 502       templ.u.tex.first_layer = stObj->base.MinLayer;
 503       templ.u.tex.last_layer = last_layer(stObj);
 504    }
 505    assert(templ.u.tex.first_layer <= templ.u.tex.last_layer);
 506    assert(templ.u.tex.first_level <= templ.u.tex.last_level);
 507    templ.target = gl_target_to_pipe(stObj->base.Target);
 508
 509    templ.swizzle_r = GET_SWZ(swizzle, 0);
 510    templ.swizzle_g = GET_SWZ(swizzle, 1);
 511    templ.swizzle_b = GET_SWZ(swizzle, 2);
 512    templ.swizzle_a = GET_SWZ(swizzle, 3);
 513
 514    return st->pipe->create_sampler_view(st->pipe, stObj->pt, &templ);
 515 }
 516
 517
 518 struct pipe_sampler_view *
 519 st_get_texture_sampler_view_from_stobj(struct st_context *st,
 520                                        struct st_texture_object *stObj,
 521                                        const struct gl_sampler_object *samp,
 522                                        bool glsl130_or_later,
 523                                        bool ignore_srgb_decode)
 524 {
 525    const struct st_sampler_view *sv;
 526    bool srgb_skip_decode = false;
 527
 528    if (!ignore_srgb_decode && samp->sRGBDecode == GL_SKIP_DECODE_EXT)
 529       srgb_skip_decode = true;
 530
 531    sv = st_texture_get_current_sampler_view(st, stObj);
 532
 533    if (sv &&
 534        sv->glsl130_or_later == glsl130_or_later &&
 535        sv->srgb_skip_decode == srgb_skip_decode) {
 536       /* Debug check: make sure that the sampler view's parameters are
 537        * what they're supposed to be.
 538        */
 539       struct pipe_sampler_view *view = sv->view;
 540       assert(stObj->pt == view->texture);
 541       assert(!check_sampler_swizzle(st, stObj, view, glsl130_or_later));
 542       assert(get_sampler_view_format(st, stObj, srgb_skip_decode) == view->format);
 543       assert(gl_target_to_pipe(stObj->base.Target) == view->target);
 544       assert(stObj->level_override ||
 545              stObj->base.MinLevel + stObj->base.BaseLevel == view->u.tex.first_level);
 546       assert(stObj->level_override || last_level(stObj) == view->u.tex.last_level);
 547       assert(stObj->layer_override || stObj->base.MinLayer == view->u.tex.first_layer);
 548       assert(stObj->layer_override || last_layer(stObj) == view->u.tex.last_layer);
 549       assert(!stObj->layer_override ||
 550              (stObj->layer_override == view->u.tex.first_layer &&
 551               stObj->layer_override == view->u.tex.last_layer));
 552       return view;
 553    }
 554
 555    /* create new sampler view */
 556    enum pipe_format format = get_sampler_view_format(st, stObj,
 557                                                      srgb_skip_decode);
 558    struct pipe_sampler_view *view =
 559          st_create_texture_sampler_view_from_stobj(st, stObj, format,
 560                                                    glsl130_or_later);
 561
 562    view = st_texture_set_sampler_view(st, stObj, view,
 563                                       glsl130_or_later, srgb_skip_decode);
 564
 565    return view;
 566 }
 567
 568
 569 struct pipe_sampler_view *
 570 st_get_buffer_sampler_view_from_stobj(struct st_context *st,
 571                                       struct st_texture_object *stObj)
 572 {
 573    const struct st_sampler_view *sv;
 574    struct st_buffer_object *stBuf =
 575       st_buffer_object(stObj->base.BufferObject);
 576
 577    if (!stBuf || !stBuf->buffer)
 578       return NULL;
 579
 580    sv = st_texture_get_current_sampler_view(st, stObj);
 581
 582    struct pipe_resource *buf = stBuf->buffer;
 583
 584    if (sv) {
 585       struct pipe_sampler_view *view = sv->view;
 586
 587       if (view->texture == buf) {
 588          /* Debug check: make sure that the sampler view's parameters are
 589           * what they're supposed to be.
 590           */
 591          assert(st_mesa_format_to_pipe_format(st,
 592                                               stObj->base._BufferObjectFormat)
 593              == view->format);
 594          assert(view->target == PIPE_BUFFER);
 595          unsigned base = stObj->base.BufferOffset;
 596          MAYBE_UNUSED unsigned size = MIN2(buf->width0 - base,
 597                            (unsigned) stObj->base.BufferSize);
 598          assert(view->u.buf.offset == base);
 599          assert(view->u.buf.size == size);
 600          return view;
 601       }
 602    }
 603
 604    unsigned base = stObj->base.BufferOffset;
 605
 606    if (base >= buf->width0)
 607       return NULL;
 608
 609    unsigned size = buf->width0 - base;
 610    size = MIN2(size, (unsigned)stObj->base.BufferSize);
 611    if (!size)
 612       return NULL;
 613
 614    /* Create a new sampler view. There is no need to clear the entire
 615     * structure (consider CPU overhead).
 616     */
 617    struct pipe_sampler_view templ;
 618
 619    templ.format =
 620       st_mesa_format_to_pipe_format(st, stObj->base._BufferObjectFormat);
 621    templ.target = PIPE_BUFFER;
 622    templ.swizzle_r = PIPE_SWIZZLE_X;
 623    templ.swizzle_g = PIPE_SWIZZLE_Y;
 624    templ.swizzle_b = PIPE_SWIZZLE_Z;
 625    templ.swizzle_a = PIPE_SWIZZLE_W;
 626    templ.u.buf.offset = base;
 627    templ.u.buf.size = size;
 628
 629    struct pipe_sampler_view *view =
 630       st->pipe->create_sampler_view(st->pipe, buf, &templ);
 631
 632    view = st_texture_set_sampler_view(st, stObj, view, false, false);
 633
 634    return view;
 635 }