src/mesa/state_tracker/st_manager.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  7.9
   4  *
   5  * Copyright (C) 2010 LunarG Inc.
   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  * Authors:
  25  *    Chia-I Wu <olv@lunarg.com>
  26  */
  27
  28 #include "state_tracker/st_api.h"
  29
  30 #include "pipe/p_context.h"
  31 #include "pipe/p_screen.h"
  32 #include "util/u_format.h"
  33 #include "util/u_pointer.h"
  34 #include "util/u_inlines.h"
  35 #include "util/u_atomic.h"
  36
  37 #include "main/mtypes.h"
  38 #include "main/context.h"
  39 #include "main/texobj.h"
  40 #include "main/teximage.h"
  41 #include "main/texstate.h"
  42 #include "main/texfetch.h"
  43 #include "main/fbobject.h"
  44 #include "main/framebuffer.h"
  45 #include "main/renderbuffer.h"
  46 #include "st_texture.h"
  47
  48 #include "st_context.h"
  49 #include "st_format.h"
  50 #include "st_cb_fbo.h"
  51 #include "st_manager.h"
  52
  53 /* these functions are defined in st_context.c */
  54 struct st_context *
  55 st_create_context(struct pipe_context *pipe,
  56                   const __GLcontextModes *visual,
  57                   struct st_context *share);
  58 void st_destroy_context(struct st_context *st);
  59 void st_flush(struct st_context *st, uint pipeFlushFlags,
  60               struct pipe_fence_handle **fence);
  61
  62 /**
  63  * Note that this function may fail.
  64  */
  65 static INLINE struct st_framebuffer *
  66 st_framebuffer(GLframebuffer *fb)
  67 {
  68    /* FBO cannot be casted.  See st_new_framebuffer */
  69    return (struct st_framebuffer *) ((fb && !fb->Name) ? fb : NULL);
  70 }
  71
  72 /**
  73  * Map an attachment to a buffer index.
  74  */
  75 static INLINE gl_buffer_index
  76 attachment_to_buffer_index(enum st_attachment_type statt)
  77 {
  78    gl_buffer_index index;
  79
  80    switch (statt) {
  81    case ST_ATTACHMENT_FRONT_LEFT:
  82       index = BUFFER_FRONT_LEFT;
  83       break;
  84    case ST_ATTACHMENT_BACK_LEFT:
  85       index = BUFFER_BACK_LEFT;
  86       break;
  87    case ST_ATTACHMENT_FRONT_RIGHT:
  88       index = BUFFER_FRONT_RIGHT;
  89       break;
  90    case ST_ATTACHMENT_BACK_RIGHT:
  91       index = BUFFER_BACK_RIGHT;
  92       break;
  93    case ST_ATTACHMENT_DEPTH_STENCIL:
  94       index = BUFFER_DEPTH;
  95       break;
  96    case ST_ATTACHMENT_ACCUM:
  97       index = BUFFER_ACCUM;
  98       break;
  99    case ST_ATTACHMENT_SAMPLE:
 100    default:
 101       index = BUFFER_COUNT;
 102       break;
 103    }
 104
 105    return index;
 106 }
 107
 108 /**
 109  * Map a buffer index to an attachment.
 110  */
 111 static INLINE enum st_attachment_type
 112 buffer_index_to_attachment(gl_buffer_index index)
 113 {
 114    enum st_attachment_type statt;
 115
 116    switch (index) {
 117    case BUFFER_FRONT_LEFT:
 118       statt = ST_ATTACHMENT_FRONT_LEFT;
 119       break;
 120    case BUFFER_BACK_LEFT:
 121       statt = ST_ATTACHMENT_BACK_LEFT;
 122       break;
 123    case BUFFER_FRONT_RIGHT:
 124       statt = ST_ATTACHMENT_FRONT_RIGHT;
 125       break;
 126    case BUFFER_BACK_RIGHT:
 127       statt = ST_ATTACHMENT_BACK_RIGHT;
 128       break;
 129    case BUFFER_DEPTH:
 130       statt = ST_ATTACHMENT_DEPTH_STENCIL;
 131       break;
 132    case BUFFER_ACCUM:
 133       statt = ST_ATTACHMENT_ACCUM;
 134       break;
 135    default:
 136       statt = ST_ATTACHMENT_INVALID;
 137       break;
 138    }
 139
 140    return statt;
 141 }
 142
 143 /**
 144  * Validate a framebuffer to make sure up-to-date pipe_textures are used.
 145  */
 146 static void
 147 st_framebuffer_validate(struct st_framebuffer *stfb, struct st_context *st)
 148 {
 149    struct pipe_screen *screen = st->pipe->screen;
 150    struct pipe_texture *textures[ST_ATTACHMENT_COUNT];
 151    uint width, height;
 152    unsigned i;
 153    boolean changed = FALSE;
 154
 155    if (!p_atomic_read(&stfb->revalidate))
 156       return;
 157
 158    /* validate the fb */
 159    if (!stfb->iface->validate(stfb->iface, stfb->statts, stfb->num_statts, textures))
 160       return;
 161
 162    width = stfb->Base.Width;
 163    height = stfb->Base.Height;
 164
 165    for (i = 0; i < stfb->num_statts; i++) {
 166       struct st_renderbuffer *strb;
 167       struct pipe_surface *ps;
 168       gl_buffer_index idx;
 169
 170       if (!textures[i])
 171          continue;
 172
 173       idx = attachment_to_buffer_index(stfb->statts[i]);
 174       if (idx >= BUFFER_COUNT) {
 175          pipe_texture_reference(&textures[i], NULL);
 176          continue;
 177       }
 178
 179       strb = st_renderbuffer(stfb->Base.Attachment[idx].Renderbuffer);
 180       assert(strb);
 181       if (strb->texture == textures[i]) {
 182          pipe_texture_reference(&textures[i], NULL);
 183          continue;
 184       }
 185
 186       ps = screen->get_tex_surface(screen, textures[i], 0, 0, 0,
 187             PIPE_BUFFER_USAGE_GPU_READ | PIPE_BUFFER_USAGE_GPU_WRITE);
 188       if (ps) {
 189          pipe_surface_reference(&strb->surface, ps);
 190          pipe_texture_reference(&strb->texture, ps->texture);
 191          /* ownership transfered */
 192          pipe_surface_reference(&ps, NULL);
 193
 194          changed = TRUE;
 195
 196          strb->Base.Width = strb->surface->width;
 197          strb->Base.Height = strb->surface->height;
 198
 199          width = strb->Base.Width;
 200          height = strb->Base.Height;
 201       }
 202
 203       pipe_texture_reference(&textures[i], NULL);
 204    }
 205
 206    if (changed) {
 207       st->dirty.st |= ST_NEW_FRAMEBUFFER;
 208       _mesa_resize_framebuffer(st->ctx, &stfb->Base, width, height);
 209
 210       assert(stfb->Base.Width == width);
 211       assert(stfb->Base.Height == height);
 212    }
 213
 214    p_atomic_set(&stfb->revalidate, FALSE);
 215 }
 216
 217 /**
 218  * Update the attachments to validate by looping the existing renderbuffers.
 219  */
 220 static void
 221 st_framebuffer_update_attachments(struct st_framebuffer *stfb)
 222 {
 223    gl_buffer_index idx;
 224
 225    stfb->num_statts = 0;
 226    for (idx = 0; idx < BUFFER_COUNT; idx++) {
 227       struct st_renderbuffer *strb;
 228       enum st_attachment_type statt;
 229
 230       strb = st_renderbuffer(stfb->Base.Attachment[idx].Renderbuffer);
 231       if (!strb || strb->software)
 232          continue;
 233
 234       statt = buffer_index_to_attachment(idx);
 235       if (statt != ST_ATTACHMENT_INVALID &&
 236           st_visual_have_buffers(stfb->iface->visual, 1 << statt))
 237          stfb->statts[stfb->num_statts++] = statt;
 238    }
 239
 240    p_atomic_set(&stfb->revalidate, TRUE);
 241 }
 242
 243 /**
 244  * Add a renderbuffer to the framebuffer.
 245  */
 246 static boolean
 247 st_framebuffer_add_renderbuffer(struct st_framebuffer *stfb,
 248                                 gl_buffer_index idx)
 249 {
 250    struct gl_renderbuffer *rb;
 251    enum pipe_format format;
 252    int samples;
 253    boolean sw;
 254
 255    /* do not distinguish depth/stencil buffers */
 256    if (idx == BUFFER_STENCIL)
 257       idx = BUFFER_DEPTH;
 258
 259    switch (idx) {
 260    case BUFFER_DEPTH:
 261       format = stfb->iface->visual->depth_stencil_format;
 262       sw = FALSE;
 263       break;
 264    case BUFFER_ACCUM:
 265       format = stfb->iface->visual->accum_format;
 266       sw = TRUE;
 267       break;
 268    default:
 269       format = stfb->iface->visual->color_format;
 270       sw = FALSE;
 271       break;
 272    }
 273
 274    if (format == PIPE_FORMAT_NONE)
 275       return FALSE;
 276
 277    samples = stfb->iface->visual->samples;
 278    if (!samples)
 279       samples = st_get_msaa();
 280
 281    rb = st_new_renderbuffer_fb(format, samples, sw);
 282    if (!rb)
 283       return FALSE;
 284
 285    if (idx != BUFFER_DEPTH) {
 286       _mesa_add_renderbuffer(&stfb->Base, idx, rb);
 287    }
 288    else {
 289       if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0))
 290          _mesa_add_renderbuffer(&stfb->Base, BUFFER_DEPTH, rb);
 291       if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1))
 292          _mesa_add_renderbuffer(&stfb->Base, BUFFER_STENCIL, rb);
 293    }
 294
 295    return TRUE;
 296 }
 297
 298 /**
 299  * Intialize a __GLcontextModes from a visual.
 300  */
 301 static void
 302 st_visual_to_context_mode(const struct st_visual *visual,
 303                           __GLcontextModes *mode)
 304 {
 305    memset(mode, 0, sizeof(*mode));
 306
 307    if (st_visual_have_buffers(visual, ST_ATTACHMENT_BACK_LEFT_MASK))
 308       mode->doubleBufferMode = GL_TRUE;
 309    if (st_visual_have_buffers(visual,
 310             ST_ATTACHMENT_FRONT_RIGHT_MASK | ST_ATTACHMENT_BACK_RIGHT_MASK))
 311       mode->stereoMode = GL_TRUE;
 312
 313    if (visual->color_format != PIPE_FORMAT_NONE) {
 314       mode->rgbMode = GL_TRUE;
 315
 316       mode->redBits =
 317          util_format_get_component_bits(visual->color_format,
 318                UTIL_FORMAT_COLORSPACE_RGB, 0);
 319       mode->greenBits =
 320          util_format_get_component_bits(visual->color_format,
 321                UTIL_FORMAT_COLORSPACE_RGB, 1);
 322       mode->blueBits =
 323          util_format_get_component_bits(visual->color_format,
 324                UTIL_FORMAT_COLORSPACE_RGB, 2);
 325       mode->alphaBits =
 326          util_format_get_component_bits(visual->color_format,
 327                UTIL_FORMAT_COLORSPACE_RGB, 3);
 328
 329       mode->rgbBits = mode->redBits +
 330          mode->greenBits + mode->blueBits + mode->alphaBits;
 331    }
 332
 333    if (visual->depth_stencil_format != PIPE_FORMAT_NONE) {
 334       mode->haveDepthBuffer = GL_TRUE;
 335       mode->haveStencilBuffer = GL_TRUE;
 336
 337       mode->depthBits =
 338          util_format_get_component_bits(visual->depth_stencil_format,
 339                UTIL_FORMAT_COLORSPACE_ZS, 0);
 340       mode->stencilBits =
 341          util_format_get_component_bits(visual->depth_stencil_format,
 342                UTIL_FORMAT_COLORSPACE_ZS, 1);
 343    }
 344
 345    if (visual->accum_format != PIPE_FORMAT_NONE) {
 346       mode->haveAccumBuffer = GL_TRUE;
 347
 348       mode->accumRedBits =
 349          util_format_get_component_bits(visual->accum_format,
 350                UTIL_FORMAT_COLORSPACE_RGB, 0);
 351       mode->accumGreenBits =
 352          util_format_get_component_bits(visual->accum_format,
 353                UTIL_FORMAT_COLORSPACE_RGB, 1);
 354       mode->accumBlueBits =
 355          util_format_get_component_bits(visual->accum_format,
 356                UTIL_FORMAT_COLORSPACE_RGB, 2);
 357       mode->accumAlphaBits =
 358          util_format_get_component_bits(visual->accum_format,
 359                UTIL_FORMAT_COLORSPACE_RGB, 3);
 360    }
 361
 362    if (visual->samples) {
 363       mode->sampleBuffers = 1;
 364       mode->samples = visual->samples;
 365    }
 366 }
 367
 368 /**
 369  * Determine the default draw or read buffer from a visual.
 370  */
 371 static void
 372 st_visual_to_default_buffer(const struct st_visual *visual,
 373                             GLenum *buffer, GLint *index)
 374 {
 375    enum st_attachment_type statt;
 376    GLenum buf;
 377    gl_buffer_index idx;
 378
 379    statt = visual->render_buffer;
 380    /* do nothing if an invalid render buffer is specified */
 381    if (statt == ST_ATTACHMENT_INVALID ||
 382        !st_visual_have_buffers(visual, 1 << statt))
 383       return;
 384
 385    switch (statt) {
 386    case ST_ATTACHMENT_FRONT_LEFT:
 387       buf = GL_FRONT_LEFT;
 388       idx = BUFFER_FRONT_LEFT;
 389       break;
 390    case ST_ATTACHMENT_BACK_LEFT:
 391       buf = GL_BACK_LEFT;
 392       idx = BUFFER_BACK_LEFT;
 393       break;
 394    case ST_ATTACHMENT_FRONT_RIGHT:
 395       buf = GL_FRONT_RIGHT;
 396       idx = BUFFER_FRONT_RIGHT;
 397       break;
 398    case ST_ATTACHMENT_BACK_RIGHT:
 399       buf = GL_BACK_RIGHT;
 400       idx = BUFFER_BACK_RIGHT;
 401       break;
 402    default:
 403       buf = GL_NONE;
 404       idx = BUFFER_COUNT;
 405       break;
 406    }
 407
 408    if (buf != GL_NONE) {
 409       if (buffer)
 410          *buffer = buf;
 411       if (index)
 412          *index = idx;
 413    }
 414 }
 415
 416 /**
 417  * Create a framebuffer from a manager interface.
 418  */
 419 static struct st_framebuffer *
 420 st_framebuffer_create(struct st_framebuffer_iface *stfbi)
 421 {
 422    struct st_framebuffer *stfb;
 423    __GLcontextModes mode;
 424    gl_buffer_index idx;
 425
 426    stfb = CALLOC_STRUCT(st_framebuffer);
 427    if (!stfb)
 428       return NULL;
 429
 430    st_visual_to_context_mode(stfbi->visual, &mode);
 431    _mesa_initialize_window_framebuffer(&stfb->Base, &mode);
 432
 433    /* modify the draw/read buffers of the fb */
 434    st_visual_to_default_buffer(stfbi->visual, &stfb->Base.ColorDrawBuffer[0],
 435          &stfb->Base._ColorDrawBufferIndexes[0]);
 436    st_visual_to_default_buffer(stfbi->visual, &stfb->Base.ColorReadBuffer,
 437          &stfb->Base._ColorReadBufferIndex);
 438
 439    stfb->iface = stfbi;
 440
 441    /* add the color buffer */
 442    idx = stfb->Base._ColorDrawBufferIndexes[0];
 443    if (!st_framebuffer_add_renderbuffer(stfb, idx)) {
 444       FREE(stfb);
 445       return NULL;
 446    }
 447
 448    st_framebuffer_add_renderbuffer(stfb, BUFFER_DEPTH);
 449    st_framebuffer_add_renderbuffer(stfb, BUFFER_ACCUM);
 450
 451    st_framebuffer_update_attachments(stfb);
 452
 453    stfb->Base.Initialized = GL_TRUE;
 454
 455    return stfb;
 456 }
 457
 458 /**
 459  * Reference a framebuffer.
 460  */
 461 static void
 462 st_framebuffer_reference(struct st_framebuffer **ptr,
 463                          struct st_framebuffer *stfb)
 464 {
 465    GLframebuffer *fb = &stfb->Base;
 466    _mesa_reference_framebuffer((GLframebuffer **) ptr, fb);
 467 }
 468
 469 static void
 470 st_context_notify_invalid_framebuffer(struct st_context_iface *stctxi,
 471                                       struct st_framebuffer_iface *stfbi)
 472 {
 473    struct st_context *st = (struct st_context *) stctxi;
 474    struct st_framebuffer *stfb;
 475
 476    /* either draw or read winsys fb */
 477    stfb = st_framebuffer(st->ctx->WinSysDrawBuffer);
 478    if (!stfb || stfb->iface != stfbi)
 479       stfb = st_framebuffer(st->ctx->WinSysReadBuffer);
 480    assert(stfb && stfb->iface == stfbi);
 481
 482    p_atomic_set(&stfb->revalidate, TRUE);
 483 }
 484
 485 static void
 486 st_context_flush(struct st_context_iface *stctxi, unsigned flags,
 487                  struct pipe_fence_handle **fence)
 488 {
 489    struct st_context *st = (struct st_context *) stctxi;
 490    st_flush(st, flags, fence);
 491    if (flags & PIPE_FLUSH_RENDER_CACHE)
 492       st_manager_flush_frontbuffer(st);
 493 }
 494
 495 static boolean
 496 st_context_teximage(struct st_context_iface *stctxi, enum st_texture_type target,
 497                     int level, enum pipe_format internal_format,
 498                     struct pipe_texture *tex, boolean mipmap)
 499 {
 500    struct st_context *st = (struct st_context *) stctxi;
 501    GLcontext *ctx = st->ctx;
 502    struct gl_texture_unit *texUnit = _mesa_get_current_tex_unit(ctx);
 503    struct gl_texture_object *texObj;
 504    struct gl_texture_image *texImage;
 505    struct st_texture_object *stObj;
 506    struct st_texture_image *stImage;
 507    GLenum internalFormat;
 508
 509    switch (target) {
 510    case ST_TEXTURE_1D:
 511       target = GL_TEXTURE_1D;
 512       break;
 513    case ST_TEXTURE_2D:
 514       target = GL_TEXTURE_2D;
 515       break;
 516    case ST_TEXTURE_3D:
 517       target = GL_TEXTURE_3D;
 518       break;
 519    case ST_TEXTURE_RECT:
 520       target = GL_TEXTURE_RECTANGLE_ARB;
 521       break;
 522    default:
 523       return FALSE;
 524       break;
 525    }
 526
 527    if (util_format_get_component_bits(internal_format,
 528             UTIL_FORMAT_COLORSPACE_RGB, 3) > 0)
 529       internalFormat = GL_RGBA;
 530    else
 531       internalFormat = GL_RGB;
 532
 533    texObj = _mesa_select_tex_object(ctx, texUnit, target);
 534    _mesa_lock_texture(ctx, texObj);
 535
 536    stObj = st_texture_object(texObj);
 537    /* switch to surface based */
 538    if (!stObj->surface_based) {
 539       _mesa_clear_texture_object(ctx, texObj);
 540       stObj->surface_based = GL_TRUE;
 541    }
 542
 543    texImage = _mesa_get_tex_image(ctx, texObj, target, level);
 544    stImage = st_texture_image(texImage);
 545    if (tex) {
 546       _mesa_init_teximage_fields(ctx, target, texImage,
 547             tex->width0, tex->height0, 1, 0, internalFormat);
 548       texImage->TexFormat = st_ChooseTextureFormat(ctx, internalFormat,
 549             GL_RGBA, GL_UNSIGNED_BYTE);
 550       _mesa_set_fetch_functions(texImage, 2);
 551    }
 552    else {
 553       _mesa_clear_texture_image(ctx, texImage);
 554    }
 555
 556    stObj->pipe = st->pipe;
 557    pipe_texture_reference(&stImage->pt, tex);
 558
 559    _mesa_dirty_texobj(ctx, texObj, GL_TRUE);
 560    _mesa_unlock_texture(ctx, texObj);
 561
 562    return TRUE;
 563 }
 564
 565 static void
 566 st_context_destroy(struct st_context_iface *stctxi)
 567 {
 568    struct st_context *st = (struct st_context *) stctxi;
 569    st_destroy_context(st);
 570 }
 571
 572 static struct st_context_iface *
 573 st_api_create_context(struct st_api *stapi, struct st_manager *smapi,
 574                       const struct st_visual *visual,
 575                       struct st_context_iface *shared_stctxi)
 576 {
 577    struct st_context *shared_ctx = (struct st_context *) shared_stctxi;
 578    struct st_context *st;
 579    struct pipe_context *pipe;
 580    __GLcontextModes mode;
 581
 582    pipe = smapi->screen->context_create(smapi->screen, NULL);
 583    if (!pipe)
 584       return NULL;
 585
 586    st_visual_to_context_mode(visual, &mode);
 587    st = st_create_context(pipe, &mode, shared_ctx);
 588    if (!st) {
 589       pipe->destroy(pipe);
 590       return NULL;
 591    }
 592
 593    st->iface.destroy = st_context_destroy;
 594
 595    st->iface.notify_invalid_framebuffer =
 596       st_context_notify_invalid_framebuffer;
 597    st->iface.flush = st_context_flush;
 598
 599    st->iface.teximage = st_context_teximage;
 600    st->iface.copy = NULL;
 601
 602    st->iface.st_context_private = (void *) smapi;
 603
 604    return &st->iface;
 605 }
 606
 607 static boolean
 608 st_api_make_current(struct st_api *stapi, struct st_context_iface *stctxi,
 609                     struct st_framebuffer_iface *stdrawi,
 610                     struct st_framebuffer_iface *streadi)
 611 {
 612    struct st_context *st = (struct st_context *) stctxi;
 613    struct st_framebuffer *stdraw, *stread, *stfb;
 614    boolean ret;
 615
 616    _glapi_check_multithread();
 617
 618    if (st) {
 619       /* reuse/create the draw fb */
 620       stfb = st_framebuffer(st->ctx->WinSysDrawBuffer);
 621       if (stfb && stfb->iface == stdrawi) {
 622          stdraw = NULL;
 623          st_framebuffer_reference(&stdraw, stfb);
 624       }
 625       else {
 626          stdraw = st_framebuffer_create(stdrawi);
 627       }
 628
 629       /* reuse/create the read fb */
 630       stfb = st_framebuffer(st->ctx->WinSysReadBuffer);
 631       if (!stfb || stfb->iface != streadi)
 632          stfb = stdraw;
 633       if (stfb && stfb->iface == streadi) {
 634          stread = NULL;
 635          st_framebuffer_reference(&stread, stfb);
 636       }
 637       else {
 638          stread = st_framebuffer_create(streadi);
 639       }
 640
 641       if (stdraw && stread) {
 642          st_framebuffer_validate(stdraw, st);
 643          if (stread != stdraw)
 644             st_framebuffer_validate(stread, st);
 645
 646          /* modify the draw/read buffers of the context */
 647          st_visual_to_default_buffer(stdraw->iface->visual,
 648                &st->ctx->Color.DrawBuffer[0], NULL);
 649          st_visual_to_default_buffer(stread->iface->visual,
 650                &st->ctx->Pixel.ReadBuffer, NULL);
 651
 652          ret = _mesa_make_current(st->ctx, &stdraw->Base, &stread->Base);
 653       }
 654       else {
 655          ret = FALSE;
 656       }
 657
 658       st_framebuffer_reference(&stdraw, NULL);
 659       st_framebuffer_reference(&stread, NULL);
 660    }
 661    else {
 662       ret = _mesa_make_current(NULL, NULL, NULL);
 663    }
 664
 665    return ret;
 666 }
 667
 668 static struct st_context_iface *
 669 st_api_get_current(struct st_api *stapi)
 670 {
 671    GET_CURRENT_CONTEXT(ctx);
 672    struct st_context *st = (ctx) ? ctx->st : NULL;
 673
 674    return (st) ? &st->iface : NULL;
 675 }
 676
 677 static boolean
 678 st_api_is_visual_supported(struct st_api *stapi,
 679                            const struct st_visual *visual)
 680 {
 681    return TRUE;
 682 }
 683
 684 static st_proc_t
 685 st_api_get_proc_address(struct st_api *stapi, const char *procname)
 686 {
 687    return (st_proc_t) _glapi_get_proc_address(procname);
 688 }
 689
 690 static void
 691 st_api_destroy(struct st_api *stapi)
 692 {
 693    FREE(stapi);
 694 }
 695
 696 /**
 697  * Flush the front buffer if the current context renders to the front buffer.
 698  */
 699 void
 700 st_manager_flush_frontbuffer(struct st_context *st)
 701 {
 702    struct st_framebuffer *stfb = st_framebuffer(st->ctx->DrawBuffer);
 703    struct st_renderbuffer *strb = NULL;
 704
 705    if (stfb)
 706       strb = st_renderbuffer(stfb->Base.Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
 707    if (!strb)
 708       return;
 709
 710    /* st_public.h */
 711    if (!stfb->iface) {
 712       struct pipe_surface *front_surf = strb->surface;
 713       st->pipe->screen->flush_frontbuffer(st->pipe->screen,
 714             front_surf, st->winsys_drawable_handle);
 715       return;
 716    }
 717
 718    stfb->iface->flush_front(stfb->iface, ST_ATTACHMENT_FRONT_LEFT);
 719 }
 720
 721 /**
 722  * Re-validate the framebuffers.
 723  */
 724 void
 725 st_manager_validate_framebuffers(struct st_context *st)
 726 {
 727    struct st_framebuffer *stdraw = st_framebuffer(st->ctx->DrawBuffer);
 728    struct st_framebuffer *stread = st_framebuffer(st->ctx->ReadBuffer);
 729
 730    /* st_public.h */
 731    if ((stdraw && !stdraw->iface) || (stread && !stread->iface)) {
 732       struct pipe_screen *screen = st->pipe->screen;
 733       if (screen->update_buffer)
 734          screen->update_buffer(screen, st->pipe->priv);
 735       return;
 736    }
 737
 738    if (stdraw)
 739       st_framebuffer_validate(stdraw, st);
 740    if (stread && stread != stdraw)
 741       st_framebuffer_validate(stread, st);
 742 }
 743
 744 /**
 745  * Add a color renderbuffer on demand.
 746  */
 747 boolean
 748 st_manager_add_color_renderbuffer(struct st_context *st, GLframebuffer *fb,
 749                                   gl_buffer_index idx)
 750 {
 751    struct st_framebuffer *stfb = st_framebuffer(fb);
 752
 753    /* FBO or st_public.h */
 754    if (!stfb || !stfb->iface)
 755       return FALSE;
 756
 757    if (stfb->Base.Attachment[idx].Renderbuffer)
 758       return TRUE;
 759
 760    switch (idx) {
 761    case BUFFER_FRONT_LEFT:
 762    case BUFFER_BACK_LEFT:
 763    case BUFFER_FRONT_RIGHT:
 764    case BUFFER_BACK_RIGHT:
 765       break;
 766    default:
 767       return FALSE;
 768       break;
 769    }
 770
 771    if (!st_framebuffer_add_renderbuffer(stfb, idx))
 772       return FALSE;
 773
 774    st_framebuffer_update_attachments(stfb);
 775    st_invalidate_state(st->ctx, _NEW_BUFFERS);
 776
 777    return TRUE;
 778 }
 779
 780 /**
 781  * Create an st_api to manage the state tracker.
 782  */
 783 struct st_api *
 784 st_manager_create_api(void)
 785 {
 786    struct st_api *stapi;
 787
 788    stapi = CALLOC_STRUCT(st_api);
 789    if (stapi) {
 790       stapi->destroy = st_api_destroy;
 791       stapi->get_proc_address = st_api_get_proc_address;
 792       stapi->is_visual_supported = st_api_is_visual_supported;
 793
 794       stapi->create_context = st_api_create_context;
 795       stapi->make_current = st_api_make_current;
 796       stapi->get_current = st_api_get_current;
 797    }
 798
 799    return stapi;
 800 }