For a Webserver I need to create the png graphics format.

I want to use as little external components as possible.

Has someone experience with the zlib format or specification? Can it be used without allocating memory?
Or with a given memoryblock for operation?

I would like to prevent allocating memory and freeing memory all the times...

Rainer Stratmann wrote

For a Webserver I need to create the png graphics format. I want to use as little external components as possible.

What is wrong with the existing png reader ?

Michael.

The text rendering example also shows how to write a png image:

http://wiki.lazarus.freepascal.org/fcl-image#Drawing_text

I don't know any bugs in the existing png reader.

My application is running in a critical environment. Also the webserver code I wrote completely myself. All with static memory. No dynamic allocating memory blocks. In these days memory is not the problem.
http://demo.klimaregelung.de
For showing measuring values I need png support.

On 08/11/2010 13:07, Rainer Stratmann wrote:
...

http://demo.klimaregelung.de For showing measuring values I need png support. _______________________________________________

Interesting demo. Do you have it in English? Do you intend to have multi-language support?

zlib's compress2 operates on memory blocks that you give it, but I am not sure whether it allocates temporary buffers. Note that I tried FPC's zlib but it crashed on Windows. Instead, on Windows, I am linking to

{$linklib Libs/mingw/libz.a}
{$linklib Libs/mingw/libmsvcrt.a}
{$linklib Libs/mingw/libgcc.a}

On the Mac, zlib is part of the system software.

Regards,

Adriaan van Os