rotating SVG images

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richmond62
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rotating SVG images

Post by richmond62 » Tue Dec 06, 2016 11:49 am

I have been messing around with Scratch . . .

I notice that all the pre-supplied 'sprites' are SVG files . . .

Within Scratch these SVG images can be rotated any which way one wants with no visible deterioration at all.

As the only ways one can import a vector image into LiveCode is either via the SVG widget or
by setting the points of a graphic object to the points of an SVG image there seems to be
NO way one can rotate them.
scritch.png
Vector "sprite" in Scratch.
scritch.png (47.85 KiB) Viewed 3193 times

[-hh]
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Re: rotating SVG images

Post by [-hh] » Tue Dec 06, 2016 2:49 pm

For rotating the points of a polygon in LC Script use the following.

Code: Select all

-- b is the angle of rotation in degrees (positive b turns clockwise, negative b turns ccw)
-- pts are the points of a polygon and (x0,y0) is the center of rotation
function hhRotateTo b,pts,x0,y0
   put sin(pi*b/180) into s; put cos(pi*b/180) into c
   repeat for each line L in pts
      if L is empty then put cr after pts2
      else
         put -x0 + item 1 of L into sx; put -y0 + item 2 of L into sy
         put cr & ( (statRound(x0+c*sx-s*sy),statRound(y0+c*sy+s*sx)) ) after pts2
      end if
   end repeat
   return char 2 to -1 of pts2
end hhRotateTo
For rotating a deliberate imported SVG use in LC Builder
(there are several lcb files that show how to "prepare" for rotation)

Code: Select all

rotate this canvas by <angle>   OR   rotate <path> by <angle>
shiftLock happens

richmond62
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Re: rotating SVG images

Post by richmond62 » Tue Dec 06, 2016 8:16 pm

Thank you.

Although, compared with rotating PNG, GIF and JPG images this does seem a bit complicated.

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