Finish depth of field

7 files changed, 60 insertions, 15 deletions

diff --git a/readme.md b/readme.md
index b535d79..6176e25 100644
--- a/readme.md
+++ b/readme.md
@@ -19,7 +19,7 @@ I never really finished it before changing to rust.
 
 ## Goals
 
+- [X] Render collection of circles outside, with blurry background
 - [ ] Render [Cornell box](https://en.wikipedia.org/wiki/Cornell_box)
-- [ ] Render collection of circles outside, with blurry background
 - [ ] Render [Utah teapot](https://en.wikipedia.org/wiki/Utah_teapot)
 - [ ] Render [Stanford dragon](https://en.wikipedia.org/wiki/Stanford_dragon)
diff --git a/src/camera/camera.rs b/src/camera/camera.rs
index e770efe..4d05e87 100644
--- a/src/camera/camera.rs
+++ b/src/camera/camera.rs
@@ -33,6 +33,7 @@
 //! ```
 use crate::Float;
 use crate::core::{Vector3f, Vector2f, Vector2i, Ray};
+use crate::sample::Sampler;
 
 /// A simple perspective camera
 pub struct Camera {
@@ -43,6 +44,9 @@ pub struct Camera {
     /// Scaling vectors from screen_origin
     qx: Vector3f,
     qy: Vector3f,
+
+    /// Value for depth of view
+    lens_radius: Option<Float>,
 }
 
 /// Settings for initializing camera
@@ -59,7 +63,9 @@ pub struct CameraSettings {
     /// The film aspect ratio, height / width
     pub filmsize: Vector2i,
     /// The lens aperture
-    pub aperture: Float,
+    ///
+    /// Depth of view is disabled if None
+    pub aperture: Option<Float>,
     /// The distance to the focus plane
     ///
     /// if None it will be set to the distance between origin and target
@@ -96,22 +102,31 @@ impl Camera {
             screen_origin,
             qx,
             qy,
+            lens_radius: set.aperture.map(|a| a / 2.0),
         }
     }
 
     /// Generates a ray a screen space point
     ///
-    /// The point coordinates should be between [0,1) with (0, 0) being the upper let corner
+    /// The point coordinates should be between [0,1) with (0, 0) being the upper left corner
     ///
     /// Will return a ray and a weight
     ///
     /// The direction of the returned way is normalized
-    pub fn generate_ray(&self, point: &Vector2f) -> (Ray, Float) {
-        let mut dir = self.screen_origin + (self.qx * point.x) - (self.qy * point.y);
-        dir.norm_in();
+    pub fn generate_ray(&self, point: &Vector2f, sampler: &mut dyn Sampler) -> (Ray, Float) {
+        // Depth of view origin offset
+        let ooffset = match self.lens_radius {
+            Some(r) => {
+                let rand_dir = sampler.get_in_circle() * r;
+                self.qx * rand_dir.x + self.qy * rand_dir.y
+            },
+            None => Vector3f::ZERO,
+        };
+
+        let dir = self.screen_origin + (self.qx * point.x) - (self.qy * point.y) - ooffset;
 
         (
-            Ray { origin: self.origin, direction: dir },
+            Ray { origin: self.origin + ooffset, direction: dir.norm() },
             1.0
             )
     }
diff --git a/src/core/vector2.rs b/src/core/vector2.rs
index b3fa443..7e40394 100644
--- a/src/core/vector2.rs
+++ b/src/core/vector2.rs
@@ -2,7 +2,7 @@
 //!
 //! This is implemented generictly with types that fit in the Number trait
 use crate::{Float, Number};
-use std::ops::{Sub, Add};
+use std::ops::{Sub, Add, Mul};
 use std::fmt;
 use std::cmp::min;
 
@@ -45,6 +45,16 @@ impl<T: Number> Add for Vector2<T> {
     }
 }
 
+impl<T: Number> Mul<T> for Vector2<T> {
+    type Output = Self;
+    fn mul(self, op: T) -> Self::Output {
+        Self::new_xy(
+            self.x * op,
+            self.y * op,
+        )
+    }
+}
+
 impl<T: Number> fmt::Display for Vector2<T> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.write_fmt(format_args!("[{}, {}]", self.x, self.y))
@@ -94,6 +104,12 @@ impl Vector2i {
     }
 }
 
+impl Vector2f {
+    pub fn len(&self) -> Float {
+        (self.x*self.x + self.y*self.y).sqrt()
+    }
+}
+
 
 #[cfg(test)]
 mod tests {
diff --git a/src/core/vector3.rs b/src/core/vector3.rs
index 1ae4db2..24b84e9 100644
--- a/src/core/vector3.rs
+++ b/src/core/vector3.rs
@@ -108,6 +108,8 @@ impl<T: Number> fmt::Display for Vector3<T> {
 }
 
 impl Vector3f {
+    pub const ZERO: Self = Vector3f {x: 0.0, y: 0.0, z: 0.0};
+
     /// Calculates the length times itself
     ///
     /// This is faster than using len * len as the square is ommited
diff --git a/src/main.rs b/src/main.rs
index 1707360..e606cba 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -13,18 +13,18 @@ fn main() {
     let res = Vector2i::new_xy(500, 500);
 
     let cam = Camera::new(&CameraSettings {
-        target: Vector3f::new_xyz(0.5, 0.0, -1.0),
-        origin: Vector3f::new_xyz(1.7, 0.0, 0.0),
+        target: Vector3f::new_xyz(0.0, 0.0, -1.0),
+        origin: Vector3f::new_xyz(1.7, 0.0, 0.3),
         up: Vector3f::new_xyz(0.0, 1.0, 0.0),
-        fov: 90.0, 
+        fov: 40.0, 
         filmsize: res,
         focus: None,
-        aperture: 0.5,
+        aperture: Some(20.0),
     });
 
     let brown = Rc::new(Lambertian::new(Spectrum::new_rgb(0.5, 0.3, 0.0)));
     let blue = Rc::new(Lambertian::new(Spectrum::new_rgb(0.0, 0.3, 0.7)));
-    let metal = Rc::new(Reflectant::new(Spectrum::new_rgb(0.75, 0.75, 0.75), Some(0.1)));
+    let metal = Rc::new(Reflectant::new(Spectrum::new_rgb(0.75, 0.75, 0.75), None));
 
     let mut scn = Scene::new();
     scn.add_objects(vec![
@@ -42,7 +42,7 @@ fn main() {
     let mut film = Film::new(res);
     let tile = film.get_tile(&film.frame);
 
-    let mut task = RenderTask::new(Box::new(tile), 10);
+    let mut task = RenderTask::new(Box::new(tile), 100);
     task.render(&ctx, &mut sampler);
 
     film.commit_tile(&task.tile);
diff --git a/src/render.rs b/src/render.rs
index 23b80ae..9a6b905 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -31,7 +31,7 @@ impl RenderTask {
             let p = corner + sampler.get_sample_2d();
 
             // Create a ray
-            let (r, _) = ctx.cam.generate_ray(&p);
+            let (r, _) = ctx.cam.generate_ray(&p, sampler);
 
             self.tile.add_sample(&p, ctx.trc.trace(sampler, &r));
         }
diff --git a/src/sample/mod.rs b/src/sample/mod.rs
index 5095501..88e1aa9 100644
--- a/src/sample/mod.rs
+++ b/src/sample/mod.rs
@@ -29,4 +29,16 @@ pub trait Sampler {
             costheta,
             )
     }
+
+    fn get_in_circle(&mut self) -> Vector2f {
+        let s2d = self.get_sample_2d();
+
+        let d = s2d.x.sqrt();
+        let theta = s2d.y * 2.0 * M_PI;
+
+        Vector2f::new_xy(
+            d * theta.cos(),
+            d * theta.sin(),
+            )
+    }
 }