opengl32: Split is_extension_supported helper.

dlls/opengl32/wgl.c

@@ -803,57 +803,45 @@ static int compar(const void *elt_a, const void *elt_b) {
 }
 
 /* Check if a GL extension is supported */
-static BOOL is_extension_supported(const char* extension)
+static BOOL check_extension_support( const char *extension, const char *available_extensions )
 {
-    enum wgl_handle_type type = get_current_context_type();
     const struct opengl_funcs *funcs = NtCurrentTeb()->glTable;
-    const char *gl_ext_string = NULL;
     size_t len;
 
     TRACE("Checking for extension '%s'\n", extension);
 
-    if (type == HANDLE_CONTEXT)
-    {
-        gl_ext_string = (const char*)glGetString(GL_EXTENSIONS);
-        if (!gl_ext_string)
-        {
-            ERR("No OpenGL extensions found, check if your OpenGL setup is correct!\n");
-            return FALSE;
-        }
-    }
-
     /* We use the GetProcAddress function from the display driver to retrieve function pointers
      * for OpenGL and WGL extensions. In case of winex11.drv the OpenGL extension lookup is done
      * using glXGetProcAddress. This function is quite unreliable in the sense that its specs don't
      * require the function to return NULL when an extension isn't found. For this reason we check
      * if the OpenGL extension required for the function we are looking up is supported. */
 
-    while ((len = strcspn(extension, " ")) != 0)
+    while ((len = strcspn( extension, " " )))
     {
         /* Check if the extension is part of the GL extension string to see if it is supported. */
-        if (has_extension(gl_ext_string, extension, len))
-            return TRUE;
+        if (has_extension( available_extensions, extension, len )) return TRUE;
 
         /* In general an OpenGL function starts as an ARB/EXT extension and at some stage
          * it becomes part of the core OpenGL library and can be reached without the ARB/EXT
          * suffix as well. In the extension table, these functions contain GL_VERSION_major_minor.
          * Check if we are searching for a core GL function */
-        if(strncmp(extension, "GL_VERSION_", 11) == 0)
+        if (!strncmp( extension, "GL_VERSION_", 11 ))
         {
             const GLubyte *gl_version = funcs->gl.p_glGetString(GL_VERSION);
             const char *version = extension + 11; /* Move past 'GL_VERSION_' */
 
-            if(!gl_version) {
-                ERR("No OpenGL version found!\n");
+            if (!gl_version)
+            {
+                ERR( "No OpenGL version found!\n" );
                 return FALSE;
             }
 
             /* Compare the major/minor version numbers of the native OpenGL library and what is required by the function.
              * The gl_version string is guaranteed to have at least a major/minor and sometimes it has a release number as well. */
-            if( (gl_version[0] > version[0]) || ((gl_version[0] == version[0]) && (gl_version[2] >= version[2])) ) {
-                return TRUE;
-            }
-            WARN("The function requires OpenGL version '%c.%c' while your drivers only provide '%c.%c'\n", version[0], version[2], gl_version[0], gl_version[2]);
+            if ((gl_version[0] > version[0]) || ((gl_version[0] == version[0]) && (gl_version[2] >= version[2]))) return TRUE;
+
+            WARN( "The function requires OpenGL version '%c.%c' while your drivers only provide '%c.%c'\n",
+                  version[0], version[2], gl_version[0], gl_version[2] );
         }
 
         if (extension[len] == ' ') len++;
@@ -863,6 +851,25 @@ static BOOL is_extension_supported(const char* extension)
     return FALSE;
 }
 
+/* Check if a GL extension is supported */
+static BOOL is_extension_supported( const char *extension )
+{
+    enum wgl_handle_type type = get_current_context_type();
+    const char *gl_ext_string = NULL;
+
+    if (type == HANDLE_CONTEXT)
+    {
+        gl_ext_string = (const char *)glGetString( GL_EXTENSIONS );
+        if (!gl_ext_string)
+        {
+            ERR( "No OpenGL extensions found, check if your OpenGL setup is correct!\n" );
+            return FALSE;
+        }
+    }
+
+    return check_extension_support( extension, gl_ext_string );
+}
+
 /***********************************************************************
  *		wglGetProcAddress (OPENGL32.@)
  */