🏙️ Add support for reading scene from file

1 files changed, 99 insertions, 1 deletions

diff --git a/racer-tracer/src/scene.rs b/racer-tracer/src/scene.rs
index c5e76da..91fa252 100644
--- a/racer-tracer/src/scene.rs
+++ b/racer-tracer/src/scene.rs
@@ -1,4 +1,14 @@
-use crate::geometry::Hittable;
+use std::{collections::HashMap, path::Path, sync::Arc};
+
+use config::File;
+use serde::Deserialize;
+
+use crate::{
+    error::TracerError,
+    geometry::{sphere::Sphere, Hittable},
+    material::{dialectric::Dialectric, lambertian::Lambertian, metal::Metal, SharedMaterial},
+    vec3::{Color, Vec3},
+};
 
 pub struct Scene {
     objects: Vec<Box<dyn Hittable>>,
@@ -14,6 +24,10 @@ impl Scene {
     pub fn add(&mut self, hittable: Box<dyn Hittable>) {
         self.objects.push(hittable);
     }
+
+    pub fn from_file<P: AsRef<Path>>(file: P) -> Result<Self, TracerError> {
+        SceneData::from_file(file)?.try_into()
+    }
 }
 
 impl Hittable for Scene {
@@ -36,3 +50,87 @@ impl Hittable for Scene {
         rec
     }
 }
+
+#[derive(Debug, Deserialize)]
+enum MaterialData {
+    Lambertian { color: Color },
+    Metal { color: Color, fuzz: f64 },
+    Dialectric { refraction_index: f64 },
+}
+
+#[derive(Debug, Deserialize)]
+enum GeometryData {
+    Sphere {
+        pos: Vec3,
+        radius: f64,
+        material: String,
+    },
+}
+
+#[derive(Deserialize)]
+struct SceneData {
+    materials: HashMap<String, MaterialData>,
+    geometry: Vec<GeometryData>,
+}
+
+impl SceneData {
+    pub fn from_file<P: AsRef<Path>>(file: P) -> Result<Self, TracerError> {
+        config::Config::builder()
+            .add_source(File::from(file.as_ref()))
+            .build()
+            .map_err(|e| {
+                TracerError::Configuration(
+                    file.as_ref().to_string_lossy().into_owned(),
+                    e.to_string(),
+                )
+            })?
+            .try_deserialize()
+            .map_err(|e| {
+                TracerError::Configuration(
+                    file.as_ref().to_string_lossy().into_owned(),
+                    e.to_string(),
+                )
+            })
+    }
+}
+
+impl TryInto<Scene> for SceneData {
+    type Error = TracerError;
+    fn try_into(self) -> Result<Scene, TracerError> {
+        let mut materials: HashMap<String, SharedMaterial> = HashMap::new();
+        self.materials
+            .into_iter()
+            .for_each(|(id, material)| match material {
+                MaterialData::Lambertian { color } => {
+                    materials.insert(id, Arc::new(Box::new(Lambertian::new(color))));
+                }
+                MaterialData::Metal { color, fuzz } => {
+                    materials.insert(id, Arc::new(Box::new(Metal::new(color, fuzz))));
+                }
+                MaterialData::Dialectric { refraction_index } => {
+                    materials.insert(id, Arc::new(Box::new(Dialectric::new(refraction_index))));
+                }
+            });
+
+        let geometry: Vec<Box<dyn Hittable>> = self
+            .geometry
+            .into_iter()
+            .map(|geo| match geo {
+                GeometryData::Sphere {
+                    pos,
+                    radius,
+                    material,
+                } => materials
+                    .get(&material)
+                    .ok_or(TracerError::UnknownMaterial(material))
+                    .map(|mat| {
+                        let apa: Box<dyn Hittable> =
+                            Box::new(Sphere::new(pos, radius, Arc::clone(mat)));
+                        apa
+                    }),
+            })
+            .collect::<Result<Vec<Box<dyn Hittable>>, TracerError>>()?;
+
+        Ok(Scene { objects: geometry })
+    }
+}