Is setting line smoothing retrospective?

[Qu0ll]

I am drawing a line without enabling line smoothing, then I enable line smoothing with:


glEnable(GL_LINE_SMOOTH);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);

and to my surprise the first line is smoothed as well (which is not what I want).

So why is this seemingly retrospective and how can I draw one line not smoothed and then another one with smoothing applied? I have tried glFlush() between drawing the lines but it didn't help.

[ZbuffeR]

Do you disable GL_LINE_SMOOTH before drawing the first line ?
Nothing to do at all with glFlush()

[Qu0ll]

OK, I do now and it is working, but why do I need to disable line smoothing BEFORE I draw the first line? Does that mean it is enabled by default?

[mhagain]

State carries over from frame to frame. So what you're doing is effectively this:

frame 1:
- clear screen
- draw line 1 // line smoothing is disabled
- enable line smoothing
- draw line 2 // line smoothing is enabled

frame 2 and above:
- clear screen
- draw line 1 // line smoothing is still enabled!!!
- enable line smoothing
- draw line 2 // line smoothing is enabled

[Qu0ll]

Yes, that is correct indeed! Thanks to you both :-)