src/mesa/state_tracker/st_cb_clear.c

   1 /**************************************************************************
   2  *
   3  * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
   4  * All Rights Reserved.
   5  * Copyright 2009 VMware, Inc.  All Rights Reserved.
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a
   8  * copy of this software and associated documentation files (the
   9  * "Software"), to deal in the Software without restriction, including
  10  * without limitation the rights to use, copy, modify, merge, publish,
  11  * distribute, sub license, and/or sell copies of the Software, and to
  12  * permit persons to whom the Software is furnished to do so, subject to
  13  * the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the
  16  * next paragraph) shall be included in all copies or substantial portions
  17  * of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  20  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  21  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  22  * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
  23  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  24  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  25  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  26  *
  27  **************************************************************************/
  28
  29  /*
  30   * Authors:
  31   *   Keith Whitwell <keith@tungstengraphics.com>
  32   *   Brian Paul
  33   *   Michel Dänzer
  34   */
  35
  36 #include "main/glheader.h"
  37 #include "main/formats.h"
  38 #include "main/macros.h"
  39 #include "program/prog_instruction.h"
  40 #include "st_context.h"
  41 #include "st_atom.h"
  42 #include "st_cb_accum.h"
  43 #include "st_cb_clear.h"
  44 #include "st_cb_fbo.h"
  45 #include "st_format.h"
  46 #include "st_program.h"
  47
  48 #include "pipe/p_context.h"
  49 #include "pipe/p_shader_tokens.h"
  50 #include "pipe/p_state.h"
  51 #include "pipe/p_defines.h"
  52 #include "util/u_format.h"
  53 #include "util/u_inlines.h"
  54 #include "util/u_simple_shaders.h"
  55 #include "util/u_draw_quad.h"
  56
  57 #include "cso_cache/cso_context.h"
  58
  59
  60 /**
  61  * Do per-context initialization for glClear.
  62  */
  63 void
  64 st_init_clear(struct st_context *st)
  65 {
  66    struct pipe_context *pipe = st->pipe;
  67    struct pipe_screen *pscreen = st->pipe->screen;
  68
  69    memset(&st->clear, 0, sizeof(st->clear));
  70
  71    st->clear.raster.gl_rasterization_rules = 1;
  72    st->clear.enable_ds_separate = pscreen->get_param(pscreen, PIPE_CAP_DEPTHSTENCIL_CLEAR_SEPARATE);
  73
  74    /* fragment shader state: color pass-through program */
  75    st->clear.fs = util_make_fragment_passthrough_shader(pipe);
  76
  77    /* vertex shader state: color/position pass-through */
  78    {
  79       const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
  80                                       TGSI_SEMANTIC_COLOR };
  81       const uint semantic_indexes[] = { 0, 0 };
  82       st->clear.vs = util_make_vertex_passthrough_shader(pipe, 2,
  83                                                          semantic_names,
  84                                                          semantic_indexes);
  85    }
  86 }
  87
  88
  89 /**
  90  * Free per-context state for glClear.
  91  */
  92 void
  93 st_destroy_clear(struct st_context *st)
  94 {
  95    if (st->clear.fs) {
  96       cso_delete_fragment_shader(st->cso_context, st->clear.fs);
  97       st->clear.fs = NULL;
  98    }
  99    if (st->clear.vs) {
 100       cso_delete_vertex_shader(st->cso_context, st->clear.vs);
 101       st->clear.vs = NULL;
 102    }
 103    if (st->clear.vbuf) {
 104       pipe_resource_reference(&st->clear.vbuf, NULL);
 105       st->clear.vbuf = NULL;
 106    }
 107 }
 108
 109
 110 /**
 111  * Draw a screen-aligned quadrilateral.
 112  * Coords are clip coords with y=0=bottom.
 113  */
 114 static void
 115 draw_quad(struct st_context *st,
 116           float x0, float y0, float x1, float y1, GLfloat z,
 117           const GLfloat color[4])
 118 {
 119    struct pipe_context *pipe = st->pipe;
 120
 121    /* XXX: Need to improve buffer_write to allow NO_WAIT (as well as
 122     * no_flush) updates to buffers where we know there is no conflict
 123     * with previous data.  Currently using max_slots > 1 will cause
 124     * synchronous rendering if the driver flushes its command buffers
 125     * between one bitmap and the next.  Our flush hook below isn't
 126     * sufficient to catch this as the driver doesn't tell us when it
 127     * flushes its own command buffers.  Until this gets fixed, pay the
 128     * price of allocating a new buffer for each bitmap cache-flush to
 129     * avoid synchronous rendering.
 130     */
 131    const GLuint max_slots = 1; /* 1024 / sizeof(st->clear.vertices); */
 132    GLuint i;
 133
 134    if (st->clear.vbuf_slot >= max_slots) {
 135       pipe_resource_reference(&st->clear.vbuf, NULL);
 136       st->clear.vbuf_slot = 0;
 137    }
 138
 139    if (!st->clear.vbuf) {
 140       st->clear.vbuf = pipe_buffer_create(pipe->screen,
 141                                           PIPE_BIND_VERTEX_BUFFER,
 142                                           PIPE_USAGE_STREAM,
 143                                           max_slots * sizeof(st->clear.vertices));
 144    }
 145
 146    /* positions */
 147    st->clear.vertices[0][0][0] = x0;
 148    st->clear.vertices[0][0][1] = y0;
 149
 150    st->clear.vertices[1][0][0] = x1;
 151    st->clear.vertices[1][0][1] = y0;
 152
 153    st->clear.vertices[2][0][0] = x1;
 154    st->clear.vertices[2][0][1] = y1;
 155
 156    st->clear.vertices[3][0][0] = x0;
 157    st->clear.vertices[3][0][1] = y1;
 158
 159    /* same for all verts: */
 160    for (i = 0; i < 4; i++) {
 161       st->clear.vertices[i][0][2] = z;
 162       st->clear.vertices[i][0][3] = 1.0;
 163       st->clear.vertices[i][1][0] = color[0];
 164       st->clear.vertices[i][1][1] = color[1];
 165       st->clear.vertices[i][1][2] = color[2];
 166       st->clear.vertices[i][1][3] = color[3];
 167    }
 168
 169    /* put vertex data into vbuf */
 170    pipe_buffer_write_nooverlap(st->pipe, st->clear.vbuf,
 171                                            st->clear.vbuf_slot
 172                                              * sizeof(st->clear.vertices),
 173                                            sizeof(st->clear.vertices),
 174                                            st->clear.vertices);
 175
 176    /* draw */
 177    util_draw_vertex_buffer(pipe,
 178                            st->cso_context,
 179                            st->clear.vbuf,
 180                            st->clear.vbuf_slot * sizeof(st->clear.vertices),
 181                            PIPE_PRIM_TRIANGLE_FAN,
 182                            4,  /* verts */
 183                            2); /* attribs/vert */
 184
 185    /* Increment slot */
 186    st->clear.vbuf_slot++;
 187 }
 188
 189
 190
 191 /**
 192  * Do glClear by drawing a quadrilateral.
 193  * The vertices of the quad will be computed from the
 194  * ctx->DrawBuffer->_X/Ymin/max fields.
 195  */
 196 static void
 197 clear_with_quad(struct gl_context *ctx,
 198                 GLboolean color, GLboolean depth, GLboolean stencil)
 199 {
 200    struct st_context *st = st_context(ctx);
 201    const struct gl_framebuffer *fb = ctx->DrawBuffer;
 202    const GLfloat fb_width = (GLfloat) fb->Width;
 203    const GLfloat fb_height = (GLfloat) fb->Height;
 204    const GLfloat x0 = (GLfloat) ctx->DrawBuffer->_Xmin / fb_width * 2.0f - 1.0f;
 205    const GLfloat x1 = (GLfloat) ctx->DrawBuffer->_Xmax / fb_width * 2.0f - 1.0f;
 206    const GLfloat y0 = (GLfloat) ctx->DrawBuffer->_Ymin / fb_height * 2.0f - 1.0f;
 207    const GLfloat y1 = (GLfloat) ctx->DrawBuffer->_Ymax / fb_height * 2.0f - 1.0f;
 208    float clearColor[4];
 209
 210    /*
 211    printf("%s %s%s%s %f,%f %f,%f\n", __FUNCTION__,
 212           color ? "color, " : "",
 213           depth ? "depth, " : "",
 214           stencil ? "stencil" : "",
 215           x0, y0,
 216           x1, y1);
 217    */
 218
 219    cso_save_blend(st->cso_context);
 220    cso_save_stencil_ref(st->cso_context);
 221    cso_save_depth_stencil_alpha(st->cso_context);
 222    cso_save_rasterizer(st->cso_context);
 223    cso_save_viewport(st->cso_context);
 224    cso_save_clip(st->cso_context);
 225    cso_save_fragment_shader(st->cso_context);
 226    cso_save_vertex_shader(st->cso_context);
 227    cso_save_vertex_elements(st->cso_context);
 228    cso_save_vertex_buffers(st->cso_context);
 229
 230    /* blend state: RGBA masking */
 231    {
 232       struct pipe_blend_state blend;
 233       memset(&blend, 0, sizeof(blend));
 234       blend.rt[0].rgb_src_factor = PIPE_BLENDFACTOR_ONE;
 235       blend.rt[0].alpha_src_factor = PIPE_BLENDFACTOR_ONE;
 236       blend.rt[0].rgb_dst_factor = PIPE_BLENDFACTOR_ZERO;
 237       blend.rt[0].alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;
 238       if (color) {
 239          if (ctx->Color.ColorMask[0][0])
 240             blend.rt[0].colormask |= PIPE_MASK_R;
 241          if (ctx->Color.ColorMask[0][1])
 242             blend.rt[0].colormask |= PIPE_MASK_G;
 243          if (ctx->Color.ColorMask[0][2])
 244             blend.rt[0].colormask |= PIPE_MASK_B;
 245          if (ctx->Color.ColorMask[0][3])
 246             blend.rt[0].colormask |= PIPE_MASK_A;
 247          if (st->ctx->Color.DitherFlag)
 248             blend.dither = 1;
 249       }
 250       cso_set_blend(st->cso_context, &blend);
 251    }
 252
 253    /* depth_stencil state: always pass/set to ref value */
 254    {
 255       struct pipe_depth_stencil_alpha_state depth_stencil;
 256       memset(&depth_stencil, 0, sizeof(depth_stencil));
 257       if (depth) {
 258          depth_stencil.depth.enabled = 1;
 259          depth_stencil.depth.writemask = 1;
 260          depth_stencil.depth.func = PIPE_FUNC_ALWAYS;
 261       }
 262
 263       if (stencil) {
 264          struct pipe_stencil_ref stencil_ref;
 265          memset(&stencil_ref, 0, sizeof(stencil_ref));
 266          depth_stencil.stencil[0].enabled = 1;
 267          depth_stencil.stencil[0].func = PIPE_FUNC_ALWAYS;
 268          depth_stencil.stencil[0].fail_op = PIPE_STENCIL_OP_REPLACE;
 269          depth_stencil.stencil[0].zpass_op = PIPE_STENCIL_OP_REPLACE;
 270          depth_stencil.stencil[0].zfail_op = PIPE_STENCIL_OP_REPLACE;
 271          depth_stencil.stencil[0].valuemask = 0xff;
 272          depth_stencil.stencil[0].writemask = ctx->Stencil.WriteMask[0] & 0xff;
 273          stencil_ref.ref_value[0] = ctx->Stencil.Clear;
 274          cso_set_stencil_ref(st->cso_context, &stencil_ref);
 275       }
 276
 277       cso_set_depth_stencil_alpha(st->cso_context, &depth_stencil);
 278    }
 279
 280    cso_set_vertex_elements(st->cso_context, 2, st->velems_util_draw);
 281
 282    cso_set_rasterizer(st->cso_context, &st->clear.raster);
 283
 284    /* viewport state: viewport matching window dims */
 285    {
 286       const GLboolean invert = (st_fb_orientation(fb) == Y_0_TOP);
 287       struct pipe_viewport_state vp;
 288       vp.scale[0] = 0.5f * fb_width;
 289       vp.scale[1] = fb_height * (invert ? -0.5f : 0.5f);
 290       vp.scale[2] = 1.0f;
 291       vp.scale[3] = 1.0f;
 292       vp.translate[0] = 0.5f * fb_width;
 293       vp.translate[1] = 0.5f * fb_height;
 294       vp.translate[2] = 0.0f;
 295       vp.translate[3] = 0.0f;
 296       cso_set_viewport(st->cso_context, &vp);
 297    }
 298
 299    cso_set_clip(st->cso_context, &st->clear.clip);
 300    cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
 301    cso_set_vertex_shader_handle(st->cso_context, st->clear.vs);
 302
 303    if (ctx->DrawBuffer->_ColorDrawBuffers[0]) {
 304       st_translate_color(ctx->Color.ClearColor,
 305                          ctx->DrawBuffer->_ColorDrawBuffers[0]->_BaseFormat,
 306                          clearColor);
 307    }
 308
 309    /* draw quad matching scissor rect */
 310    draw_quad(st, x0, y0, x1, y1, (GLfloat) ctx->Depth.Clear, clearColor);
 311
 312    /* Restore pipe state */
 313    cso_restore_blend(st->cso_context);
 314    cso_restore_stencil_ref(st->cso_context);
 315    cso_restore_depth_stencil_alpha(st->cso_context);
 316    cso_restore_rasterizer(st->cso_context);
 317    cso_restore_viewport(st->cso_context);
 318    cso_restore_clip(st->cso_context);
 319    cso_restore_fragment_shader(st->cso_context);
 320    cso_restore_vertex_shader(st->cso_context);
 321    cso_restore_vertex_elements(st->cso_context);
 322    cso_restore_vertex_buffers(st->cso_context);
 323 }
 324
 325
 326 /**
 327  * Determine if we need to clear the depth buffer by drawing a quad.
 328  */
 329 static INLINE GLboolean
 330 check_clear_color_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)
 331 {
 332    if (ctx->Scissor.Enabled &&
 333        (ctx->Scissor.X != 0 ||
 334         ctx->Scissor.Y != 0 ||
 335         ctx->Scissor.Width < rb->Width ||
 336         ctx->Scissor.Height < rb->Height))
 337       return GL_TRUE;
 338
 339    if (!ctx->Color.ColorMask[0][0] ||
 340        !ctx->Color.ColorMask[0][1] ||
 341        !ctx->Color.ColorMask[0][2] ||
 342        !ctx->Color.ColorMask[0][3])
 343       return GL_TRUE;
 344
 345    return GL_FALSE;
 346 }
 347
 348
 349 /**
 350  * Determine if we need to clear the combiend depth/stencil buffer by
 351  * drawing a quad.
 352  */
 353 static INLINE GLboolean
 354 check_clear_depth_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)
 355 {
 356    const GLuint stencilMax = 0xff;
 357    GLboolean maskStencil
 358       = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;
 359
 360    assert(rb->Format == MESA_FORMAT_S8 ||
 361           rb->Format == MESA_FORMAT_Z24_S8 ||
 362           rb->Format == MESA_FORMAT_S8_Z24);
 363
 364    if (ctx->Scissor.Enabled &&
 365        (ctx->Scissor.X != 0 ||
 366         ctx->Scissor.Y != 0 ||
 367         ctx->Scissor.Width < rb->Width ||
 368         ctx->Scissor.Height < rb->Height))
 369       return GL_TRUE;
 370
 371    if (maskStencil)
 372       return GL_TRUE;
 373
 374    return GL_FALSE;
 375 }
 376
 377
 378 /**
 379  * Determine if we need to clear the depth buffer by drawing a quad.
 380  */
 381 static INLINE GLboolean
 382 check_clear_depth_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,
 383                             boolean ds_separate)
 384 {
 385    const struct st_renderbuffer *strb = st_renderbuffer(rb);
 386    const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);
 387
 388    if (ctx->Scissor.Enabled &&
 389        (ctx->Scissor.X != 0 ||
 390         ctx->Scissor.Y != 0 ||
 391         ctx->Scissor.Width < rb->Width ||
 392         ctx->Scissor.Height < rb->Height))
 393       return GL_TRUE;
 394
 395    if (!ds_separate && isDS && ctx->DrawBuffer->Visual.stencilBits > 0)
 396       return GL_TRUE;
 397
 398    return GL_FALSE;
 399 }
 400
 401
 402 /**
 403  * Determine if we need to clear the stencil buffer by drawing a quad.
 404  */
 405 static INLINE GLboolean
 406 check_clear_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,
 407                               boolean ds_separate)
 408 {
 409    const struct st_renderbuffer *strb = st_renderbuffer(rb);
 410    const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);
 411    const GLuint stencilMax = 0xff;
 412    const GLboolean maskStencil
 413       = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;
 414
 415    assert(rb->Format == MESA_FORMAT_S8 ||
 416           rb->Format == MESA_FORMAT_Z24_S8 ||
 417           rb->Format == MESA_FORMAT_S8_Z24);
 418
 419    if (maskStencil)
 420       return GL_TRUE;
 421
 422    if (ctx->Scissor.Enabled &&
 423        (ctx->Scissor.X != 0 ||
 424         ctx->Scissor.Y != 0 ||
 425         ctx->Scissor.Width < rb->Width ||
 426         ctx->Scissor.Height < rb->Height))
 427       return GL_TRUE;
 428
 429    /* This is correct, but it is necessary to look at the depth clear
 430     * value held in the surface when it comes time to issue the clear,
 431     * rather than taking depth and stencil clear values from the
 432     * current state.
 433     */
 434    if (!ds_separate && isDS && ctx->DrawBuffer->Visual.depthBits > 0)
 435       return GL_TRUE;
 436
 437    return GL_FALSE;
 438 }
 439
 440
 441
 442 /**
 443  * Called when we need to flush.
 444  */
 445 void
 446 st_flush_clear(struct st_context *st)
 447 {
 448    /* Release vertex buffer to avoid synchronous rendering if we were
 449     * to map it in the next frame.
 450     */
 451    pipe_resource_reference(&st->clear.vbuf, NULL);
 452    st->clear.vbuf_slot = 0;
 453 }
 454
 455
 456
 457 /**
 458  * Called via ctx->Driver.Clear()
 459  */
 460 static void
 461 st_Clear(struct gl_context *ctx, GLbitfield mask)
 462 {
 463    static const GLbitfield BUFFER_BITS_DS
 464       = (BUFFER_BIT_DEPTH | BUFFER_BIT_STENCIL);
 465    struct st_context *st = st_context(ctx);
 466    struct gl_renderbuffer *depthRb
 467       = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
 468    struct gl_renderbuffer *stencilRb
 469       = ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
 470    GLbitfield quad_buffers = 0x0;
 471    GLbitfield clear_buffers = 0x0;
 472    GLuint i;
 473
 474    /* This makes sure the pipe has the latest scissor, etc values */
 475    st_validate_state( st );
 476
 477    if (mask & BUFFER_BITS_COLOR) {
 478       for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
 479          GLuint b = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];
 480
 481          if (mask & (1 << b)) {
 482             struct gl_renderbuffer *rb
 483                = ctx->DrawBuffer->Attachment[b].Renderbuffer;
 484             struct st_renderbuffer *strb = st_renderbuffer(rb);
 485
 486             if (!strb || !strb->surface)
 487                continue;
 488
 489             if (check_clear_color_with_quad( ctx, rb ))
 490                quad_buffers |= PIPE_CLEAR_COLOR;
 491             else
 492                clear_buffers |= PIPE_CLEAR_COLOR;
 493          }
 494       }
 495    }
 496
 497    if ((mask & BUFFER_BITS_DS) == BUFFER_BITS_DS && depthRb == stencilRb) {
 498       /* clearing combined depth + stencil */
 499       struct st_renderbuffer *strb = st_renderbuffer(depthRb);
 500
 501       if (strb->surface) {
 502          if (check_clear_depth_stencil_with_quad(ctx, depthRb))
 503             quad_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
 504          else
 505             clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
 506       }
 507    }
 508    else {
 509       /* separate depth/stencil clears */
 510       /* I don't think truly separate buffers are actually possible in gallium or hw? */
 511       if (mask & BUFFER_BIT_DEPTH) {
 512          struct st_renderbuffer *strb = st_renderbuffer(depthRb);
 513
 514          if (strb->surface) {
 515             if (check_clear_depth_with_quad(ctx, depthRb,
 516                                             st->clear.enable_ds_separate))
 517                quad_buffers |= PIPE_CLEAR_DEPTH;
 518             else
 519                clear_buffers |= PIPE_CLEAR_DEPTH;
 520          }
 521       }
 522       if (mask & BUFFER_BIT_STENCIL) {
 523          struct st_renderbuffer *strb = st_renderbuffer(stencilRb);
 524
 525          if (strb->surface) {
 526             if (check_clear_stencil_with_quad(ctx, stencilRb,
 527                                               st->clear.enable_ds_separate))
 528                quad_buffers |= PIPE_CLEAR_STENCIL;
 529             else
 530                clear_buffers |= PIPE_CLEAR_STENCIL;
 531          }
 532       }
 533    }
 534
 535    /*
 536     * If we're going to use clear_with_quad() for any reason, use it for
 537     * everything possible.
 538     */
 539    if (quad_buffers) {
 540       quad_buffers |= clear_buffers;
 541       clear_with_quad(ctx,
 542                       quad_buffers & PIPE_CLEAR_COLOR,
 543                       quad_buffers & PIPE_CLEAR_DEPTH,
 544                       quad_buffers & PIPE_CLEAR_STENCIL);
 545    } else if (clear_buffers) {
 546       /* driver cannot know it can clear everything if the buffer
 547        * is a combined depth/stencil buffer but this wasn't actually
 548        * required from the visual. Hence fix this up to avoid potential
 549        * read-modify-write in the driver.
 550        */
 551       float clearColor[4];
 552
 553       if ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) &&
 554           ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) != PIPE_CLEAR_DEPTHSTENCIL) &&
 555           (depthRb == stencilRb) &&
 556           (ctx->DrawBuffer->Visual.depthBits == 0 ||
 557            ctx->DrawBuffer->Visual.stencilBits == 0))
 558          clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
 559
 560       if (ctx->DrawBuffer->_ColorDrawBuffers[0]) {
 561          st_translate_color(ctx->Color.ClearColor,
 562                             ctx->DrawBuffer->_ColorDrawBuffers[0]->_BaseFormat,
 563                             clearColor);
 564       }
 565
 566       st->pipe->clear(st->pipe, clear_buffers, ctx->Color.ClearColor,
 567                       ctx->Depth.Clear, ctx->Stencil.Clear);
 568    }
 569    if (mask & BUFFER_BIT_ACCUM)
 570       st_clear_accum_buffer(ctx,
 571                             ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
 572 }
 573
 574
 575 void
 576 st_init_clear_functions(struct dd_function_table *functions)
 577 {
 578    functions->Clear = st_Clear;
 579 }