Why you should use OpenGL and not DirectX

Chat about anything not covered in these forums, but keep it civil!

Post » Fri Feb 05, 2010 9:09 am

Controller:
[url:13jm53vw]http://sourceforge.net/projects/wgois/[/url:13jm53vw]

Sound:
[url:13jm53vw]http://connect.creativelabs.com/developer/Wiki/OpenAL%20SDK%20for%20Windows.aspx[/url:13jm53vw]
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Post » Fri Feb 05, 2010 7:39 pm

OpenAL is sweet, I can tell firsthand (also: EPIC uses it)
OOIS I keep hearing about, they say its good but haven't seen any real games that use it.
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Post » Tue Aug 10, 2010 8:24 pm

[quote="Ashley":2t5gcgpu]
Here's how you draw a quad in OpenGL:
[code:2t5gcgpu]glBegin(GL_QUADS);
glVertex3f(0,0,0); // top left corner
glVertex3f(1,0,0); // top right corner
glVertex3f(1,1,0); // bottom right corner
glVertex3f(0,1,0); // bottom left corner
glEnd();[/code:2t5gcgpu]

You might also notice this essentially naturally is a batching system.[/quote:2t5gcgpu]

You'll find out that this is called Immediate Mode in OpenGL and is currently deprecated, as it is horribly slow. The fast form is pretty much the same as Microsoft. It's optimal for drawing bunches of things. Meshes shouldn't change most of the time anyway, only transforms.

Edit: why is it slow? because you send all the data to the video card for each frame. The other mode (batched?) is in DirectX's fashion, as you get everything buffered in the video card, indexing avoids duplicate vertexes thus saving precious VRAM and then you just instance those buffers, which frees up a WHOLE BUNCH of bandwidth. Going with immediate mode would make the OpenGL version slower than the DirectX version.

List of OpenGL ways of drawing (some are named as extensions and now may be core to OGL4)
[url:2t5gcgpu]http://www.allegro.cc/forums/thread/603880/862408#target[/url:2t5gcgpu]
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Post » Tue Aug 10, 2010 11:23 pm

Wow, that's quite a bump.

From the "new posts" page, it looked like Deadeye had posted!!!!
I didn't think it was him.
He's been gone a couple of months now.

Krush.
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