From 6de8cfc84edbc80196ad144f2886031a898f5ed7 Mon Sep 17 00:00:00 2001
From: Arne Dußin
Date: Fri, 7 May 2021 18:06:02 +0200
Subject: Add player movement

---
 src/systems/movement.rs | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 src/systems/movement.rs

(limited to 'src/systems/movement.rs')

diff --git a/src/systems/movement.rs b/src/systems/movement.rs
new file mode 100644
index 0000000..61c572a
--- /dev/null
+++ b/src/systems/movement.rs
@@ -0,0 +1,43 @@
+use std::time::{Duration, Instant};
+
+use specs::prelude::*;
+
+use crate::components::{Pos, Velocity};
+
+pub struct SysMovement
+{
+    delta_time: Duration,
+    last_run:   Instant,
+}
+
+impl SysMovement
+{
+    pub fn new() -> Self
+    {
+        Self {
+            delta_time: Duration::ZERO,
+            last_run:   Instant::now(),
+        }
+    }
+}
+
+impl Default for SysMovement
+{
+    fn default() -> Self { Self::new() }
+}
+
+impl<'a> System<'a> for SysMovement
+{
+    type SystemData = (WriteStorage<'a, Pos>, ReadStorage<'a, Velocity>);
+
+    fn run(&mut self, (mut pos, vel): Self::SystemData)
+    {
+        let now = Instant::now();
+        self.delta_time = now - self.last_run;
+        self.last_run = now;
+
+        for (pos, vel) in (&mut pos, &vel).join() {
+            pos.0 += vel.0 * self.delta_time.as_secs_f64();
+        }
+    }
+}
-- 
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