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 +1,46 @@
+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 {
+    /// the cone's radius, sqaured
+    radius_squared: f64,
+}
+
+impl Cone {
+    pub const DEFAULT_RADIUS: f64 = 1.0;
+
+    pub fn new() -> Self {
+        Self {
+            radius_squared: Self::DEFAULT_RADIUS.powi(2),
+        }
+    }
+
+    pub fn set_radius(self, radius: f64) -> Self {
+        Self { radius_squared: radius.powi(2) }
+    }
+}
+
+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];
+
+        let dist_from_center_squared = x.powi(2) + y.powi(2);
+
+        match dist_from_center_squared > self.radius_squared{
+            true => -1f64,
+            false => 1.0 - 2.0*(dist_from_center_squared / self.radius_squared).sqrt()
+        }
+    }
+}