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 OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  20  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  22  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  23  * DEALINGS IN THE SOFTWARE.
  24  *
  25  * Authors:
  26  *    Chia-I Wu <olv@lunarg.com>
  27  */
  28
  29 #include "state_tracker/st_gl_api.h"
  30
  31 #include "pipe/p_context.h"
  32 #include "pipe/p_screen.h"
  33 #include "util/u_format.h"
  34 #include "util/u_pointer.h"
  35 #include "util/u_inlines.h"
  36 #include "util/u_atomic.h"
  37
  38 #include "main/mtypes.h"
  39 #include "main/context.h"
  40 #include "main/texobj.h"
  41 #include "main/teximage.h"
  42 #include "main/texstate.h"
  43 #include "main/texfetch.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  * Cast wrapper to convert a GLframebuffer to an st_framebuffer.
  64  * Return NULL if the GLframebuffer is a user-created framebuffer.
  65  * We'll only return non-null for window system framebuffers.
  66  * Note that this function may fail.
  67  */
  68 static INLINE struct st_framebuffer *
  69 st_ws_framebuffer(GLframebuffer *fb)
  70 {
  71    /* FBO cannot be casted.  See st_new_framebuffer */
  72    return (struct st_framebuffer *) ((fb && !fb->Name) ? fb : NULL);
  73 }
  74
  75 /**
  76  * Map an attachment to a buffer index.
  77  */
  78 static INLINE gl_buffer_index
  79 attachment_to_buffer_index(enum st_attachment_type statt)
  80 {
  81    gl_buffer_index index;
  82
  83    switch (statt) {
  84    case ST_ATTACHMENT_FRONT_LEFT:
  85       index = BUFFER_FRONT_LEFT;
  86       break;
  87    case ST_ATTACHMENT_BACK_LEFT:
  88       index = BUFFER_BACK_LEFT;
  89       break;
  90    case ST_ATTACHMENT_FRONT_RIGHT:
  91       index = BUFFER_FRONT_RIGHT;
  92       break;
  93    case ST_ATTACHMENT_BACK_RIGHT:
  94       index = BUFFER_BACK_RIGHT;
  95       break;
  96    case ST_ATTACHMENT_DEPTH_STENCIL:
  97       index = BUFFER_DEPTH;
  98       break;
  99    case ST_ATTACHMENT_ACCUM:
 100       index = BUFFER_ACCUM;
 101       break;
 102    case ST_ATTACHMENT_SAMPLE:
 103    default:
 104       index = BUFFER_COUNT;
 105       break;
 106    }
 107
 108    return index;
 109 }
 110
 111 /**
 112  * Map a buffer index to an attachment.
 113  */
 114 static INLINE enum st_attachment_type
 115 buffer_index_to_attachment(gl_buffer_index index)
 116 {
 117    enum st_attachment_type statt;
 118
 119    switch (index) {
 120    case BUFFER_FRONT_LEFT:
 121       statt = ST_ATTACHMENT_FRONT_LEFT;
 122       break;
 123    case BUFFER_BACK_LEFT:
 124       statt = ST_ATTACHMENT_BACK_LEFT;
 125       break;
 126    case BUFFER_FRONT_RIGHT:
 127       statt = ST_ATTACHMENT_FRONT_RIGHT;
 128       break;
 129    case BUFFER_BACK_RIGHT:
 130       statt = ST_ATTACHMENT_BACK_RIGHT;
 131       break;
 132    case BUFFER_DEPTH:
 133       statt = ST_ATTACHMENT_DEPTH_STENCIL;
 134       break;
 135    case BUFFER_ACCUM:
 136       statt = ST_ATTACHMENT_ACCUM;
 137       break;
 138    default:
 139       statt = ST_ATTACHMENT_INVALID;
 140       break;
 141    }
 142
 143    return statt;
 144 }
 145
 146 /**
 147  * Validate a framebuffer to make sure up-to-date pipe_textures are used.
 148  */
 149 static void
 150 st_framebuffer_validate(struct st_framebuffer *stfb, struct st_context *st)
 151 {
 152    struct pipe_screen *screen = st->pipe->screen;
 153    struct pipe_resource *textures[ST_ATTACHMENT_COUNT];
 154    uint width, height;
 155    unsigned i;
 156    boolean changed = FALSE;
 157
 158    if (!p_atomic_read(&stfb->revalidate))
 159       return;
 160
 161    /* validate the fb */
 162    if (!stfb->iface->validate(stfb->iface, stfb->statts, stfb->num_statts, textures))
 163       return;
 164
 165    width = stfb->Base.Width;
 166    height = stfb->Base.Height;
 167
 168    for (i = 0; i < stfb->num_statts; i++) {
 169       struct st_renderbuffer *strb;
 170       struct pipe_surface *ps;
 171       gl_buffer_index idx;
 172
 173       if (!textures[i])
 174          continue;
 175
 176       idx = attachment_to_buffer_index(stfb->statts[i]);
 177       if (idx >= BUFFER_COUNT) {
 178          pipe_resource_reference(&textures[i], NULL);
 179          continue;
 180       }
 181
 182       strb = st_renderbuffer(stfb->Base.Attachment[idx].Renderbuffer);
 183       assert(strb);
 184       if (strb->texture == textures[i]) {
 185          pipe_resource_reference(&textures[i], NULL);
 186          continue;
 187       }
 188
 189       ps = screen->get_tex_surface(screen, textures[i], 0, 0, 0,
 190                                    PIPE_BIND_RENDER_TARGET);
 191       if (ps) {
 192          pipe_surface_reference(&strb->surface, ps);
 193          pipe_resource_reference(&strb->texture, ps->texture);
 194          /* ownership transfered */
 195          pipe_surface_reference(&ps, NULL);
 196
 197          changed = TRUE;
 198
 199          strb->Base.Width = strb->surface->width;
 200          strb->Base.Height = strb->surface->height;
 201
 202          width = strb->Base.Width;
 203          height = strb->Base.Height;
 204       }
 205
 206       pipe_resource_reference(&textures[i], NULL);
 207    }
 208
 209    if (changed) {
 210       st->dirty.st |= ST_NEW_FRAMEBUFFER;
 211       _mesa_resize_framebuffer(st->ctx, &stfb->Base, width, height);
 212
 213       assert(stfb->Base.Width == width);
 214       assert(stfb->Base.Height == height);
 215    }
 216
 217    p_atomic_set(&stfb->revalidate, FALSE);
 218 }
 219
 220 /**
 221  * Update the attachments to validate by looping the existing renderbuffers.
 222  */
 223 static void
 224 st_framebuffer_update_attachments(struct st_framebuffer *stfb)
 225 {
 226    gl_buffer_index idx;
 227
 228    stfb->num_statts = 0;
 229    for (idx = 0; idx < BUFFER_COUNT; idx++) {
 230       struct st_renderbuffer *strb;
 231       enum st_attachment_type statt;
 232
 233       strb = st_renderbuffer(stfb->Base.Attachment[idx].Renderbuffer);
 234       if (!strb || strb->software)
 235          continue;
 236
 237       statt = buffer_index_to_attachment(idx);
 238       if (statt != ST_ATTACHMENT_INVALID &&
 239           st_visual_have_buffers(stfb->iface->visual, 1 << statt))
 240          stfb->statts[stfb->num_statts++] = statt;
 241    }
 242
 243    p_atomic_set(&stfb->revalidate, TRUE);
 244 }
 245
 246 /**
 247  * Add a renderbuffer to the framebuffer.
 248  */
 249 static boolean
 250 st_framebuffer_add_renderbuffer(struct st_framebuffer *stfb,
 251                                 gl_buffer_index idx)
 252 {
 253    struct gl_renderbuffer *rb;
 254    enum pipe_format format;
 255    int samples;
 256    boolean sw;
 257
 258    /* do not distinguish depth/stencil buffers */
 259    if (idx == BUFFER_STENCIL)
 260       idx = BUFFER_DEPTH;
 261
 262    switch (idx) {
 263    case BUFFER_DEPTH:
 264       format = stfb->iface->visual->depth_stencil_format;
 265       sw = FALSE;
 266       break;
 267    case BUFFER_ACCUM:
 268       format = stfb->iface->visual->accum_format;
 269       sw = TRUE;
 270       break;
 271    default:
 272       format = stfb->iface->visual->color_format;
 273       sw = FALSE;
 274       break;
 275    }
 276
 277    if (format == PIPE_FORMAT_NONE)
 278       return FALSE;
 279
 280    samples = stfb->iface->visual->samples;
 281    if (!samples)
 282       samples = st_get_msaa();
 283
 284    rb = st_new_renderbuffer_fb(format, samples, sw);
 285    if (!rb)
 286       return FALSE;
 287
 288    if (idx != BUFFER_DEPTH) {
 289       _mesa_add_renderbuffer(&stfb->Base, idx, rb);
 290    }
 291    else {
 292       if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 0))
 293          _mesa_add_renderbuffer(&stfb->Base, BUFFER_DEPTH, rb);
 294       if (util_format_get_component_bits(format, UTIL_FORMAT_COLORSPACE_ZS, 1))
 295          _mesa_add_renderbuffer(&stfb->Base, BUFFER_STENCIL, rb);
 296    }
 297
 298    return TRUE;
 299 }
 300
 301 /**
 302  * Intialize a __GLcontextModes from a visual.
 303  */
 304 static void
 305 st_visual_to_context_mode(const struct st_visual *visual,
 306                           __GLcontextModes *mode)
 307 {
 308    memset(mode, 0, sizeof(*mode));
 309
 310    if (st_visual_have_buffers(visual, ST_ATTACHMENT_BACK_LEFT_MASK))
 311       mode->doubleBufferMode = GL_TRUE;
 312    if (st_visual_have_buffers(visual,
 313             ST_ATTACHMENT_FRONT_RIGHT_MASK | ST_ATTACHMENT_BACK_RIGHT_MASK))
 314       mode->stereoMode = GL_TRUE;
 315
 316    if (visual->color_format != PIPE_FORMAT_NONE) {
 317       mode->rgbMode = GL_TRUE;
 318
 319       mode->redBits =
 320          util_format_get_component_bits(visual->color_format,
 321                UTIL_FORMAT_COLORSPACE_RGB, 0);
 322       mode->greenBits =
 323          util_format_get_component_bits(visual->color_format,
 324                UTIL_FORMAT_COLORSPACE_RGB, 1);
 325       mode->blueBits =
 326          util_format_get_component_bits(visual->color_format,
 327                UTIL_FORMAT_COLORSPACE_RGB, 2);
 328       mode->alphaBits =
 329          util_format_get_component_bits(visual->color_format,
 330                UTIL_FORMAT_COLORSPACE_RGB, 3);
 331
 332       mode->rgbBits = mode->redBits +
 333          mode->greenBits + mode->blueBits + mode->alphaBits;
 334    }
 335
 336    if (visual->depth_stencil_format != PIPE_FORMAT_NONE) {
 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       mode->haveDepthBuffer = mode->depthBits > 0;
 345       mode->haveStencilBuffer = mode->stencilBits > 0;
 346    }
 347
 348    if (visual->accum_format != PIPE_FORMAT_NONE) {
 349       mode->haveAccumBuffer = GL_TRUE;
 350
 351       mode->accumRedBits =
 352          util_format_get_component_bits(visual->accum_format,
 353                UTIL_FORMAT_COLORSPACE_RGB, 0);
 354       mode->accumGreenBits =
 355          util_format_get_component_bits(visual->accum_format,
 356                UTIL_FORMAT_COLORSPACE_RGB, 1);
 357       mode->accumBlueBits =
 358          util_format_get_component_bits(visual->accum_format,
 359                UTIL_FORMAT_COLORSPACE_RGB, 2);
 360       mode->accumAlphaBits =
 361          util_format_get_component_bits(visual->accum_format,
 362                UTIL_FORMAT_COLORSPACE_RGB, 3);
 363    }
 364
 365    if (visual->samples) {
 366       mode->sampleBuffers = 1;
 367       mode->samples = visual->samples;
 368    }
 369 }
 370
 371 /**
 372  * Determine the default draw or read buffer from a visual.
 373  */
 374 static void
 375 st_visual_to_default_buffer(const struct st_visual *visual,
 376                             GLenum *buffer, GLint *index)
 377 {
 378    enum st_attachment_type statt;
 379    GLenum buf;
 380    gl_buffer_index idx;
 381
 382    statt = visual->render_buffer;
 383    /* do nothing if an invalid render buffer is specified */
 384    if (statt == ST_ATTACHMENT_INVALID ||
 385        !st_visual_have_buffers(visual, 1 << statt))
 386       return;
 387
 388    switch (statt) {
 389    case ST_ATTACHMENT_FRONT_LEFT:
 390       buf = GL_FRONT_LEFT;
 391       idx = BUFFER_FRONT_LEFT;
 392       break;
 393    case ST_ATTACHMENT_BACK_LEFT:
 394       buf = GL_BACK_LEFT;
 395       idx = BUFFER_BACK_LEFT;
 396       break;
 397    case ST_ATTACHMENT_FRONT_RIGHT:
 398       buf = GL_FRONT_RIGHT;
 399       idx = BUFFER_FRONT_RIGHT;
 400       break;
 401    case ST_ATTACHMENT_BACK_RIGHT:
 402       buf = GL_BACK_RIGHT;
 403       idx = BUFFER_BACK_RIGHT;
 404       break;
 405    default:
 406       buf = GL_NONE;
 407       idx = BUFFER_COUNT;
 408       break;
 409    }
 410
 411    if (buf != GL_NONE) {
 412       if (buffer)
 413          *buffer = buf;
 414       if (index)
 415          *index = idx;
 416    }
 417 }
 418
 419 /**
 420  * Create a framebuffer from a manager interface.
 421  */
 422 static struct st_framebuffer *
 423 st_framebuffer_create(struct st_framebuffer_iface *stfbi)
 424 {
 425    struct st_framebuffer *stfb;
 426    __GLcontextModes mode;
 427    gl_buffer_index idx;
 428
 429    stfb = CALLOC_STRUCT(st_framebuffer);
 430    if (!stfb)
 431       return NULL;
 432
 433    st_visual_to_context_mode(stfbi->visual, &mode);
 434    _mesa_initialize_window_framebuffer(&stfb->Base, &mode);
 435
 436    /* modify the draw/read buffers of the fb */
 437    st_visual_to_default_buffer(stfbi->visual, &stfb->Base.ColorDrawBuffer[0],
 438          &stfb->Base._ColorDrawBufferIndexes[0]);
 439    st_visual_to_default_buffer(stfbi->visual, &stfb->Base.ColorReadBuffer,
 440          &stfb->Base._ColorReadBufferIndex);
 441
 442    stfb->iface = stfbi;
 443
 444    /* add the color buffer */
 445    idx = stfb->Base._ColorDrawBufferIndexes[0];
 446    if (!st_framebuffer_add_renderbuffer(stfb, idx)) {
 447       FREE(stfb);
 448       return NULL;
 449    }
 450
 451    st_framebuffer_add_renderbuffer(stfb, BUFFER_DEPTH);
 452    st_framebuffer_add_renderbuffer(stfb, BUFFER_ACCUM);
 453
 454    st_framebuffer_update_attachments(stfb);
 455
 456    stfb->Base.Initialized = GL_TRUE;
 457
 458    return stfb;
 459 }
 460
 461 /**
 462  * Reference a framebuffer.
 463  */
 464 static void
 465 st_framebuffer_reference(struct st_framebuffer **ptr,
 466                          struct st_framebuffer *stfb)
 467 {
 468    GLframebuffer *fb = &stfb->Base;
 469    _mesa_reference_framebuffer((GLframebuffer **) ptr, fb);
 470 }
 471
 472 static void
 473 st_context_notify_invalid_framebuffer(struct st_context_iface *stctxi,
 474                                       struct st_framebuffer_iface *stfbi)
 475 {
 476    struct st_context *st = (struct st_context *) stctxi;
 477    struct st_framebuffer *stfb;
 478
 479    /* either draw or read winsys fb */
 480    stfb = st_ws_framebuffer(st->ctx->WinSysDrawBuffer);
 481    if (!stfb || stfb->iface != stfbi)
 482       stfb = st_ws_framebuffer(st->ctx->WinSysReadBuffer);
 483    assert(stfb && stfb->iface == stfbi);
 484
 485    p_atomic_set(&stfb->revalidate, TRUE);
 486 }
 487
 488 static void
 489 st_context_flush(struct st_context_iface *stctxi, unsigned flags,
 490                  struct pipe_fence_handle **fence)
 491 {
 492    struct st_context *st = (struct st_context *) stctxi;
 493    st_flush(st, flags, fence);
 494    if (flags & PIPE_FLUSH_RENDER_CACHE)
 495       st_manager_flush_frontbuffer(st);
 496 }
 497
 498 static boolean
 499 st_context_teximage(struct st_context_iface *stctxi, enum st_texture_type target,
 500                     int level, enum pipe_format internal_format,
 501                     struct pipe_resource *tex, boolean mipmap)
 502 {
 503    struct st_context *st = (struct st_context *) stctxi;
 504    GLcontext *ctx = st->ctx;
 505    struct gl_texture_unit *texUnit = _mesa_get_current_tex_unit(ctx);
 506    struct gl_texture_object *texObj;
 507    struct gl_texture_image *texImage;
 508    struct st_texture_object *stObj;
 509    struct st_texture_image *stImage;
 510    GLenum internalFormat;
 511
 512    switch (target) {
 513    case ST_TEXTURE_1D:
 514       target = GL_TEXTURE_1D;
 515       break;
 516    case ST_TEXTURE_2D:
 517       target = GL_TEXTURE_2D;
 518       break;
 519    case ST_TEXTURE_3D:
 520       target = GL_TEXTURE_3D;
 521       break;
 522    case ST_TEXTURE_RECT:
 523       target = GL_TEXTURE_RECTANGLE_ARB;
 524       break;
 525    default:
 526       return FALSE;
 527       break;
 528    }
 529
 530    if (util_format_get_component_bits(internal_format,
 531             UTIL_FORMAT_COLORSPACE_RGB, 3) > 0)
 532       internalFormat = GL_RGBA;
 533    else
 534       internalFormat = GL_RGB;
 535
 536    texObj = _mesa_select_tex_object(ctx, texUnit, target);
 537    _mesa_lock_texture(ctx, texObj);
 538
 539    stObj = st_texture_object(texObj);
 540    /* switch to surface based */
 541    if (!stObj->surface_based) {
 542       _mesa_clear_texture_object(ctx, texObj);
 543       stObj->surface_based = GL_TRUE;
 544    }
 545
 546    texImage = _mesa_get_tex_image(ctx, texObj, target, level);
 547    stImage = st_texture_image(texImage);
 548    if (tex) {
 549       _mesa_init_teximage_fields(ctx, target, texImage,
 550             tex->width0, tex->height0, 1, 0, internalFormat);
 551       texImage->TexFormat = st_ChooseTextureFormat(ctx, internalFormat,
 552             GL_RGBA, GL_UNSIGNED_BYTE);
 553       _mesa_set_fetch_functions(texImage, 2);
 554    }
 555    else {
 556       _mesa_clear_texture_image(ctx, texImage);
 557    }
 558
 559    pipe_resource_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 }
 696
 697 /**
 698  * Flush the front buffer if the current context renders to the front buffer.
 699  */
 700 void
 701 st_manager_flush_frontbuffer(struct st_context *st)
 702 {
 703    struct st_framebuffer *stfb = st_ws_framebuffer(st->ctx->DrawBuffer);
 704    struct st_renderbuffer *strb = NULL;
 705
 706    if (stfb)
 707       strb = st_renderbuffer(stfb->Base.Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
 708    if (!strb)
 709       return;
 710
 711    stfb->iface->flush_front(stfb->iface, ST_ATTACHMENT_FRONT_LEFT);
 712 }
 713
 714 /**
 715  * Return the surface of an EGLImage.
 716  */
 717 struct pipe_surface *
 718 st_manager_get_egl_image_surface(struct st_context *st,
 719                                  void *eglimg, unsigned usage)
 720 {
 721    struct st_manager *smapi =
 722       (struct st_manager *) st->iface.st_context_private;
 723    struct st_egl_image stimg;
 724    struct pipe_surface *ps;
 725
 726    if (!smapi || !smapi->get_egl_image)
 727       return NULL;
 728
 729    memset(&stimg, 0, sizeof(stimg));
 730    stimg.stctxi = &st->iface;
 731    stimg.egl_image = eglimg;
 732    if (!smapi->get_egl_image(smapi, &stimg))
 733       return NULL;
 734
 735    ps = smapi->screen->get_tex_surface(smapi->screen,
 736          stimg.texture, stimg.face, stimg.level, stimg.zslice, usage);
 737    pipe_resource_reference(&stimg.texture, NULL);
 738
 739    return ps;
 740 }
 741
 742 /**
 743  * Re-validate the framebuffers.
 744  */
 745 void
 746 st_manager_validate_framebuffers(struct st_context *st)
 747 {
 748    struct st_framebuffer *stdraw = st_ws_framebuffer(st->ctx->DrawBuffer);
 749    struct st_framebuffer *stread = st_ws_framebuffer(st->ctx->ReadBuffer);
 750
 751    if (stdraw)
 752       st_framebuffer_validate(stdraw, st);
 753    if (stread && stread != stdraw)
 754       st_framebuffer_validate(stread, st);
 755 }
 756
 757 /**
 758  * Add a color renderbuffer on demand.
 759  */
 760 boolean
 761 st_manager_add_color_renderbuffer(struct st_context *st, GLframebuffer *fb,
 762                                   gl_buffer_index idx)
 763 {
 764    struct st_framebuffer *stfb = st_ws_framebuffer(fb);
 765
 766    /* FBO */
 767    if (!stfb)
 768       return FALSE;
 769
 770    if (stfb->Base.Attachment[idx].Renderbuffer)
 771       return TRUE;
 772
 773    switch (idx) {
 774    case BUFFER_FRONT_LEFT:
 775    case BUFFER_BACK_LEFT:
 776    case BUFFER_FRONT_RIGHT:
 777    case BUFFER_BACK_RIGHT:
 778       break;
 779    default:
 780       return FALSE;
 781       break;
 782    }
 783
 784    if (!st_framebuffer_add_renderbuffer(stfb, idx))
 785       return FALSE;
 786
 787    st_framebuffer_update_attachments(stfb);
 788    st_invalidate_state(st->ctx, _NEW_BUFFERS);
 789
 790    return TRUE;
 791 }
 792
 793 struct st_api st_gl_api = {
 794    st_api_destroy,
 795    st_api_get_proc_address,
 796    st_api_is_visual_supported,
 797    st_api_create_context,
 798    st_api_make_current,
 799    st_api_get_current,
 800 };
 801
 802 /**
 803  * Return the st_api for this state tracker. This might either be GL, GLES1,
 804  * GLES2 that mostly depends on the build and link options. But these
 805  * functions remain the same either way.
 806  */
 807 struct st_api *
 808 st_gl_api_create(void)
 809 {
 810    return &st_gl_api;
 811 }