feat(sphere): add texture sphere

scenes/demo-3.lisp

@@ -17,32 +17,7 @@
       (color 0 0.6 0)
       50 0.25))
 
-(set 's1
+(set 'mandelbrot-red
-     (sphere
-      (point 0 1 0) 1 blue))
-(set 's2
-     (sphere
-      (point 2 0.5 2) 0.5 green))
-
-(defun spiral-sphere (i n)
-  (sphere
-   (progn
-     (print "Spiral Sphere at: ")
-     (println (point
-               (* 2 (cos (/ (* i 6.2) n)))
-               0.5
-               (* 2 (sin (/ (* i 6.2) n)))))
-     )
-   0.5 red))
-
-(defun spiral (scn i n)
-  (if (< i n)
-      (scene-add
-       (spiral scn (+ i 1) n)
-       (spiral-sphere i n))
-      scn))
-
-(set 'mandelbrot
      (mandelbrot-texture
       1800.0
       (point2 -0.7489967346191402 -0.06952285766601607)
@@ -52,9 +27,27 @@
       (color 0.3 0 0)
       ))
 
+(set 'mandelbrot-blue
+     (mandelbrot-texture
+      1800.0
+      (point2 -0.7489967346191402 -0.06952285766601607)
+      1000
+      (color 0 0 0.3)
+      (color 0 0 0.3)
+      (color 0 0 0.3)
+      ))
+
+(set 's1
+     (sphere
+      (point 0 1 0) 1 blue))
+(set 's2
+     (sphere
+      (point 2 0.5 2) 0.5 green))
+
+
 (set 'p1
      (texture-plane
-      mandelbrot
+      mandelbrot-red
       (point 0 0 0)
       (vector 0 1 0)
       1.0

src/raytracer/lisp.rs

@@ -2,6 +2,7 @@ use std::path::PathBuf;
 
 use crate::raytracer::{
     scene::Scene,
+    sphere::TextureSphere,
     texture::TextureWrapper,
     types::{Light, Point2},
 };
@@ -74,6 +75,22 @@ pub fn sphere(
     Ok(ForeignDataWrapper::new(RTObjectWrapper::from(Sphere::new(*pos, rad, *mat))).into())
 }
 
+#[native_lisp_function(eval)]
+pub fn texture_sphere(
+    pos: ForeignDataWrapper<Point3>,
+    rad: f64,
+    tex: ForeignDataWrapper<TextureWrapper>,
+) -> Result<ForeignDataWrapper<RTObjectWrapper>, EvalError> {
+    Ok(
+        ForeignDataWrapper::new(RTObjectWrapper::from(TextureSphere::new(
+            *pos,
+            rad,
+            tex.clone(),
+        )))
+        .into(),
+    )
+}
+
 #[native_lisp_function(eval)]
 pub fn plane(
     pos: ForeignDataWrapper<Point3>,
@@ -539,6 +556,10 @@ pub fn mk_raytrace(layer: &mut EnvironmentLayer) {
         Expression::Function(mandelbrot_texture),
     );
     layer.set("sphere".to_string(), Expression::Function(sphere));
+    layer.set(
+        "texture-sphere".to_string(),
+        Expression::Function(texture_sphere),
+    );
     layer.set("scene".to_string(), Expression::Function(scene));
     layer.set("scene-add".to_string(), Expression::Function(scene_add));
     layer.set("camera".to_string(), Expression::Function(camera));

src/raytracer/sphere.rs

@@ -1,4 +1,7 @@
-use super::types::{Intersect, Material, Point3, Ray, Scalar, Vector3};
+use super::{
+    texture::TextureWrapper,
+    types::{Intersect, Material, Point2, Point3, Ray, Scalar, Vector3},
+};
 
 extern crate nalgebra as na;
 
@@ -13,6 +16,17 @@ pub struct Sphere {
     material: Material,
 }
 
+/// A sphere in 3D space
+#[derive(PartialEq, Clone, Debug)]
+pub struct TextureSphere {
+    /// Center of the sphere
+    center: Point3,
+    /// Radius of the sphere
+    radius: Scalar,
+    /// texture of the sphere
+    texture: TextureWrapper,
+}
+
 impl Sphere {
     /// Create a new sphere at `center` with `radius` and `material`.
     pub fn new(center: Point3, radius: Scalar, material: Material) -> Sphere {
@@ -27,13 +41,12 @@ impl Sphere {
 /// Numerical error tolerance
 const EPSILON: Scalar = 1e-5;
 
-impl Intersect for Sphere {
+fn intersect(ray: &Ray, center: &Point3, radius: Scalar) -> Option<(Point3, Vector3, Scalar)> {
-    fn intersect(&self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, Material)> {
+    let co = ray.origin - center;
-        let co = ray.origin - self.center;
 
     let a = ray.direction.dot(&ray.direction);
     let b = 2.0 * ray.direction.dot(&co);
-        let c = co.dot(&co) - (self.radius * self.radius);
+    let c = co.dot(&co) - (radius * radius);
     let d = b * b - 4.0 * a * c;
 
     if d >= 0.0 {
@@ -53,24 +66,22 @@ impl Intersect for Sphere {
             let isect_pt: Point3 = ray.origin + ray.direction * t;
 
             if c >= 0.0 {
-                    return Some((
+                return Some((isect_pt, (isect_pt - center) / radius, t));
-                        isect_pt,
-                        (isect_pt - self.center) / self.radius,
-                        t,
-                        self.material.clone(),
-                    ));
             } else {
-                    return Some((
+                return Some((isect_pt, -(isect_pt - center) / radius, t));
-                        isect_pt,
-                        -(isect_pt - self.center) / self.radius,
-                        t,
-                        self.material.clone(),
-                    ));
             }
         }
     }
 
     None
+}
+
+impl Intersect for Sphere {
+    fn intersect(&self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, Material)> {
+        match intersect(ray, &self.center, self.radius) {
+            Some((isect_pt, normal, t)) => Some((isect_pt, normal, t, self.material.clone())),
+            None => None,
+        }
     }
 }
 
@@ -89,3 +100,46 @@ impl PartialOrd for Sphere {
         None
     }
 }
+
+impl TextureSphere {
+    /// Create a new sphere at `center` with `radius` and `texture`.
+    pub fn new(center: Point3, radius: Scalar, texture: TextureWrapper) -> TextureSphere {
+        TextureSphere {
+            center,
+            radius,
+            texture,
+        }
+    }
+}
+
+impl Intersect for TextureSphere {
+    fn intersect(&self, ray: &Ray) -> Option<(Point3, Vector3, Scalar, Material)> {
+        match intersect(ray, &self.center, self.radius) {
+            Some((isect_pt, normal, t)) => {
+                let n_isect_pt = (isect_pt - self.center) / self.radius;
+                let uv: Point2 = Point2::new(
+                    0.5 + (n_isect_pt.z.atan2(n_isect_pt.x) / (2.0 * std::f64::consts::PI)),
+                    0.5 - (n_isect_pt.y).asin() / std::f64::consts::PI,
+                );
+                Some((isect_pt, normal, t, self.texture.material_at(uv)))
+            }
+            None => None,
+        }
+    }
+}
+
+impl std::fmt::Display for TextureSphere {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "(sphere center: {}, radius: {}, texture: {})",
+            self.center, self.radius, self.texture
+        )
+    }
+}
+
+impl PartialOrd for TextureSphere {
+    fn partial_cmp(&self, _other: &Self) -> Option<std::cmp::Ordering> {
+        None
+    }
+}