[self-interest] OpenGL

Josh Flowers joshflowers at mac.com
Thu Jun 12 01:31:34 UTC 2003

On Wednesday, June 11, 2003, at 08:04 PM, Jecel Assumpcao Jr wrote:

> On Tuesday 10 June 2003 16:43, Josh Flowers wrote:
>> How does self handle text?  I didn't see any glue code that dealt
>> with text, and so I'd hoped that self was doing the text rendering.
>> If that's the case, then GL's text support shouldn't be a problem.
> The 'drawString:At:GC:' method calls platform specific code to do the
> real work.

My mistake - and I'd even implemented the draw_text(const char* text, 
int x, int y) method in my GlutWindow.c file....  It was just too long 
ago I guess.

>> I'm not sure what kind of 2D texture support you need....
> Imagine a red, metalic cylinder. With a white stripe near the bottom.
> And an orange circle in the middle wrapped half way around the
> cylinder.

I can think of any number of ways to do this, but if what you're saying 
is that the white stripe is one texture, and the orange circle is the 
other, I get your point.

>> You're also correct that GL doesn't scale down to low end machines
>> very well, but it should be usable on 90%+ of the desk/laptop
>> machines out there, which would be a good start.
> My problem is that is also doesn't scale up. When I get a machine that
> is 10 times faster than today's, it is going to look exactly the same.
> It might say it is doing 430 frames per second, but on a monitor with a
> 70Hz refresh rate that is a lie. You won't notice this, of course,
> since by then we will have 10 times as many polygons on the screen in
> applications that don't run at all on today's machines. But today's
> applications won't be any better and that is my complaint.

Well, having read your idea's about how to implement a more scaleable 
UI, I think you've got a good solution.  There are of course technical 
details that would need to get worked out, but there always are (for 
instance, it might be difficult to ensure that the different rendering 
techniques did not look too different - I've done some very minimal 
work trying to 'dissolve' from a GL rendered scene to a ray traced one, 
and the visual differences between the two were just too great (often 
times objects would have slightly different shapes, or placement).  But 
again, my work was very precursory.

> Steve Dekorte wrote:
>> The advantage is much, much faster rendering(2d, or 3d). Self is
>> painfully slow(dragging an outliner around involves waiting for it to
>> catch up with the mouse) on my dual 1.2Ghz Mac and I'm
>> guessing(hoping) it's because of the rendering costs.
> I got a 1/3 second delay on a 600MHz Pentium II and less than half that
> on a 277MHz UltraSparc II. On the latter it is only noticeable if you
> are testing for the effect.

I can vouch for Steve, Self has always been very sluggish on a Mac.

> BTW, I hope my comments don't make it seem like I am against linking
> Self and OpenGL. Quite the opposite! OpenGL is here now and this
> shouldn't be hard to do, so why not?

Well said - now if only I could find more time to work on it.  Anyone 
is welcome to my GlutWindow.c file if they'd like.


"there must be in the indians' social bond something singularly 
captivating, and far superior to be boasted of among us; for thousands 
of Europeans are Indians, and we have no examples of even one of those 
Aborigines having from choice become Europeans."

Michel Guillaume Jean de Crevecoeur - Letters from an American Farmer

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