- vbuf->vertices = (uint *) vbuf->render->allocate_vertices(vbuf->render,
- (ushort) vbuf->vertex_size,
- (ushort) vbuf->max_vertices);
+
+ /* even number */
+ vbuf->max_vertices = vbuf->max_vertices & ~1;
+
+ if(vbuf->max_vertices >= UNDEFINED_VERTEX_ID)
+ vbuf->max_vertices = UNDEFINED_VERTEX_ID - 1;
+
+ /* Must always succeed -- driver gives us a
+ * 'max_vertex_buffer_bytes' which it guarantees it can allocate,
+ * and it will flush itself if necessary to do so. If this does
+ * fail, we are basically without usable hardware.
+ */
+ vbuf->render->allocate_vertices(vbuf->render,
+ (ushort) vbuf->vertex_size,
+ (ushort) vbuf->max_vertices);
+
+ vbuf->vertices = (uint *) vbuf->render->map_vertices( vbuf->render );
+