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/framebuffer.h"
  44 #include "main/renderbuffer.h"
  45 #include "st_texture.h"
  46
  47 #include "st_context.h"
  48 #include "st_format.h"
  49 #include "st_cb_fbo.h"
  50 #include "st_manager.h"
  51
  52 /* these functions are defined in st_context.c */
  53 struct st_context *
  54 st_create_context(struct pipe_context *pipe,
  55                   const __GLcontextModes *visual,
  56                   struct st_context *share);
  57 void st_destroy_context(struct st_context *st);
  58 void st_flush(struct st_context *st, uint pipeFlushFlags,
  59               struct pipe_fence_handle **fence);
  60
  61 /**
  62  * Cast wrapper to convert a GLframebuffer to an st_framebuffer.
  63  * Return NULL if the GLframebuffer is a user-created framebuffer.
  64  * We'll only return non-null for window system framebuffers.
  65  * Note that this function may fail.
  66  */
  67 static INLINE struct st_framebuffer *
  68 st_ws_framebuffer(GLframebuffer *fb)
  69 {
  70    /* FBO cannot be casted.  See st_new_framebuffer */
  71    return (struct st_framebuffer *) ((fb && !fb->Name) ? fb : NULL);
  72 }
  73
  74 /**
  75  * Map an attachment to a buffer index.
  76  */
  77 static INLINE gl_buffer_index
  78 attachment_to_buffer_index(enum st_attachment_type statt)
  79 {
  80    gl_buffer_index index;
  81
  82    switch (statt) {
  83    case ST_ATTACHMENT_FRONT_LEFT:
  84       index = BUFFER_FRONT_LEFT;
  85       break;
  86    case ST_ATTACHMENT_BACK_LEFT:
  87       index = BUFFER_BACK_LEFT;
  88       break;
  89    case ST_ATTACHMENT_FRONT_RIGHT:
  90       index = BUFFER_FRONT_RIGHT;
  91       break;
  92    case ST_ATTACHMENT_BACK_RIGHT:
  93       index = BUFFER_BACK_RIGHT;
  94       break;
  95    case ST_ATTACHMENT_DEPTH_STENCIL:
  96       index = BUFFER_DEPTH;
  97       break;
  98    case ST_ATTACHMENT_ACCUM:
  99       index = BUFFER_ACCUM;
 100       break;
 101    case ST_ATTACHMENT_SAMPLE:
 102    default:
 103       index = BUFFER_COUNT;
 104       break;
 105    }
 106
 107    return index;
 108 }
 109
 110 /**
 111  * Map a buffer index to an attachment.
 112  */
 113 static INLINE enum st_attachment_type
 114 buffer_index_to_attachment(gl_buffer_index index)
 115 {
 116    enum st_attachment_type statt;
 117
 118    switch (index) {
 119    case BUFFER_FRONT_LEFT:
 120       statt = ST_ATTACHMENT_FRONT_LEFT;
 121       break;
 122    case BUFFER_BACK_LEFT:
 123       statt = ST_ATTACHMENT_BACK_LEFT;
 124       break;
 125    case BUFFER_FRONT_RIGHT:
 126       statt = ST_ATTACHMENT_FRONT_RIGHT;
 127       break;
 128    case BUFFER_BACK_RIGHT:
 129       statt = ST_ATTACHMENT_BACK_RIGHT;
 130       break;
 131    case BUFFER_DEPTH:
 132       statt = ST_ATTACHMENT_DEPTH_STENCIL;
 133       break;
 134    case BUFFER_ACCUM:
 135       statt = ST_ATTACHMENT_ACCUM;
 136       break;
 137    default:
 138       statt = ST_ATTACHMENT_INVALID;
 139       break;
 140    }
 141
 142    return statt;
 143 }
 144
 145 /**
 146  * Validate a framebuffer to make sure up-to-date pipe_textures are used.
 147  */
 148 static void
 149 st_framebuffer_validate(struct st_framebuffer *stfb, struct st_context *st)
 150 {
 151    struct pipe_screen *screen = st->pipe->screen;
 152    struct pipe_texture *textures[ST_ATTACHMENT_COUNT];
 153    uint width, height;
 154    unsigned i;
 155    boolean changed = FALSE;
 156
 157    if (!p_atomic_read(&stfb->revalidate))
 158       return;
 159
 160    /* validate the fb */
 161    if (!stfb->iface->validate(stfb->iface, stfb->statts, stfb->num_statts, textures))
 162       return;
 163
 164    width = stfb->Base.Width;
 165    height = stfb->Base.Height;
 166
 167    for (i = 0; i < stfb->num_statts; i++) {
 168       struct st_renderbuffer *strb;
 169       struct pipe_surface *ps;
 170       gl_buffer_index idx;
 171
 172       if (!textures[i])
 173          continue;
 174
 175       idx = attachment_to_buffer_index(stfb->statts[i]);
 176       if (idx >= BUFFER_COUNT) {
 177          pipe_texture_reference(&textures[i], NULL);
 178          continue;
 179       }
 180
 181       strb = st_renderbuffer(stfb->Base.Attachment[idx].Renderbuffer);
 182       assert(strb);
 183       if (strb->texture == textures[i]) {
 184          pipe_texture_reference(&textures[i], NULL);
 185          continue;
 186       }
 187
 188       ps = screen->get_tex_surface(screen, textures[i], 0, 0, 0,
 189             PIPE_BUFFER_USAGE_GPU_READ | PIPE_BUFFER_USAGE_GPU_WRITE);
 190       if (ps) {
 191          pipe_surface_reference(&strb->surface, ps);
 192          pipe_texture_reference(&strb->texture, ps->texture);
 193          /* ownership transfered */
 194          pipe_surface_reference(&ps, NULL);
 195
 196          changed = TRUE;
 197
 198          strb->Base.Width = strb->surface->width;
 199          strb->Base.Height = strb->surface->height;
 200
 201          width = strb->Base.Width;
 202          height = strb->Base.Height;
 203       }
 204
 205       pipe_texture_reference(&textures[i], NULL);
 206    }
 207
 208    if (changed) {
 209       st->dirty.st |= ST_NEW_FRAMEBUFFER;
 210       _mesa_resize_framebuffer(st->ctx, &stfb->Base, width, height);
 211
 212       assert(stfb->Base.Width == width);
 213       assert(stfb->Base.Height == height);
 214    }
 215
 216    p_atomic_set(&stfb->revalidate, FALSE);
 217 }
 218
 219 /**
 220  * Update the attachments to validate by looping the existing renderbuffers.
 221  */
 222 static void
 223 st_framebuffer_update_attachments(struct st_framebuffer *stfb)
 224 {
 225    gl_buffer_index idx;
 226
 227    stfb->num_statts = 0;
 228    for (idx = 0; idx < BUFFER_COUNT; idx++) {
 229       struct st_renderbuffer *strb;
 230       enum st_attachment_type statt;
 231
 232       strb = st_renderbuffer(stfb->Base.Attachment[idx].Renderbuffer);
 233       if (!strb || strb->software)
 234          continue;
 235
 236       statt = buffer_index_to_attachment(idx);
 237       if (statt != ST_ATTACHMENT_INVALID &&
 238           st_visual_have_buffers(stfb->iface->visual, 1 << statt))
 239          stfb->statts[stfb->num_statts++] = statt;
 240    }
 241
 242    p_atomic_set(&stfb->revalidate, TRUE);
 243 }
 244
 245 /**
 246  * Add a renderbuffer to the framebuffer.
 247  */
 248 static boolean
 249 st_framebuffer_add_renderbuffer(struct st_framebuffer *stfb,
 250                                 gl_buffer_index idx)
 251 {
 252    struct gl_renderbuffer *rb;
 253    enum pipe_format format;
 254    int samples;
 255    boolean sw;
 256
 257    /* do not distinguish depth/stencil buffers */
 258    if (idx == BUFFER_STENCIL)
 259       idx = BUFFER_DEPTH;
 260
 261    switch (idx) {
 262    case BUFFER_DEPTH:
 263       format = stfb->iface->visual->depth_stencil_format;
 264       sw = FALSE;
 265       break;
 266    case BUFFER_ACCUM:
 267       format = stfb->iface->visual->accum_format;
 268       sw = TRUE;
 269       break;
 270    default:
 271       format = stfb->iface->visual->color_format;
 272       sw = FALSE;
 273       break;
 274    }
 275
 276    if (format == PIPE_FORMAT_NONE)
 277       return FALSE;
 278
 279    samples = stfb->iface->visual->samples;
 280    if (!samples)
 281       samples = st_get_msaa();
 282
 283    rb = st_new_renderbuffer_fb(format, samples, sw);
 284    if (!rb)
 285       return FALSE;
 286
 287    if (idx != BUFFER_DEPTH) {
 288       _mesa_add_renderbuffer(&stfb->Base, idx, rb);
 289    }
 290    else {
 291       if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0))
 292          _mesa_add_renderbuffer(&stfb->Base, BUFFER_DEPTH, rb);
 293       if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1))
 294          _mesa_add_renderbuffer(&stfb->Base, BUFFER_STENCIL, rb);
 295    }
 296
 297    return TRUE;
 298 }
 299
 300 /**
 301  * Intialize a __GLcontextModes from a visual.
 302  */
 303 static void
 304 st_visual_to_context_mode(const struct st_visual *visual,
 305                           __GLcontextModes *mode)
 306 {
 307    memset(mode, 0, sizeof(*mode));
 308
 309    if (st_visual_have_buffers(visual, ST_ATTACHMENT_BACK_LEFT_MASK))
 310       mode->doubleBufferMode = GL_TRUE;
 311    if (st_visual_have_buffers(visual,
 312             ST_ATTACHMENT_FRONT_RIGHT_MASK | ST_ATTACHMENT_BACK_RIGHT_MASK))
 313       mode->stereoMode = GL_TRUE;
 314
 315    if (visual->color_format != PIPE_FORMAT_NONE) {
 316       mode->rgbMode = GL_TRUE;
 317
 318       mode->redBits =
 319          util_format_get_component_bits(visual->color_format,
 320                UTIL_FORMAT_COLORSPACE_RGB, 0);
 321       mode->greenBits =
 322          util_format_get_component_bits(visual->color_format,
 323                UTIL_FORMAT_COLORSPACE_RGB, 1);
 324       mode->blueBits =
 325          util_format_get_component_bits(visual->color_format,
 326                UTIL_FORMAT_COLORSPACE_RGB, 2);
 327       mode->alphaBits =
 328          util_format_get_component_bits(visual->color_format,
 329                UTIL_FORMAT_COLORSPACE_RGB, 3);
 330
 331       mode->rgbBits = mode->redBits +
 332          mode->greenBits + mode->blueBits + mode->alphaBits;
 333    }
 334
 335    if (visual->depth_stencil_format != PIPE_FORMAT_NONE) {
 336       mode->haveDepthBuffer = GL_TRUE;
 337       mode->haveStencilBuffer = GL_TRUE;
 338
 339       mode->depthBits =
 340          util_format_get_component_bits(visual->depth_stencil_format,
 341                UTIL_FORMAT_COLORSPACE_ZS, 0);
 342       mode->stencilBits =
 343          util_format_get_component_bits(visual->depth_stencil_format,
 344                UTIL_FORMAT_COLORSPACE_ZS, 1);
 345    }
 346
 347    if (visual->accum_format != PIPE_FORMAT_NONE) {
 348       mode->haveAccumBuffer = GL_TRUE;
 349
 350       mode->accumRedBits =
 351          util_format_get_component_bits(visual->accum_format,
 352                UTIL_FORMAT_COLORSPACE_RGB, 0);
 353       mode->accumGreenBits =
 354          util_format_get_component_bits(visual->accum_format,
 355                UTIL_FORMAT_COLORSPACE_RGB, 1);
 356       mode->accumBlueBits =
 357          util_format_get_component_bits(visual->accum_format,
 358                UTIL_FORMAT_COLORSPACE_RGB, 2);
 359       mode->accumAlphaBits =
 360          util_format_get_component_bits(visual->accum_format,
 361                UTIL_FORMAT_COLORSPACE_RGB, 3);
 362    }
 363
 364    if (visual->samples) {
 365       mode->sampleBuffers = 1;
 366       mode->samples = visual->samples;
 367    }
 368 }
 369
 370 /**
 371  * Determine the default draw or read buffer from a visual.
 372  */
 373 static void
 374 st_visual_to_default_buffer(const struct st_visual *visual,
 375                             GLenum *buffer, GLint *index)
 376 {
 377    enum st_attachment_type statt;
 378    GLenum buf;
 379    gl_buffer_index idx;
 380
 381    statt = visual->render_buffer;
 382    /* do nothing if an invalid render buffer is specified */
 383    if (statt == ST_ATTACHMENT_INVALID ||
 384        !st_visual_have_buffers(visual, 1 << statt))
 385       return;
 386
 387    switch (statt) {
 388    case ST_ATTACHMENT_FRONT_LEFT:
 389       buf = GL_FRONT_LEFT;
 390       idx = BUFFER_FRONT_LEFT;
 391       break;
 392    case ST_ATTACHMENT_BACK_LEFT:
 393       buf = GL_BACK_LEFT;
 394       idx = BUFFER_BACK_LEFT;
 395       break;
 396    case ST_ATTACHMENT_FRONT_RIGHT:
 397       buf = GL_FRONT_RIGHT;
 398       idx = BUFFER_FRONT_RIGHT;
 399       break;
 400    case ST_ATTACHMENT_BACK_RIGHT:
 401       buf = GL_BACK_RIGHT;
 402       idx = BUFFER_BACK_RIGHT;
 403       break;
 404    default:
 405       buf = GL_NONE;
 406       idx = BUFFER_COUNT;
 407       break;
 408    }
 409
 410    if (buf != GL_NONE) {
 411       if (buffer)
 412          *buffer = buf;
 413       if (index)
 414          *index = idx;
 415    }
 416 }
 417
 418 /**
 419  * Create a framebuffer from a manager interface.
 420  */
 421 static struct st_framebuffer *
 422 st_framebuffer_create(struct st_framebuffer_iface *stfbi)
 423 {
 424    struct st_framebuffer *stfb;
 425    __GLcontextModes mode;
 426    gl_buffer_index idx;
 427
 428    stfb = CALLOC_STRUCT(st_framebuffer);
 429    if (!stfb)
 430       return NULL;
 431
 432    st_visual_to_context_mode(stfbi->visual, &mode);
 433    _mesa_initialize_window_framebuffer(&stfb->Base, &mode);
 434
 435    /* modify the draw/read buffers of the fb */
 436    st_visual_to_default_buffer(stfbi->visual, &stfb->Base.ColorDrawBuffer[0],
 437          &stfb->Base._ColorDrawBufferIndexes[0]);
 438    st_visual_to_default_buffer(stfbi->visual, &stfb->Base.ColorReadBuffer,
 439          &stfb->Base._ColorReadBufferIndex);
 440
 441    stfb->iface = stfbi;
 442
 443    /* add the color buffer */
 444    idx = stfb->Base._ColorDrawBufferIndexes[0];
 445    if (!st_framebuffer_add_renderbuffer(stfb, idx)) {
 446       FREE(stfb);
 447       return NULL;
 448    }
 449
 450    st_framebuffer_add_renderbuffer(stfb, BUFFER_DEPTH);
 451    st_framebuffer_add_renderbuffer(stfb, BUFFER_ACCUM);
 452
 453    st_framebuffer_update_attachments(stfb);
 454
 455    stfb->Base.Initialized = GL_TRUE;
 456
 457    return stfb;
 458 }
 459
 460 /**
 461  * Reference a framebuffer.
 462  */
 463 static void
 464 st_framebuffer_reference(struct st_framebuffer **ptr,
 465                          struct st_framebuffer *stfb)
 466 {
 467    GLframebuffer *fb = &stfb->Base;
 468    _mesa_reference_framebuffer((GLframebuffer **) ptr, fb);
 469 }
 470
 471 static void
 472 st_context_notify_invalid_framebuffer(struct st_context_iface *stctxi,
 473                                       struct st_framebuffer_iface *stfbi)
 474 {
 475    struct st_context *st = (struct st_context *) stctxi;
 476    struct st_framebuffer *stfb;
 477
 478    /* either draw or read winsys fb */
 479    stfb = st_ws_framebuffer(st->ctx->WinSysDrawBuffer);
 480    if (!stfb || stfb->iface != stfbi)
 481       stfb = st_ws_framebuffer(st->ctx->WinSysReadBuffer);
 482    assert(stfb && stfb->iface == stfbi);
 483
 484    p_atomic_set(&stfb->revalidate, TRUE);
 485 }
 486
 487 static void
 488 st_context_flush(struct st_context_iface *stctxi, unsigned flags,
 489                  struct pipe_fence_handle **fence)
 490 {
 491    struct st_context *st = (struct st_context *) stctxi;
 492    st_flush(st, flags, fence);
 493    if (flags & PIPE_FLUSH_RENDER_CACHE)
 494       st_manager_flush_frontbuffer(st);
 495 }
 496
 497 static boolean
 498 st_context_teximage(struct st_context_iface *stctxi, enum st_texture_type target,
 499                     int level, enum pipe_format internal_format,
 500                     struct pipe_texture *tex, boolean mipmap)
 501 {
 502    struct st_context *st = (struct st_context *) stctxi;
 503    GLcontext *ctx = st->ctx;
 504    struct gl_texture_unit *texUnit = _mesa_get_current_tex_unit(ctx);
 505    struct gl_texture_object *texObj;
 506    struct gl_texture_image *texImage;
 507    struct st_texture_object *stObj;
 508    struct st_texture_image *stImage;
 509    GLenum internalFormat;
 510
 511    switch (target) {
 512    case ST_TEXTURE_1D:
 513       target = GL_TEXTURE_1D;
 514       break;
 515    case ST_TEXTURE_2D:
 516       target = GL_TEXTURE_2D;
 517       break;
 518    case ST_TEXTURE_3D:
 519       target = GL_TEXTURE_3D;
 520       break;
 521    case ST_TEXTURE_RECT:
 522       target = GL_TEXTURE_RECTANGLE_ARB;
 523       break;
 524    default:
 525       return FALSE;
 526       break;
 527    }
 528
 529    if (util_format_get_component_bits(internal_format,
 530             UTIL_FORMAT_COLORSPACE_RGB, 3) > 0)
 531       internalFormat = GL_RGBA;
 532    else
 533       internalFormat = GL_RGB;
 534
 535    texObj = _mesa_select_tex_object(ctx, texUnit, target);
 536    _mesa_lock_texture(ctx, texObj);
 537
 538    stObj = st_texture_object(texObj);
 539    /* switch to surface based */
 540    if (!stObj->surface_based) {
 541       _mesa_clear_texture_object(ctx, texObj);
 542       stObj->surface_based = GL_TRUE;
 543    }
 544
 545    texImage = _mesa_get_tex_image(ctx, texObj, target, level);
 546    stImage = st_texture_image(texImage);
 547    if (tex) {
 548       _mesa_init_teximage_fields(ctx, target, texImage,
 549             tex->width0, tex->height0, 1, 0, internalFormat);
 550       texImage->TexFormat = st_ChooseTextureFormat(ctx, internalFormat,
 551             GL_RGBA, GL_UNSIGNED_BYTE);
 552       _mesa_set_fetch_functions(texImage, 2);
 553    }
 554    else {
 555       _mesa_clear_texture_image(ctx, texImage);
 556    }
 557
 558    stObj->pipe = st->pipe;
 559    pipe_texture_reference(&stImage->pt, tex);
 560
 561    _mesa_dirty_texobj(ctx, texObj, GL_TRUE);
 562    _mesa_unlock_texture(ctx, texObj);
 563
 564    return TRUE;
 565 }
 566
 567 static void
 568 st_context_destroy(struct st_context_iface *stctxi)
 569 {
 570    struct st_context *st = (struct st_context *) stctxi;
 571    st_destroy_context(st);
 572 }
 573
 574 static struct st_context_iface *
 575 st_api_create_context(struct st_api *stapi, struct st_manager *smapi,
 576                       const struct st_visual *visual,
 577                       struct st_context_iface *shared_stctxi)
 578 {
 579    struct st_context *shared_ctx = (struct st_context *) shared_stctxi;
 580    struct st_context *st;
 581    struct pipe_context *pipe;
 582    __GLcontextModes mode;
 583
 584    pipe = smapi->screen->context_create(smapi->screen, NULL);
 585    if (!pipe)
 586       return NULL;
 587
 588    st_visual_to_context_mode(visual, &mode);
 589    st = st_create_context(pipe, &mode, shared_ctx);
 590    if (!st) {
 591       pipe->destroy(pipe);
 592       return NULL;
 593    }
 594
 595    st->iface.destroy = st_context_destroy;
 596
 597    st->iface.notify_invalid_framebuffer =
 598       st_context_notify_invalid_framebuffer;
 599    st->iface.flush = st_context_flush;
 600
 601    st->iface.teximage = st_context_teximage;
 602    st->iface.copy = NULL;
 603
 604    st->iface.st_context_private = (void *) smapi;
 605
 606    return &st->iface;
 607 }
 608
 609 static boolean
 610 st_api_make_current(struct st_api *stapi, struct st_context_iface *stctxi,
 611                     struct st_framebuffer_iface *stdrawi,
 612                     struct st_framebuffer_iface *streadi)
 613 {
 614    struct st_context *st = (struct st_context *) stctxi;
 615    struct st_framebuffer *stdraw, *stread, *stfb;
 616    boolean ret;
 617
 618    _glapi_check_multithread();
 619
 620    if (st) {
 621       /* reuse/create the draw fb */
 622       stfb = st_ws_framebuffer(st->ctx->WinSysDrawBuffer);
 623       if (stfb && stfb->iface == stdrawi) {
 624          stdraw = NULL;
 625          st_framebuffer_reference(&stdraw, stfb);
 626       }
 627       else {
 628          stdraw = st_framebuffer_create(stdrawi);
 629       }
 630
 631       /* reuse/create the read fb */
 632       stfb = st_ws_framebuffer(st->ctx->WinSysReadBuffer);
 633       if (!stfb || stfb->iface != streadi)
 634          stfb = stdraw;
 635       if (stfb && stfb->iface == streadi) {
 636          stread = NULL;
 637          st_framebuffer_reference(&stread, stfb);
 638       }
 639       else {
 640          stread = st_framebuffer_create(streadi);
 641       }
 642
 643       if (stdraw && stread) {
 644          st_framebuffer_validate(stdraw, st);
 645          if (stread != stdraw)
 646             st_framebuffer_validate(stread, st);
 647
 648          /* modify the draw/read buffers of the context */
 649          st_visual_to_default_buffer(stdraw->iface->visual,
 650                &st->ctx->Color.DrawBuffer[0], NULL);
 651          st_visual_to_default_buffer(stread->iface->visual,
 652                &st->ctx->Pixel.ReadBuffer, NULL);
 653
 654          ret = _mesa_make_current(st->ctx, &stdraw->Base, &stread->Base);
 655       }
 656       else {
 657          ret = FALSE;
 658       }
 659
 660       st_framebuffer_reference(&stdraw, NULL);
 661       st_framebuffer_reference(&stread, NULL);
 662    }
 663    else {
 664       ret = _mesa_make_current(NULL, NULL, NULL);
 665    }
 666
 667    return ret;
 668 }
 669
 670 static struct st_context_iface *
 671 st_api_get_current(struct st_api *stapi)
 672 {
 673    GET_CURRENT_CONTEXT(ctx);
 674    struct st_context *st = (ctx) ? ctx->st : NULL;
 675
 676    return (st) ? &st->iface : NULL;
 677 }
 678
 679 static boolean
 680 st_api_is_visual_supported(struct st_api *stapi,
 681                            const struct st_visual *visual)
 682 {
 683    return TRUE;
 684 }
 685
 686 static st_proc_t
 687 st_api_get_proc_address(struct st_api *stapi, const char *procname)
 688 {
 689    return (st_proc_t) _glapi_get_proc_address(procname);
 690 }
 691
 692 static void
 693 st_api_destroy(struct st_api *stapi)
 694 {
 695    FREE(stapi);
 696 }
 697
 698 /**
 699  * Flush the front buffer if the current context renders to the front buffer.
 700  */
 701 void
 702 st_manager_flush_frontbuffer(struct st_context *st)
 703 {
 704    struct st_framebuffer *stfb = st_ws_framebuffer(st->ctx->DrawBuffer);
 705    struct st_renderbuffer *strb = NULL;
 706
 707    if (stfb)
 708       strb = st_renderbuffer(stfb->Base.Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
 709    if (!strb)
 710       return;
 711
 712    /* st_public.h */
 713    if (!stfb->iface) {
 714       struct pipe_surface *front_surf = strb->surface;
 715       st->pipe->screen->flush_frontbuffer(st->pipe->screen,
 716             front_surf, st->winsys_drawable_handle);
 717       return;
 718    }
 719
 720    stfb->iface->flush_front(stfb->iface, ST_ATTACHMENT_FRONT_LEFT);
 721 }
 722
 723 /**
 724  * Re-validate the framebuffers.
 725  */
 726 void
 727 st_manager_validate_framebuffers(struct st_context *st)
 728 {
 729    struct st_framebuffer *stdraw = st_ws_framebuffer(st->ctx->DrawBuffer);
 730    struct st_framebuffer *stread = st_ws_framebuffer(st->ctx->ReadBuffer);
 731
 732    /* st_public.h */
 733    if ((stdraw && !stdraw->iface) || (stread && !stread->iface)) {
 734       struct pipe_screen *screen = st->pipe->screen;
 735       if (screen->update_buffer)
 736          screen->update_buffer(screen, st->pipe->priv);
 737       return;
 738    }
 739
 740    if (stdraw)
 741       st_framebuffer_validate(stdraw, st);
 742    if (stread && stread != stdraw)
 743       st_framebuffer_validate(stread, st);
 744 }
 745
 746 /**
 747  * Add a color renderbuffer on demand.
 748  */
 749 boolean
 750 st_manager_add_color_renderbuffer(struct st_context *st, GLframebuffer *fb,
 751                                   gl_buffer_index idx)
 752 {
 753    struct st_framebuffer *stfb = st_ws_framebuffer(fb);
 754
 755    /* FBO or st_public.h */
 756    if (!stfb || !stfb->iface)
 757       return FALSE;
 758
 759    if (stfb->Base.Attachment[idx].Renderbuffer)
 760       return TRUE;
 761
 762    switch (idx) {
 763    case BUFFER_FRONT_LEFT:
 764    case BUFFER_BACK_LEFT:
 765    case BUFFER_FRONT_RIGHT:
 766    case BUFFER_BACK_RIGHT:
 767       break;
 768    default:
 769       return FALSE;
 770       break;
 771    }
 772
 773    if (!st_framebuffer_add_renderbuffer(stfb, idx))
 774       return FALSE;
 775
 776    st_framebuffer_update_attachments(stfb);
 777    st_invalidate_state(st->ctx, _NEW_BUFFERS);
 778
 779    return TRUE;
 780 }
 781
 782 /**
 783  * Create an st_api to manage the state tracker.
 784  */
 785 struct st_api *
 786 st_manager_create_api(void)
 787 {
 788    struct st_api *stapi;
 789
 790    stapi = CALLOC_STRUCT(st_api);
 791    if (stapi) {
 792       stapi->destroy = st_api_destroy;
 793       stapi->get_proc_address = st_api_get_proc_address;
 794       stapi->is_visual_supported = st_api_is_visual_supported;
 795
 796       stapi->create_context = st_api_create_context;
 797       stapi->make_current = st_api_make_current;
 798       stapi->get_current = st_api_get_current;
 799    }
 800
 801    return stapi;
 802 }