upd interval struct

4 files changed, 54 insertions, 8 deletions

diff --git a/src/interval.rs b/src/interval.rs
new file mode 100644
index 0000000..24b1841
--- /dev/null
+++ b/src/interval.rs
@@ -0,0 +1,41 @@
+pub struct Interval {
+    pub min: f32,
+    pub max: f32,
+}
+
+impl Interval {
+    pub fn new(min: f32, max: f32) -> Self {
+        Self { min, max }
+    }
+
+    pub fn size(&self) -> f32 {
+        self.max - self.min
+    }
+
+    pub fn contains(&self, x: f32) -> bool {
+        self.min <= x && x <= self.max
+    }
+
+    pub fn surrounds(&self, x: f32) -> bool {
+        self.min < x && x < self.max
+    }
+}
+
+impl Default for Interval {
+    fn default() -> Self {
+        Self {
+            min: f32::NEG_INFINITY,
+            max: f32::INFINITY
+        }
+    }
+}
+
+pub const INTERVAL_EMPTY: Interval = Interval {
+    min: f32::INFINITY,
+    max: f32::NEG_INFINITY
+};
+
+pub const INTERVAL_UNIVERSE: Interval = Interval {
+    min: f32::NEG_INFINITY,
+    max: f32::INFINITY
+};
diff --git a/src/main.rs b/src/main.rs
index db7d2ee..3f3b866 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ mod global;
 mod calculus;
 mod renderer;
 mod object;
+mod interval;
 
 use crate::global::*;
 use crate::renderer::render;
diff --git a/src/object.rs b/src/object.rs
index 0da9148..c1bce61 100644
--- a/src/object.rs
+++ b/src/object.rs
@@ -1,4 +1,5 @@
 use crate::calculus::calculus::{Point3, Ray, Vec3};
+use crate::interval::Interval;
 
 #[derive(Clone)]
 pub struct HitRecord {
@@ -27,7 +28,7 @@ impl HitRecord {
 }
 
 pub trait Hittable {
-    fn hit(&self, r: &Ray, ray_tmin: f32, ray_tmax: f32, rec: &mut HitRecord) -> bool;
+    fn hit(&self, r: &Ray, ray_t: Interval, rec: &mut HitRecord) -> bool;
 }
 
 pub struct Sphere {
@@ -43,7 +44,7 @@ impl Sphere {
 }
 
 impl Hittable for Sphere {
-    fn hit(&self, r: &Ray, ray_tmin: f32, ray_tmax: f32, rec: &mut HitRecord) -> bool {
+    fn hit(&self, r: &Ray, ray_t: Interval, rec: &mut HitRecord) -> bool {
         let oc = self.center.sub(&r.origin);
         let a = r.direction.mag_sqr();
         let h = r.direction.dot_prod(&oc);
@@ -56,9 +57,9 @@ impl Hittable for Sphere {
         let sqrtd = discriminant.sqrt();
 
         let mut root = (h - sqrtd) / a;
-        if root <= ray_tmin || ray_tmax <= root {
+        if root <= ray_t.min || ray_t.max <= root {
             root = (h + sqrtd) / a;
-            if root <= ray_tmin || ray_tmax <= root {
+            if root <= ray_t.min || ray_t.max <= root {
                 return false;
             }
         }
@@ -89,14 +90,15 @@ impl HittableList {
 }
 
 impl Hittable for HittableList {
-    fn hit(&self, r: &Ray, ray_tmin: f32, ray_tmax: f32, rec: &mut HitRecord) -> bool {
+    fn hit(&self, r: &Ray, ray_t: Interval, rec: &mut HitRecord) -> bool {
         let mut temp_rec = HitRecord::default();
         let mut hit_anything = false;
-        let mut closest_so_far = ray_tmax;
+        let mut closest_so_far = ray_t.max;
 
         self.objects.iter().for_each(
             |object| {
-                if object.hit(r, ray_tmin, closest_so_far, &mut temp_rec) {
+                let interval = Interval::new(ray_t.min, closest_so_far);
+                if object.hit(r, interval, &mut temp_rec) {
                     hit_anything = true;
                     closest_so_far = temp_rec.t;
                     *rec = temp_rec.clone();
diff --git a/src/renderer.rs b/src/renderer.rs
index 4936d9e..72ecf4e 100644
--- a/src/renderer.rs
+++ b/src/renderer.rs
@@ -1,10 +1,12 @@
 use crate::calculus::calculus::{Point3, Ray, Vec3};
 use crate::global::{Color, DisplayBuffer, Pixel, CAMERA_CENTER, FOCAL_LENGTH, IMG_HEIGHT, IMG_WIDTH, VIEWPORT_HEIGHT, VIEWPORT_WIDTH};
+use crate::interval::Interval;
 use crate::object::{HitRecord, Hittable, HittableList, Sphere};
 
 fn ray_color(ray: &Ray, world: &HittableList) -> Color {
     let mut rec = HitRecord::default();
-    if world.hit(ray, 0.0, f32::INFINITY, &mut rec) {
+    let ray_t = Interval::new(0.0, f32::INFINITY);
+    if world.hit(ray, ray_t, &mut rec) {
         let color = Color::new(1.0, 1.0, 1.0)
             .add(&Color::new(
                 rec.normal.x,