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devel / alt.html / Re: Placing compound SVG items around coordinate (0,0)

Placing compound SVG items around coordinate (0,0)

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From: janis_pa...@hotmail.com (Janis Papanagnou)
Newsgroups: alt.html
Subject: Placing compound SVG items around coordinate (0,0)
Date: Sat, 18 Nov 2023 08:53:00 +0100
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by: Janis Papanagnou - Sat, 18 Nov 2023 07:53 UTC

I'm trying to construct a graphical symmetrically composed element -
say, a compass rose - with <svg> tags in a HTML source context.
My intention was - to simplify the transformations - to center the
element around coordinate (0,0). But I have problems even with a
simple composed graphical element. I had composed a simple element
placed in one quadrant of the coordinate system with some center
point (x,y) (where x, y unequal 0) like this:

+------
| / \
| \ /

but if (for example) I scale that then the _center_ of the composed
item gets relocated, but I want it persist. (SVG code below.[*])

So I tried to compose the element around (0,0) as illustrated here:

/|\
---+---
\|/

so that scaling and other point-symmetric derivations can be defined
easily without disturbing that symmetry.

I've looked for tutorials on the Web but the spare information I
found was more confusing than helpful to me. - Is there maybe any
good source you can recommend? Or maybe some small HTML/SVG code
sample how to center compound graphical items around (0,0)?

Janis

[*] Myself I was stuck with using fixed (not (0,0)-centered)
coordinates like

Re: Placing compound SVG items around coordinate (0,0)

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From: janis_pa...@hotmail.com (Janis Papanagnou)
Newsgroups: alt.html
Subject: Re: Placing compound SVG items around coordinate (0,0)
Date: Sun, 19 Nov 2023 02:58:04 +0100
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by: Janis Papanagnou - Sun, 19 Nov 2023 01:58 UTC

On 18.11.2023 08:53, Janis Papanagnou wrote:
> [...]

Solved it. - The problem, e.g. that parts of the SVG had got cropped,
vanished after relocating the viewBox definition from the outer <svg>
to the inner. (Then the change of cx/cy to 0/0 was effective without
any visible cropping.)

Janis

>
> [*] Myself I was stuck with using fixed (not (0,0)-centered)
> coordinates like
>
> <svg id="def" xmlns="http://www.w3.org/2000/svg" version="1.1"
> width="600" height="400" viewBox="-200 -100 600 400"
> xlink="http://www.w3.org/1999/xlink"
> style="position: relative; overflow: hidden;
> left: 0px; top: 0px; display: block;">
> <svg>
> <g id="str" transform="scale(0.2)">
> <circle cx="100" cy="100" r="100"/>
> <polygon points=" ... "/>
> </g>
> ...
>

Subject	Author
Placing compound SVG items around coordinate (0,0)	Janis Papanagnou
Re: Placing compound SVG items around coordinate (0,0)	Janis Papanagnou