From 4af669099be04e9fd52a9c941ee12238c7fcc73a Mon Sep 17 00:00:00 2001
From: Michael Zhang <mail@mzhang.io>
Date: Tue, 31 Jan 2023 13:50:23 -0600
Subject: [PATCH] Input parser

---
 assignment-1/examples/sample-1.txt |  8 ++++
 assignment-1/examples/sample-2.txt | 10 +++++
 assignment-1/src/input_file.rs     | 66 ++++++++++++++++++++++++++++--
 assignment-1/src/main.rs           | 10 +++--
 assignment-1/src/scene_data.rs     |  3 ++
 assignment-1/src/vec3.rs           |  3 +-
 assignment-1/src/view.rs           |  1 +
 7 files changed, 94 insertions(+), 7 deletions(-)
 create mode 100644 assignment-1/examples/sample-1.txt
 create mode 100644 assignment-1/examples/sample-2.txt

diff --git a/assignment-1/examples/sample-1.txt b/assignment-1/examples/sample-1.txt
new file mode 100644
index 000000000..25d5532
--- /dev/null
+++ b/assignment-1/examples/sample-1.txt
@@ -0,0 +1,8 @@
+imsize 256 256
+eye 0 0 0
+viewdir 0 0 -1
+hfov 90
+updir 0 1 0
+bkgcolor 0.1 0.1 0.1
+mtlcolor 0 0 1
+sphere 0 0 -5 2
diff --git a/assignment-1/examples/sample-2.txt b/assignment-1/examples/sample-2.txt
new file mode 100644
index 000000000..ca22d17
--- /dev/null
+++ b/assignment-1/examples/sample-2.txt
@@ -0,0 +1,10 @@
+imsize 512 256
+eye 0 0 0
+viewdir 0 0 -1
+hfov 130
+updir 0 1 1
+bkgcolor 0.1 0.1 0.1
+mtlcolor 0 1 0
+sphere -0.5 -1 -8 3
+mtlcolor 1 0 0
+sphere 3 1 -3 1
diff --git a/assignment-1/src/input_file.rs b/assignment-1/src/input_file.rs
index 4a4d8e8..6eb7fca 100644
--- a/assignment-1/src/input_file.rs
+++ b/assignment-1/src/input_file.rs
@@ -1,9 +1,69 @@
-use std::path::Path;
+use std::{fs::File, io::Read, path::Path};
 
 use anyhow::Result;
 
-use crate::scene_data::Scene;
+use crate::{
+  scene_data::{Object, Scene, Sphere},
+  vec3::Vec3,
+};
 
 pub fn parse_input_file(path: impl AsRef<Path>) -> Result<Scene> {
-  todo!()
+  let contents = {
+    let mut contents = String::new();
+    let mut file = File::open(path.as_ref())?;
+    file.read_to_string(&mut contents)?;
+    contents
+  };
+
+  let mut scene = Scene::default();
+  let mut material_color = None;
+
+  for line in contents.lines() {
+    let mut parts = line.split_whitespace();
+    let keyword = match parts.next() {
+      Some(v) => v,
+      None => continue,
+    };
+
+    if keyword == "imsize" {
+      let parts = parts
+        .map(|s| s.parse::<usize>().map_err(|e| e.into()))
+        .collect::<Result<Vec<_>>>()?;
+      if let [width, height] = parts[..] {
+        scene.image_width = width;
+        scene.image_height = height;
+      }
+    }
+    // Do float parsing instead
+    else {
+      let parts = parts
+        .map(|s| s.parse::<f64>().map_err(|e| e.into()))
+        .collect::<Result<Vec<_>>>()?;
+
+      let read_vec3 = || {
+        if parts.len() < 3 {
+          bail!("Vec3 requires 3 components.");
+        }
+        Ok(Vec3::new(parts[0], parts[1], parts[2]))
+      };
+
+      match keyword {
+        "eye" => scene.eye_pos = read_vec3()?,
+        "viewdir" => scene.view_dir = read_vec3()?,
+        "updir" => scene.up_dir = read_vec3()?,
+
+        "hfov" => scene.hfov = parts[0],
+        "bkgcolor" => scene.bkg_color = read_vec3()?,
+        "mtlcolor" => material_color = Some(read_vec3()?),
+
+        "sphere" => scene.objects.push(Object::Sphere(Sphere {
+          center: read_vec3()?,
+          radius: parts[3],
+        })),
+        _ => bail!("Unknown keyword {keyword}"),
+      }
+    }
+  }
+
+  Ok(scene)
 }
diff --git a/assignment-1/src/main.rs b/assignment-1/src/main.rs
index 4d01571..a41aa25 100644
--- a/assignment-1/src/main.rs
+++ b/assignment-1/src/main.rs
@@ -1,3 +1,6 @@
+#[macro_use]
+extern crate anyhow;
+
 mod input_file;
 mod ray;
 mod scene_data;
@@ -8,12 +11,12 @@ use std::path::PathBuf;
 
 use anyhow::Result;
 use clap::Parser;
-use vec3::Vec3;
-use view::Rect;
 
 use crate::input_file::parse_input_file;
+use crate::vec3::Vec3;
+use crate::view::Rect;
 
-/// Noise image generator.
+/// Simple raycaster.
 #[derive(Parser)]
 #[clap(author, version, about, long_about = None)]
 struct Opt {
@@ -33,6 +36,7 @@ fn main() -> Result<()> {
   let opt = Opt::parse();
 
   let scene = parse_input_file(&opt.input_path)?;
+  println!("Scene: {scene:?}");
 
   // Compute viewing directions
   let u = Vec3::cross(scene.view_dir, scene.up_dir).unit();
diff --git a/assignment-1/src/scene_data.rs b/assignment-1/src/scene_data.rs
index cf2b8e2..547856e 100644
--- a/assignment-1/src/scene_data.rs
+++ b/assignment-1/src/scene_data.rs
@@ -1,10 +1,12 @@
 use crate::vec3::Vec3;
 
+#[derive(Debug)]
 pub struct Sphere {
   pub center: Vec3,
   pub radius: f64,
 }
 
+#[derive(Debug)]
 pub enum Object {
   Sphere(Sphere),
   Cylinder {
@@ -15,6 +17,7 @@ pub enum Object {
   },
 }
 
+#[derive(Debug, Default)]
 pub struct Scene {
   pub eye_pos: Vec3,
   pub view_dir: Vec3,
diff --git a/assignment-1/src/vec3.rs b/assignment-1/src/vec3.rs
index 4c7aee9..bceef2b 100644
--- a/assignment-1/src/vec3.rs
+++ b/assignment-1/src/vec3.rs
@@ -2,7 +2,7 @@ use std::ops::{Add, Mul};
 
 use num::Float;
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[derive(Copy, Clone, Default, Debug, PartialEq, Eq)]
 pub struct Vec3<T = f64> {
   pub x: T,
   pub y: T,
@@ -25,6 +25,7 @@ impl<T: Float> Vec3<T> {
     )
   }
 
+  /// Vector L2-norm
   pub fn norm(&self) -> T {
     (self.x.powi(2) + self.y.powi(2) + self.z.powi(2)).sqrt()
   }
diff --git a/assignment-1/src/view.rs b/assignment-1/src/view.rs
index da5e522..4e4dd04 100644
--- a/assignment-1/src/view.rs
+++ b/assignment-1/src/view.rs
@@ -1,5 +1,6 @@
 use crate::vec3::Vec3;
 
+#[derive(Debug)]
 pub struct Rect {
   pub upper_left: Vec3,
   pub upper_right: Vec3,