I have come back to GDL after a couple of years and my first project is a custom window. I decided to use the opportunity to refresh my GDL so I went step by step through orientating a window via placement, using the ref line and mirrored/flipped to establish UV etc. What I found was that the copy/paste from the manual.
! 2D script bRotated = round_int (SYMB_ROTANGLE) = 180 if bRotated then rot2 180 endif if SYMB_MIRRORED then mul2 -1, 1 endif if WIDO_REVEAL_SIDE exor bRotated then add2
When I did the same using circles etc to draft the orientation I get
I searched the forum but did not easily find essential info or bug reports on this.
The sample code undoes the mirrorings/flips defined by the user relative to the wall. Rotating a wall 180° is not the same as mirroring a wall on an axis parallel to it. In the “On Screen View Options” toolbar turn on “Wall & Beam Refernce Lines” to see the difference in wall direction.
So the inside/outside of a composite wall is not defined by the order of the layers, it can be changed by the user. There is also a menu command at Edit / Reference Line and Plane / Invert Wall Direction.