Transformation Center and Centrepoint

Hi,

 In reading Tuesday's minutes, I see that the SVG working group resolved
"svg wants to allow rotation about centrepoint in svg, to align with
css. sysntax not yet decided". It's hard from the minutes to understand
exactly what this means. I am assuming that the centerpoint is the
center of the bounding box. In animation, this is not what you always
want. Consider rotating a five pointed star, the center of the bounding
box is not the center of the star. Inkscape has two attributes, one for
x and one for y, that set the transformation center of an object which
is then used for rotating, scaling, and skewing. By default the
transformation center is the center of the bounding box but it can be
changed by the user. Inkscape automatically sets these attributes to the
center if one uses the start/polygon tool to draw the star. It seems to
be that a transformation center is a natural property of an object. We
should consider adding this to the list of allowed properties and then
use this point as the center point for rotation, scaling, and skewing,
if it is set.


      Tav

<path id="MyStar" d="..."
 inkscape:transform-center-x="1.768"
 inkscape:transform-center-y="-9.168"
 ... />

Received on Wednesday, 2 March 2011 10:23:37 UTC