src/mesa/main/buffers.c

   1 /*
   2  * Mesa 3-D graphics library
   3  * Version:  6.5.2
   4  *
   5  * Copyright (C) 1999-2006  Brian Paul   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 "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
  25
  26 /**
  27  * \file buffers.c
  28  * General framebuffer-related functions, like glClear, glScissor, etc.
  29  */
  30
  31
  32
  33 #include "glheader.h"
  34 #include "buffers.h"
  35 #include "colormac.h"
  36 #include "context.h"
  37 #include "enums.h"
  38 #include "fbobject.h"
  39 #include "state.h"
  40
  41
  42 #define BAD_MASK ~0u
  43
  44
  45 #if _HAVE_FULL_GL
  46 void GLAPIENTRY
  47 _mesa_ClearIndex( GLfloat c )
  48 {
  49    GET_CURRENT_CONTEXT(ctx);
  50    ASSERT_OUTSIDE_BEGIN_END(ctx);
  51
  52    if (ctx->Color.ClearIndex == (GLuint) c)
  53       return;
  54
  55    FLUSH_VERTICES(ctx, _NEW_COLOR);
  56    ctx->Color.ClearIndex = (GLuint) c;
  57
  58    if (!ctx->Visual.rgbMode && ctx->Driver.ClearIndex) {
  59       /* it's OK to call glClearIndex in RGBA mode but it should be a NOP */
  60       (*ctx->Driver.ClearIndex)( ctx, ctx->Color.ClearIndex );
  61    }
  62 }
  63 #endif
  64
  65
  66 /**
  67  * Specify the clear values for the color buffers.
  68  *
  69  * \param red red color component.
  70  * \param green green color component.
  71  * \param blue blue color component.
  72  * \param alpha alpha component.
  73  *
  74  * \sa glClearColor().
  75  *
  76  * Clamps the parameters and updates gl_colorbuffer_attrib::ClearColor.  On a
  77  * change, flushes the vertices and notifies the driver via the
  78  * dd_function_table::ClearColor callback.
  79  */
  80 void GLAPIENTRY
  81 _mesa_ClearColor( GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha )
  82 {
  83    GLfloat tmp[4];
  84    GET_CURRENT_CONTEXT(ctx);
  85    ASSERT_OUTSIDE_BEGIN_END(ctx);
  86
  87    tmp[0] = CLAMP(red,   0.0F, 1.0F);
  88    tmp[1] = CLAMP(green, 0.0F, 1.0F);
  89    tmp[2] = CLAMP(blue,  0.0F, 1.0F);
  90    tmp[3] = CLAMP(alpha, 0.0F, 1.0F);
  91
  92    if (TEST_EQ_4V(tmp, ctx->Color.ClearColor))
  93       return; /* no change */
  94
  95    FLUSH_VERTICES(ctx, _NEW_COLOR);
  96    COPY_4V(ctx->Color.ClearColor, tmp);
  97
  98    if (ctx->Visual.rgbMode && ctx->Driver.ClearColor) {
  99       /* it's OK to call glClearColor in CI mode but it should be a NOP */
 100       (*ctx->Driver.ClearColor)(ctx, ctx->Color.ClearColor);
 101    }
 102 }
 103
 104
 105 /**
 106  * Clear buffers.
 107  *
 108  * \param mask bit-mask indicating the buffers to be cleared.
 109  *
 110  * Flushes the vertices and verifies the parameter. If __GLcontextRec::NewState
 111  * is set then calls _mesa_update_state() to update gl_frame_buffer::_Xmin,
 112  * etc. If the rasterization mode is set to GL_RENDER then requests the driver
 113  * to clear the buffers, via the dd_function_table::Clear callback.
 114  */
 115 void GLAPIENTRY
 116 _mesa_Clear( GLbitfield mask )
 117 {
 118    GET_CURRENT_CONTEXT(ctx);
 119    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 120
 121    if (MESA_VERBOSE & VERBOSE_API)
 122       _mesa_debug(ctx, "glClear 0x%x\n", mask);
 123
 124    if (mask & ~(GL_COLOR_BUFFER_BIT |
 125                 GL_DEPTH_BUFFER_BIT |
 126                 GL_STENCIL_BUFFER_BIT |
 127                 GL_ACCUM_BUFFER_BIT)) {
 128       /* invalid bit set */
 129       _mesa_error( ctx, GL_INVALID_VALUE, "glClear(0x%x)", mask);
 130       return;
 131    }
 132
 133    if (ctx->NewState) {
 134       _mesa_update_state( ctx );        /* update _Xmin, etc */
 135    }
 136
 137    if (ctx->DrawBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 138       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
 139                   "glClear(incomplete framebuffer)");
 140       return;
 141    }
 142
 143    if (ctx->RenderMode == GL_RENDER) {
 144       GLbitfield bufferMask;
 145
 146       /* don't clear depth buffer if depth writing disabled */
 147       if (!ctx->Depth.Mask)
 148          mask &= ~GL_DEPTH_BUFFER_BIT;
 149
 150       /* Build the bitmask to send to device driver's Clear function.
 151        * Note that the GL_COLOR_BUFFER_BIT flag will expand to 0, 1, 2 or 4
 152        * of the BUFFER_BIT_FRONT/BACK_LEFT/RIGHT flags, or one of the
 153        * BUFFER_BIT_COLORn flags.
 154        */
 155       bufferMask = 0;
 156       if (mask & GL_COLOR_BUFFER_BIT) {
 157          bufferMask |= ctx->DrawBuffer->_ColorDrawBufferMask[0];
 158       }
 159
 160       if ((mask & GL_DEPTH_BUFFER_BIT)
 161           && ctx->DrawBuffer->Visual.haveDepthBuffer) {
 162          bufferMask |= BUFFER_BIT_DEPTH;
 163       }
 164
 165       if ((mask & GL_STENCIL_BUFFER_BIT)
 166           && ctx->DrawBuffer->Visual.haveStencilBuffer) {
 167          bufferMask |= BUFFER_BIT_STENCIL;
 168       }
 169
 170       if ((mask & GL_ACCUM_BUFFER_BIT)
 171           && ctx->DrawBuffer->Visual.haveAccumBuffer) {
 172          bufferMask |= BUFFER_BIT_ACCUM;
 173       }
 174
 175       ASSERT(ctx->Driver.Clear);
 176       ctx->Driver.Clear(ctx, bufferMask);
 177    }
 178 }
 179
 180
 181
 182 /**
 183  * Return bitmask of BUFFER_BIT_* flags indicating which color buffers are
 184  * available to the rendering context.
 185  * This depends on the framebuffer we're writing to.  For window system
 186  * framebuffers we look at the framebuffer's visual.  But for user-
 187  * create framebuffers we look at the number of supported color attachments.
 188  */
 189 static GLbitfield
 190 supported_buffer_bitmask(const GLcontext *ctx, GLuint framebufferID)
 191 {
 192    GLbitfield mask = 0x0;
 193
 194    if (framebufferID > 0) {
 195       /* A user-created renderbuffer */
 196       GLuint i;
 197       ASSERT(ctx->Extensions.EXT_framebuffer_object);
 198       for (i = 0; i < ctx->Const.MaxColorAttachments; i++) {
 199          mask |= (BUFFER_BIT_COLOR0 << i);
 200       }
 201    }
 202    else {
 203       /* A window system renderbuffer */
 204       GLint i;
 205       mask = BUFFER_BIT_FRONT_LEFT; /* always have this */
 206       if (ctx->Visual.stereoMode) {
 207          mask |= BUFFER_BIT_FRONT_RIGHT;
 208          if (ctx->Visual.doubleBufferMode) {
 209             mask |= BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT;
 210          }
 211       }
 212       else if (ctx->Visual.doubleBufferMode) {
 213          mask |= BUFFER_BIT_BACK_LEFT;
 214       }
 215
 216       for (i = 0; i < ctx->Visual.numAuxBuffers; i++) {
 217          mask |= (BUFFER_BIT_AUX0 << i);
 218       }
 219    }
 220
 221    return mask;
 222 }
 223
 224
 225 /**
 226  * Helper routine used by glDrawBuffer and glDrawBuffersARB.
 227  * Given a GLenum naming one or more color buffers (such as
 228  * GL_FRONT_AND_BACK), return the corresponding bitmask of BUFFER_BIT_* flags.
 229  */
 230 static GLbitfield
 231 draw_buffer_enum_to_bitmask(GLenum buffer)
 232 {
 233    switch (buffer) {
 234       case GL_NONE:
 235          return 0;
 236       case GL_FRONT:
 237          return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT;
 238       case GL_BACK:
 239          return BUFFER_BIT_BACK_LEFT | BUFFER_BIT_BACK_RIGHT;
 240       case GL_RIGHT:
 241          return BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT;
 242       case GL_FRONT_RIGHT:
 243          return BUFFER_BIT_FRONT_RIGHT;
 244       case GL_BACK_RIGHT:
 245          return BUFFER_BIT_BACK_RIGHT;
 246       case GL_BACK_LEFT:
 247          return BUFFER_BIT_BACK_LEFT;
 248       case GL_FRONT_AND_BACK:
 249          return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT
 250               | BUFFER_BIT_FRONT_RIGHT | BUFFER_BIT_BACK_RIGHT;
 251       case GL_LEFT:
 252          return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT;
 253       case GL_FRONT_LEFT:
 254          return BUFFER_BIT_FRONT_LEFT;
 255       case GL_AUX0:
 256          return BUFFER_BIT_AUX0;
 257       case GL_AUX1:
 258          return BUFFER_BIT_AUX1;
 259       case GL_AUX2:
 260          return BUFFER_BIT_AUX2;
 261       case GL_AUX3:
 262          return BUFFER_BIT_AUX3;
 263       case GL_COLOR_ATTACHMENT0_EXT:
 264          return BUFFER_BIT_COLOR0;
 265       case GL_COLOR_ATTACHMENT1_EXT:
 266          return BUFFER_BIT_COLOR1;
 267       case GL_COLOR_ATTACHMENT2_EXT:
 268          return BUFFER_BIT_COLOR2;
 269       case GL_COLOR_ATTACHMENT3_EXT:
 270          return BUFFER_BIT_COLOR3;
 271       default:
 272          /* error */
 273          return BAD_MASK;
 274    }
 275 }
 276
 277
 278 /**
 279  * Helper routine used by glReadBuffer.
 280  * Given a GLenum naming a color buffer, return the index of the corresponding
 281  * renderbuffer (a BUFFER_* value).
 282  * return -1 for an invalid buffer.
 283  */
 284 static GLint
 285 read_buffer_enum_to_index(GLenum buffer)
 286 {
 287    switch (buffer) {
 288       case GL_FRONT:
 289          return BUFFER_FRONT_LEFT;
 290       case GL_BACK:
 291          return BUFFER_BACK_LEFT;
 292       case GL_RIGHT:
 293          return BUFFER_FRONT_RIGHT;
 294       case GL_FRONT_RIGHT:
 295          return BUFFER_FRONT_RIGHT;
 296       case GL_BACK_RIGHT:
 297          return BUFFER_BACK_RIGHT;
 298       case GL_BACK_LEFT:
 299          return BUFFER_BACK_LEFT;
 300       case GL_LEFT:
 301          return BUFFER_FRONT_LEFT;
 302       case GL_FRONT_LEFT:
 303          return BUFFER_FRONT_LEFT;
 304       case GL_AUX0:
 305          return BUFFER_AUX0;
 306       case GL_AUX1:
 307          return BUFFER_AUX1;
 308       case GL_AUX2:
 309          return BUFFER_AUX2;
 310       case GL_AUX3:
 311          return BUFFER_AUX3;
 312       case GL_COLOR_ATTACHMENT0_EXT:
 313          return BUFFER_COLOR0;
 314       case GL_COLOR_ATTACHMENT1_EXT:
 315          return BUFFER_COLOR1;
 316       case GL_COLOR_ATTACHMENT2_EXT:
 317          return BUFFER_COLOR2;
 318       case GL_COLOR_ATTACHMENT3_EXT:
 319          return BUFFER_COLOR3;
 320       default:
 321          /* error */
 322          return -1;
 323    }
 324 }
 325
 326
 327 /**
 328  * Called by glDrawBuffer().
 329  * Specify which renderbuffer(s) to draw into for the first color output.
 330  * <buffer> can name zero, one, two or four renderbuffers!
 331  * \sa _mesa_DrawBuffersARB
 332  *
 333  * \param buffer  buffer token such as GL_LEFT or GL_FRONT_AND_BACK, etc.
 334  */
 335 void GLAPIENTRY
 336 _mesa_DrawBuffer(GLenum buffer)
 337 {
 338    GLuint bufferID;
 339    GLbitfield destMask;
 340    GET_CURRENT_CONTEXT(ctx);
 341    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx); /* too complex... */
 342
 343    if (MESA_VERBOSE & VERBOSE_API) {
 344       _mesa_debug(ctx, "glDrawBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));
 345    }
 346
 347    bufferID = ctx->DrawBuffer->Name;
 348
 349    if (buffer == GL_NONE) {
 350       destMask = 0x0;
 351    }
 352    else {
 353       const GLbitfield supportedMask = supported_buffer_bitmask(ctx, bufferID);
 354       destMask = draw_buffer_enum_to_bitmask(buffer);
 355       if (destMask == BAD_MASK) {
 356          /* totally bogus buffer */
 357          _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffer(buffer)");
 358          return;
 359       }
 360       destMask &= supportedMask;
 361       if (destMask == 0x0) {
 362          /* none of the named color buffers exist! */
 363          _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffer(buffer)");
 364          return;
 365       }
 366    }
 367
 368    /* if we get here, there's no error so set new state */
 369    _mesa_drawbuffers(ctx, 1, &buffer, &destMask);
 370 }
 371
 372
 373 /**
 374  * Called by glDrawBuffersARB; specifies the destination color renderbuffers
 375  * for N fragment program color outputs.
 376  * \sa _mesa_DrawBuffer
 377  * \param n  number of outputs
 378  * \param buffers  array [n] of renderbuffer names.  Unlike glDrawBuffer, the
 379  *                 names cannot specify more than one buffer.  For example,
 380  *                 GL_FRONT_AND_BACK is illegal.
 381  */
 382 void GLAPIENTRY
 383 _mesa_DrawBuffersARB(GLsizei n, const GLenum *buffers)
 384 {
 385    GLint output;
 386    GLuint bufferID;
 387    GLbitfield usedBufferMask, supportedMask;
 388    GLbitfield destMask[MAX_DRAW_BUFFERS];
 389    GET_CURRENT_CONTEXT(ctx);
 390    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 391
 392    if (!ctx->Extensions.ARB_draw_buffers) {
 393       _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB");
 394       return;
 395    }
 396    if (n < 1 || n > (GLsizei) ctx->Const.MaxDrawBuffers) {
 397       _mesa_error(ctx, GL_INVALID_VALUE, "glDrawBuffersARB(n)");
 398       return;
 399    }
 400
 401    bufferID = ctx->DrawBuffer->Name;
 402
 403    supportedMask = supported_buffer_bitmask(ctx, bufferID);
 404    usedBufferMask = 0x0;
 405
 406    /* complicated error checking... */
 407    for (output = 0; output < n; output++) {
 408       if (buffers[output] == GL_NONE) {
 409          destMask[output] = 0x0;
 410       }
 411       else {
 412          destMask[output] = draw_buffer_enum_to_bitmask(buffers[output]);
 413          if (destMask[output] == BAD_MASK
 414              || _mesa_bitcount(destMask[output]) > 1) {
 415             _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffersARB(buffer)");
 416             return;
 417          }
 418          destMask[output] &= supportedMask;
 419          if (destMask[output] == 0) {
 420             _mesa_error(ctx, GL_INVALID_OPERATION,
 421                         "glDrawBuffersARB(unsupported buffer)");
 422             return;
 423          }
 424          if (destMask[output] & usedBufferMask) {
 425             /* can't specify a dest buffer more than once! */
 426             _mesa_error(ctx, GL_INVALID_OPERATION,
 427                         "glDrawBuffersARB(duplicated buffer)");
 428             return;
 429          }
 430
 431          /* update bitmask */
 432          usedBufferMask |= destMask[output];
 433       }
 434    }
 435
 436    /* OK, if we get here, there were no errors so set the new state */
 437    _mesa_drawbuffers(ctx, n, buffers, destMask);
 438 }
 439
 440
 441 /**
 442  * Set color output state.  Traditionally, there was only one color
 443  * output, but fragment programs can now have several distinct color
 444  * outputs (see GL_ARB_draw_buffers).  This function sets the state
 445  * for one such color output.
 446  * \param ctx  current context
 447  * \param output  which fragment program output
 448  * \param buffer  buffer to write to (like GL_LEFT)
 449  * \param destMask  BUFFER_* bitmask
 450  *                  (like BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT).
 451  */
 452 static void
 453 set_color_output(GLcontext *ctx, GLuint output, GLenum buffer,
 454                  GLbitfield destMask)
 455 {
 456    struct gl_framebuffer *fb = ctx->DrawBuffer;
 457
 458    ASSERT(output < ctx->Const.MaxDrawBuffers);
 459
 460    /* Set per-FBO state */
 461    fb->ColorDrawBuffer[output] = buffer;
 462    fb->_ColorDrawBufferMask[output] = destMask;
 463    /* not really needed, will be set later */
 464    fb->_NumColorDrawBuffers[output] = 0;
 465
 466    /* Set traditional state var */
 467    ctx->Color.DrawBuffer[output] = buffer;
 468 }
 469
 470
 471 /**
 472  * Helper routine used by _mesa_DrawBuffer, _mesa_DrawBuffersARB and
 473  * _mesa_PopAttrib to set drawbuffer state.
 474  * All error checking will have been done prior to calling this function
 475  * so nothing should go wrong at this point.
 476  * \param ctx  current context
 477  * \param n    number of color outputs to set
 478  * \param buffers  array[n] of colorbuffer names, like GL_LEFT.
 479  * \param destMask  array[n] of BUFFER_* bitmasks which correspond to the
 480  *                  colorbuffer names.  (i.e. GL_FRONT_AND_BACK =>
 481  *                  BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT).
 482  */
 483 void
 484 _mesa_drawbuffers(GLcontext *ctx, GLuint n, const GLenum *buffers,
 485                   const GLbitfield *destMask)
 486 {
 487    GLbitfield mask[MAX_DRAW_BUFFERS];
 488    GLuint output;
 489
 490    if (!destMask) {
 491       /* compute destMask values now */
 492       const GLuint bufferID = ctx->DrawBuffer->Name;
 493       const GLbitfield supportedMask = supported_buffer_bitmask(ctx, bufferID);
 494       for (output = 0; output < n; output++) {
 495          mask[output] = draw_buffer_enum_to_bitmask(buffers[output]);
 496          ASSERT(mask[output] != BAD_MASK);
 497          mask[output] &= supportedMask;
 498       }
 499       destMask = mask;
 500    }
 501
 502    for (output = 0; output < n; output++) {
 503       set_color_output(ctx, output, buffers[output], destMask[output]);
 504    }
 505
 506    /* set remaining color outputs to NONE */
 507    for (output = n; output < ctx->Const.MaxDrawBuffers; output++) {
 508       set_color_output(ctx, output, GL_NONE, 0x0);
 509    }
 510
 511    ctx->NewState |= _NEW_COLOR;
 512
 513    /*
 514     * Call device driver function.
 515     */
 516    if (ctx->Driver.DrawBuffers)
 517       ctx->Driver.DrawBuffers(ctx, n, buffers);
 518    else if (ctx->Driver.DrawBuffer)
 519       ctx->Driver.DrawBuffer(ctx, buffers[0]);
 520 }
 521
 522
 523
 524 /**
 525  * Called by glReadBuffer to set the source renderbuffer for reading pixels.
 526  * \param mode color buffer such as GL_FRONT, GL_BACK, etc.
 527  */
 528 void GLAPIENTRY
 529 _mesa_ReadBuffer(GLenum buffer)
 530 {
 531    struct gl_framebuffer *fb;
 532    GLbitfield supportedMask;
 533    GLint srcBuffer;
 534    GLuint bufferID;
 535    GET_CURRENT_CONTEXT(ctx);
 536    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
 537
 538    fb = ctx->ReadBuffer;
 539    bufferID = fb->Name;
 540
 541    if (MESA_VERBOSE & VERBOSE_API)
 542       _mesa_debug(ctx, "glReadBuffer %s\n", _mesa_lookup_enum_by_nr(buffer));
 543
 544    if (bufferID > 0 && buffer == GL_NONE) {
 545       /* This is legal for user-created framebuffer objects */
 546       srcBuffer = -1;
 547    }
 548    else {
 549       /* general case / window-system framebuffer */
 550       srcBuffer = read_buffer_enum_to_index(buffer);
 551       if (srcBuffer == -1) {
 552          _mesa_error(ctx, GL_INVALID_ENUM, "glReadBuffer(buffer=0x%x)", buffer);
 553          return;
 554       }
 555       supportedMask = supported_buffer_bitmask(ctx, bufferID);
 556       if (((1 << srcBuffer) & supportedMask) == 0) {
 557          _mesa_error(ctx, GL_INVALID_OPERATION, "glReadBuffer(buffer=0x%x)", buffer);
 558          return;
 559       }
 560    }
 561
 562    if (bufferID == 0) {
 563       ctx->Pixel.ReadBuffer = buffer;
 564    }
 565    fb->ColorReadBuffer = buffer;
 566    fb->_ColorReadBufferIndex = srcBuffer;
 567
 568    ctx->NewState |= _NEW_PIXEL;
 569
 570    /*
 571     * Call device driver function.
 572     */
 573    if (ctx->Driver.ReadBuffer)
 574       (*ctx->Driver.ReadBuffer)(ctx, buffer);
 575 }
 576
 577
 578 #if _HAVE_FULL_GL
 579
 580 /**
 581  * XXX THIS IS OBSOLETE - drivers should take care of detecting window
 582  * size changes and act accordingly, likely calling _mesa_resize_framebuffer().
 583  *
 584  * GL_MESA_resize_buffers extension.
 585  *
 586  * When this function is called, we'll ask the window system how large
 587  * the current window is.  If it's a new size, we'll call the driver's
 588  * ResizeBuffers function.  The driver will then resize its color buffers
 589  * as needed, and maybe call the swrast's routine for reallocating
 590  * swrast-managed depth/stencil/accum/etc buffers.
 591  * \note This function should only be called through the GL API, not
 592  * from device drivers (as was done in the past).
 593  */
 594
 595 void _mesa_resizebuffers( GLcontext *ctx )
 596 {
 597    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 598
 599    if (MESA_VERBOSE & VERBOSE_API)
 600       _mesa_debug(ctx, "glResizeBuffersMESA\n");
 601
 602    if (!ctx->Driver.GetBufferSize) {
 603       return;
 604    }
 605
 606    if (ctx->WinSysDrawBuffer) {
 607       GLuint newWidth, newHeight;
 608       GLframebuffer *buffer = ctx->WinSysDrawBuffer;
 609
 610       assert(buffer->Name == 0);
 611
 612       /* ask device driver for size of output buffer */
 613       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 614
 615       /* see if size of device driver's color buffer (window) has changed */
 616       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 617          if (ctx->Driver.ResizeBuffers)
 618             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 619       }
 620    }
 621
 622    if (ctx->WinSysReadBuffer
 623        && ctx->WinSysReadBuffer != ctx->WinSysDrawBuffer) {
 624       GLuint newWidth, newHeight;
 625       GLframebuffer *buffer = ctx->WinSysReadBuffer;
 626
 627       assert(buffer->Name == 0);
 628
 629       /* ask device driver for size of read buffer */
 630       ctx->Driver.GetBufferSize( buffer, &newWidth, &newHeight );
 631
 632       /* see if size of device driver's color buffer (window) has changed */
 633       if (buffer->Width != newWidth || buffer->Height != newHeight) {
 634          if (ctx->Driver.ResizeBuffers)
 635             ctx->Driver.ResizeBuffers(ctx, buffer, newWidth, newHeight );
 636       }
 637    }
 638
 639    ctx->NewState |= _NEW_BUFFERS;  /* to update scissor / window bounds */
 640 }
 641
 642
 643 /*
 644  * XXX THIS IS OBSOLETE
 645  */
 646 void GLAPIENTRY
 647 _mesa_ResizeBuffersMESA( void )
 648 {
 649    GET_CURRENT_CONTEXT(ctx);
 650
 651    if (ctx->Extensions.MESA_resize_buffers)
 652       _mesa_resizebuffers( ctx );
 653 }
 654
 655
 656 /*
 657  * XXX move somewhere else someday?
 658  */
 659 void GLAPIENTRY
 660 _mesa_SampleCoverageARB(GLclampf value, GLboolean invert)
 661 {
 662    GET_CURRENT_CONTEXT(ctx);
 663
 664    if (!ctx->Extensions.ARB_multisample) {
 665       _mesa_error(ctx, GL_INVALID_OPERATION, "glSampleCoverageARB");
 666       return;
 667    }
 668
 669    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH( ctx );
 670    ctx->Multisample.SampleCoverageValue = (GLfloat) CLAMP(value, 0.0, 1.0);
 671    ctx->Multisample.SampleCoverageInvert = invert;
 672    ctx->NewState |= _NEW_MULTISAMPLE;
 673 }
 674
 675 #endif /* _HAVE_FULL_GL */
 676
 677
 678
 679 /**
 680  * Define the scissor box.
 681  *
 682  * \param x, y coordinates of the scissor box lower-left corner.
 683  * \param width width of the scissor box.
 684  * \param height height of the scissor box.
 685  *
 686  * \sa glScissor().
 687  *
 688  * Verifies the parameters and updates __GLcontextRec::Scissor. On a
 689  * change flushes the vertices and notifies the driver via
 690  * the dd_function_table::Scissor callback.
 691  */
 692 void
 693 _mesa_set_scissor(GLcontext *ctx,
 694                   GLint x, GLint y, GLsizei width, GLsizei height)
 695 {
 696    if (x == ctx->Scissor.X &&
 697        y == ctx->Scissor.Y &&
 698        width == ctx->Scissor.Width &&
 699        height == ctx->Scissor.Height)
 700       return;
 701
 702    FLUSH_VERTICES(ctx, _NEW_SCISSOR);
 703    ctx->Scissor.X = x;
 704    ctx->Scissor.Y = y;
 705    ctx->Scissor.Width = width;
 706    ctx->Scissor.Height = height;
 707
 708    if (ctx->Driver.Scissor)
 709       ctx->Driver.Scissor( ctx, x, y, width, height );
 710 }
 711
 712
 713 void GLAPIENTRY
 714 _mesa_Scissor( GLint x, GLint y, GLsizei width, GLsizei height )
 715 {
 716    GET_CURRENT_CONTEXT(ctx);
 717    ASSERT_OUTSIDE_BEGIN_END(ctx);
 718
 719    if (width < 0 || height < 0) {
 720       _mesa_error( ctx, GL_INVALID_VALUE, "glScissor" );
 721       return;
 722    }
 723
 724    if (MESA_VERBOSE & VERBOSE_API)
 725       _mesa_debug(ctx, "glScissor %d %d %d %d\n", x, y, width, height);
 726
 727    _mesa_set_scissor(ctx, x, y, width, height);
 728 }
 729
 730
 731
 732 /**********************************************************************/
 733 /** \name Initialization */
 734 /*@{*/
 735
 736 /**
 737  * Initialize the context's scissor state.
 738  * \param ctx  the GL context.
 739  */
 740 void
 741 _mesa_init_scissor(GLcontext *ctx)
 742 {
 743    /* Scissor group */
 744    ctx->Scissor.Enabled = GL_FALSE;
 745    ctx->Scissor.X = 0;
 746    ctx->Scissor.Y = 0;
 747    ctx->Scissor.Width = 0;
 748    ctx->Scissor.Height = 0;
 749 }
 750
 751
 752 /**
 753  * Initialize the context's multisample state.
 754  * \param ctx  the GL context.
 755  */
 756 void
 757 _mesa_init_multisample(GLcontext *ctx)
 758 {
 759    ctx->Multisample.Enabled = GL_FALSE;
 760    ctx->Multisample.SampleAlphaToCoverage = GL_FALSE;
 761    ctx->Multisample.SampleAlphaToOne = GL_FALSE;
 762    ctx->Multisample.SampleCoverage = GL_FALSE;
 763    ctx->Multisample.SampleCoverageValue = 1.0;
 764    ctx->Multisample.SampleCoverageInvert = GL_FALSE;
 765 }
 766
 767 /*@}*/