Support Text on Path

[GoogleCodeExporter]

I just downloaded svgfig today, so maybe what I'm asking can already be
done, sorry if that's the case. (And thanks for creating svgfig!!)

What steps will reproduce the problem?
1. Create a text: tbox = Text(1.5, 0.5, "hello")
2. Transform the text: Fig(Fig(tbox, trans="x*cos(y), x*sin(y)")).SVG(...)

What is the expected output? What do you see instead?
I expected the text to be transformed too, but the text was nice and
horizontal.

What version of the product are you using? On what operating system?
1.1.6 (windows)

Please provide any additional information below:

I can understand why transforming text could be troublesome, however, it
would be enough for svgfig to support text on path. I'm thinking on
creating a "Line" and use that as a path. If the Line gets transformed, I
guess the text will be rendered following said transformed line.

Original issue reported on code.google.com by agus...@gmail.com on 12 Jun 2008 at 1:40

[GoogleCodeExporter]

Hi,

This is the correct behavior for Text--- usually people will want to set a 
label that
follows data through a coordinate transformation, but not distort with it.  
This is
where SVGFig differs from SVG: in SVG, a transformation completely distorts 
whatever
it's applied to, including line widths and the radii of data points, which is 
not
what people want when they make mathematical figures.

I can't remember the interface, but there's some option for Text (or a 
relative) that
calculates a linear approximation to the coordinate transformation at the point 
where
it is to be drawn and asks SVG to linear-transform the resulting SVG("text").

But that's just a linear transformation which will only look right if the text 
string
is short and the coordinate transformation is not too non-linear at that point. 
 What
you'd like to do, transform a Line and then put the text along it, is definitely
possible, though it is an SVG feature, rather than SVGFig.  You can transform a 
Line
and get SVGFig to output the resulting SVG("path", d="...").  Then give that 
path an
"id" attribute and create an SVG("textPath", ...) element.  See
http://www.w3.org/TR/SVG11/text.html#TextOnAPath for how to get SVG to do this 
for
you.  The SVGFig part is just generating the curvy path and linking things up 
into an
SVG document more conveniently.

There's a third option (if you're still looking for more), and that is to 
follow the
example of the SVGFig logo.  I created the text in Inkscape, then used an 
Inkscape
feature which converted the text into a path.  In SVGFig, I did a pathToPath
conversion (not necessary in 2.0) and applied a generic non-linear 
transformation. 
That messed things up a bit, because Inkscape used the minimum number of control
points, and the coordinate transformation only moved the control points.  So I 
went
back to Inkscape and additionally used the "add more points" feature to make 
the text
full of nearby control points, so that the coordinate transformation distorted 
it
more naturally.

Good luck!

Original comment by jpivar...@gmail.com on 12 Jun 2008 at 3:20

• Added labels: Type-Other
• Removed labels: Type-Defect

[GoogleCodeExporter]

Ok, thanks for your recommendations.
If I got it right, I should create the textPath with the SVG command, and not 
using
svfig's "Text" command. I'll look into that. I'm a bit confused by the "get 
SVGFig to
output the resulting SVG("path"... and give it an id" is that doable from 
svgfig or
do I need manual intervention?

Never mind, after some fiddling around I got it to work. See the following small
sample :-) Thanks!!

from svgfig import *
from math import *
import random

caja = Rect(0,1, 2,2, fill="blue", stroke="red")
path1 = Line (0.2, 1.2, 1.8, 1.2, id="path1")

text1 = SVG("text", SVG("textPath", "svgfig", xlink__href="#path1"), 
font_size=5,
stroke="none", fill="white", text_anchor="start")

Fig(Fig(caja, path1, text1, trans="-y*cos(x+0.6), 
y*sin(x+0.6)")).SVG(window(-6, 6,
-6, 6)).save()

Original comment by agus...@gmail.com on 13 Jun 2008 at 10:49