World: r3wp

Where to start when I would like to learn how to write own extension? 
This page is out -of-date:/
http://www.rebol.com/r3/docs/concepts/extensions-examples.html

Here's a minimal example of an extension:
https://gist.github.com/0677266b8511d83ce76a

Also christian did an ODBC extension

fine... I can compile the minimal example, have problems with the 
samples above. The ODBC source is where?

don't think the odbc sources are published at the moment

see the announce group

the primary change compared to the docs is that many things have 
been renamed

some things

I don't see the ODBC source, only link to dll and docs.

Hmm... I thought I once saw the source

maybe that was the first attempt....

AFAIK his is the only working extension released

I did some early extensions .. but I doubt that they work now

With the sample2.c example I have problem with undefined RXI_SERIES_INFO 
and RXI_GET_CHAR

(I'm using #include "reb-host.h" from A110)

I think RXI_SERIES_INFO is now RL_SERIES

works

with RL_GET_CHAR

i think you could also replace RXI_GET_CHAR by first obtaining a 
pointer using RL_SERIES(ser, RXI_SER_DATA) and then just indexing 
into this directly

well, RL_GET_CHAR is probably better

all RL_* functions are safe to call from extensions

(macros, safe to use)

I did several extensions for windows, and you can find the source 
code and the dlls here: http://www.colineau.fr/rebol/R3_extensions.html
. This code may not be up to date, but recently I have compiled new 
versions. If necessary, I can upload them.

Oops, I forgot about your stuff jocko .. does it all still work?

I would appreciate a very simple example how to make extension using 
external DLL. So I could write for example ImageMagick extension.

Max was supposed to bing kind of R2 DLL interface in R3, but ... 
:-)

bing=bring

funny, I intended also to try interfacing with ImageMagick (maybe 
the ImageMagick Com + component.), as I have a need for another project.

Concerning the extensions dll's and source files, I think that they 
are no more compatible. I should check and put the latest versions.

pages updated with the new versions (binaries and sources) compatibles 
a110 :
http://www.colineau.fr/rebol/R3_extensions.html

I use IM extensively with R2 so I will need it with R3 as well. I 
think it must be easy.. if you know where to start.

if you download the OpenGL demo, there is a complete working setup. 
 it has a makefile and a visual studio 2008 setup .  it should help 
you out.

I'm completely C/C++ newbie, so I would like to know, how to make 
the extension, if I have precompiled DLL.
For example, In R2 I can simply download the DLL like this one:
http://zlib.net/zlib125-dll.zip

And simply do:

zlib.dll: load/library %zlib1.dll

zlib-version: make routine! [ return: [string!] ] zlib.dll "zlibVersion"
zlib-version
;== "1.2.5"


Is there someone who can write a simple tutorial - C extension with 
the zlib-version command?

I understand the REBOL part of it, but would like to see how to do 
the DLL trick part. Including the correct gcc command.

I would like to start with simple gcc instead of dealing with VS 
projects.

Oldes, I have uploaded an ImageMagick extension.

Nice

Oldes, I've built you a simple "zlib-version" extension.

Could you upload the C source as well? Btw.. I would rather use linkage 
to MagickWand.dll to be able use direct commands instead of command 
line like IM commands.

Great, I will check the zlib:) I'm looking forward to learn something.

No tutorial yet, but see I hope it helps nevertheless:
http://bolka.at/2010/rebol3/ext-zlib-20101108.zip

Extract this into your hostkit folder, so that you'll have an ext-zlib/ 
folder in the hostkit.

Then run make, and you should see something like the following:
$ make

gcc -DTO_WIN32 -I ../src/include -I include -mdll -L . -lzlib1 -o 
zlib.dll zlib.c

Afterwards you should have a fresh "zlib.dll" which is the extension.

Now run the accompanying zlib.r, and you should get:
$ r3-a110-3-1 -q zlib.r
1.2.5

it works.. thanks.. but I must say, that in R2 it was easier;-)

is there a reason why there is:
#include <stdio.h>
#include <string.h> 
?

stdio.h is a leftover and not needed.

string.h is for strlen.

And isn't the conversion to a REBOL string quite complicated?

Yes, a bit. There may be a simpler way. Or we could bundle a few 
such helper functions into a support library (as Max did in his OpenGL 
work).