This is another devilry. 30 years this worked perfectly and abruptly it failed. Looks like in 902 the
get_opengl_mouse_state@ (ix,iy,iflag)
(iflag=9) stopped to get any different iflag when you push simultaeously left Ctrl and left mouse buttons in OpenGL screen.
The RightCtrl+LeftMouseDown generates iflag=9 OK. Mouse and keyboard interruptions are handled like this:
i=winio@('%pv%^og[double,depth16]&', iwid, ihgt,CBmouse)
I use get_opengl_mouse_state@ and not CALL_BACK_REASON because
clearwin_string@('CALL_BACK_REASON')
does not offer an option when you keep Ctrl and left mouse down simultaneously (it still shows the reason ='MOUSE MOVE' as if Ctrl key is not down)
Both these interrupt functions are called inside CBmouse to handle plot moves.
/* The OpenGL implementation of this compiler was incredible good from the start in 1990th. And shock is that not a single user of this compiler found it in 1/3 of century. This correlates with even more surprising fact that not a single user requested mainstream ways of multi-processing with this compiler. I fail to understand the Fortran users, and find the key explanation of this absurd in the same devilry and if devilty then The Matrix too. Because if not devilry and not Matrix then what? Altzheimer and dementia?