Is there any way to soft primitives corners?
For example:

Rounded rectangle:

al_draw_filled_rounded_rectangle( 100, 100, 400, 250, 20, 20, al_map_rgb( 90, 60, 90 ) );

Triangle ( hmm... )

al_draw_filled_triangle( 100, 50, 50, 150, 150, 200, al_map_rgb( 90, 60, 90 ) );

Circle ( there are no corners, but... )

al_draw_filled_circle( 100, 100, 80, al_map_rgb( 90, 60, 90 ) );

Like antyaliasing or something like this

Thank you

EDIT:
------------------------------------
WoW!
I just installed Windows 8, and this not working!

What the...
I try with ALLEGRO_REQUIRE, but it's not working too...

What has Apple to rounded corners?

So what about multisampling, why it doesn't work :/

Before creating display

...
al_set_new_display_option(ALLEGRO_SAMPLE_BUFFERS, 1, ALLEGRO_SUGGEST);
al_set_new_display_option(ALLEGRO_SAMPLES, 4, ALLEGRO_SUGGEST);

ALLEGRO_DISPLAY *display = al_create_new_display( 800, 600 );
...

EDIT:
Sorry, i missunderstood youd question
Yes, i'm drawind directly...

But in windows 7 everything is ok... Grr...

I tried:

They need to sue MS for their use of rounded corners in Microsoft Bob.

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[EDIT]

From the same website, it says Apple sued Digital Research for look and feel concerning GEM 1.1 back in 1985.

I seriously doubt Apple would mess with small fry like us.

Back on the farm we had a stove from the '50's that had rounded corners all over the place. "Streamlined", they called it, even though it didn't move.

I love it when the 'graphics department' (hmm) at j0rb do me a border with rounded rectangles. It's clear to me but so, so painfully unclear to them that selecting a rounded-rectangle in photoshop and dragging the horizontal twice as far as the vertical, then doing so but smaller to create and edge will result in horrid, out of shape corners. I'm not sure why that's relevant. I guess I want to say F**K YOU to my graphics department on a platform they won't ever visit.

So F**K YOU, useless tossers. I could do your job in 1/8th of the time, with superior results. So there.

Phew. Now, where am I....

Yeah, I know, I know...

...trust me, I know.

They patent everything and see what sticks. If you had money, you could too.

e.g., The gap I display between your last read post and the next one would be filed away as a great invention.

Isn't the rounded corner a design thing? Such things should not need to be patented. It's kind of art work and is as such protected as soon as the artist has created the art work. I mean' this would put everything in right perspective.

Here:
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{"name":"img_02.gif","src":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/6\/1\/6128bc6e33c1286afbcb2837bf06ecc9.gif","w":523,"h":369,"tn":"\/\/djungxnpq2nug.cloudfront.net\/image\/cache\/6\/1\/6128bc6e33c1286afbcb2837bf06ecc9"}

Two interfaces with rounded buttons. One wouldn't say that one is stolen from the other. There's more to it than only the rounded corners.