Re: BLT Graph Derivative

Hi Bob,

good to see things starting now!

We're just about to start requirements definition. I'd appreciate any
input or feedback that the Tcl community would like to provide.
I know that a number of folks have been talking or asking about this
for some time, and I believe that Torsten Berg has actually done some

Yes, I have started ripping the vector command out of BLT and making
it work independently under Tcl 8.4 and 8.5. Regard this as a case
study to see how complicated it is and to learn how BLT is coded and
organized internally. My approach and the resulting source code may
not be perfect and some things may even be "un-C-ish". But I realized
the whole work could be done in comparatively few days.

You can find some more information about the degree of success and the
implementation in the "BLT overhaul" thread here on c.l.t. I have put
the current source code here:

Some of the things I have changed starting from the original BLT
sources are:

1. removed the use of the bltAlloc package to now use ckalloc and
2. removed the use of the bltHash package to now use Tcl_Hash... (this
might result in some problems for 64bit systems, I am not sure.
Integrating the TIP 69 into the core would then overcome this
potential problem).
3. changed the string based Tcl commands to Tcl_Obj commands where
4. avoid the use of the internal Tcl C API to make vector stubs-

I can (and will) give some more specific information when I'm home
again next week (I'm attending a symposium right now and there's not
much time here).


Relevant Pages

  • Can BLT be replaced by Tcl packages ?
    ... I have a Tcl software which uses several commands of the BLT package. ...
  • Re: Found it once on wiki
    ... Seems BLT 2.4 is known not to work with Tcl 8.5 ... I plan to return to school, Computer Information Systems did not exist when I was in school [how may here programmed in CUPL under CORC;} I'm interested in signal processing, FFT papers were just being written when I was in school. ... Someone pointed towards some BLT code. ...
  • Re: BLT overhaul
    ... I assume you're using the BLT 2.4z source to start? ... We just tweak it for new tcl releases, and 8.5 doesn't look like a show-stopper for us. ... tried to get rid of BLT's copies of Tcl internals, ... leave different namespaces) and such. ...
  • Re: Found it once on wiki
    ... Seems BLT 2.4 is known not to work with Tcl 8.5 ... I'd like to become competent in a couple of languages (FORTH, Tcl) ... Computer Information Systems did not exist when I was in school [how may ... what's already there in the Tcl core. ...
  • Re: BLT vs Tcl/Tk 8.5.2 ?
    ... current cvs HEAD of Tcl and BLT and the above error is gone. ... I compiled on MacOS X with target X11 and without patching the BLT ... bltUnixFont.c:1298: warning: pointer targets in passing argument 1 of ... bltUnixFont.c:1837: warning: assignment discards qualifiers from ...