[SDL] For all who search a SDL_OPENGLBLIT example

[Joseph Carter]

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On Mon, Nov 05, 2001 at 01:22:05PM +0100, Fabio Franchello wrote:
>         I  noticed that  the requests for an  explanation about
> SDL_OPENGLBLIT mode  are  always  present. For those that want to go a
> little  beyond  the "testgl -logo"  experience, I just want  to  signal
> that my  SDL port of the NeHeGL Basecode includes  a basic documented
> example on  how  to set  up the graphic mode and how to use it.  Plus,
> it's a basecode,  a framework,  so you can start developing you
> SDL_OPENGLBLIT app wight into it.

*ahem*

Let me try to put this in as simple terms as I can put it:

  ____   ___       _   _  ___ _____       _   _ ____  _____=20
 |  _ \ / _ \     | \ | |/ _ \_   _|     | | | / ___|| ____|
 | | | | | | |    |  \| | | | || |       | | | \___ \|  _| =20
 | |_| | |_| |    | |\  | |_| || |       | |_| |___) | |___=20
 |____/ \___/     |_| \_|\___/ |_|        \___/|____/|_____|

   ___  ____  _____ _   _  ____ _     ____  _     ___ _____=20
  / _ \|  _ \| ____| \ | |/ ___| |   | __ )| |   |_ _|_   _|
 | | | | |_) |  _| |  \| | |  _| |   |  _ \| |    | |  | | =20
 | |_| |  __/| |___| |\  | |_| | |___| |_) | |___ | |  | | =20
  \___/|_|   |_____|_| \_|\____|_____|____/|_____|___| |_| =20


Just DO NOT use it.  Ten good reasons why SDL_OPENGLBLIT should be
outright removed from SDL:

	1. It is a terrible hack.
	2. It is slow.
	3. It doesn't work with some cards and drivers.
	4. It is slow.
	5. It is a matter of public record Sam advises against using it.
	6. It is slow.
	7. It is possible to upload any surface to OpenGL.
	8. It is slow.
	9. It is easy to get OpenGL to give you raw screen coordinates.
	10. IT IS SLOW!

CAN WE PLEASE finally have a FAQ item about this?  Every week someone who
apparently feels no inclination to read the damned list archives for all
of the multitudes of previous discussions about how WRONG it is to EVER
use SDL_OPENGLBLIT, many of them including code examples demonstrating how
to never have to use it again.

Rather than actually discover this, people continue to insist on trying to
use it rather than actually learning what a projection matrix is and how
to actually set one up so they can feed raw pixel coordinates to OpenGL
for glVertex2f/glVertex2fv..  It should be clear to everyone by now that
people will continue to make this massive leap of ignorance until the main
libsdl.org website screams in big blinking letters not to.  I'm not even
sure that'll communicate the point to some people.


It's only fitting that a mess like SDL_OPENGLBLIT be combined with NeHe
stuff, a mess of its own.  But unfortunately people mistakenly believe
that NeHe stuff is actually useful for something.

--=20
Joseph Carter <knghtbrd@bluecherry.net>            Free software developer

<Zoid> I still think you guys are nuts merging Q and QW. :P
<knghtbrd> Of course we're nuts.  Even John said so.  =3D>
<taniwha> Zoid: we're nuts, but we're productive nuts:)


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