- /* See if this function has already been dynamically added */
- {
- GLuint i;
- for (i = 0; i < NumExtEntryPoints; i++) {
- if (strcmp(ExtEntryTable[i].Name, funcName) == 0) {
- /* function already registered */
- if (ExtEntryTable[i].Offset == offset) {
- return GL_TRUE; /* offsets match */
- }
- else if (ExtEntryTable[i].Offset == ~0
- && offset < DISPATCH_TABLE_SIZE) {
- /* need to patch-up the dispatch code */
- if (offset != ~0) {
- fill_in_entrypoint_offset(ExtEntryTable[i].Address, offset);
- ExtEntryTable[i].Offset = offset;
- }
- return GL_TRUE;
- }
- else {
- return GL_FALSE; /* bad offset! */
- }
- }
+ return entry;
+}
+
+
+/**
+ * Fill-in the dispatch stub for the named function.
+ *
+ * This function is intended to be called by a hardware driver. When called,
+ * a dispatch stub may be created created for the function. A pointer to this
+ * dispatch function will be returned by glXGetProcAddress.
+ *
+ * \param function_names Array of pointers to function names that should
+ * share a common dispatch offset.
+ * \param parameter_signature String representing the types of the parameters
+ * passed to the named function. Parameter types
+ * are converted to characters using the following
+ * rules:
+ * - 'i' for \c GLint, \c GLuint, and \c GLenum
+ * - 'p' for any pointer type
+ * - 'f' for \c GLfloat and \c GLclampf
+ * - 'd' for \c GLdouble and \c GLclampd
+ *
+ * \returns
+ * The offset in the dispatch table of the named function. A pointer to the
+ * driver's implementation of the named function should be stored at
+ * \c dispatch_table[\c offset].
+ *
+ * \sa glXGetProcAddress
+ *
+ * \warning
+ * This function can only handle up to 8 names at a time. As far as I know,
+ * the maximum number of names ever associated with an existing GL function is
+ * 4 (\c glPointParameterfSGIS, \c glPointParameterfEXT,
+ * \c glPointParameterfARB, and \c glPointParameterf), so this should not be
+ * too painful of a limitation.
+ *
+ * \todo
+ * Determine whether or not \c parameter_signature should be allowed to be
+ * \c NULL. It doesn't seem like much of a hardship for drivers to have to
+ * pass in an empty string.
+ *
+ * \todo
+ * Determine if code should be added to reject function names that start with
+ * 'glX'.
+ *
+ * \bug
+ * Add code to compare \c parameter_signature with the parameter signature of
+ * a static function. In order to do that, we need to find a way to \b get
+ * the parameter signature of a static function.
+ */
+
+PUBLIC int
+_glapi_add_dispatch( const char * const * function_names,
+ const char * parameter_signature )
+{
+ static int next_dynamic_offset = _gloffset_FIRST_DYNAMIC;
+ const char * const real_sig = (parameter_signature != NULL)
+ ? parameter_signature : "";
+ struct _glapi_function * entry[8];
+ GLboolean is_static[8];
+ unsigned i;
+ unsigned j;
+ int offset = ~0;
+ int new_offset;
+
+
+ (void) memset( is_static, 0, sizeof( is_static ) );
+ (void) memset( entry, 0, sizeof( entry ) );
+
+ for ( i = 0 ; function_names[i] != NULL ; i++ ) {
+ /* Do some trivial validation on the name of the function.
+ */
+
+#ifdef MANGLE
+ if (!function_names[i] || function_names[i][0] != 'm' || function_names[i][1] != 'g' || function_names[i][2] != 'l')
+ return GL_FALSE;
+#else
+ if (!function_names[i] || function_names[i][0] != 'g' || function_names[i][1] != 'l')
+ return GL_FALSE;
+#endif
+
+
+ /* Determine if the named function already exists. If the function does
+ * exist, it must have the same parameter signature as the function
+ * being added.
+ */
+
+ new_offset = get_static_proc_offset(function_names[i]);
+ if (new_offset >= 0) {
+ /* FIXME: Make sure the parameter signatures match! How do we get
+ * FIXME: the parameter signature for static functions?
+ */
+
+ if ( (offset != ~0) && (new_offset != offset) ) {
+ return -1;
+ }
+
+ is_static[i] = GL_TRUE;
+ offset = new_offset;
+ }
+
+
+ for ( j = 0 ; j < NumExtEntryPoints ; j++ ) {
+ if (strcmp(ExtEntryTable[j].name, function_names[i]) == 0) {
+ /* The offset may be ~0 if the function name was added by
+ * glXGetProcAddress but never filled in by the driver.
+ */
+
+ if (ExtEntryTable[j].dispatch_offset != ~0) {
+ if (strcmp(real_sig, ExtEntryTable[j].parameter_signature)
+ != 0) {
+ return -1;
+ }
+
+ if ( (offset != ~0) && (ExtEntryTable[j].dispatch_offset != offset) ) {
+ return -1;
+ }
+
+ offset = ExtEntryTable[j].dispatch_offset;
+ }
+
+ entry[i] = & ExtEntryTable[j];
+ break;
+ }