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_screen *pscreen = st->pipe->screen;
  67
  68    memset(&st->clear, 0, sizeof(st->clear));
  69
  70    st->clear.raster.gl_rasterization_rules = 1;
  71    st->clear.enable_ds_separate = pscreen->get_param(pscreen, PIPE_CAP_DEPTHSTENCIL_CLEAR_SEPARATE);
  72 }
  73
  74
  75 /**
  76  * Free per-context state for glClear.
  77  */
  78 void
  79 st_destroy_clear(struct st_context *st)
  80 {
  81    if (st->clear.fs) {
  82       cso_delete_fragment_shader(st->cso_context, st->clear.fs);
  83       st->clear.fs = NULL;
  84    }
  85    if (st->clear.vs) {
  86       cso_delete_vertex_shader(st->cso_context, st->clear.vs);
  87       st->clear.vs = NULL;
  88    }
  89    if (st->clear.vbuf) {
  90       pipe_resource_reference(&st->clear.vbuf, NULL);
  91       st->clear.vbuf = NULL;
  92    }
  93 }
  94
  95
  96 /**
  97  * Helper function to set the fragment shaders.
  98  */
  99 static INLINE void
 100 set_fragment_shader(struct st_context *st)
 101 {
 102    if (!st->clear.fs)
 103       st->clear.fs = util_make_fragment_passthrough_shader(st->pipe);
 104
 105    cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
 106 }
 107
 108
 109 /**
 110  * Helper function to set the vertex shader.
 111  */
 112 static INLINE void
 113 set_vertex_shader(struct st_context *st)
 114 {
 115    /* vertex shader - still required to provide the linkage between
 116     * fragment shader input semantics and vertex_element/buffers.
 117     */
 118    if (!st->clear.vs)
 119    {
 120       const uint semantic_names[] = { TGSI_SEMANTIC_POSITION,
 121                                       TGSI_SEMANTIC_COLOR };
 122       const uint semantic_indexes[] = { 0, 0 };
 123       st->clear.vs = util_make_vertex_passthrough_shader(st->pipe, 2,
 124                                                          semantic_names,
 125                                                          semantic_indexes);
 126    }
 127
 128    cso_set_vertex_shader_handle(st->cso_context, st->clear.vs);
 129 }
 130
 131
 132 /**
 133  * Draw a screen-aligned quadrilateral.
 134  * Coords are clip coords with y=0=bottom.
 135  */
 136 static void
 137 draw_quad(struct st_context *st,
 138           float x0, float y0, float x1, float y1, GLfloat z,
 139           const GLfloat color[4])
 140 {
 141    struct pipe_context *pipe = st->pipe;
 142
 143    /* XXX: Need to improve buffer_write to allow NO_WAIT (as well as
 144     * no_flush) updates to buffers where we know there is no conflict
 145     * with previous data.  Currently using max_slots > 1 will cause
 146     * synchronous rendering if the driver flushes its command buffers
 147     * between one bitmap and the next.  Our flush hook below isn't
 148     * sufficient to catch this as the driver doesn't tell us when it
 149     * flushes its own command buffers.  Until this gets fixed, pay the
 150     * price of allocating a new buffer for each bitmap cache-flush to
 151     * avoid synchronous rendering.
 152     */
 153    const GLuint max_slots = 1; /* 1024 / sizeof(st->clear.vertices); */
 154    GLuint i;
 155
 156    if (st->clear.vbuf_slot >= max_slots) {
 157       pipe_resource_reference(&st->clear.vbuf, NULL);
 158       st->clear.vbuf_slot = 0;
 159    }
 160
 161    if (!st->clear.vbuf) {
 162       st->clear.vbuf = pipe_buffer_create(pipe->screen,
 163                                           PIPE_BIND_VERTEX_BUFFER,
 164                                           PIPE_USAGE_STREAM,
 165                                           max_slots * sizeof(st->clear.vertices));
 166    }
 167
 168    /* positions */
 169    st->clear.vertices[0][0][0] = x0;
 170    st->clear.vertices[0][0][1] = y0;
 171
 172    st->clear.vertices[1][0][0] = x1;
 173    st->clear.vertices[1][0][1] = y0;
 174
 175    st->clear.vertices[2][0][0] = x1;
 176    st->clear.vertices[2][0][1] = y1;
 177
 178    st->clear.vertices[3][0][0] = x0;
 179    st->clear.vertices[3][0][1] = y1;
 180
 181    /* same for all verts: */
 182    for (i = 0; i < 4; i++) {
 183       st->clear.vertices[i][0][2] = z;
 184       st->clear.vertices[i][0][3] = 1.0;
 185       st->clear.vertices[i][1][0] = color[0];
 186       st->clear.vertices[i][1][1] = color[1];
 187       st->clear.vertices[i][1][2] = color[2];
 188       st->clear.vertices[i][1][3] = color[3];
 189    }
 190
 191    /* put vertex data into vbuf */
 192    pipe_buffer_write_nooverlap(st->pipe, st->clear.vbuf,
 193                                            st->clear.vbuf_slot
 194                                              * sizeof(st->clear.vertices),
 195                                            sizeof(st->clear.vertices),
 196                                            st->clear.vertices);
 197
 198    /* draw */
 199    util_draw_vertex_buffer(pipe,
 200                            st->cso_context,
 201                            st->clear.vbuf,
 202                            st->clear.vbuf_slot * sizeof(st->clear.vertices),
 203                            PIPE_PRIM_TRIANGLE_FAN,
 204                            4,  /* verts */
 205                            2); /* attribs/vert */
 206
 207    /* Increment slot */
 208    st->clear.vbuf_slot++;
 209 }
 210
 211
 212
 213 /**
 214  * Do glClear by drawing a quadrilateral.
 215  * The vertices of the quad will be computed from the
 216  * ctx->DrawBuffer->_X/Ymin/max fields.
 217  */
 218 static void
 219 clear_with_quad(struct gl_context *ctx,
 220                 GLboolean color, GLboolean depth, GLboolean stencil)
 221 {
 222    struct st_context *st = st_context(ctx);
 223    const struct gl_framebuffer *fb = ctx->DrawBuffer;
 224    const GLfloat fb_width = (GLfloat) fb->Width;
 225    const GLfloat fb_height = (GLfloat) fb->Height;
 226    const GLfloat x0 = (GLfloat) ctx->DrawBuffer->_Xmin / fb_width * 2.0f - 1.0f;
 227    const GLfloat x1 = (GLfloat) ctx->DrawBuffer->_Xmax / fb_width * 2.0f - 1.0f;
 228    const GLfloat y0 = (GLfloat) ctx->DrawBuffer->_Ymin / fb_height * 2.0f - 1.0f;
 229    const GLfloat y1 = (GLfloat) ctx->DrawBuffer->_Ymax / fb_height * 2.0f - 1.0f;
 230    float clearColor[4];
 231
 232    /*
 233    printf("%s %s%s%s %f,%f %f,%f\n", __FUNCTION__,
 234           color ? "color, " : "",
 235           depth ? "depth, " : "",
 236           stencil ? "stencil" : "",
 237           x0, y0,
 238           x1, y1);
 239    */
 240
 241    cso_save_blend(st->cso_context);
 242    cso_save_stencil_ref(st->cso_context);
 243    cso_save_depth_stencil_alpha(st->cso_context);
 244    cso_save_rasterizer(st->cso_context);
 245    cso_save_viewport(st->cso_context);
 246    cso_save_clip(st->cso_context);
 247    cso_save_fragment_shader(st->cso_context);
 248    cso_save_vertex_shader(st->cso_context);
 249    cso_save_vertex_elements(st->cso_context);
 250    cso_save_vertex_buffers(st->cso_context);
 251
 252    /* blend state: RGBA masking */
 253    {
 254       struct pipe_blend_state blend;
 255       memset(&blend, 0, sizeof(blend));
 256       blend.rt[0].rgb_src_factor = PIPE_BLENDFACTOR_ONE;
 257       blend.rt[0].alpha_src_factor = PIPE_BLENDFACTOR_ONE;
 258       blend.rt[0].rgb_dst_factor = PIPE_BLENDFACTOR_ZERO;
 259       blend.rt[0].alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;
 260       if (color) {
 261          if (ctx->Color.ColorMask[0][0])
 262             blend.rt[0].colormask |= PIPE_MASK_R;
 263          if (ctx->Color.ColorMask[0][1])
 264             blend.rt[0].colormask |= PIPE_MASK_G;
 265          if (ctx->Color.ColorMask[0][2])
 266             blend.rt[0].colormask |= PIPE_MASK_B;
 267          if (ctx->Color.ColorMask[0][3])
 268             blend.rt[0].colormask |= PIPE_MASK_A;
 269          if (st->ctx->Color.DitherFlag)
 270             blend.dither = 1;
 271       }
 272       cso_set_blend(st->cso_context, &blend);
 273    }
 274
 275    /* depth_stencil state: always pass/set to ref value */
 276    {
 277       struct pipe_depth_stencil_alpha_state depth_stencil;
 278       memset(&depth_stencil, 0, sizeof(depth_stencil));
 279       if (depth) {
 280          depth_stencil.depth.enabled = 1;
 281          depth_stencil.depth.writemask = 1;
 282          depth_stencil.depth.func = PIPE_FUNC_ALWAYS;
 283       }
 284
 285       if (stencil) {
 286          struct pipe_stencil_ref stencil_ref;
 287          memset(&stencil_ref, 0, sizeof(stencil_ref));
 288          depth_stencil.stencil[0].enabled = 1;
 289          depth_stencil.stencil[0].func = PIPE_FUNC_ALWAYS;
 290          depth_stencil.stencil[0].fail_op = PIPE_STENCIL_OP_REPLACE;
 291          depth_stencil.stencil[0].zpass_op = PIPE_STENCIL_OP_REPLACE;
 292          depth_stencil.stencil[0].zfail_op = PIPE_STENCIL_OP_REPLACE;
 293          depth_stencil.stencil[0].valuemask = 0xff;
 294          depth_stencil.stencil[0].writemask = ctx->Stencil.WriteMask[0] & 0xff;
 295          stencil_ref.ref_value[0] = ctx->Stencil.Clear;
 296          cso_set_stencil_ref(st->cso_context, &stencil_ref);
 297       }
 298
 299       cso_set_depth_stencil_alpha(st->cso_context, &depth_stencil);
 300    }
 301
 302    cso_set_vertex_elements(st->cso_context, 2, st->velems_util_draw);
 303
 304    cso_set_rasterizer(st->cso_context, &st->clear.raster);
 305
 306    /* viewport state: viewport matching window dims */
 307    {
 308       const GLboolean invert = (st_fb_orientation(fb) == Y_0_TOP);
 309       struct pipe_viewport_state vp;
 310       vp.scale[0] = 0.5f * fb_width;
 311       vp.scale[1] = fb_height * (invert ? -0.5f : 0.5f);
 312       vp.scale[2] = 1.0f;
 313       vp.scale[3] = 1.0f;
 314       vp.translate[0] = 0.5f * fb_width;
 315       vp.translate[1] = 0.5f * fb_height;
 316       vp.translate[2] = 0.0f;
 317       vp.translate[3] = 0.0f;
 318       cso_set_viewport(st->cso_context, &vp);
 319    }
 320
 321    cso_set_clip(st->cso_context, &st->clear.clip);
 322    set_fragment_shader(st);
 323    set_vertex_shader(st);
 324
 325    if (ctx->DrawBuffer->_ColorDrawBuffers[0]) {
 326       st_translate_color(ctx->Color.ClearColorUnclamped,
 327                          ctx->DrawBuffer->_ColorDrawBuffers[0]->_BaseFormat,
 328                          clearColor);
 329    }
 330
 331    /* draw quad matching scissor rect */
 332    draw_quad(st, x0, y0, x1, y1, (GLfloat) ctx->Depth.Clear, clearColor);
 333
 334    /* Restore pipe state */
 335    cso_restore_blend(st->cso_context);
 336    cso_restore_stencil_ref(st->cso_context);
 337    cso_restore_depth_stencil_alpha(st->cso_context);
 338    cso_restore_rasterizer(st->cso_context);
 339    cso_restore_viewport(st->cso_context);
 340    cso_restore_clip(st->cso_context);
 341    cso_restore_fragment_shader(st->cso_context);
 342    cso_restore_vertex_shader(st->cso_context);
 343    cso_restore_vertex_elements(st->cso_context);
 344    cso_restore_vertex_buffers(st->cso_context);
 345 }
 346
 347
 348 /**
 349  * Determine if we need to clear the depth buffer by drawing a quad.
 350  */
 351 static INLINE GLboolean
 352 check_clear_color_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)
 353 {
 354    if (ctx->Scissor.Enabled &&
 355        (ctx->Scissor.X != 0 ||
 356         ctx->Scissor.Y != 0 ||
 357         ctx->Scissor.Width < rb->Width ||
 358         ctx->Scissor.Height < rb->Height))
 359       return GL_TRUE;
 360
 361    if (!ctx->Color.ColorMask[0][0] ||
 362        !ctx->Color.ColorMask[0][1] ||
 363        !ctx->Color.ColorMask[0][2] ||
 364        !ctx->Color.ColorMask[0][3])
 365       return GL_TRUE;
 366
 367    return GL_FALSE;
 368 }
 369
 370
 371 /**
 372  * Determine if we need to clear the combiend depth/stencil buffer by
 373  * drawing a quad.
 374  */
 375 static INLINE GLboolean
 376 check_clear_depth_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb)
 377 {
 378    const GLuint stencilMax = 0xff;
 379    GLboolean maskStencil
 380       = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;
 381
 382    assert(rb->Format == MESA_FORMAT_S8 ||
 383           rb->Format == MESA_FORMAT_Z24_S8 ||
 384           rb->Format == MESA_FORMAT_S8_Z24 ||
 385           rb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
 386
 387    if (ctx->Scissor.Enabled &&
 388        (ctx->Scissor.X != 0 ||
 389         ctx->Scissor.Y != 0 ||
 390         ctx->Scissor.Width < rb->Width ||
 391         ctx->Scissor.Height < rb->Height))
 392       return GL_TRUE;
 393
 394    if (maskStencil)
 395       return GL_TRUE;
 396
 397    return GL_FALSE;
 398 }
 399
 400
 401 /**
 402  * Determine if we need to clear the depth buffer by drawing a quad.
 403  */
 404 static INLINE GLboolean
 405 check_clear_depth_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,
 406                             boolean ds_separate)
 407 {
 408    const struct st_renderbuffer *strb = st_renderbuffer(rb);
 409    const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);
 410
 411    if (ctx->Scissor.Enabled &&
 412        (ctx->Scissor.X != 0 ||
 413         ctx->Scissor.Y != 0 ||
 414         ctx->Scissor.Width < rb->Width ||
 415         ctx->Scissor.Height < rb->Height))
 416       return GL_TRUE;
 417
 418    if (!ds_separate && isDS && ctx->DrawBuffer->Visual.stencilBits > 0)
 419       return GL_TRUE;
 420
 421    return GL_FALSE;
 422 }
 423
 424
 425 /**
 426  * Determine if we need to clear the stencil buffer by drawing a quad.
 427  */
 428 static INLINE GLboolean
 429 check_clear_stencil_with_quad(struct gl_context *ctx, struct gl_renderbuffer *rb,
 430                               boolean ds_separate)
 431 {
 432    const struct st_renderbuffer *strb = st_renderbuffer(rb);
 433    const GLboolean isDS = util_format_is_depth_and_stencil(strb->surface->format);
 434    const GLuint stencilMax = 0xff;
 435    const GLboolean maskStencil
 436       = (ctx->Stencil.WriteMask[0] & stencilMax) != stencilMax;
 437
 438    assert(rb->Format == MESA_FORMAT_S8 ||
 439           rb->Format == MESA_FORMAT_Z24_S8 ||
 440           rb->Format == MESA_FORMAT_S8_Z24 ||
 441           rb->Format == MESA_FORMAT_Z32_FLOAT_X24S8);
 442
 443    if (maskStencil)
 444       return GL_TRUE;
 445
 446    if (ctx->Scissor.Enabled &&
 447        (ctx->Scissor.X != 0 ||
 448         ctx->Scissor.Y != 0 ||
 449         ctx->Scissor.Width < rb->Width ||
 450         ctx->Scissor.Height < rb->Height))
 451       return GL_TRUE;
 452
 453    /* This is correct, but it is necessary to look at the depth clear
 454     * value held in the surface when it comes time to issue the clear,
 455     * rather than taking depth and stencil clear values from the
 456     * current state.
 457     */
 458    if (!ds_separate && isDS && ctx->DrawBuffer->Visual.depthBits > 0)
 459       return GL_TRUE;
 460
 461    return GL_FALSE;
 462 }
 463
 464
 465
 466 /**
 467  * Called when we need to flush.
 468  */
 469 void
 470 st_flush_clear(struct st_context *st)
 471 {
 472    /* Release vertex buffer to avoid synchronous rendering if we were
 473     * to map it in the next frame.
 474     */
 475    pipe_resource_reference(&st->clear.vbuf, NULL);
 476    st->clear.vbuf_slot = 0;
 477 }
 478
 479
 480
 481 /**
 482  * Called via ctx->Driver.Clear()
 483  */
 484 static void
 485 st_Clear(struct gl_context *ctx, GLbitfield mask)
 486 {
 487    static const GLbitfield BUFFER_BITS_DS
 488       = (BUFFER_BIT_DEPTH | BUFFER_BIT_STENCIL);
 489    struct st_context *st = st_context(ctx);
 490    struct gl_renderbuffer *depthRb
 491       = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
 492    struct gl_renderbuffer *stencilRb
 493       = ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
 494    GLbitfield quad_buffers = 0x0;
 495    GLbitfield clear_buffers = 0x0;
 496    GLuint i;
 497
 498    /* This makes sure the pipe has the latest scissor, etc values */
 499    st_validate_state( st );
 500
 501    if (mask & BUFFER_BITS_COLOR) {
 502       for (i = 0; i < ctx->DrawBuffer->_NumColorDrawBuffers; i++) {
 503          GLuint b = ctx->DrawBuffer->_ColorDrawBufferIndexes[i];
 504
 505          if (mask & (1 << b)) {
 506             struct gl_renderbuffer *rb
 507                = ctx->DrawBuffer->Attachment[b].Renderbuffer;
 508             struct st_renderbuffer *strb = st_renderbuffer(rb);
 509
 510             if (!strb || !strb->surface)
 511                continue;
 512
 513             if (check_clear_color_with_quad( ctx, rb ))
 514                quad_buffers |= PIPE_CLEAR_COLOR;
 515             else
 516                clear_buffers |= PIPE_CLEAR_COLOR;
 517          }
 518       }
 519    }
 520
 521    if ((mask & BUFFER_BITS_DS) == BUFFER_BITS_DS && depthRb == stencilRb) {
 522       /* clearing combined depth + stencil */
 523       struct st_renderbuffer *strb = st_renderbuffer(depthRb);
 524
 525       if (strb->surface) {
 526          if (check_clear_depth_stencil_with_quad(ctx, depthRb))
 527             quad_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
 528          else
 529             clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
 530       }
 531    }
 532    else {
 533       /* separate depth/stencil clears */
 534       /* I don't think truly separate buffers are actually possible in gallium or hw? */
 535       if (mask & BUFFER_BIT_DEPTH) {
 536          struct st_renderbuffer *strb = st_renderbuffer(depthRb);
 537
 538          if (strb->surface) {
 539             if (check_clear_depth_with_quad(ctx, depthRb,
 540                                             st->clear.enable_ds_separate))
 541                quad_buffers |= PIPE_CLEAR_DEPTH;
 542             else
 543                clear_buffers |= PIPE_CLEAR_DEPTH;
 544          }
 545       }
 546       if (mask & BUFFER_BIT_STENCIL) {
 547          struct st_renderbuffer *strb = st_renderbuffer(stencilRb);
 548
 549          if (strb->surface) {
 550             if (check_clear_stencil_with_quad(ctx, stencilRb,
 551                                               st->clear.enable_ds_separate))
 552                quad_buffers |= PIPE_CLEAR_STENCIL;
 553             else
 554                clear_buffers |= PIPE_CLEAR_STENCIL;
 555          }
 556       }
 557    }
 558
 559    /*
 560     * If we're going to use clear_with_quad() for any reason, use it for
 561     * everything possible.
 562     */
 563    if (quad_buffers) {
 564       quad_buffers |= clear_buffers;
 565       clear_with_quad(ctx,
 566                       quad_buffers & PIPE_CLEAR_COLOR,
 567                       quad_buffers & PIPE_CLEAR_DEPTH,
 568                       quad_buffers & PIPE_CLEAR_STENCIL);
 569    } else if (clear_buffers) {
 570       /* driver cannot know it can clear everything if the buffer
 571        * is a combined depth/stencil buffer but this wasn't actually
 572        * required from the visual. Hence fix this up to avoid potential
 573        * read-modify-write in the driver.
 574        */
 575       float clearColor[4];
 576
 577       if ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) &&
 578           ((clear_buffers & PIPE_CLEAR_DEPTHSTENCIL) != PIPE_CLEAR_DEPTHSTENCIL) &&
 579           (depthRb == stencilRb) &&
 580           (ctx->DrawBuffer->Visual.depthBits == 0 ||
 581            ctx->DrawBuffer->Visual.stencilBits == 0))
 582          clear_buffers |= PIPE_CLEAR_DEPTHSTENCIL;
 583
 584       if (ctx->DrawBuffer->_ColorDrawBuffers[0]) {
 585          st_translate_color(ctx->Color.ClearColor,
 586                             ctx->DrawBuffer->_ColorDrawBuffers[0]->_BaseFormat,
 587                             clearColor);
 588       }
 589
 590       st->pipe->clear(st->pipe, clear_buffers, ctx->Color.ClearColorUnclamped,
 591                       ctx->Depth.Clear, ctx->Stencil.Clear);
 592    }
 593    if (mask & BUFFER_BIT_ACCUM)
 594       st_clear_accum_buffer(ctx,
 595                             ctx->DrawBuffer->Attachment[BUFFER_ACCUM].Renderbuffer);
 596 }
 597
 598
 599 void
 600 st_init_clear_functions(struct dd_function_table *functions)
 601 {
 602    functions->Clear = st_Clear;
 603 }