src/mesa/drivers/dri/common/utils.c

   1 /*
   2  * (C) Copyright IBM Corporation 2002, 2004
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * the Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  20  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  21  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  22  * USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file utils.c
  27  * Utility functions for DRI drivers.
  28  *
  29  * \author Ian Romanick <idr@us.ibm.com>
  30  */
  31
  32 #include <string.h>
  33 #include <stdlib.h>
  34 #include "mtypes.h"
  35 #include "extensions.h"
  36 #include "utils.h"
  37
  38 #if !defined( DRI_NEW_INTERFACE_ONLY )
  39 #include "xf86dri.h"        /* For XF86DRIQueryVersion prototype. */
  40 #endif
  41
  42 #if defined(USE_X86_ASM)
  43 #include "x86/common_x86_asm.h"
  44 #endif
  45
  46 #if defined(USE_PPC_ASM)
  47 #include "ppc/common_ppc_features.h"
  48 #endif
  49
  50 unsigned
  51 driParseDebugString( const char * debug,
  52                      const struct dri_debug_control * control  )
  53 {
  54    unsigned   flag;
  55
  56
  57    flag = 0;
  58    if ( debug != NULL ) {
  59       while( control->string != NULL ) {
  60          if ( !strcmp( debug, "all" ) ||
  61               strstr( debug, control->string ) != NULL ) {
  62             flag |= control->flag;
  63          }
  64
  65          control++;
  66       }
  67    }
  68
  69    return flag;
  70 }
  71
  72
  73
  74 /**
  75  * Create the \c GL_RENDERER string for DRI drivers.
  76  *
  77  * Almost all DRI drivers use a \c GL_RENDERER string of the form:
  78  *
  79  *    "Mesa DRI <chip> <driver date> <AGP speed) <CPU information>"
  80  *
  81  * Using the supplied chip name, driver data, and AGP speed, this function
  82  * creates the string.
  83  *
  84  * \param buffer         Buffer to hold the \c GL_RENDERER string.
  85  * \param hardware_name  Name of the hardware.
  86  * \param driver_date    Driver date.
  87  * \param agp_mode       AGP mode (speed).
  88  *
  89  * \returns
  90  * The length of the string stored in \c buffer.  This does \b not include
  91  * the terminating \c NUL character.
  92  */
  93 unsigned
  94 driGetRendererString( char * buffer, const char * hardware_name,
  95                       const char * driver_date, GLuint agp_mode )
  96 {
  97 #define MAX_INFO   4
  98    const char * cpu[MAX_INFO];
  99    unsigned   next = 0;
 100    unsigned   i;
 101    unsigned   offset;
 102
 103
 104    offset = sprintf( buffer, "Mesa DRI %s %s", hardware_name, driver_date );
 105
 106    /* Append any AGP-specific information.
 107     */
 108    switch ( agp_mode ) {
 109    case 1:
 110    case 2:
 111    case 4:
 112    case 8:
 113       offset += sprintf( & buffer[ offset ], " AGP %ux", agp_mode );
 114       break;
 115
 116    default:
 117       break;
 118    }
 119
 120    /* Append any CPU-specific information.
 121     */
 122 #ifdef USE_X86_ASM
 123    if ( _mesa_x86_cpu_features ) {
 124       cpu[next] = " x86";
 125       next++;
 126    }
 127 # ifdef USE_MMX_ASM
 128    if ( cpu_has_mmx ) {
 129       cpu[next] = (cpu_has_mmxext) ? "/MMX+" : "/MMX";
 130       next++;
 131    }
 132 # endif
 133 # ifdef USE_3DNOW_ASM
 134    if ( cpu_has_3dnow ) {
 135       cpu[next] = (cpu_has_3dnowext) ? "/3DNow!+" : "/3DNow!";
 136       next++;
 137    }
 138 # endif
 139 # ifdef USE_SSE_ASM
 140    if ( cpu_has_xmm ) {
 141       cpu[next] = (cpu_has_xmm2) ? "/SSE2" : "/SSE";
 142       next++;
 143    }
 144 # endif
 145
 146 #elif defined(USE_SPARC_ASM)
 147
 148    cpu[0] = " SPARC";
 149    next = 1;
 150
 151 #elif defined(USE_PPC_ASM)
 152    if ( _mesa_ppc_cpu_features ) {
 153       cpu[next] = (cpu_has_64) ? " PowerPC 64" : " PowerPC";
 154       next++;
 155    }
 156
 157 # ifdef USE_VMX_ASM
 158    if ( cpu_has_vmx ) {
 159       cpu[next] = "/Altivec";
 160       next++;
 161    }
 162 # endif
 163
 164    if ( ! cpu_has_fpu ) {
 165       cpu[next] = "/No FPU";
 166       next++;
 167    }
 168 #endif
 169
 170    for ( i = 0 ; i < next ; i++ ) {
 171       const size_t len = strlen( cpu[i] );
 172
 173       strncpy( & buffer[ offset ], cpu[i], len );
 174       offset += len;
 175    }
 176
 177    return offset;
 178 }
 179
 180
 181
 182
 183 void driInitExtensions( GLcontext * ctx,
 184                         const char * const extensions_to_enable[],
 185                         GLboolean  enable_imaging )
 186 {
 187    unsigned   i;
 188
 189    if ( enable_imaging ) {
 190       _mesa_enable_imaging_extensions( ctx );
 191    }
 192
 193    for ( i = 0 ; extensions_to_enable[i] != NULL ; i++ ) {
 194       _mesa_enable_extension( ctx, extensions_to_enable[i] );
 195    }
 196 }
 197
 198
 199
 200
 201 #ifndef DRI_NEW_INTERFACE_ONLY
 202 /**
 203  * Utility function used by drivers to test the verions of other components.
 204  *
 205  * \deprecated
 206  * All drivers using the new interface should use \c driCheckDriDdxVersions2
 207  * instead.  This function is implemented using a call that is not available
 208  * to drivers using the new interface.  Furthermore, the information gained
 209  * by this call (the DRI and DDX version information) is already provided to
 210  * the driver via the new interface.
 211  */
 212 GLboolean
 213 driCheckDriDdxDrmVersions(__DRIscreenPrivate *sPriv,
 214                           const char * driver_name,
 215                           int dri_major, int dri_minor,
 216                           int ddx_major, int ddx_minor,
 217                           int drm_major, int drm_minor)
 218 {
 219    static const char format[] = "%s DRI driver expected %s version %d.%d.x "
 220        "but got version %d.%d.%d";
 221    int major, minor, patch;
 222
 223    /* Check the DRI version */
 224    if (XF86DRIQueryVersion(sPriv->display, &major, &minor, &patch)) {
 225       if (major != dri_major || minor < dri_minor) {
 226          __driUtilMessage(format, driver_name, "DRI", dri_major, dri_minor,
 227                           major, minor, patch);
 228          return GL_FALSE;
 229       }
 230    }
 231
 232    /* Check that the DDX driver version is compatible */
 233    if (sPriv->ddxMajor != ddx_major || sPriv->ddxMinor < ddx_minor) {
 234       __driUtilMessage(format, driver_name, "DDX", ddx_major, ddx_minor,
 235                        sPriv->ddxMajor, sPriv->ddxMinor, sPriv->ddxPatch);
 236       return GL_FALSE;
 237    }
 238
 239    /* Check that the DRM driver version is compatible */
 240    if (sPriv->drmMajor != drm_major || sPriv->drmMinor < drm_minor) {
 241       __driUtilMessage(format, driver_name, "DRM", drm_major, drm_minor,
 242                        sPriv->drmMajor, sPriv->drmMinor, sPriv->drmPatch);
 243       return GL_FALSE;
 244    }
 245
 246    return GL_TRUE;
 247 }
 248 #endif /* DRI_NEW_INTERFACE_ONLY */
 249
 250 /**
 251  * Utility function used by drivers to test the verions of other components.
 252  *
 253  * If one of the version requirements is not met, a message is logged using
 254  * \c __driUtilMessage.
 255  *
 256  * \param driver_name  Name of the driver.  Used in error messages.
 257  * \param driActual    Actual DRI version supplied __driCreateNewScreen.
 258  * \param driExpected  Minimum DRI version required by the driver.
 259  * \param ddxActual    Actual DDX version supplied __driCreateNewScreen.
 260  * \param ddxExpected  Minimum DDX version required by the driver.
 261  * \param drmActual    Actual DRM version supplied __driCreateNewScreen.
 262  * \param drmExpected  Minimum DRM version required by the driver.
 263  *
 264  * \returns \c GL_TRUE if all version requirements are met.  Otherwise,
 265  *          \c GL_FALSE is returned.
 266  *
 267  * \sa __driCreateNewScreen, driCheckDriDdxDrmVersions, __driUtilMessage
 268  */
 269 GLboolean
 270 driCheckDriDdxDrmVersions2(const char * driver_name,
 271                            const __DRIversion * driActual,
 272                            const __DRIversion * driExpected,
 273                            const __DRIversion * ddxActual,
 274                            const __DRIversion * ddxExpected,
 275                            const __DRIversion * drmActual,
 276                            const __DRIversion * drmExpected)
 277 {
 278    static const char format[] = "%s DRI driver expected %s version %d.%d.x "
 279        "but got version %d.%d.%d";
 280
 281
 282    /* Check the DRI version */
 283    if ( (driActual->major != driExpected->major)
 284         || (driActual->minor < driExpected->minor) ) {
 285       __driUtilMessage(format, driver_name, "DRI",
 286                        driExpected->major, driExpected->minor,
 287                        driActual->major, driActual->minor, driActual->patch);
 288       return GL_FALSE;
 289    }
 290
 291    /* Check that the DDX driver version is compatible */
 292    if ( (ddxActual->major != ddxExpected->major)
 293         || (ddxActual->minor < ddxExpected->minor) ) {
 294       __driUtilMessage(format, driver_name, "DDX",
 295                        ddxExpected->major, ddxExpected->minor,
 296                        ddxActual->major, ddxActual->minor, ddxActual->patch);
 297       return GL_FALSE;
 298    }
 299
 300    /* Check that the DRM driver version is compatible */
 301    if ( (drmActual->major != drmExpected->major)
 302         || (drmActual->minor < drmExpected->minor) ) {
 303       __driUtilMessage(format, driver_name, "DRM",
 304                        drmExpected->major, drmExpected->minor,
 305                        drmActual->major, drmActual->minor, drmActual->patch);
 306       return GL_FALSE;
 307    }
 308
 309    return GL_TRUE;
 310 }
 311
 312
 313 GLboolean driClipRectToFramebuffer( const GLframebuffer *buffer,
 314                                     GLint *x, GLint *y,
 315                                     GLsizei *width, GLsizei *height )
 316 {
 317    /* left clipping */
 318    if (*x < buffer->_Xmin) {
 319       *width -= (buffer->_Xmin - *x);
 320       *x = buffer->_Xmin;
 321    }
 322
 323    /* right clipping */
 324    if (*x + *width > buffer->_Xmax)
 325       *width -= (*x + *width - buffer->_Xmax - 1);
 326
 327    if (*width <= 0)
 328       return GL_FALSE;
 329
 330    /* bottom clipping */
 331    if (*y < buffer->_Ymin) {
 332       *height -= (buffer->_Ymin - *y);
 333       *y = buffer->_Ymin;
 334    }
 335
 336    /* top clipping */
 337    if (*y + *height > buffer->_Ymax)
 338       *height -= (*y + *height - buffer->_Ymax - 1);
 339
 340    if (*height <= 0)
 341       return GL_FALSE;
 342
 343    return GL_TRUE;
 344 }
 345
 346
 347
 348 /**
 349  * Creates a set of \c __GLcontextModes that a driver will expose.
 350  *
 351  * A set of \c __GLcontextModes will be created based on the supplied
 352  * parameters.  The number of modes processed will be 2 *
 353  * \c num_depth_stencil_bits * \c num_db_modes.
 354  *
 355  * For the most part, data is just copied from \c depth_bits, \c stencil_bits,
 356  * \c db_modes, and \c visType into each \c __GLcontextModes element.
 357  * However, the meanings of \c fb_format and \c fb_type require further
 358  * explanation.  The \c fb_format specifies which color components are in
 359  * each pixel and what the default order is.  For example, \c GL_RGB specifies
 360  * that red, green, blue are available and red is in the "most significant"
 361  * position and blue is in the "least significant".  The \c fb_type specifies
 362  * the bit sizes of each component and the actual ordering.  For example, if
 363  * \c GL_UNSIGNED_SHORT_5_6_5_REV is specified with \c GL_RGB, bits [15:11]
 364  * are the blue value, bits [10:5] are the green value, and bits [4:0] are
 365  * the red value.
 366  *
 367  * One sublte issue is the combination of \c GL_RGB  or \c GL_BGR and either
 368  * of the \c GL_UNSIGNED_INT_8_8_8_8 modes.  The resulting mask values in the
 369  * \c __GLcontextModes structure is \b identical to the \c GL_RGBA or
 370  * \c GL_BGRA case, except the \c alphaMask is zero.  This means that, as
 371  * far as this routine is concerned, \c GL_RGB with \c GL_UNSIGNED_INT_8_8_8_8
 372  * still uses 32-bits.
 373  *
 374  * If in doubt, look at the tables used in the function.
 375  *
 376  * \param ptr_to_modes  Pointer to a pointer to a linked list of
 377  *                      \c __GLcontextModes.  Upon completion, a pointer to
 378  *                      the next element to be process will be stored here.
 379  *                      If the function fails and returns \c GL_FALSE, this
 380  *                      value will be unmodified, but some elements in the
 381  *                      linked list may be modified.
 382  * \param fb_format     Format of the framebuffer.  Currently only \c GL_RGB,
 383  *                      \c GL_RGBA, \c GL_BGR, and \c GL_BGRA are supported.
 384  * \param fb_type       Type of the pixels in the framebuffer.  Currently only
 385  *                      \c GL_UNSIGNED_SHORT_5_6_5,
 386  *                      \c GL_UNSIGNED_SHORT_5_6_5_REV,
 387  *                      \c GL_UNSIGNED_INT_8_8_8_8, and
 388  *                      \c GL_UNSIGNED_INT_8_8_8_8_REV are supported.
 389  * \param depth_bits    Array of depth buffer sizes to be exposed.
 390  * \param stencil_bits  Array of stencil buffer sizes to be exposed.
 391  * \param num_depth_stencil_bits  Number of entries in both \c depth_bits and
 392  *                      \c stencil_bits.
 393  * \param db_modes      Array of buffer swap modes.  If an element has a
 394  *                      value of \c GLX_NONE, then it represents a
 395  *                      single-buffered mode.  Other valid values are
 396  *                      \c GLX_SWAP_EXCHANGE_OML, \c GLX_SWAP_COPY_OML, and
 397  *                      \c GLX_SWAP_UNDEFINED_OML.  See the
 398  *                      GLX_OML_swap_method extension spec for more details.
 399  * \param num_db_modes  Number of entries in \c db_modes.
 400  * \param visType       GLX visual type.  Usually either \c GLX_TRUE_COLOR or
 401  *                      \c GLX_DIRECT_COLOR.
 402  *
 403  * \returns
 404  * \c GL_TRUE on success or \c GL_FALSE on failure.  Currently the only
 405  * cause of failure is a bad parameter (i.e., unsupported \c fb_format or
 406  * \c fb_type).
 407  *
 408  * \todo
 409  * There is currently no way to support packed RGB modes (i.e., modes with
 410  * exactly 3 bytes per pixel) or floating-point modes.  This could probably
 411  * be done by creating some new, private enums with clever names likes
 412  * \c GL_UNSIGNED_3BYTE_8_8_8, \c GL_4FLOAT_32_32_32_32,
 413  * \c GL_4HALF_16_16_16_16, etc.  We can cross that bridge when we come to it.
 414  */
 415 GLboolean
 416 driFillInModes( __GLcontextModes ** ptr_to_modes,
 417                 GLenum fb_format, GLenum fb_type,
 418                 const uint8_t * depth_bits, const uint8_t * stencil_bits,
 419                 unsigned num_depth_stencil_bits,
 420                 const GLenum * db_modes, unsigned num_db_modes,
 421                 int visType )
 422 {
 423    static const uint8_t bits_table[3][4] = {
 424      /* R  G  B  A */
 425       { 5, 6, 5, 0 }, /* Any GL_UNSIGNED_SHORT_5_6_5 */
 426       { 8, 8, 8, 0 }, /* Any RGB with any GL_UNSIGNED_INT_8_8_8_8 */
 427       { 8, 8, 8, 8 }  /* Any RGBA with any GL_UNSIGNED_INT_8_8_8_8 */
 428    };
 429
 430    /* The following arrays are all indexed by the fb_type masked with 0x07.
 431     * Given the four supported fb_type values, this results in valid array
 432     * indices of 3, 4, 5, and 7.
 433     */
 434    static const uint32_t masks_table_rgb[8][4] = {
 435       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 436       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 437       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 438       { 0x0000F800, 0x000007E0, 0x0000001F, 0x00000000 }, /* 5_6_5       */
 439       { 0x0000001F, 0x000007E0, 0x0000F800, 0x00000000 }, /* 5_6_5_REV   */
 440       { 0xFF000000, 0x00FF0000, 0x0000FF00, 0x00000000 }, /* 8_8_8_8     */
 441       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 442       { 0x000000FF, 0x0000FF00, 0x00FF0000, 0x00000000 }  /* 8_8_8_8_REV */
 443    };
 444
 445    static const uint32_t masks_table_rgba[8][4] = {
 446       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 447       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 448       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 449       { 0x0000F800, 0x000007E0, 0x0000001F, 0x00000000 }, /* 5_6_5       */
 450       { 0x0000001F, 0x000007E0, 0x0000F800, 0x00000000 }, /* 5_6_5_REV   */
 451       { 0xFF000000, 0x00FF0000, 0x0000FF00, 0x000000FF }, /* 8_8_8_8     */
 452       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 453       { 0x000000FF, 0x0000FF00, 0x00FF0000, 0xFF000000 }, /* 8_8_8_8_REV */
 454    };
 455
 456    static const uint32_t masks_table_bgr[8][4] = {
 457       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 458       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 459       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 460       { 0x0000001F, 0x000007E0, 0x0000F800, 0x00000000 }, /* 5_6_5       */
 461       { 0x0000F800, 0x000007E0, 0x0000001F, 0x00000000 }, /* 5_6_5_REV   */
 462       { 0x0000FF00, 0x00FF0000, 0xFF000000, 0x00000000 }, /* 8_8_8_8     */
 463       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 464       { 0x00FF0000, 0x0000FF00, 0x000000FF, 0x00000000 }, /* 8_8_8_8_REV */
 465    };
 466
 467    static const uint32_t masks_table_bgra[8][4] = {
 468       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 469       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 470       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 471       { 0x0000001F, 0x000007E0, 0x0000F800, 0x00000000 }, /* 5_6_5       */
 472       { 0x0000F800, 0x000007E0, 0x0000001F, 0x00000000 }, /* 5_6_5_REV   */
 473       { 0x0000FF00, 0x00FF0000, 0xFF000000, 0x000000FF }, /* 8_8_8_8     */
 474       { 0x00000000, 0x00000000, 0x00000000, 0x00000000 },
 475       { 0x00FF0000, 0x0000FF00, 0x000000FF, 0xFF000000 }, /* 8_8_8_8_REV */
 476    };
 477
 478    static const uint8_t bytes_per_pixel[8] = {
 479       0, 0, 0, 2, 2, 4, 0, 4
 480    };
 481
 482    const uint8_t  * bits;
 483    const uint32_t * masks;
 484    const int index = fb_type & 0x07;
 485    __GLcontextModes * modes = *ptr_to_modes;
 486    unsigned i;
 487    unsigned j;
 488    unsigned k;
 489
 490
 491    if ( bytes_per_pixel[ index ] == 0 ) {
 492       fprintf( stderr, "[%s:%u] Framebuffer type 0x%04x has 0 bytes per pixel.\n",
 493                __func__, __LINE__, fb_type );
 494       return GL_FALSE;
 495    }
 496
 497
 498    /* Valid types are GL_UNSIGNED_SHORT_5_6_5 and GL_UNSIGNED_INT_8_8_8_8 and
 499     * the _REV versions.
 500     *
 501     * Valid formats are GL_RGBA, GL_RGB, and GL_BGRA.
 502     */
 503
 504    switch ( fb_format ) {
 505       case GL_RGB:
 506          bits = (bytes_per_pixel[ index ] == 2)
 507              ? bits_table[0] : bits_table[1];
 508          masks = masks_table_rgb[ index ];
 509          break;
 510
 511       case GL_RGBA:
 512          bits = (bytes_per_pixel[ index ] == 2)
 513              ? bits_table[0] : bits_table[2];
 514          masks = masks_table_rgba[ index ];
 515          break;
 516
 517       case GL_BGR:
 518          bits = (bytes_per_pixel[ index ] == 2)
 519              ? bits_table[0] : bits_table[1];
 520          masks = masks_table_bgr[ index ];
 521          break;
 522
 523       case GL_BGRA:
 524          bits = (bytes_per_pixel[ index ] == 2)
 525              ? bits_table[0] : bits_table[2];
 526          masks = masks_table_bgra[ index ];
 527          break;
 528
 529       default:
 530          fprintf( stderr, "[%s:%u] Framebuffer format 0x%04x is not GL_RGB, GL_RGBA, GL_BGR, or GL_BGRA.\n",
 531                __func__, __LINE__, fb_format );
 532          return GL_FALSE;
 533    }
 534
 535
 536     for ( k = 0 ; k < num_depth_stencil_bits ; k++ ) {
 537         for ( i = 0 ; i < num_db_modes ; i++ ) {
 538             for ( j = 0 ; j < 2 ; j++ ) {
 539
 540                 modes->redBits   = bits[0];
 541                 modes->greenBits = bits[1];
 542                 modes->blueBits  = bits[2];
 543                 modes->alphaBits = bits[3];
 544                 modes->redMask   = masks[0];
 545                 modes->greenMask = masks[1];
 546                 modes->blueMask  = masks[2];
 547                 modes->alphaMask = masks[3];
 548                 modes->rgbBits   = modes->redBits + modes->greenBits
 549                     + modes->blueBits + modes->alphaBits;
 550
 551                 modes->accumRedBits   = 16 * j;
 552                 modes->accumGreenBits = 16 * j;
 553                 modes->accumBlueBits  = 16 * j;
 554                 modes->accumAlphaBits = (masks[3] != 0) ? 16 * j : 0;
 555                 modes->visualRating = (j == 0) ? GLX_NONE : GLX_SLOW_CONFIG;
 556
 557                 modes->stencilBits = stencil_bits[k];
 558                 modes->depthBits = depth_bits[k];
 559
 560                 modes->visualType = visType;
 561                 modes->renderType = GLX_RGBA_BIT;
 562                 modes->drawableType = GLX_WINDOW_BIT;
 563                 modes->rgbMode = GL_TRUE;
 564
 565                 if ( db_modes[i] == GLX_NONE ) {
 566                     modes->doubleBufferMode = GL_FALSE;
 567                 }
 568                 else {
 569                     modes->doubleBufferMode = GL_TRUE;
 570                     modes->swapMethod = db_modes[i];
 571                 }
 572
 573                 modes = modes->next;
 574             }
 575         }
 576     }
 577
 578     *ptr_to_modes = modes;
 579     return GL_TRUE;
 580 }