Vizsage

I've just imported the WIS mathematics library -- an excellent collection of mathematics routines -- onto Google Code. (You'll find the Actionscript 2 version of the library at its original site)

This library carries a BSD-ish license and includes support for

• Geometric Objects and Intersection calculations
• Integral and Differential equation calculations
• Bezier, Quadric, Polynomial, Complex, Vector and Matrix calculations
• Symbolic expression parsing

I'm converting the library to Actionscript 3 from Actionscript 2 as time and necessity allow. (That's converting as in getting it to work, and converting as in getting it to be object/pattern oriented). Right now it builds without errors and only a few warnings, but I haven't applied any of the unit tests or checked it for correctness or compatibility.

If you see the value of updating this well-thought out collection of functions, please get in touch and I will add you as a developer. The code is quite modular: it will be straigforward to take modest chunks and get them working independently. I wrote the original author and maintainer, who responded "By all means, continue in the evolution/integration of my library to support AS3" -- but please let me know of any other efforts to update this code, or if a similar or superior math library exists, so that I don't waste my time :).

Email me [flip at the mrflip with the dot and the com] or comment on this post if you'd like to pitch in!

Labels: actionscript, algebra, as, as3, as3mathlib, bezier, derivative, equation, flex, integral, intersection, Math, Mathematics, matrix, polynomial, symbolic, vector

Posted by flip at 9/01/2007 02:49:00 AM | Permalink | Comments | links to this post

The Actionscript 3 Cookbook is a very helpful reference, and the example code that came with it has many good examples. Unfortunately there's a modicum of bitrot in the code: compiler warnings and errors when compiling under strict mode.

Here is a patch against the version of the code I downloaded on 2007-08-24:

files/AS3CB-patch-2007-08-24.diff

Apply it thusly.

Labels: actionscript, actionscript cookbook, diff, flex, o'reilly, oreilly, patch

Posted by flip at 8/24/2007 03:08:00 PM | Permalink | Comments | links to this post

I'm working on something that uses (an algorithm similar to) texture mapping, for which I want to precalculate the .invert() of a whole bunch of .transform.matrix objects. I'll post something about that in the next coupla days. Meanwhile, I found something perplexing in the Actionscript documentation but the possibility exists that I am just a dope so please point out an error in my reasoning. As you may know, you can represent any arbitrary combination of 2-D scalings, skews, rotations and translations using standard matrix operations. The Actionscript docs for the Matrix class mention this in passing, but has elements .b and .c switched: it should be

and not .

I whipped up a MatrixMathDemo in flex to demonstrate the issue:

• Demo
• Source
• Docs

and a writeup on Mathematical matrices and the actionscript Matrix transformations [PDF]. The 2d, 3d, 4th tabs compare the Matrix methods concat(), invert() and (deltaP/p)ointTransform() respectively with an explicit calculation of the corresponding Matrix operation: they show that in fact the documentation has b and c switched. (The code is free to reuse or modify (but give credit) in case that's useful.) Some references:

• This flash-specific tutorial at senocular.com is good, though the matrices are transposed from what is typically presented.
• The posts on the flashcoders list A little matrix.invert() mystery and followup are explained by b and c being switched; they link to post on a french blog that is helpful if you parlez.
• To brush up on matrix mathematics, please see the Matrix and Quaternion FAQ or Wikpedia.

Labels: actionscript, adobe, concat, error, flex, invert, Mathematics, matrices, matrix, rotate, scale, shear, transform, translate

Posted by flip at 8/20/2007 12:09:00 PM | Permalink | Comments | links to this post

• Emacs modes for Flex:
• XML: nXML-mode for Emacs from James Clark Using Emacs for XML documents
• Actionscript: actionscript-mode.el for editing actionscript files in emacs.
• At least right now it seems you want this xml mode and this actionscript-mode.el.
• Then, add

  (setq auto-mode-alist (append (list
   '("\\.as\\'"   . actionscript-mode)
   '("\\.\\(xml\\|xsl\\|rng\\|xhtml\\|mxml\\)\\'" . nxml-mode)
   ;; add more modes here
   ) auto-mode-alist))
  
  ;;
  ;; ------------------ Magic for XML Mode ----------------
  ;;
  
  (setq nxml-mode-hook
      '(lambda ()
   (setq tab-width        2
         indent-tabs-mode nil)
         (set-variable 'nxml-child-indent     2)
         (set-variable 'nxml-attribute-indent 2)
         ))
  

• You can use M-x customize-group RET nxml-highlighting-faces RET to fix your colors the way you like 'em.
• Setting up asdoc to work within Flex Builder:
• First, install ant support (Ant is an offshoot of apache and is like Makefile only more betterer.)
• Then set up a build.xml in your docs/ directory to build the documentation set.
• I had to modify mine a bit: I added <property name="Templates.dir" location="${FlexSDK.dir}/asdoc/templates/"/> <arg line='-templates-path ${Templates.dir}'/>
• I also linked the flex home to a no-funny-characters dir:

      ln -s "/Applications/Applications/Adobe Flex Builder 2" /work/ProgramStores/Flex
     cd /work/ProgramStores/Flex
     ln -s "Flex SDK 2" FlexSDK

  Then I exported the location for the asdoc file:

      export FLEX_HOME=/work/ProgramStores/Flex/FlexSDK

  or else I got the error message:

      Exception in thread "main" java.lang.NoClassDefFoundError: Flex

Labels: actionscript, as, elisp, emacs, flex, mode, mxml, xml

Posted by flip at 7/25/2007 04:51:00 AM | Permalink | Comments | links to this post

How to fix CTAGS to work with ActionScript, from the vim-taglist project:

• ActionScript Add the following lines to the $HOME/.ctags or $HOME/ctags.conf file:

  --langdef=actionscript
  --langmap=actionscript:.as
  --regex-actionscript=/^[ \t]*[(private| public|static) ( \t)]*function[ \t]+([A-Za-z0-9_]+)[ \t]*\(/\1/f, function, functions/
  --regex-actionscript=/^[ \t]*[(public) ( \t)]*function[ \t]+(set|get) [ \t]+([A-Za-z0-9_]+)[ \t]*\(/\1 \2/p,property, properties/
  --regex-actionscript=/^[ \t]*[(private| public|static) ( \t)]*var[ \t]+([A-Za-z0-9_]+)[ \t]*/\1/v,variable, variables/
  --regex-actionscript=/.*\.prototype \.([A-Za-z0-9 ]+)=([ \t]?)function( [ \t]?)*\(/\1/ f,function, functions/
  --regex-actionscript=/^[ \t]*class[ \t]+([A-Za-z0-9_]+)[ \t]*/\1/c,class, classes/
  

  Add the following lines to the ~/.vimrc or $HOME\_vimrc file:

  " actionscript language
  let tlist_actionscript_settings = 'actionscript;c:class;f:method;p:property;v:variable'
  

I actually just add these lines to my maintenance Makefile:

CTAGLANGS = --langdef=actionscript \
--langmap=actionscript:.as \
--regex-actionscript='/^[ \t]*[(private| public|static) ( \t)]*function[\t]+([A-Za-z0-9_]+)[ \t]*\(/\1/f, function, functions/' \
--regex-actionscript='/^[ \t]*[(public) ( \t)]*function[ \t]+(set|get) [ \t]+([A-Za-z0-9_]+)[ \t]*\(/\1 \2/p,property, properties/' \
--regex-actionscript='/^[ \t]*[(private| public|static) ( \t)]*var[  \t]+([A-Za-z0-9_]+)[\t]*/\1/v,variable, variables/' \
--regex-actionscript='/.*\.prototype \.([A-Za-z0-9 ]+)=([ \t]?)function( [  \t]?)*\(/\1/f,function, functions/' \
--regex-actionscript='/^[ \t]*class[ \t]+([A-Za-z0-9_]+)[ \t]*/\1/c,class, classes/'

.PHONY: ctags
ctags:
-rm -f TAGS
find . -name "*.as" -or -name "*.mxml" | ctags -eL - $(CTAGLANGS)

Take off the -e (ctags -L - $(CTAGLANGS)) if you're one of those vi users (I'm being polite because, after all, it's from them comes this tip)

Labels: actionscript, ctags, emacs, flex, make, Makefile, regex, TAGS, vi

Posted by flip at 7/24/2007 12:14:00 AM | Permalink | Comments | links to this post

Hints I gathered for learning Flex:

• Browse the Flex SDK source -- everything that's in flex (except the charting components) is in the SDK, and they use design patterns and all that awesomehood. Oh yeah, it's free.
• The flexcoders archive for the FlexCoders mailing list, and the flashcoders archive for the flashcoders list make things much easier to follow. (If you have a better solution for following a large-traffic mailing list do tell).
• Flex Blogs:
  • MoockBlog
  • Darron Schall
  • EverythingFlex
  • Zeus Labs
  • Mark Shepherd
  • Quietly Scheming
  • Flex.org

Labels: actionscript, flex, flexcoders, learn, learning, SDK

Posted by flip at 6/20/2007 06:59:00 PM | Permalink | Comments | links to this post