[Plplot-general] contour rendering to PBM, or how to get libpng working on Win32

[John M. <jv...@li...>]

Quick version:
1) PBM driver renders crosshatch pattern in contour plot where PNG
driver renders patches of color. How to make PBM give the same image as
PNG?

Or...
2) Does anyone have a listing of files and clear instructions to get
libpng, zlib, and gd all installed and working with plplot on Windows
2000 using MinGW/MSYS?

Longer version:
I apologize in advance if I've missed this in the documentation
somewhere (and in the source, where I poked around for a bit).

I've currently got this very hacky plplot code that renders some data as
a contour plot to an image file which is then read in from the
filesystem by another part of the program for rendering on the screen.
Ugly, yes. But it works.

On Linux, I use PNG to accomplish this, and it works.

I need the same application to work in Windows, but I can't seem to get
libpng, zlib, and gd to play ball. (I finally got it down to the point
where configure said that my gd DLL didn't support PNG or JPG, which the
site that provided the binary DLL claims it does, and I gave up.)

So I figured since PBM appears supported, why not use that instead?

The problem is that I get a crosshatch pattern instead of solid color
patches for my contour plot, which makes it nigh useless, since the
"weave" of the crosshatching is so wide.

Nothing else changed in *my* code except to change the driver from PNG
to PBM (two lines, one to set the driver and one to set the filename),
so there must be something I need to know about the PBM driver to make
it perform as the PNG one does.

Having taken the code back from Windows to Linux, I see it behaves
precisely the same way, so it isn't some freaking Windows-specific
issue.

Many thanks in advance for any help you've got. :^)

Regards,
matt