fix: Correct SVG transformations in GCode Preview

[rianadon]

If a printer is not configured to have a (0,0) (xmin, ymin) coordinate, the GCode preview currently does not show up like in the picture below. For example, my printer's x goes from -113 to +113 and y from -74 to +74.

I fixed two issues with the SVG generation:

• The final 2 parameters of viewBox are the width & height of the image, not the +x and +y values.
• When flipping the image, the min & max coordinates should be added instead of subtracted. Imagine the print bed has minimum x 100 and maximum x 200. When flipped across the origin, it's going to end up far away and need to be translated 300px back.

Now, the preview shows up:

Signed-off-by: Ryan Adolf [email protected]

[pedrolamas]

Thanks for this @rianadon.

Am I correct in saying that this will fix #363 ?

[rianadon]

I didn't see that issue! But yes, it will fix #363.

I had the same issues with a nonzero position_min and the flip image settings, but those went away after the changes.

[matmen]

LGTM

[pedrolamas]

@rianadon Please add a footer to the main PR comment with a "Signed-off-by" line, following the CONTRIBUTING guidelines.

Thank you!

[rianadon]

Sorry my bad! I've updated the description.