From: Tomas Wenström <tomas.wenstrom@gmail.com>
Date: Tue, 19 Jan 2021 18:42:34 +0000 (+0100)
Subject: Limit stick point to unit vector
X-Git-Url: http://git.dolda2000.com/gitweb/?p=kaka%2Frust-sdl-test.git;a=commitdiff_plain;h=eca2559123ae3c7ef184bf42ec60680fcddb38f6

Limit stick point to unit vector
---

diff --git a/src/common.rs b/src/common.rs
index 01c0238..0d82903 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -14,10 +14,26 @@ pub struct Point2D<T> {
 }
 
 impl Point2D<f64> {
-    pub fn length(self) -> f64 {
+    pub fn length(&self) -> f64 {
         ((self.x * self.x) + (self.y * self.y)).sqrt()
     }
 
+    pub fn normalize(&self) -> Self {
+	let l = self.length();
+	Self {
+	    x: self.x / l,
+	    y: self.y / l,
+	}
+    }
+
+    pub fn radians(&self) -> Radians {
+	Radians(self.y.atan2(self.x))
+    }
+
+    pub fn degrees(&self) -> Degrees {
+	self.radians().to_degrees()
+    }
+
     pub fn to_i32(self) -> Point2D<i32> {
 	Point2D {
 	    x: self.x as i32,
diff --git a/src/core/controller.rs b/src/core/controller.rs
index 832480d..9d23257 100644
--- a/src/core/controller.rs
+++ b/src/core/controller.rs
@@ -1,5 +1,5 @@
 use common::Point2D;
-use hashmap;
+use {hashmap, point};
 use common::Radians;
 use sdl2::HapticSubsystem;
 use sdl2::JoystickSubsystem;
@@ -68,7 +68,6 @@ pub struct Stick {
     pub x: f32,
     pub y: f32,
     pub a: Radians,
-    pub len: f32,
 }
 
 impl Stick {
@@ -82,11 +81,6 @@ impl Stick {
 	    Err(_) => panic!("invalid y axis {}", self.idy),
 	};
 	self.a = Radians(self.y.atan2(self.x) as f64);
-	self.len = {
-	    let x = (self.x / self.y).abs().min(1.0);
-	    let y = (self.y / self.x).abs().min(1.0);
-	    (self.x.powi(2) + self.y.powi(2)).sqrt() / (x.powi(2) + y.powi(2)).sqrt()
-	}
     }
 
     #[inline(always)] #[allow(dead_code)] fn up(&self) -> bool { self.y > 0.99 }
@@ -94,15 +88,17 @@ impl Stick {
     #[inline(always)] #[allow(dead_code)] fn left(&self) -> bool { self.x < -0.99 }
     #[inline(always)] #[allow(dead_code)] fn right(&self) -> bool { self.x > 0.99 }
 
-    pub fn to_point(&self) -> Point2D<f64> {
-	Point2D {
-	    x: self.x as f64,
-	    y: self.y as f64,
-	}
+    pub fn to_axis_point(&self) -> Point2D<f64> {
+	point!(self.x as f64, self.y as f64)
     }
 
-    pub fn to_adjusted_point(&self) -> Point2D<f64> {
-	Point2D::from(self.a) * self.len as f64
+    pub fn to_point(&self) -> Point2D<f64> {
+	let p = point!(self.x as f64, self.y as f64);
+	if p.length() > 1.0 {
+	    p.normalize()
+	} else {
+	    p
+	}
     }
 }
 
diff --git a/src/core/game.rs b/src/core/game.rs
index 8474fab..f48d9b3 100644
--- a/src/core/game.rs
+++ b/src/core/game.rs
@@ -170,7 +170,7 @@ impl Object for Character {
 	    for _i in 0..100 {
 		objects.push(Box::new(Boll {
 		    pos: self.pos,
-		    vel: ctrl.aim.to_adjusted_point() * (3.0 + rand::random::<f64>()) + point!(normal.sample(&mut rand::thread_rng()), normal.sample(&mut rand::thread_rng())) + self.vel,
+		    vel: ctrl.aim.to_point() * (3.0 + rand::random::<f64>()) + point!(normal.sample(&mut rand::thread_rng()), normal.sample(&mut rand::thread_rng())) + self.vel,
 		    bounces: 2,
 		}));
 	    }
@@ -207,12 +207,12 @@ impl Object for Character {
 	let l = 300.0;
 	let pos = (self.pos.x as i32, self.pos.y as i32);
 	// axis values
-	let p = (self.pos + ctrl.aim.to_point() * l).to_i32().into();
+	let p = (self.pos + ctrl.aim.to_axis_point() * l).to_i32().into();
 	canvas.set_draw_color((0, 255, 0));
 	canvas.draw_line(pos, p).unwrap();
 	draw_cross(canvas, p);
-	// adjusted values
-	let p = (self.pos + ctrl.aim.to_adjusted_point() * l).to_i32().into();
+	// values limited to unit vector
+	let p = (self.pos + ctrl.aim.to_point() * l).to_i32().into();
 	canvas.set_draw_color((255, 0, 0));
 	canvas.draw_line(pos, p).unwrap();
 	draw_cross(canvas, p);