Implemented From trait for JoypadInput in Libretro core (#83)

* First version of the libretro core implementation

* Fixed issues the frames' color encoding and now supplying mock audio data to the libretro runtime

I was supplying argb color data instead of rgba. I fixed that.

* Fixed the ARGB encoding (which was all VERY wrong)

* Implemented controller 1 inputs

Controller 2's code is commented because it doesn't seem to work for some reason. I'll need to investigate that at a later time.

* Re-implemented controller 2 as I found it was related to the emulator's back end.

Saving is still not implemented.

* Fixed controller 2. (It has to be written in $4016 like controller 1).

Saving is still not implemented.

* Some reformating before Pull Request.

* Fixed requested changes for Pull Request.

* Cleaned up controller_state in core

* Implemented From trait for JoypadInput

Co-authored-by: zer0x64 <[email protected]>

nestadia-libretro/src/lib.rs

@@ -31,18 +31,18 @@ bitflags! {
     }
 }
 
-impl ControllerState {
-    fn from(button: JoypadButton) -> ControllerState {
+impl From<JoypadButton> for ControllerState {
+    fn from(button: JoypadButton) -> Self {
         match button {
-            JoypadButton::A => ControllerState::A,
-            JoypadButton::B => ControllerState::B,
-            JoypadButton::Start => ControllerState::START,
-            JoypadButton::Select => ControllerState::SELECT,
-            JoypadButton::Down => ControllerState::DOWN,
-            JoypadButton::Left => ControllerState::LEFT,
-            JoypadButton::Right => ControllerState::RIGHT,
-            JoypadButton::Up => ControllerState::UP,
-            _ => ControllerState::NONE,
+            JoypadButton::A => Self::A,
+            JoypadButton::B => Self::B,
+            JoypadButton::Start => Self::START,
+            JoypadButton::Select => Self::SELECT,
+            JoypadButton::Down => Self::DOWN,
+            JoypadButton::Left => Self::LEFT,
+            JoypadButton::Right => Self::RIGHT,
+            JoypadButton::Up => Self::UP,
+            _ => Self::NONE,
         }
     }
 }