Support MonoGame 3.8

As the title says, currently using penumbra with monogame 3.8 throws exception: System.Exception: 'This MGFX effect is for an older release of MonoGame and needs to be rebuilt.'

[spiercey]

Just a note, looks like there have been some changes to the GraphicsDevice setup in 3.8 which results in the RenderTarget2Ds in Penumbra Component getting the default 480x360 resolution if you set up Penumba in the Game constructor as in the docs. (Even if you set your backbuffer and viewports on Graphics and GraphicsDevice correctly).

I’ve had to switch all of my resolution setup and penumbra creation to the Game.Initialize() method (after base.Initialize();).

It also seem like you now need to call graphics.ApplyChanges(); manually after setting up the GraphicsDeviceManager.

Everything seems to work fine after moving the GraphicsDeviceManager and Penumbra setup out of the constructor though.

[discosultan]

@spiercey Thanks for sharing the fork! I haven’t had time to upgrade to MonoGame 3.8 yet but am planning to sometime this month. Your work definitely helps me speed things up.