Bevy 0.17 introduces this idea of "Messages" which mostly replace the
previous usage of "Events." The old events still exist, but are meant
more for targetted actions -- something happening and immediately
triggering a function call on an observer.
Closes#16
Bevy provides Deref and DerefMut derives, so that's nice. I'm not sure
it makes any sense to keep the field private since those derefs expose
the Vec2 anyway. I added an `impl Default` anyway, though.
The spacebar fires the gun, bullets are spawned on top of the ship with
a velocity that sends them forward (relative to the ship).
I still need a despawn mechanism, and a fire rate control. To despawn
things, I'm already planning a `Lifetime` component. For rate of fire,
an additional component will be created and attached to the player ship.
Something something quaternions are hard. I thought I would take the two
"things", add them together, and then put them back into the transform.
That's clearly not how it works :v
The rotation component is also redundant with Bevy's transform
component.
This new component and system fill the physics role, but the input
handling code needs to be updated.
Player steering still functions because it uses the `Rotation` component
to direct the force vector. The force is correctly applied to the linear
velocity vector. An improvement would be to have a force/impulse
accumulator so I could account for mass, but I'm not going to do that
right now.
Replacing the `Position` component with direct manipulation of the
transform functionally completed the TODO. The functions weren't exactly
combined, but the resulting behavior might as well have been.
I've updated the docstring to (exist, actually. yay syntax) describe the
system accurately.
The position component is redundant with the built-in Bevy Transform.
I've updated the velocity integrator to use the transform directly.
Physics still works, but things still set their initial locations
through the Position component. I'll need to fix all those call sites.
The physics sim bits (that aren't Rapier2d) are now in their own
submodule. I've included the `Wrapping` marker component because it
doesn't really have anywhere else to live, and it's kinda sorta related
to the physics. It controls the motion of objects... that's physics. :p
There are name collisions between Rapier2d's `Velocity` and my own, but
that's a problem for later. I've used more specific type paths where
necessary to maintain the previous behavior.
The `physics::Position` component can go away completely. It's just an
extra copy of some of the built-in `Transform` data. I'm pretty sure it
only exists because I didn't realize I could rely on directly
manipulating the transform when I started this project.
