fix: check for GO existence before sending message (#80)

The camera was calling `msg.post(sender, MSG_SHAKE_COMPLETED) without
checking if sender is still present at that point. Since this is a
callback, the shake can end at a point in time where the sender is no
longer alive.

Sample error produced when this happens below :
`ERROR:GAMEOBJECT: Instance '/instance80' could not be found when
dispatching message 'shake_completed' sent from game:/camera#script`

Co-authored-by: berru <berru@riseup.net>

Removed set_window_scaling_factor from docs

Updated camera.lua (#73)

Sorted a issue where it used DISPLAY_WIDTH instead of DISPLAY_HEIGHT for vertical camera shaking

Co-authored-by: Mobjunk <34821598+Mobjunk@users.noreply.github.com>

Check window width and height in render script

Fixes #68

Add world_to_window function (#64)

Set stencil mask

Implement frustum culling (#54)

Not sure this fits your style @britzl but I figured I'd at least get the ball rolling. I assume passing frustum to a project <1.3.1 just has no effect?

Make sure to keep follow lerp within 0 and 1

Fixes #51

Use viewport width and height in projection calcs (#52)

Clip node clips the profiler if we don't disable stencil test. So dis…

…abled it after drawing gui. (#48)