Add cone generator

src/noise_fns/generators.rs

@@ -1,11 +1,12 @@
 pub use self::{
     checkerboard::*, constant::*, cylinders::*, fractals::*, open_simplex::*, perlin::*,
-    perlin_surflet::*, simplex::*, super_simplex::*, value::*, worley::*,
+    perlin_surflet::*, simplex::*, super_simplex::*, value::*, worley::*, cone::*,
 };
 
 mod checkerboard;
 mod constant;
 mod cylinders;
+mod cone;
 mod fractals;
 mod open_simplex;
 mod perlin;

src/noise_fns/generators/cone.rs

@@ -0,0 +1,47 @@
+use crate::noise_fns::NoiseFn;
+
+/// Noise function that outputs a cone.
+/// 
+/// This noise function takes a 2d point and outputs a cone that is aligned along the z axis.
+/// The origin has a value of 1 and points with a distance from the origin beyond the radius
+/// of the cone are -1.
+#[derive(Clone, Copy, Debug)]
+pub struct Cone {
+    /// radius of the cone.
+    pub radius: f64,
+}
+
+impl Cone {
+    pub const DEFAULT_RADIUS: f64 = 1.0;
+
+    pub fn new() -> Self {
+        Self {
+            radius: Self::DEFAULT_RADIUS,
+        }
+    }
+
+    pub fn set_radius(self, radius: f64) -> Self {
+        Self { radius }
+    }
+}
+
+impl Default for Cone {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl NoiseFn<f64, 2> for Cone {
+    fn get(&self, point: [f64; 2]) -> f64 {
+        let x = point[0];
+        let y = point[1];
+
+        // Calculate the distance of the point from the origin.
+        let dist_from_center = (x.powi(2) + y.powi(2)).sqrt();
+
+        match dist_from_center > self.radius{
+            true => -1f64,
+            false => 1.0 - 2.0*(dist_from_center / self.radius)
+        }
+    }
+}