[CoreSupport] Represent the extension string(s) as an array of GLboolean - _glewGetExtensionString and _glewGetExtensionEnable

glewinfo output is identical.
TODO core context glGetStringi support.
TODO MX support.

auto/Makefile

@@ -199,12 +199,10 @@ $(S.DEST)/glew.c: $(EXT)/.dummy
 	$(BIN)/make_def_var.pl GL $(GL_EXT_SPEC) >> $@
 	echo -e "\n#endif /* !GLEW_MX */\n" >> $@;
 	echo -e "\nstatic const char * _glewExtensionLookup[] = {" >> $@;
-	$(BIN)/make_index.pl $(GL_EXT_SPEC) >> $@
+	$(BIN)/make_index.pl $(GL_CORE_SPEC) $(GL_EXT_SPEC) >> $@
 	echo -e "  NULL\n};\n" >> $@;
 	echo -e "\n#if !defined(GLEW_MX)" >> $@;
-	echo -e "\nstatic GLboolean* _glewEnabled[] = {" >> $@;
 	$(BIN)/make_enable_index.pl $(GL_CORE_SPEC) $(GL_EXT_SPEC) >> $@
-	echo -e "  NULL\n};\n" >> $@;
 	echo -e "\n#endif /* !GLEW_MX */\n" >> $@;
 	$(BIN)/make_initd.pl GL $(GL_CORE_SPEC) >> $@
 	$(BIN)/make_initd.pl GL $(GL_EXT_SPEC) >> $@

auto/bin/make_enable_index.pl

@@ -22,6 +22,12 @@ if (@ARGV)
 {
     @extlist = @ARGV;
 
+    print "/* Detected in the extension string or strings */\n";
+    print "static GLboolean  _glewExtensionString[" . scalar @extlist . "];\n";
+
+    print "/* Detected via extension string or experimental mode */\n";
+    print "static GLboolean* _glewExtensionEnabled[] = {\n";;
+
     foreach my $ext (sort @extlist)
     {
         my ($extname, $exturl, $extstring, $types, $tokens, $functions, $exacts) = 
@@ -34,4 +40,6 @@ if (@ARGV)
         print "  &__$extvar,\n";
         print "#endif\n";
     }
+
+    print "  NULL\n};\n";
 }

auto/bin/make_index.pl

@@ -32,7 +32,7 @@ if (@ARGV)
             parse_ext($ext);
 
         print "#ifdef $extname\n";
-        print "  \"$extstring\",\n";
+        print "  \"$extname\",\n";
         print "#endif\n";
     }
 }

auto/bin/make_list.pl

@@ -42,15 +42,10 @@ if (@ARGV)
 
 		#my $pextvar = prefix_varname($extvar);
 
-		print "#ifdef $extname\n";
-
-		if (length($extstring))
-		{
-				print "  " . $extvar . " = _glewSearchExtension(\"$extstring\", extStart, extEnd);\n";
-		}
-
 		if (keys %$functions)
 		{
+			print "#ifdef $extname\n";
+
 			if ($extname =~ /WGL_.*/)
 			{
 				print "  if (glewExperimental || " . $extvar . "|| crippled) " . $extvar . "= !_glewInit_$extname(GLEW_CONTEXT_ARG_VAR_INIT);\n";
@@ -59,8 +54,9 @@ if (@ARGV)
 			{
 				print "  if (glewExperimental || " . $extvar . ") " . $extvar . " = !_glewInit_$extname(GLEW_CONTEXT_ARG_VAR_INIT);\n";
 			}
-		}
+			
 			print "#endif /* $extname */\n";
 		}
+	}
 
 }

auto/src/glew_head.c

@@ -207,6 +207,7 @@ static GLuint _glewStrCLen (const GLubyte* s, GLubyte c)
   return (s[i] == '\0' || s[i] == c) ? i : 0;
 }
 
+#if 0
 static GLboolean _glewStrSame (const GLubyte* a, const GLubyte* b, GLuint n)
 {
   GLuint i=0;
@@ -215,6 +216,7 @@ static GLboolean _glewStrSame (const GLubyte* a, const GLubyte* b, GLuint n)
   while (i < n && a[i] != '\0' && b[i] != '\0' && a[i] == b[i]) i++;
   return i == n ? GL_TRUE : GL_FALSE;
 }
+#endif
 
 static GLboolean _glewStrSame1 (const GLubyte** a, GLuint* na, const GLubyte* b, GLuint nb)
 {
@@ -268,23 +270,3 @@ static GLboolean _glewStrSame3 (const GLubyte** a, GLuint* na, const GLubyte* b,
   }
   return GL_FALSE;
 }
-
-/*
- * Search for name in the extensions string. Use of strstr()
- * is not sufficient because extension names can be prefixes of
- * other extension names. Could use strtok() but the constant
- * string returned by glGetString might be in read-only memory.
- */
-static GLboolean _glewSearchExtension (const char* name, const GLubyte *start, const GLubyte *end)
-{
-  const GLubyte* p;
-  GLuint len = _glewStrLen((const GLubyte*)name);
-  p = start;
-  while (p < end)
-  {
-    GLuint n = _glewStrCLen(p, ' ');
-    if (len == n && _glewStrSame((const GLubyte*)name, p, n)) return GL_TRUE;
-    p += n+1;
-  }
-  return GL_FALSE;
-}

auto/src/glew_init_gl.c

@@ -1,14 +1,60 @@
 /* ------------------------------------------------------------------------- */
 
+static int _glewExtensionCompare(const void *a, const void *b)
+{
+   return strcmp((const char *) a, *(const char**) b);
+}
+
+static GLboolean *_glewGetExtensionString(const char *name)
+{
+  const char **n = (const char **) bsearch(name, _glewExtensionLookup, sizeof(_glewExtensionLookup)/sizeof(char *)-1, sizeof(char *), _glewExtensionCompare);
+  int i;
+
+  if (n)
+  {
+      i = n-_glewExtensionLookup;
+      return _glewExtensionString+i;
+  }
+
+  return NULL;
+}
+
+static GLboolean *_glewGetExtensionEnable(const char *name)
+{
+  const char **n = (const char **) bsearch(name, _glewExtensionLookup, sizeof(_glewExtensionLookup)/sizeof(char *)-1, sizeof(char *), _glewExtensionCompare);
+  int i;
+
+  if (n)
+  {
+      i = n-_glewExtensionLookup;
+      return _glewExtensionEnabled[i];
+  }
+
+  return NULL;
+}
+
+static char *_glewNextSpace(char *i)
+{
+  char *j = i;
+  if (j)
+    while (*j!=' ' && *j) ++j;
+  return j;
+}
+
+static char *_glewNextNonSpace(char *i)
+{
+  char *j = i;
+  if (j)
+    while (*j==' ') ++j;
+  return j;
+}
+
 GLboolean GLEWAPIENTRY glewGetExtension (const char* name)
 {
-  const GLubyte* start;
+  GLboolean *enable = _glewGetExtensionString(name);
-  const GLubyte* end;
+  if (enable)
-  start = (const GLubyte*)glGetString(GL_EXTENSIONS);
+    return *enable;
-  if (start == 0)
   return GL_FALSE;
-  end = start + _glewStrLen(start);
-  return _glewSearchExtension(name, start, end);
 }
 
 /* ------------------------------------------------------------------------- */
@@ -21,8 +67,12 @@ GLenum GLEWAPIENTRY glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
   const GLubyte* s;
   GLuint dot;
   GLint major, minor;
-  const GLubyte* extStart;
+  char *begin;
-  const GLubyte* extEnd;
+  char *end;
+  char *i;
+  char *j;
+  GLboolean *enable;
+
   /* query opengl version */
   s = glGetString(GL_VERSION);
   dot = _glewStrCLen(s, '.');
@@ -37,7 +87,6 @@ GLenum GLEWAPIENTRY glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
   if (major<0 || major>9)
     return GLEW_ERROR_NO_GL_VERSION;
   
-
   if (major == 1 && minor == 0)
   {
     return GLEW_ERROR_GL_VERSION_10_ONLY;
@@ -64,10 +113,35 @@ GLenum GLEWAPIENTRY glewContextInit (GLEW_CONTEXT_ARG_DEF_LIST)
     GLEW_VERSION_1_1   = GLEW_VERSION_1_2   == GL_TRUE || ( major == 1 && minor >= 1 ) ? GL_TRUE : GL_FALSE;
   }
 
-  /* query opengl extensions string */
+  memset(_glewExtensionString,0,sizeof(_glewExtensionString));
-  extStart = glGetString(GL_EXTENSIONS);
-  if (extStart == 0)
-    extStart = (const GLubyte*)"";
-  extEnd = extStart + _glewStrLen(extStart);
 
-  /* initialize extensions */
+  if (GLEW_VERSION_3_0)
+  {
+    /* TODO */
+  }
+  else
+  {
+    begin = (char *) glGetString(GL_EXTENSIONS);
+    if (begin)
+    {
+      begin = strdup(begin);
+      end = begin + strlen(begin);
+      for (i=begin; i<end; i = j + 1)
+      {
+        i = _glewNextNonSpace(i);
+        j = _glewNextSpace(i);
+        *j = 0;
+
+        /* Based on extension string(s), glewGetExtension purposes */
+        enable = _glewGetExtensionString(i);
+        if (enable)
+          *enable = GL_TRUE;
+
+        /* Based on extension string(s), experimental mode, glewIsSupported purposes */
+        enable = _glewGetExtensionEnable(i);
+        if (enable)
+          *enable = GL_TRUE;
+      }
+      free(begin);
+    }
+  }