From f3f56ed5f183f8461cc91cb6430d97c725ba159c Mon Sep 17 00:00:00 2001
From: Julian T <julian@jtle.dk>
Date: Sun, 7 Feb 2021 00:37:58 +0100
Subject: Move to double to avoid rounding error

This rounding errors seems to happen when adding floats very close to 1
to a relatively large number.

325.0 + 0.99999034 = 326.0

This is a problem as this sample should be counted at the 325 pixel.
However this will be a lesser problem when filtering is implemented.
---
 src/camera/film.rs    |  9 ++++++---
 src/core/vector2.rs   | 10 ++++++++++
 src/lib.rs            |  6 +++++-
 src/main.rs           |  2 +-
 src/sample/mod.rs     |  5 ++---
 src/sample/uniform.rs |  5 +++--
 6 files changed, 27 insertions(+), 10 deletions(-)

(limited to 'src')

diff --git a/src/camera/film.rs b/src/camera/film.rs
index 2ff7239..7a7f2dc 100644
--- a/src/camera/film.rs
+++ b/src/camera/film.rs
@@ -132,11 +132,14 @@ impl FilmTile {
     pub fn add_sample(&mut self, inp: &Vector2f, c: Spectrum) {
         let point = Vector2i::from(inp.floor());
         // Subtract the offset
-        let point = point - self.bounds.min;
+        let point = (point - self.bounds.min).cap(self.size.x-1, self.size.y-1);
 
         let index = point.x + point.y * self.size.x;
 
-        let pixel = self.pixels.get_mut(index as usize).unwrap();
-        pixel.add(&c, 1.0);
+        if let Some(pixel) = self.pixels.get_mut(index as usize) {
+            pixel.add(&c, 1.0);
+        } else {
+            println!("Could not get pixel {} inp: {}, index: {}", point, inp, index);
+        }
     }
 }
diff --git a/src/core/vector2.rs b/src/core/vector2.rs
index 858068e..b3fa443 100644
--- a/src/core/vector2.rs
+++ b/src/core/vector2.rs
@@ -4,6 +4,7 @@
 use crate::{Float, Number};
 use std::ops::{Sub, Add};
 use std::fmt;
+use std::cmp::min;
 
 #[derive(Clone, Copy)]
 pub struct Vector2<T: Number> {
@@ -84,6 +85,15 @@ impl From<Vector2f> for Vector2i {
     }
 }
 
+impl Vector2i {
+    pub fn cap(&self, x: i32, y: i32) -> Self {
+        Self::new_xy(
+            min(self.x, x),
+            min(self.y, y),
+            )
+    }
+}
+
 
 #[cfg(test)]
 mod tests {
diff --git a/src/lib.rs b/src/lib.rs
index 0ec6700..7da6627 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -8,6 +8,7 @@ pub mod sample;
 use std::ops::{Add, Sub, Mul, DivAssign, Neg};
 use std::cmp;
 use std::fmt;
+use std::f64::consts::PI;
 
 /// Trait used to implement generics
 ///
@@ -25,8 +26,11 @@ pub trait Number:
 
 impl Number for i32 {}
 impl Number for f32 {}
+impl Number for f64 {}
 
 /// Used for representing floating point values throughout the program
 /// 
 /// A higher precision type will require more ram
-pub type Float = f32;
+pub type Float = f64;
+
+pub const M_PI: Float = PI;
diff --git a/src/main.rs b/src/main.rs
index c6bc14e..1604ae3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -32,7 +32,7 @@ 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/sample/mod.rs b/src/sample/mod.rs
index 84ac755..5095501 100644
--- a/src/sample/mod.rs
+++ b/src/sample/mod.rs
@@ -1,6 +1,5 @@
-use crate::Float;
+use crate::{M_PI, Float};
 use crate::core::{Vector3f, Vector2f};
-use std::f32::consts::PI;
 
 mod uniform;
 
@@ -20,7 +19,7 @@ pub trait Sampler {
     fn get_unit_vector(&mut self) -> Vector3f {
         let s2d = self.get_sample_2d();
 
-        let lambda = distribute_between(s2d.x, -PI, PI);
+        let lambda = distribute_between(s2d.x, -M_PI, M_PI);
         let costheta = 2.0 * s2d.y - 1.0;
         let sintheta = costheta.acos().sin();
 
diff --git a/src/sample/uniform.rs b/src/sample/uniform.rs
index cc6825a..e2f0b7c 100644
--- a/src/sample/uniform.rs
+++ b/src/sample/uniform.rs
@@ -15,13 +15,14 @@ impl UniformSampler {
     pub fn new() -> Self {
         Self {
             r: Pcg32::seed_from_u64(1),
-            d: Uniform::from(0.0..1.0),
+            d: Uniform::new(0.0, 1.0),
         }
     }
 }
 
 impl Sampler for UniformSampler {
     fn get_sample(&mut self) -> Float {
-        self.d.sample(&mut self.r)
+        let sample = self.d.sample(&mut self.r);
+        sample
     }
 }
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