Re: [GD-DEVEL] trouble with antialiasing

Hi Pierre,

Hmmm, maybe I'm looking at the wrong docs, or the docs need
updating... I was reading http://www.libgd.org/OldDrawing, under
gdImageSetAntiAliased(), and it says "Antialiased lines can be drawn
on both truecolor and palette-based images."

Also, I'm not clear on why the line from the example did not come out
antialiased -- only lines at angles other than 45 degrees seemed to
use any shades other than the exact one I specified.  Is this an 
artifact of the particular algorithm being used?

thanks,
Eric

On Sat, Oct 27, 2007 at 10:37:52AM +0200, Pierre wrote:
> Hi Eric,
> 
> On 10/26/07, Eric Tucker <[email protected]> wrote:
> > Hi,
> >
> > I am having trouble getting even the most basic antialiasing to work.
> > I copied the example right out of the manual and built it in as much
> > isolation as possible, but am still getting a non-antialiased line.
> > My test source file is included below, and I am building it with:
> >
> >     gcc -lgd -o gtest gtest.c
> >
> > This is on Fedora Core 6, with gd-2.0.35-1.fc6 and
> > gd-devel-2.0.35-1.fc6.
> >
> > I was able to get it to antialias by both (a) creating the image
> > instead with gdImageCreateTrueColor(), and (b) changing the second
> > 99 to a 49, thus making the line be at less than a 45-degree angle.
> > But these seem arbitrary to me -- I was just thrashing around
> > randomly -- and I don't see why the original code does not work.
> >
> > Am I missing something obvious here?
> 
> >     im = gdImageCreate(100, 100);
> 
> im = gdImageCreateTrueColor(100,100);
> 
> Truecolor image has AA support.
> 
> Cheers,
> --Pierrre