Initial work on proper character movement

src/fighter/state/fall.rs

@@ -0,0 +1,55 @@
+use bevy::prelude::*;
+
+use super::{FighterStateImpl, FighterStateContext, FighterStateTransition, ground, walk};
+use crate::fighter::state::{FighterState, air};
+use crate::fighter::state::ground::GroundedStateCommon;
+use crate::fighter::state::wait::WaitState;
+use crate::fighter::{FighterAttributes, FighterVelocity, collision, motion};
+use crate::game_settings::GameSettings;
+use crate::stage::line::StageCollision;
+
+#[derive(Debug, Clone, Copy, Hash)]
+pub struct FallState;
+
+impl FighterStateImpl for FallState {
+    const NAME: &'static str = "Fall";
+    fn check_interrupt(
+        &self,
+        state_context: &FighterStateContext,
+    ) -> Option<FighterState> {
+        None
+    }
+    
+    fn on_enter(&mut self, _state_context: &mut super::FighterStateContext) {}
+    
+    fn update(&mut self, state_context: &mut super::FighterStateContext) {
+        air::integrate_gravity(state_context.velocity, state_context.fighter_attribs);
+        air::apply_air_motion(state_context.velocity, state_context.translation, state_context.prev_translation);
+    }
+
+    fn check_collision_interrupt(
+        &mut self,
+        state_context: &mut FighterStateContext,
+    ) -> Option<FighterState> {
+        if let Some(res) = collision::air_collide_with_stage(state_context) {
+            // Adjust translation
+            state_context.translation.0 = res.hit_position - state_context.ecb.get_bottom_point();
+            let grounded_common = GroundedStateCommon {
+                current_line_id: res.line_id
+            };
+            Some(FighterState::Wait(WaitState { grounded_common } ))
+        } else {
+            None
+        }
+    }
+}
+
+pub fn check_input(state_context: &FighterStateContext) -> Option<FighterState> {
+    let input_frame = state_context.input.get_last_frame();
+
+    if input_frame.movement.x.abs() < state_context.game_settings.input_common.stick_deadzone {
+        return Some(FighterState::Fall(FallState));
+    }
+    None
+}
+