Added back cpu intersection

src/ds/aabb.rs

@@ -1,5 +1,4 @@
-use crate::ds;
-use crate::object::Intersectable;
+use crate::{ds, object::Renderable};
 
 pub struct Aabb { // Axis aligned bounding box
     x: ds::Interval,
@@ -47,7 +46,7 @@ impl Aabb {
     }
 }
 
-impl Intersectable for Aabb {
+impl Renderable for Aabb {
     fn intersects(&self, ray: &ds::Ray) -> bool {
         let axes = [ // each slab we check
             (&self.x, ray.origin.x, ray.direction.x),
@@ -82,4 +81,12 @@ impl Intersectable for Aabb {
         }
         return true
     }
+
+    fn as_any(&self) -> &dyn std::any::Any {
+        self
+    }
+
+    fn center(&self) -> crate::ds::Vector3 {
+        ds::Vector3::new(self.x.middle(), self.y.middle(), self.z.middle())
+    }
 }

src/ds/interval.rs

@@ -56,4 +56,8 @@ impl Interval {
     pub fn max(&self) -> f64 {
         self.max
     }
+
+    pub fn middle(&self) -> f64 {
+        (self.max - self.min)/2.0 + self.min
+    }
 }

src/ds/mod.rs

@@ -1,11 +1,11 @@
 pub mod vector3;
 pub mod math;
-// pub mod interval;
-// pub mod aabb;
-// pub mod ray
+pub mod interval;
+pub mod aabb;
+pub mod ray;
 
 pub use vector3::Vector3;
 
-// pub use interval::Interval;
-// pub use aabb::Aabb;
-// pub use ray::Ray;
+pub use interval::Interval;
+pub use aabb::Aabb;
+pub use ray::Ray;

src/main.rs

@@ -340,13 +340,13 @@ fn main() {
         Box::new(object::Sphere::new(&ds::Vector3::new(4.0,   0.3, 3.0), 0.25, GpuMaterial::new(0x000000FF,  0,  0))),
 
         // grass block
-        Box::new(object::Quad::new(&ds::Vector3::new(1.0, 0.0, 5.0), &ds::Vector3::new(0.0, 0.0, 1.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
-        Box::new(object::Quad::new(&ds::Vector3::new(1.0, 0.0, 6.0), &ds::Vector3::new(1.0, 0.0, 0.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
-        Box::new(object::Quad::new(&ds::Vector3::new(2.0, 0.0, 6.0), &ds::Vector3::new(0.0, 0.0,-1.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
-        Box::new(object::Quad::new(&ds::Vector3::new(2.0, 0.0, 5.0), &ds::Vector3::new(-1.0,0.0, 0.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
+        Box::new(object::Quad::new(&ds::Vector3::new( 0.5, -0.5,  5.5), &ds::Vector3::new( 1.0, 0.0, 0.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
+        Box::new(object::Quad::new(&ds::Vector3::new( 1.5, -0.5,  5.5), &ds::Vector3::new( 0.0, 0.0, 1.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
+        Box::new(object::Quad::new(&ds::Vector3::new( 0.5, -0.5,  6.5), &ds::Vector3::new( 0.0, 0.0,-1.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
+        Box::new(object::Quad::new(&ds::Vector3::new( 1.5, -0.5,  6.5), &ds::Vector3::new(-1.0, 0.0, 0.0), &ds::Vector3::new(0.0, 1.0, 0.0), GpuMaterial::texture(1, 0, 0))),
+        Box::new(object::Quad::new(&ds::Vector3::new( 0.5,  0.5,  5.5), &ds::Vector3::new( 1.0, 0.0, 0.0), &ds::Vector3::new(0.0, 0.0, 1.0), GpuMaterial::texture(2, 0, 0))),
+        Box::new(object::Quad::new(&ds::Vector3::new( 0.5, -0.5,  5.5), &ds::Vector3::new( 1.0, 0.0, 0.0), &ds::Vector3::new(0.0, 0.0, 1.0), GpuMaterial::texture(0, 0, 0))),
 
-        Box::new(object::Quad::new(&ds::Vector3::new(1.0, 1.0, 5.0), &ds::Vector3::new(1.0, 0.0, 0.0), &ds::Vector3::new(0.0, 0.0, 1.0), GpuMaterial::texture(2, 0, 0))),
-        Box::new(object::Quad::new(&ds::Vector3::new(1.0, 0.0, 5.0), &ds::Vector3::new(1.0, 0.0, 0.0), &ds::Vector3::new(0.0, 0.0, 1.0), GpuMaterial::texture(0, 0, 0))),
 
         Box::new(object::Quad::new(&ds::Vector3::new(10.0, 2.0, 7.0), &ds::Vector3::new(0.5, 1.0, 0.5), &ds::Vector3::new(1.0, 0.5, 0.0), GpuMaterial::texture(0, 0, 0))),
 

src/object/quad.rs

@@ -54,6 +54,33 @@ impl Renderable for Quad {
     fn center(&self) -> crate::ds::Vector3 {
         self.q + self.u/2.0 + self.v/2.0
     }
+
+    fn intersects(&self, ray: &ds::Ray) -> bool {
+        let denominator = self.normal.dot(&ray.direction);
+
+        if denominator.abs() < 0.00000001 {
+            return false;
+        }
+
+        let t = (self.d - self.normal.dot(&ray.origin)) / denominator;
+
+        if t < 0.0 { return false; }
+
+        let intersection = ray.at(t);
+        let planar_hit = intersection - self.q;
+
+        let u_len_sq = self.u.length_sq();
+        let v_len_sq = self.v.length_sq();
+
+        let alpha = self.u.dot(&planar_hit) / u_len_sq;
+        let beta =  self.v.dot(&planar_hit) / v_len_sq;
+
+        if alpha < 0.0 || alpha > 1.0 || beta < 0.0 || beta > 1.0 {
+            return false;
+        }
+
+        return true
+    }
 }
 
 impl ToGpu<GpuQuad> for Quad {

src/object/renderable.rs

@@ -1,6 +1,7 @@
 pub trait Renderable: Send + Sync {
     fn as_any(&self) -> &dyn std::any::Any;
     fn center(&self) -> crate::ds::Vector3;
+    fn intersects(&self, ray: &crate::ds::Ray) -> bool;
 }
 
 pub trait ToGpu<T> {

src/object/sphere.rs

@@ -42,6 +42,23 @@ impl Renderable for Sphere {
     fn center(&self) -> crate::ds::Vector3 {
         self.center
     }
+
+    fn intersects(&self, ray: &ds::Ray) -> bool {
+        let oc = self.center - ray.origin;
+        let a  = ray.direction.dot(&ray.direction);
+        let h  = ray.direction.dot(&oc);
+        let c  = oc.dot(&oc) - self.radius * self.radius;
+        let discriminant = h*h - a*c;
+
+        if discriminant < 0.0 {
+            return false;
+        }
+
+        let t1 = (h - discriminant.sqrt()) / a;
+        let t2 = (h + discriminant.sqrt()) / a;
+
+        return t1 > 1e-8 || t2 > 1e-8
+    }
 }
 
 impl ToGpu<GpuSphere> for Sphere {

src/shaders/material.wgsl

@@ -151,5 +151,5 @@ fn get_texture_color(record: HitRecord) -> vec3<f32> {
     let pct_across = abs(dot(offset, quad.u) / dot(quad.u, quad.u)) * 16.0;
     let pct_up     = abs(dot(offset, quad.v) / dot(quad.v, quad.v)) * 16.0;
 
-    return textureLoad(textures, vec2u((15-u32(pct_across)), (15-u32(pct_up)) + 16 * u32(material.texture_id)), 0).rgb * 255.0;
+    return textureLoad(textures, vec2u(u32(pct_across), (15-u32(pct_up)) + 16 * u32(material.texture_id)), 0).rgb * 255.0;
 }