URL: http://www.eukleides.org

Ngôn ngữ vẽ hình hình học Ơ-cờ-lít đã có bản thử nghiệm, phiên bản 1.5.

Nhiều cải tiến đáng kể ...

Ngôn ngữ lập trình sáng sủa, và cũng lạnh lùng hơn ...

• Hỗ trợ xử lý ảnh động
  


• Có hẳn câu lệnh mới loci để vẽ quỹ tích, tập hợp điểm (Số nhiều của locus , trước đây, muốn vẽ quỹ tích phải dùng trace, và tính toán tọa độ các loại bằng ... sọ khỉ )


• Và nhiều nhiều nữa

Dưới đây là trích dẫn nhuyên ven của Tác giả Christian

Ghi chú

• Tài liệu hướng dẫn đang chuẩn bị viết, nhưng nói chung, xài theo kiểu bản 1.0 vẫn tốt tươi


• Xin phép bác Admin cho tôi được để nguyên văn dài thoòng loòng thế này mà không code nó nhé !!! (Quote còn tệ hơn )
  

Dear Eukleides friends,

I fairly think Eukleides 1.0 is quite an efficient language for creating
geometric figures. Nevertheless, I'm not satisfied with it because its
implementation makes it really difficult to extend. That's why I started
last year to rewrite it from scratch, adding by the way all the
features I found desirable. I'm now done with the first step, a virtual
machine based interpreter which I'll try to describe a bit:

* Direct PostScript output.

Unlike the former version, `eukleides' doesn't use PSTricks anymore.
It is meant to directly produce EPS figures, not to preprocess
(La)TeX files. Another program named `euktopst' will care for that.

* Dynamically loaded keywords.

I used the `gettext' system, so one just has to create a PO file to
add a localized version. I've done a French one as an example. (To
get a template, run `make pot' in the `po/' directory of the
distribution.)

* Loops, tests, user-defined functions and commands, basic I/O.

Eukleides can now be considered a real programming language.

* Include files.

Which allows to write ones own libraries.

* Ordered sets of points to handle polygons and loci.

With the former version, it was only possible to draw a locus (using
the `trace' command). Now loci are like any other geometrical
object and can be used the same way.

* Better language design (well... at least I hope so .

With Eukleides 1.0, command's arguments must be enclosed in round
braces like function's arguments. In fact this is useless since
commands do not return a value, so I decided to suppress that.

A Eukleides 1.0 script usually contains a lot of `draw' commands
which seems to me rather inelegant. Now to draw several objects one
just has to list them in a ``drawing block'', that is a sequence of
lines starting with `draw' and ending with `end'.

Interactive variable did not satisfy me either, so:
x interactive(0,.1,"A",right)
is now written:
horizontal x(#A,.1) = 0
Furthermore, interactive variable are often used to define mobile
points:
xa interactive(0,.2,"A",right)
ya interactive(0,.2,"A",up)
A = point(xa,ya)
Now, one just have to write:
mobile A(.2) = point(0,0)
Since the point's name is A, the interpreter assumes it is linked to
the #A state (but of course, one can give a different state argument
if needed).

The snapshot feature will also be different with `gEukleides' (which
is going to replace `xeukleides'). It will be based on ``init
directives'', that is a line starting with a sharp sign like:
# A -10 a 5 b -15
which means to interpret the figure as if the down arrow key would
have been hit 10 times in #A state, the right arrow key 5 times in #A
state and the left arrow key 15 times in #B state.

Since only the first encountered init directive is used, `gEukleides'
will only have to add such a line at top of the edited script to take
a snapshot. I admit these directives may be a bit difficult to read
but they'll allow to keep track of several snapshots.

Init directives are also implemented in `eukleides', you can even use
one as a command line option.

* Animated output (ImageMagick required).

Using an interactive variable together with the `--animate' command
line option allows to produce a multi-page PS document which can be
easily converted into an animated GIF or MNG file.

Except a few other slight differences, the remaining is quite identical
to Eukleides 1.0. Since it is a complete rewrite, I carefully tested
every piece of code but there's probably a ton of bugs left. And I did
not yet write any documentation.

Anyway, I decided to make a private prerelease for people I think could
be interested. You can download it at:

<http://www.eukleides.org/download/eukleides-1.5.0pre3.tar.bz2>

and play with it if you want . I wrote a set of scripts to illustrate
all the changes and the new features, and put it in the `bin/' directory
of the distribution.

I now plan to:

* Step 2: Implement `euktopst'.

* Step 3: Implement `gEukleides' using GTK+ 2 and GtkSourceView. I'll
add features like printing, conversion to EPS and other formats.

* Step 4: Write the documentation (I think I'm still going to use
Texinfo) and make the first public release.

* Step 5: Sleep :-D

* Step 6: Clean the code and comment it a bit. Write some Eukleides
configuration files for VIM and maybe Emacs.

Christian Obrecht