there is a glClearColor 0 0 0 0 inside a_g_paint, or it should be 0 0 0 1? you can use a global noun say BColor to hold its value. If you want another color, you change the content, eg 1 0 0 1, of this noun, and then gl_sel and gl_paint to trigger a paint event to render according to the current state.
On Sun, Mar 1, 2020, 8:43 AM Brian Schott <schott.br...@gmail.com> wrote: > Bill, > > You're going right over my head. > Can you show how a verb like "white" can change the background color to > white, for example, > or how a more general verb "background" can take a rgb vector argument? I'm > not versed in callbacks, for example. > Without such a feature "logo" style free inputs cannot be issued by the > user. Unless you are saying a parser must be created that takes keystrokes > like a_g_char does. > With the old opengl I constructed verbs like `white` routinely. > > Thanks, > > On Sat, Feb 29, 2020 at 7:16 PM bill lam <bbill....@gmail.com> wrote: > > > you can setup state for drawing outside paint event, but all actual > drawing > > must happen inside paint event, the verb a_g_paint, the callback verb. It > > is useless if you call the verb from your code or copying the commands > > inside and execute them from your code. > > > > For opengl drawing you need a opengl context. The opengl context is only > > valid inside paint event . > > > > -- > (B=) > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
