Blender Git Loki

2.5

New: Custom region draw callbacks.

For Martin: an example is now in space_view3d/view3d_edit.c
On middlemouse rotate view, it draws a small square in center.

It works likes this:

#include "ED_space_api.h"

handle= ED_region_draw_cb_activate(region->type, drawfunc, type)

and to stop it:

ED_region_draw_cb_exit(region->type, handle)

drawfunc is of type (const bContext *C, ARegion *ar)
currently it gets called only as type REGION_DRAW_POST, later we
can add more (PRE, POST_XRAY, POST_2D, etc).

For correct usage, these calls should return leaving view transform
unaltered.