initial check-in (post crash)

1 files changed, 1627 insertions, 0 deletions

diff --git a/src/glut/glx/glut_dstr.c b/src/glut/glx/glut_dstr.c
new file mode 100644
index 00000000000..74643b83be8
--- /dev/null
+++ b/src/glut/glx/glut_dstr.c
@@ -0,0 +1,1627 @@
+
+/* Copyright (c) Mark J. Kilgard, 1997. */
+
+/* This program is freely distributable without licensing fees
+   and is provided without guarantee or warrantee expressed or
+   implied. This program is -not- in the public domain. */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "glutint.h"
+
+/* glxcaps matches the criteria macros listed in glutint.h, but
+   only list the first set (those that correspond to GLX visual
+   attributes). */
+static int glxcap[NUM_GLXCAPS] =
+{
+  GLX_RGBA,
+  GLX_BUFFER_SIZE,
+  GLX_DOUBLEBUFFER,
+  GLX_STEREO,
+  GLX_AUX_BUFFERS,
+  GLX_RED_SIZE,
+  GLX_GREEN_SIZE,
+  GLX_BLUE_SIZE,
+  GLX_ALPHA_SIZE,
+  GLX_DEPTH_SIZE,
+  GLX_STENCIL_SIZE,
+  GLX_ACCUM_RED_SIZE,
+  GLX_ACCUM_GREEN_SIZE,
+  GLX_ACCUM_BLUE_SIZE,
+  GLX_ACCUM_ALPHA_SIZE,
+  GLX_LEVEL,
+};
+
+#ifdef TEST
+
+#if !defined(_WIN32)
+char *__glutProgramName = "dstr";
+Display *__glutDisplay;
+int __glutScreen;
+XVisualInfo *(*__glutDetermineVisualFromString) (char *string, Bool * treatAsSingle,
+  Criterion * requiredCriteria, int nRequired, int requiredMask, void **fbc) = NULL;
+char *__glutDisplayString = NULL;
+#endif
+static int verbose = 0;
+
+static char *compstr[] =
+{
+  "none", "=", "!=", "<=", ">=", ">", "<", "~"
+};
+static char *capstr[] =
+{
+  "rgba", "bufsize", "double", "stereo", "auxbufs", "red", "green", "blue", "alpha",
+  "depth", "stencil", "acred", "acgreen", "acblue", "acalpha", "level", "xvisual",
+  "transparent", "samples", "xstaticgray", "xgrayscale", "xstaticcolor", "xpseudocolor",
+  "xtruecolor", "xdirectcolor", "slow", "conformant", "num"
+};
+
+static void
+printCriteria(Criterion * criteria, int ncriteria)
+{
+  int i;
+  printf("Criteria: %d\n", ncriteria);
+  for (i = 0; i < ncriteria; i++) {
+    printf("  %s %s %d\n",
+      capstr[criteria[i].capability],
+      compstr[criteria[i].comparison],
+      criteria[i].value);
+  }
+}
+
+#endif /* TEST */
+
+static int isMesaGLX = -1;
+
+static int
+determineMesaGLX(void)
+{
+#ifdef GLX_VERSION_1_1
+  const char *vendor, *version, *ch;
+
+  vendor = glXGetClientString(__glutDisplay, GLX_VENDOR);
+  if (!strcmp(vendor, "Brian Paul")) {
+    version = glXGetClientString(__glutDisplay, GLX_VERSION);
+    for (ch = version; *ch != ' ' && *ch != '\0'; ch++);
+    for (; *ch == ' ' && *ch != '\0'; ch++);
+
+#define MESA_NAME "Mesa "  /* Trailing space is intentional. */
+
+    if (!strncmp(MESA_NAME, ch, sizeof(MESA_NAME) - 1)) {
+      return 1;
+    }
+  }
+#else
+  /* Recent versions for Mesa should support GLX 1.1 and
+     therefore glXGetClientString.  If we get into this case,
+     we would be compiling against a true OpenGL not supporting
+     GLX 1.1, and the resulting compiled library won't work well 
+     with Mesa then. */
+#endif
+  return 0;
+}
+
+static XVisualInfo **
+getMesaVisualList(int *n)
+{
+  XVisualInfo **vlist, *vinfo;
+  int attribs[23];
+  int i, x, cnt;
+
+  vlist = (XVisualInfo **) malloc((32 + 16) * sizeof(XVisualInfo *));
+  if (!vlist)
+    __glutFatalError("out of memory.");
+
+  cnt = 0;
+  for (i = 0; i < 32; i++) {
+    x = 0;
+    attribs[x] = GLX_RGBA;
+    x++;
+    attribs[x] = GLX_RED_SIZE;
+    x++;
+    attribs[x] = 1;
+    x++;
+    attribs[x] = GLX_GREEN_SIZE;
+    x++;
+    attribs[x] = 1;
+    x++;
+    attribs[x] = GLX_BLUE_SIZE;
+    x++;
+    attribs[x] = 1;
+    x++;
+    if (i & 1) {
+      attribs[x] = GLX_DEPTH_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+    }
+    if (i & 2) {
+      attribs[x] = GLX_STENCIL_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+    }
+    if (i & 4) {
+      attribs[x] = GLX_ACCUM_RED_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+      attribs[x] = GLX_ACCUM_GREEN_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+      attribs[x] = GLX_ACCUM_BLUE_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+    }
+    if (i & 8) {
+      attribs[x] = GLX_ALPHA_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+      if (i & 4) {
+        attribs[x] = GLX_ACCUM_ALPHA_SIZE;
+        x++;
+        attribs[x] = 1;
+        x++;
+      }
+    }
+    if (i & 16) {
+      attribs[x] = GLX_DOUBLEBUFFER;
+      x++;
+    }
+    attribs[x] = None;
+    x++;
+    assert(x <= sizeof(attribs) / sizeof(attribs[0]));
+    vinfo = glXChooseVisual(__glutDisplay, __glutScreen, attribs);
+    if (vinfo) {
+      vlist[cnt] = vinfo;
+      cnt++;
+    }
+  }
+  for (i = 0; i < 16; i++) {
+    x = 0;
+    if (i & 1) {
+      attribs[x] = GLX_DEPTH_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+    }
+    if (i & 2) {
+      attribs[x] = GLX_STENCIL_SIZE;
+      x++;
+      attribs[x] = 1;
+      x++;
+    }
+    if (i & 4) {
+      attribs[x] = GLX_DOUBLEBUFFER;
+      x++;
+    }
+    if (i & 8) {
+      attribs[x] = GLX_LEVEL;
+      x++;
+      attribs[x] = 1;
+      x++;
+#if defined(GLX_TRANSPARENT_TYPE_EXT) && defined(GLX_TRANSPARENT_INDEX_EXT)
+      attribs[x] = GLX_TRANSPARENT_TYPE_EXT;
+      x++;
+      attribs[x] = GLX_TRANSPARENT_INDEX_EXT;
+      x++;
+#endif
+    }
+    attribs[x] = None;
+    x++;
+    assert(x <= sizeof(attribs) / sizeof(attribs[0]));
+    vinfo = glXChooseVisual(__glutDisplay, __glutScreen, attribs);
+    if (vinfo) {
+      vlist[cnt] = vinfo;
+      cnt++;
+    }
+  }
+
+  *n = cnt;
+  return vlist;
+}
+
+static FrameBufferMode *
+loadVisuals(int *nitems_return)
+{
+  XVisualInfo *vinfo, **vlist, template;
+  FrameBufferMode *fbmodes, *mode;
+  int n, i, j, rc, glcapable;
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIS_multisample)
+  int multisample;
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_info)
+  int visual_info;
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_rating)
+  int visual_rating;
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIX_fbconfig)
+  int fbconfig;
+#endif
+
+  isMesaGLX = determineMesaGLX();
+  if (isMesaGLX) {
+    vlist = getMesaVisualList(&n);
+  } else {
+#if !defined(_WIN32)
+    template.screen = __glutScreen;
+    vinfo = XGetVisualInfo(__glutDisplay, VisualScreenMask, &template, &n);
+#else
+    vinfo = XGetVisualInfo(__glutDisplay, 0, &template, &n);
+#endif
+    if (vinfo == NULL) {
+      *nitems_return = 0;
+      return NULL;
+    }
+    assert(n > 0);
+
+    /* Make an array of XVisualInfo* pointers to help the Mesa
+       case because each glXChooseVisual call returns a
+       distinct XVisualInfo*, not a handy array like
+       XGetVisualInfo.  (Mesa expects us to return the _exact_
+       pointer returned by glXChooseVisual so we could not just
+       copy the returned structure.) */
+    vlist = (XVisualInfo **) malloc(n * sizeof(XVisualInfo *));
+    if (!vlist)
+      __glutFatalError("out of memory.");
+    for (i = 0; i < n; i++) {
+      vlist[i] = &vinfo[i];
+    }
+  }
+
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIS_multisample)
+  multisample = __glutIsSupportedByGLX("GLX_SGIS_multisample");
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_info)
+  visual_info = __glutIsSupportedByGLX("GLX_EXT_visual_info");
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_rating)
+  visual_rating = __glutIsSupportedByGLX("GLX_EXT_visual_rating");
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIX_fbconfig)
+  fbconfig = __glutIsSupportedByGLX("GLX_SGIX_fbconfig");
+#endif
+
+  fbmodes = (FrameBufferMode *) malloc(n * sizeof(FrameBufferMode));
+  if (fbmodes == NULL) {
+    *nitems_return = -1;
+    return NULL;
+  }
+  for (i = 0; i < n; i++) {
+    mode = &fbmodes[i];
+    mode->vi = vlist[i];
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIX_fbconfig)
+    mode->fbc = NULL;
+#endif
+    rc = glXGetConfig(__glutDisplay, vlist[i], GLX_USE_GL, &glcapable);
+    if (rc == 0 && glcapable) {
+      mode->valid = 1;  /* Assume the best until proven
+                           otherwise. */
+      for (j = 0; j < NUM_GLXCAPS; j++) {
+        rc = glXGetConfig(__glutDisplay, vlist[i], glxcap[j], &mode->cap[j]);
+        if (rc != 0) {
+          mode->valid = 0;
+        }
+      }
+#if defined(_WIN32)
+      mode->cap[XVISUAL] = ChoosePixelFormat(XHDC, vlist[i]);
+#else
+      mode->cap[XVISUAL] = (int) vlist[i]->visualid;
+#endif
+      mode->cap[XSTATICGRAY] = 0;
+      mode->cap[XGRAYSCALE] = 0;
+      mode->cap[XSTATICCOLOR] = 0;
+      mode->cap[XPSEUDOCOLOR] = 0;
+      mode->cap[XTRUECOLOR] = 0;
+      mode->cap[XDIRECTCOLOR] = 0;
+#if !defined(_WIN32)
+#if defined(__cplusplus) || defined(c_plusplus)
+      switch (vlist[i]->c_class) {
+#else
+      switch (vlist[i]->class) {
+#endif
+      case StaticGray:
+        mode->cap[XSTATICGRAY] = 1;
+        break;
+      case GrayScale:
+        mode->cap[XGRAYSCALE] = 1;
+        break;
+      case StaticColor:
+        mode->cap[XSTATICCOLOR] = 1;
+        break;
+      case PseudoColor:
+        mode->cap[XPSEUDOCOLOR] = 1;
+        break;
+      case TrueColor:
+        mode->cap[XTRUECOLOR] = 1;
+        break;
+      case DirectColor:
+        mode->cap[XDIRECTCOLOR] = 1;
+        break;
+      }
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_rating)
+      if (visual_rating) {
+        int rating;
+
+/* [email protected] reported that DEC UNIX (OSF1) V4.0
+   564 for Alpha did not properly define GLX_VISUAL_CAVEAT_EXT
+   in <GL/glx.h> despite claiming to support
+   GLX_EXT_visual_rating. */
+#ifndef GLX_VISUAL_CAVEAT_EXT
+#define GLX_VISUAL_CAVEAT_EXT 0x20
+#endif
+
+        rc = glXGetConfig(__glutDisplay,
+	  vlist[i], GLX_VISUAL_CAVEAT_EXT, &rating);
+        if (rc != 0) {
+          mode->cap[SLOW] = 0;
+          mode->cap[CONFORMANT] = 1;
+        } else {
+          switch (rating) {
+          case GLX_SLOW_VISUAL_EXT:
+            mode->cap[SLOW] = 1;
+            mode->cap[CONFORMANT] = 1;
+            break;
+
+/* IRIX 5.3 for the R10K Indigo2 may have shipped without this
+   properly defined in /usr/include/GL/glxtokens.h */
+#ifndef GLX_NON_CONFORMANT_VISUAL_EXT
+#define GLX_NON_CONFORMANT_VISUAL_EXT   0x800D
+#endif
+
+          case GLX_NON_CONFORMANT_VISUAL_EXT:
+            mode->cap[SLOW] = 0;
+            mode->cap[CONFORMANT] = 0;
+            break;
+          case GLX_NONE_EXT:
+          default:     /* XXX Hopefully this is a good default
+                           assumption. */
+            mode->cap[SLOW] = 0;
+            mode->cap[CONFORMANT] = 1;
+            break;
+          }
+        }
+      } else {
+        mode->cap[TRANSPARENT] = 0;
+      }
+#else
+      mode->cap[SLOW] = 0;
+      mode->cap[CONFORMANT] = 1;
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_info)
+      if (visual_info) {
+        int transparent;
+
+/* [email protected] reported that DEC UNIX (OSF1) V4.0
+   564 for Alpha did not properly define
+   GLX_TRANSPARENT_TYPE_EXT in <GL/glx.h> despite claiming to
+   support GLX_EXT_visual_info. */
+#ifndef GLX_TRANSPARENT_TYPE_EXT
+#define GLX_TRANSPARENT_TYPE_EXT 0x23
+#endif
+
+        rc = glXGetConfig(__glutDisplay,
+          vlist[i], GLX_TRANSPARENT_TYPE_EXT, &transparent);
+        if (rc != 0) {
+          mode->cap[TRANSPARENT] = 0;
+        } else {
+          mode->cap[TRANSPARENT] = (transparent != GLX_NONE_EXT);
+        }
+      } else {
+        mode->cap[TRANSPARENT] = 0;
+      }
+#else
+      mode->cap[TRANSPARENT] = 0;
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIS_multisample)
+      if (multisample) {
+        rc = glXGetConfig(__glutDisplay,
+	  vlist[i], GLX_SAMPLES_SGIS, &mode->cap[SAMPLES]);
+        if (rc != 0) {
+          mode->cap[SAMPLES] = 0;
+        }
+      } else {
+        mode->cap[SAMPLES] = 0;
+      }
+#else
+      mode->cap[SAMPLES] = 0;
+#endif
+    } else {
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIX_fbconfig)
+      if (fbconfig) {
+        GLXFBConfigSGIX fbc;
+        int fbconfigID, drawType, renderType;
+
+        fbc = glXGetFBConfigFromVisualSGIX(__glutDisplay, vlist[i]);
+        if (fbc) {
+          rc = glXGetFBConfigAttribSGIX(__glutDisplay, fbc,
+	    GLX_FBCONFIG_ID_SGIX, &fbconfigID);
+          if ((rc == 0) && (fbconfigID != None)) {
+            rc = glXGetFBConfigAttribSGIX(__glutDisplay, fbc,
+	      GLX_DRAWABLE_TYPE_SGIX, &drawType);
+            if ((rc == 0) && (drawType & GLX_WINDOW_BIT_SGIX)) {
+              rc = glXGetFBConfigAttribSGIX(__glutDisplay, fbc,
+	        GLX_RENDER_TYPE_SGIX, &renderType);
+              if ((rc == 0) && (renderType & GLX_RGBA_BIT_SGIX)) {
+                mode->fbc = fbc;
+                mode->valid = 1;  /* Assume the best until
+                                     proven otherwise. */
+
+		assert(glxcap[0] == GLX_RGBA);
+                mode->cap[0] = 1;
+
+                /* Start with "j = 1" to skip the GLX_RGBA attribute. */
+                for (j = 1; j < NUM_GLXCAPS; j++) {
+                  rc = glXGetFBConfigAttribSGIX(__glutDisplay,
+		    fbc, glxcap[j], &mode->cap[j]);
+                  if (rc != 0) {
+                    mode->valid = 0;
+                  }
+                }
+
+                mode->cap[XVISUAL] = (int) vlist[i]->visualid;
+                mode->cap[XSTATICGRAY] = 0;
+                mode->cap[XGRAYSCALE] = 0;
+                mode->cap[XSTATICCOLOR] = 0;
+                mode->cap[XPSEUDOCOLOR] = 0;
+                mode->cap[XTRUECOLOR] = 0;
+                mode->cap[XDIRECTCOLOR] = 0;
+#if defined(__cplusplus) || defined(c_plusplus)
+                switch (vlist[i]->c_class) {
+#else
+                switch (vlist[i]->class) {
+#endif
+                case StaticGray:
+                  mode->cap[XSTATICGRAY] = 1;
+                  break;
+                case GrayScale:
+                  mode->cap[XGRAYSCALE] = 1;
+                  break;
+                case StaticColor:
+                  mode->cap[XSTATICCOLOR] = 1;
+                  break;
+                case PseudoColor:
+                  mode->cap[XPSEUDOCOLOR] = 1;
+                  break;
+                case TrueColor:
+                  mode->cap[XTRUECOLOR] = 1;
+                  break;
+                case DirectColor:
+                  mode->cap[XDIRECTCOLOR] = 1;
+                  break;
+                }
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_rating)
+                if (visual_rating) {
+                  int rating;
+
+/* [email protected] reported that DEC UNIX (OSF1) V4.0
+   564 for Alpha did not properly define GLX_VISUAL_CAVEAT_EXT
+   in <GL/glx.h> despite claiming to support
+   GLX_EXT_visual_rating. */
+#ifndef GLX_VISUAL_CAVEAT_EXT
+#define GLX_VISUAL_CAVEAT_EXT 0x20
+#endif
+
+                  rc = glXGetFBConfigAttribSGIX(__glutDisplay,
+		    fbc, GLX_VISUAL_CAVEAT_EXT, &rating);
+                  if (rc != 0) {
+                    mode->cap[SLOW] = 0;
+                    mode->cap[CONFORMANT] = 1;
+                  } else {
+                    switch (rating) {
+                    case GLX_SLOW_VISUAL_EXT:
+                      mode->cap[SLOW] = 1;
+                      mode->cap[CONFORMANT] = 1;
+                      break;
+
+/* IRIX 5.3 for the R10K Indigo2 may have shipped without this
+   properly defined in /usr/include/GL/glxtokens.h */
+#ifndef GLX_NON_CONFORMANT_VISUAL_EXT
+#define GLX_NON_CONFORMANT_VISUAL_EXT   0x800D
+#endif
+
+                    case GLX_NON_CONFORMANT_VISUAL_EXT:
+                      mode->cap[SLOW] = 0;
+                      mode->cap[CONFORMANT] = 0;
+                      break;
+                    case GLX_NONE_EXT:
+                    default:  /* XXX Hopefully this is a good
+                                  default assumption. */
+                      mode->cap[SLOW] = 0;
+                      mode->cap[CONFORMANT] = 1;
+                      break;
+                    }
+                  }
+                } else {
+                  mode->cap[TRANSPARENT] = 0;
+                }
+#else
+                mode->cap[SLOW] = 0;
+                mode->cap[CONFORMANT] = 1;
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_info)
+                if (visual_info) {
+                  int transparent;
+
+/* [email protected] reported that DEC UNIX (OSF1) V4.0
+   564 for Alpha did not properly define
+   GLX_TRANSPARENT_TYPE_EXT in <GL/glx.h> despite claiming to
+   support GLX_EXT_visual_info. */
+#ifndef GLX_TRANSPARENT_TYPE_EXT
+#define GLX_TRANSPARENT_TYPE_EXT 0x23
+#endif
+
+                  rc = glXGetFBConfigAttribSGIX(__glutDisplay,
+		    fbc, GLX_TRANSPARENT_TYPE_EXT, &transparent);
+                  if (rc != 0) {
+                    mode->cap[TRANSPARENT] = 0;
+                  } else {
+                    mode->cap[TRANSPARENT] = (transparent != GLX_NONE_EXT);
+                  }
+                } else {
+                  mode->cap[TRANSPARENT] = 0;
+                }
+#else
+                mode->cap[TRANSPARENT] = 0;
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIS_multisample)
+                if (multisample) {
+                  rc = glXGetFBConfigAttribSGIX(__glutDisplay,
+		    fbc, GLX_SAMPLES_SGIS, &mode->cap[SAMPLES]);
+                  if (rc != 0) {
+                    mode->cap[SAMPLES] = 0;
+                  }
+                } else {
+                  mode->cap[SAMPLES] = 0;
+                }
+#else
+                mode->cap[SAMPLES] = 0;
+#endif
+
+              } else {
+                /* Fbconfig is not RGBA; GLUT only uses RGBA
+                   FBconfigs. */
+                /* XXX Code could be exteneded to handle color
+                   index FBconfigs, but seems a color index
+                   window-renderable FBconfig would also be
+                   advertised as an X visual. */
+                mode->valid = 0;
+              }
+            } else {
+              /* Fbconfig does not support window rendering;
+                 not a valid FBconfig for GLUT windows. */
+              mode->valid = 0;
+            }
+          } else {
+            /* FBconfig ID is None (zero); not a valid
+               FBconfig. */
+            mode->valid = 0;
+          }
+        } else {
+          /* FBconfig ID is None (zero); not a valid FBconfig. */
+          mode->valid = 0;
+        }
+      } else {
+        /* No SGIX_fbconfig GLX sever implementation support. */
+        mode->valid = 0;
+      }
+#else
+      /* No SGIX_fbconfig GLX extension API support. */
+      mode->valid = 0;
+#endif
+    }
+  }
+
+  free(vlist);
+  *nitems_return = n;
+  return fbmodes;
+}
+
+static XVisualInfo *
+findMatch(FrameBufferMode * fbmodes, int nfbmodes,
+  Criterion * criteria, int ncriteria, void **fbc)
+{
+  FrameBufferMode *found;
+  int *bestScore, *thisScore;
+  int i, j, numok, result, worse, better;
+
+  found = NULL;
+  numok = 1;            /* "num" capability is indexed from 1,
+                           not 0. */
+
+  /* XXX alloca canidate. */
+  bestScore = (int *) malloc(ncriteria * sizeof(int));
+  if (!bestScore)
+    __glutFatalError("out of memory.");
+  for (j = 0; j < ncriteria; j++) {
+    /* Very negative number. */
+    bestScore[j] = -32768;
+  }
+
+  /* XXX alloca canidate. */
+  thisScore = (int *) malloc(ncriteria * sizeof(int));
+  if (!thisScore)
+    __glutFatalError("out of memory.");
+
+  for (i = 0; i < nfbmodes; i++) {
+    if (fbmodes[i].valid) {
+#ifdef TEST
+#if !defined(_WIN32)
+      if (verbose)
+        printf("Visual 0x%x\n", fbmodes[i].vi->visualid);
+#endif
+#endif
+
+      worse = 0;
+      better = 0;
+
+      for (j = 0; j < ncriteria; j++) {
+        int cap, cvalue, fbvalue;
+
+        cap = criteria[j].capability;
+        cvalue = criteria[j].value;
+        if (cap == NUM) {
+          fbvalue = numok;
+        } else {
+          fbvalue = fbmodes[i].cap[cap];
+        }
+#ifdef TEST
+        if (verbose)
+          printf("  %s %s %d to %d\n",
+            capstr[cap], compstr[criteria[j].comparison], cvalue, fbvalue);
+#endif
+        switch (criteria[j].comparison) {
+        case EQ:
+          result = cvalue == fbvalue;
+          thisScore[j] = 1;
+          break;
+        case NEQ:
+          result = cvalue != fbvalue;
+          thisScore[j] = 1;
+          break;
+        case LT:
+          result = fbvalue < cvalue;
+          thisScore[j] = fbvalue - cvalue;
+          break;
+        case GT:
+          result = fbvalue > cvalue;
+          thisScore[j] = fbvalue - cvalue;
+          break;
+        case LTE:
+          result = fbvalue <= cvalue;
+          thisScore[j] = fbvalue - cvalue;
+          break;
+        case GTE:
+          result = (fbvalue >= cvalue);
+          thisScore[j] = fbvalue - cvalue;
+          break;
+        case MIN:
+          result = fbvalue >= cvalue;
+          thisScore[j] = cvalue - fbvalue;
+          break;
+        }
+
+#ifdef TEST
+        if (verbose)
+          printf("                result=%d   score=%d   bestScore=%d\n", result, thisScore[j], bestScore[j]);
+#endif
+
+        if (result) {
+          if (better || thisScore[j] > bestScore[j]) {
+            better = 1;
+          } else if (thisScore[j] == bestScore[j]) {
+            /* Keep looking. */
+          } else {
+            goto nextFBM;
+          }
+        } else {
+          if (cap == NUM) {
+            worse = 1;
+          } else {
+            goto nextFBM;
+          }
+        }
+
+      }
+
+      if (better && !worse) {
+        found = &fbmodes[i];
+        for (j = 0; j < ncriteria; j++) {
+          bestScore[j] = thisScore[j];
+        }
+      }
+      numok++;
+
+    nextFBM:;
+
+    }
+  }
+  free(bestScore);
+  free(thisScore);
+  if (found) {
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIX_fbconfig)
+    *fbc = found->fbc;
+#endif
+    return found->vi;
+  } else {
+    return NULL;
+  }
+}
+
+static int
+parseCriteria(char *word, Criterion * criterion, int *mask,
+  Bool * allowDoubleAsSingle)
+{
+  char *cstr, *vstr, *response;
+  int comparator, value;
+  int rgb, rgba, acc, acca, count, i;
+
+  cstr = strpbrk(word, "=><!~");
+  if (cstr) {
+    switch (cstr[0]) {
+    case '=':
+      comparator = EQ;
+      vstr = &cstr[1];
+      break;
+    case '~':
+      comparator = MIN;
+      vstr = &cstr[1];
+      break;
+    case '>':
+      if (cstr[1] == '=') {
+        comparator = GTE;
+        vstr = &cstr[2];
+      } else {
+        comparator = GT;
+        vstr = &cstr[1];
+      }
+      break;
+    case '<':
+      if (cstr[1] == '=') {
+        comparator = LTE;
+        vstr = &cstr[2];
+      } else {
+        comparator = LT;
+        vstr = &cstr[1];
+      }
+      break;
+    case '!':
+      if (cstr[1] == '=') {
+        comparator = NEQ;
+        vstr = &cstr[2];
+      } else {
+        return -1;
+      }
+      break;
+    default:
+      return -1;
+    }
+    value = (int) strtol(vstr, &response, 0);
+    if (response == vstr) {
+      /* Not a valid number. */
+      return -1;
+    }
+    *cstr = '\0';
+  } else {
+    comparator = NONE;
+  }
+  switch (word[0]) {
+  case 'a':
+    if (!strcmp(word, "alpha")) {
+      criterion[0].capability = ALPHA_SIZE;
+      if (comparator == NONE) {
+        criterion[0].comparison = GTE;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << RGBA);
+      *mask |= (1 << ALPHA_SIZE);
+      *mask |= (1 << RGBA_MODE);
+      return 1;
+    }
+    acca = !strcmp(word, "acca");
+    acc = !strcmp(word, "acc");
+    if (acc || acca) {
+      criterion[0].capability = ACCUM_RED_SIZE;
+      criterion[1].capability = ACCUM_GREEN_SIZE;
+      criterion[2].capability = ACCUM_BLUE_SIZE;
+      criterion[3].capability = ACCUM_ALPHA_SIZE;
+      if (acca) {
+        count = 4;
+      } else {
+        count = 3;
+        criterion[3].comparison = MIN;
+        criterion[3].value = 0;
+      }
+      if (comparator == NONE) {
+        comparator = GTE;
+        value = 8;
+      }
+      for (i = 0; i < count; i++) {
+        criterion[i].comparison = comparator;
+        criterion[i].value = value;
+      }
+      *mask |= (1 << ACCUM_RED_SIZE);
+      return 4;
+    }
+    if (!strcmp(word, "auxbufs")) {
+      criterion[0].capability = AUX_BUFFERS;
+      if (comparator == NONE) {
+        criterion[0].comparison = MIN;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << AUX_BUFFERS);
+      return 1;
+    }
+    return -1;
+  case 'b':
+    if (!strcmp(word, "blue")) {
+      criterion[0].capability = BLUE_SIZE;
+      if (comparator == NONE) {
+        criterion[0].comparison = GTE;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << RGBA);
+      *mask |= (1 << RGBA_MODE);
+      return 1;
+    }
+    if (!strcmp(word, "buffer")) {
+      criterion[0].capability = BUFFER_SIZE;
+      if (comparator == NONE) {
+        criterion[0].comparison = GTE;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      return 1;
+    }
+    return -1;
+  case 'c':
+    if (!strcmp(word, "conformant")) {
+      criterion[0].capability = CONFORMANT;
+      if (comparator == NONE) {
+        criterion[0].comparison = EQ;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << CONFORMANT);
+      return 1;
+    }
+    return -1;
+  case 'd':
+    if (!strcmp(word, "depth")) {
+      criterion[0].capability = DEPTH_SIZE;
+      if (comparator == NONE) {
+        criterion[0].comparison = GTE;
+        criterion[0].value = 12;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << DEPTH_SIZE);
+      return 1;
+    }
+    if (!strcmp(word, "double")) {
+      criterion[0].capability = DOUBLEBUFFER;
+      if (comparator == NONE) {
+        criterion[0].comparison = EQ;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << DOUBLEBUFFER);
+      return 1;
+    }
+    return -1;
+  case 'g':
+    if (!strcmp(word, "green")) {
+      criterion[0].capability = GREEN_SIZE;
+      if (comparator == NONE) {
+        criterion[0].comparison = GTE;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << RGBA);
+      *mask |= (1 << RGBA_MODE);
+      return 1;
+    }
+    return -1;
+  case 'i':
+    if (!strcmp(word, "index")) {
+      criterion[0].capability = RGBA;
+      criterion[0].comparison = EQ;
+      criterion[0].value = 0;
+      *mask |= (1 << RGBA);
+      *mask |= (1 << CI_MODE);
+      criterion[1].capability = BUFFER_SIZE;
+      if (comparator == NONE) {
+        criterion[1].comparison = GTE;
+        criterion[1].value = 1;
+      } else {
+        criterion[1].comparison = comparator;
+        criterion[1].value = value;
+      }
+      return 2;
+    }
+    return -1;
+  case 'l':
+    if (!strcmp(word, "luminance")) {
+      criterion[0].capability = RGBA;
+      criterion[0].comparison = EQ;
+      criterion[0].value = 1;
+
+      criterion[1].capability = RED_SIZE;
+      if (comparator == NONE) {
+        criterion[1].comparison = GTE;
+        criterion[1].value = 1;
+      } else {
+        criterion[1].comparison = comparator;
+        criterion[1].value = value;
+      }
+
+      criterion[2].capability = GREEN_SIZE;
+      criterion[2].comparison = EQ;
+      criterion[2].value = 0;
+
+      criterion[3].capability = BLUE_SIZE;
+      criterion[3].comparison = EQ;
+      criterion[3].value = 0;
+
+      *mask |= (1 << RGBA);
+      *mask |= (1 << RGBA_MODE);
+      *mask |= (1 << LUMINANCE_MODE);
+      return 4;
+    }
+    return -1;
+  case 'n':
+    if (!strcmp(word, "num")) {
+      criterion[0].capability = NUM;
+      if (comparator == NONE) {
+        return -1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+        return 1;
+      }
+    }
+    return -1;
+  case 'r':
+    if (!strcmp(word, "red")) {
+      criterion[0].capability = RED_SIZE;
+      if (comparator == NONE) {
+        criterion[0].comparison = GTE;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << RGBA);
+      *mask |= (1 << RGBA_MODE);
+      return 1;
+    }
+    rgba = !strcmp(word, "rgba");
+    rgb = !strcmp(word, "rgb");
+    if (rgb || rgba) {
+      criterion[0].capability = RGBA;
+      criterion[0].comparison = EQ;
+      criterion[0].value = 1;
+
+      criterion[1].capability = RED_SIZE;
+      criterion[2].capability = GREEN_SIZE;
+      criterion[3].capability = BLUE_SIZE;
+      criterion[4].capability = ALPHA_SIZE;
+      if (rgba) {
+        count = 5;
+      } else {
+        count = 4;
+        criterion[4].comparison = MIN;
+        criterion[4].value = 0;
+      }
+      if (comparator == NONE) {
+        comparator = GTE;
+        value = 1;
+      }
+      for (i = 1; i < count; i++) {
+        criterion[i].comparison = comparator;
+        criterion[i].value = value;
+      }
+      *mask |= (1 << RGBA);
+      *mask |= (1 << RGBA_MODE);
+      return 5;
+    }
+    return -1;
+  case 's':
+    if (!strcmp(word, "stencil")) {
+      criterion[0].capability = STENCIL_SIZE;
+      if (comparator == NONE) {
+        criterion[0].comparison = MIN;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << STENCIL_SIZE);
+      return 1;
+    }
+    if (!strcmp(word, "single")) {
+      criterion[0].capability = DOUBLEBUFFER;
+      if (comparator == NONE) {
+        criterion[0].comparison = EQ;
+        criterion[0].value = 0;
+        *allowDoubleAsSingle = True;
+        *mask |= (1 << DOUBLEBUFFER);
+        return 1;
+      } else {
+        return -1;
+      }
+    }
+    if (!strcmp(word, "stereo")) {
+      criterion[0].capability = STEREO;
+      if (comparator == NONE) {
+        criterion[0].comparison = EQ;
+        criterion[0].value = 1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << STEREO);
+      return 1;
+    }
+    if (!strcmp(word, "samples")) {
+      criterion[0].capability = SAMPLES;
+      if (comparator == NONE) {
+        criterion[0].comparison = LTE;
+        criterion[0].value = 4;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << SAMPLES);
+      return 1;
+    }
+    if (!strcmp(word, "slow")) {
+      criterion[0].capability = SLOW;
+      if (comparator == NONE) {
+        /* Just "slow" means permit fast visuals, but accept
+           slow ones in preference. Presumably the slow ones
+           must be higher quality or something else desirable. */
+        criterion[0].comparison = GTE;
+        criterion[0].value = 0;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+      }
+      *mask |= (1 << SLOW);
+      return 1;
+    }
+    return -1;
+#if defined(_WIN32)
+  case 'w':
+    if (!strcmp(word, "win32pfd")) {
+      criterion[0].capability = XVISUAL;
+      if (comparator == NONE) {
+        return -1;
+      } else {
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+        return 1;
+      }
+    }
+    return -1;
+#endif
+#if !defined(_WIN32)
+  case 'x':
+    if (!strcmp(word, "xvisual")) {
+      if (comparator == NONE) {
+        return -1;
+      } else {
+        criterion[0].capability = XVISUAL;
+        criterion[0].comparison = comparator;
+        criterion[0].value = value;
+        /* Set everything in "mask" so that no default criteria
+           get used.  Assume the program really wants the
+           xvisual specified. */
+        *mask |= ~0;
+        return 1;
+      }
+    }
+    /* Be a little over-eager to fill in the comparison and
+       value so we won't have to replicate the code after each
+       string match. */
+    if (comparator == NONE) {
+      criterion[0].comparison = EQ;
+      criterion[0].value = 1;
+    } else {
+      criterion[0].comparison = comparator;
+      criterion[0].value = value;
+    }
+
+    if (!strcmp(word, "xstaticgray")) {
+      criterion[0].capability = XSTATICGRAY;
+      *mask |= (1 << XSTATICGRAY);  /* Indicates _any_ visual
+                                       class selected. */
+      return 1;
+    }
+    if (!strcmp(word, "xgrayscale")) {
+      criterion[0].capability = XGRAYSCALE;
+      *mask |= (1 << XSTATICGRAY);  /* Indicates _any_ visual
+                                       class selected. */
+      return 1;
+    }
+    if (!strcmp(word, "xstaticcolor")) {
+      criterion[0].capability = XSTATICCOLOR;
+      *mask |= (1 << XSTATICGRAY);  /* Indicates _any_ visual
+                                       class selected. */
+      return 1;
+    }
+    if (!strcmp(word, "xpseudocolor")) {
+      criterion[0].capability = XPSEUDOCOLOR;
+      *mask |= (1 << XSTATICGRAY);  /* Indicates _any_ visual
+                                       class selected. */
+      return 1;
+    }
+    if (!strcmp(word, "xtruecolor")) {
+      criterion[0].capability = XTRUECOLOR;
+      *mask |= (1 << XSTATICGRAY);  /* Indicates _any_ visual
+                                       class selected. */
+      return 1;
+    }
+    if (!strcmp(word, "xdirectcolor")) {
+      criterion[0].capability = XDIRECTCOLOR;
+      *mask |= (1 << XSTATICGRAY);  /* Indicates _any_ visual
+                                       class selected. */
+      return 1;
+    }
+    return -1;
+#endif
+  default:
+    return -1;
+  }
+}
+
+static Criterion *
+parseModeString(char *mode, int *ncriteria, Bool * allowDoubleAsSingle,
+  Criterion * requiredCriteria, int nRequired, int requiredMask)
+{
+  Criterion *criteria = NULL;
+  int n, mask, parsed, i;
+  char *copy, *word;
+
+  *allowDoubleAsSingle = False;
+  copy = __glutStrdup(mode);
+  /* Attempt to estimate how many criteria entries should be
+     needed. */
+  n = 0;
+  word = strtok(copy, " \t");
+  while (word) {
+    n++;
+    word = strtok(NULL, " \t");
+  }
+  /* Overestimate by 4 times ("rgba" might add four criteria
+     entries) plus add in possible defaults plus space for
+     required criteria. */
+  criteria = (Criterion *) malloc((4 * n + 30 + nRequired) * sizeof(Criterion));
+  if (!criteria) {
+    __glutFatalError("out of memory.");
+  }
+
+  /* Re-copy the copy of the mode string. */
+  strcpy(copy, mode);
+
+  /* First add the required criteria (these match at the
+     highest priority). Typically these will be used to force a
+     specific level (layer), transparency, and/or visual type. */
+  mask = requiredMask;
+  for (i = 0; i < nRequired; i++) {
+    criteria[i] = requiredCriteria[i];
+  }
+  n = nRequired;
+
+  word = strtok(copy, " \t");
+  while (word) {
+    parsed = parseCriteria(word, &criteria[n], &mask, allowDoubleAsSingle);
+    if (parsed >= 0) {
+      n += parsed;
+    } else {
+      __glutWarning("Unrecognized display string word: %s (ignoring)\n", word);
+    }
+    word = strtok(NULL, " \t");
+  }
+
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIS_multisample)
+  if (__glutIsSupportedByGLX("GLX_SGIS_multisample")) {
+    if (!(mask & (1 << SAMPLES))) {
+      criteria[n].capability = SAMPLES;
+      criteria[n].comparison = EQ;
+      criteria[n].value = 0;
+      n++;
+    } else {
+      /* Multisample visuals are marked nonconformant.  If
+         multisampling was requeste and no conformant
+         preference was set, assume that we will settle for a
+         non-conformant visual to get multisampling. */
+      if (!(mask & (1 << CONFORMANT))) {
+        criteria[n].capability = CONFORMANT;
+        criteria[n].comparison = MIN;
+        criteria[n].value = 0;
+        n++;
+        mask |= (1 << CONFORMANT);
+      }
+    }
+  }
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_info)
+  if (__glutIsSupportedByGLX("GLX_EXT_visual_info")) {
+    if (!(mask & (1 << TRANSPARENT))) {
+      criteria[n].capability = TRANSPARENT;
+      criteria[n].comparison = EQ;
+      criteria[n].value = 0;
+      n++;
+    }
+  }
+#endif
+#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_rating)
+  if (__glutIsSupportedByGLX("GLX_EXT_visual_rating")) {
+    if (!(mask & (1 << SLOW))) {
+      criteria[n].capability = SLOW;
+      criteria[n].comparison = EQ;
+      criteria[n].value = 0;
+      n++;
+    }
+    if (!(mask & (1 << CONFORMANT))) {
+      criteria[n].capability = CONFORMANT;
+      criteria[n].comparison = EQ;
+      criteria[n].value = 1;
+      n++;
+    }
+  }
+#endif
+  if (!(mask & (1 << ACCUM_RED_SIZE))) {
+    criteria[n].capability = ACCUM_RED_SIZE;
+    criteria[n].comparison = MIN;
+    criteria[n].value = 0;
+    criteria[n + 1].capability = ACCUM_GREEN_SIZE;
+    criteria[n + 1].comparison = MIN;
+    criteria[n + 1].value = 0;
+    criteria[n + 2].capability = ACCUM_BLUE_SIZE;
+    criteria[n + 2].comparison = MIN;
+    criteria[n + 2].value = 0;
+    criteria[n + 3].capability = ACCUM_ALPHA_SIZE;
+    criteria[n + 3].comparison = MIN;
+    criteria[n + 3].value = 0;
+    n += 4;
+  }
+  if (!(mask & (1 << AUX_BUFFERS))) {
+    criteria[n].capability = AUX_BUFFERS;
+    criteria[n].comparison = MIN;
+    criteria[n].value = 0;
+    n++;
+  }
+  if (!(mask & (1 << RGBA))) {
+    criteria[n].capability = RGBA;
+    criteria[n].comparison = EQ;
+    criteria[n].value = 1;
+    criteria[n + 1].capability = RED_SIZE;
+    criteria[n + 1].comparison = GTE;
+    criteria[n + 1].value = 1;
+    criteria[n + 2].capability = GREEN_SIZE;
+    criteria[n + 2].comparison = GTE;
+    criteria[n + 2].value = 1;
+    criteria[n + 3].capability = BLUE_SIZE;
+    criteria[n + 3].comparison = GTE;
+    criteria[n + 3].value = 1;
+    criteria[n + 4].capability = ALPHA_SIZE;
+    criteria[n + 4].comparison = MIN;
+    criteria[n + 4].value = 0;
+    n += 5;
+    mask |= (1 << RGBA_MODE);
+  }
+#if !defined(_WIN32)
+  if (!(mask & (1 << XSTATICGRAY))) {
+    assert(isMesaGLX != -1);
+    if ((mask & (1 << RGBA_MODE)) && !isMesaGLX) {
+      /* Normally, request an RGBA mode visual be TrueColor,
+         except in the case of Mesa where we trust Mesa (and
+         other code in GLUT) to handle any type of RGBA visual
+         reasonably. */
+      if (mask & (1 << LUMINANCE_MODE)) {
+	/* If RGBA luminance was requested, actually go for
+	   a StaticGray visual. */
+        criteria[n].capability = XSTATICGRAY;
+      } else {
+        criteria[n].capability = XTRUECOLOR;
+      }
+      criteria[n].value = 1;
+      criteria[n].comparison = EQ;
+
+      n++;
+    }
+    if (mask & (1 << CI_MODE)) {
+      criteria[n].capability = XPSEUDOCOLOR;
+      criteria[n].value = 1;
+      criteria[n].comparison = EQ;
+      n++;
+    }
+  }
+#endif
+  if (!(mask & (1 << STEREO))) {
+    criteria[n].capability = STEREO;
+    criteria[n].comparison = EQ;
+    criteria[n].value = 0;
+    n++;
+  }
+  if (!(mask & (1 << DOUBLEBUFFER))) {
+    criteria[n].capability = DOUBLEBUFFER;
+    criteria[n].comparison = EQ;
+    criteria[n].value = 0;
+    *allowDoubleAsSingle = True;
+    n++;
+  }
+  if (!(mask & (1 << DEPTH_SIZE))) {
+    criteria[n].capability = DEPTH_SIZE;
+    criteria[n].comparison = MIN;
+    criteria[n].value = 0;
+    n++;
+  }
+  if (!(mask & (1 << STENCIL_SIZE))) {
+    criteria[n].capability = STENCIL_SIZE;
+    criteria[n].comparison = MIN;
+    criteria[n].value = 0;
+    n++;
+  }
+  if (!(mask & (1 << LEVEL))) {
+    criteria[n].capability = LEVEL;
+    criteria[n].comparison = EQ;
+    criteria[n].value = 0;
+    n++;
+  }
+  if (n) {
+    /* Since over-estimated the size needed; squeeze it down to
+       reality. */
+    criteria = (Criterion *) realloc(criteria, n * sizeof(Criterion));
+    if (!criteria) {
+      /* Should never happen since should be shrinking down! */
+      __glutFatalError("out of memory.");
+    }
+  } else {
+    /* For portability, avoid "realloc(ptr,0)" call. */
+    free(criteria);
+    criteria = NULL;
+  }
+
+  free(copy);
+  *ncriteria = n;
+  return criteria;
+}
+
+static FrameBufferMode *fbmodes = NULL;
+static int nfbmodes = 0;
+
+static XVisualInfo *
+getVisualInfoFromString(char *string, Bool * treatAsSingle,
+  Criterion * requiredCriteria, int nRequired, int requiredMask, void **fbc)
+{
+  Criterion *criteria;
+  XVisualInfo *visinfo;
+  Bool allowDoubleAsSingle;
+  int ncriteria, i;
+
+  if (!fbmodes) {
+    fbmodes = loadVisuals(&nfbmodes);
+  }
+  criteria = parseModeString(string, &ncriteria,
+    &allowDoubleAsSingle, requiredCriteria, nRequired, requiredMask);
+  if (criteria == NULL) {
+    __glutWarning("failed to parse mode string");
+    return NULL;
+  }
+#ifdef TEST
+  printCriteria(criteria, ncriteria);
+#endif
+  visinfo = findMatch(fbmodes, nfbmodes, criteria, ncriteria, fbc);
+  if (visinfo) {
+    *treatAsSingle = 0;
+  } else {
+    if (allowDoubleAsSingle) {
+      /* Rewrite criteria so that we now look for a double
+         buffered visual which will then get treated as a
+         single buffered visual. */
+      for (i = 0; i < ncriteria; i++) {
+        if (criteria[i].capability == DOUBLEBUFFER
+          && criteria[i].comparison == EQ
+          && criteria[i].value == 0) {
+          criteria[i].value = 1;
+        }
+      }
+      visinfo = findMatch(fbmodes, nfbmodes, criteria, ncriteria, fbc);
+      if (visinfo) {
+        *treatAsSingle = 1;
+      }
+    }
+  }
+  free(criteria);
+
+  if (visinfo) {
+#if defined(_WIN32)
+    /* We could have a valid pixel format for drawing to a
+       bitmap. However, we don't want to draw into a bitmap, we 
+       need one that can be used with a window, so make sure
+       that this is true. */
+    if (!(visinfo->dwFlags & PFD_DRAW_TO_WINDOW))
+      return NULL;
+#endif
+    return visinfo;
+  } else {
+    return NULL;
+  }
+}
+
+/* CENTRY */
+void APIENTRY
+glutInitDisplayString(const char *string)
+{
+#ifdef _WIN32
+  XHDC = GetDC(GetDesktopWindow());
+#endif
+
+  __glutDetermineVisualFromString = getVisualInfoFromString;
+  if (__glutDisplayString) {
+    free(__glutDisplayString);
+  }
+  if (string) {
+    __glutDisplayString = __glutStrdup(string);
+    if (!__glutDisplayString)
+      __glutFatalError("out of memory.");
+  } else {
+    __glutDisplayString = NULL;
+  }
+}
+/* ENDCENTRY */
+
+#ifdef TEST
+
+Criterion requiredWindowCriteria[] =
+{
+  {LEVEL, EQ, 0},
+  {TRANSPARENT, EQ, 0}
+};
+int numRequiredWindowCriteria = sizeof(requiredWindowCriteria) / sizeof(Criterion);
+int requiredWindowCriteriaMask = (1 << LEVEL) | (1 << TRANSPARENT);
+
+Criterion requiredOverlayCriteria[] =
+{
+  {LEVEL, EQ, 1},
+  {TRANSPARENT, EQ, 1},
+  {XPSEUDOCOLOR, EQ, 1},
+  {RGBA, EQ, 0},
+  {BUFFER_SIZE, GTE, 1}
+};
+int numRequiredOverlayCriteria = sizeof(requiredOverlayCriteria) / sizeof(Criterion);
+int requiredOverlayCriteriaMask =
+(1 << LEVEL) | (1 << TRANSPARENT) | (1 << XSTATICGRAY) | (1 << RGBA) | (1 << CI_MODE);
+
+int
+main(int argc, char **argv)
+{
+  Display *dpy;
+  XVisualInfo *vinfo;
+  Bool treatAsSingle;
+  char *str, buffer[1024];
+  int tty = isatty(fileno(stdin));
+  int overlay = 0, showconfig = 0;
+#if defined(GLX_VERSION_1_1) && defined(GLX_SGIX_fbconfig)
+  GLXFBConfigSGIX fbc;
+#else
+  void *fbc;
+#endif
+
+#if !defined(_WIN32)
+  dpy = XOpenDisplay(NULL);
+  if (dpy == NULL) {
+    printf("Could not connect to X server\n");
+    exit(1);
+  }
+  __glutDisplay = dpy;
+  __glutScreen = DefaultScreen(__glutDisplay);
+#endif
+  while (!feof(stdin)) {
+    if (tty)
+      printf("dstr> ");
+    str = gets(buffer);
+    if (str) {
+      printf("\n");
+      if (!strcmp("v", str)) {
+        verbose = 1 - verbose;
+        printf("verbose = %d\n\n", verbose);
+      } else if (!strcmp("s", str)) {
+        showconfig = 1 - showconfig;
+        printf("showconfig = %d\n\n", showconfig);
+      } else if (!strcmp("o", str)) {
+        overlay = 1 - overlay;
+        printf("overlay = %d\n\n", overlay);
+      } else {
+        if (overlay) {
+          vinfo = getVisualInfoFromString(str, &treatAsSingle,
+            requiredOverlayCriteria, numRequiredOverlayCriteria, requiredOverlayCriteriaMask, (void**) &fbc);
+        } else {
+          vinfo = getVisualInfoFromString(str, &treatAsSingle,
+            requiredWindowCriteria, numRequiredWindowCriteria, requiredWindowCriteriaMask, (void**) &fbc);
+        }
+        if (vinfo) {
+          printf("\n");
+          if (!tty)
+            printf("Display string: %s", str);
+#ifdef _WIN32
+          printf("Visual = 0x%x\n", 0);
+#else
+          printf("Visual = 0x%x%s\n", vinfo->visualid, fbc ? " (needs FBC)" : "");
+#endif
+          if (treatAsSingle) {
+            printf("Treat as SINGLE.\n");
+          }
+          if (showconfig) {
+            int glxCapable, bufferSize, level, renderType, doubleBuffer,
+              stereo, auxBuffers, redSize, greenSize, blueSize,
+              alphaSize, depthSize, stencilSize, acRedSize, acGreenSize,
+              acBlueSize, acAlphaSize;
+
+            glXGetConfig(dpy, vinfo, GLX_BUFFER_SIZE, &bufferSize);
+            glXGetConfig(dpy, vinfo, GLX_LEVEL, &level);
+            glXGetConfig(dpy, vinfo, GLX_RGBA, &renderType);
+            glXGetConfig(dpy, vinfo, GLX_DOUBLEBUFFER, &doubleBuffer);
+            glXGetConfig(dpy, vinfo, GLX_STEREO, &stereo);
+            glXGetConfig(dpy, vinfo, GLX_AUX_BUFFERS, &auxBuffers);
+            glXGetConfig(dpy, vinfo, GLX_RED_SIZE, &redSize);
+            glXGetConfig(dpy, vinfo, GLX_GREEN_SIZE, &greenSize);
+            glXGetConfig(dpy, vinfo, GLX_BLUE_SIZE, &blueSize);
+            glXGetConfig(dpy, vinfo, GLX_ALPHA_SIZE, &alphaSize);
+            glXGetConfig(dpy, vinfo, GLX_DEPTH_SIZE, &depthSize);
+            glXGetConfig(dpy, vinfo, GLX_STENCIL_SIZE, &stencilSize);
+            glXGetConfig(dpy, vinfo, GLX_ACCUM_RED_SIZE, &acRedSize);
+            glXGetConfig(dpy, vinfo, GLX_ACCUM_GREEN_SIZE, &acGreenSize);
+            glXGetConfig(dpy, vinfo, GLX_ACCUM_BLUE_SIZE, &acBlueSize);
+            glXGetConfig(dpy, vinfo, GLX_ACCUM_ALPHA_SIZE, &acAlphaSize);
+            printf("RGBA = (%d, %d, %d, %d)\n", redSize, greenSize, blueSize, alphaSize);
+            printf("acc  = (%d, %d, %d, %d)\n", acRedSize, acGreenSize, acBlueSize, acAlphaSize);
+            printf("db   = %d\n", doubleBuffer);
+            printf("str  = %d\n", stereo);
+            printf("aux  = %d\n", auxBuffers);
+            printf("lvl  = %d\n", level);
+            printf("buf  = %d\n", bufferSize);
+            printf("rgba = %d\n", renderType);
+            printf("z    = %d\n", depthSize);
+            printf("s    = %d\n", stencilSize);
+          }
+        } else {
+          printf("\n");
+          printf("No match.\n");
+        }
+        printf("\n");
+      }
+    }
+  }
+  printf("\n");
+  return 0;
+}
+#endif