Stub program to generate a simple ppm image and define basic types.

src/main.rs

@@ -0,0 +1,129 @@
+#[macro_use]
+extern crate log;
+extern crate stderrlog;
+
+use std::fs::File;
+use std::io::Write;
+
+struct Vector {
+    x: f64,
+    y: f64,
+    z: f64,
+}
+
+struct ISect {
+    t: f64,
+    p: Vector,
+    n: Vector,
+    hit: bool,
+}
+
+struct Sphere {
+    center: Vector,
+    radius: f64,
+}
+
+struct Plane {
+    p: Vector,
+    n: Vector,
+}
+
+struct Ray {
+    org: Vector,
+    dir: Vector,
+}
+
+struct World {
+    spheres: Vec<Sphere>,
+    plane: Plane,
+
+    width: usize,
+    height: usize,
+    n_subsamples: u32,
+    n_aosamples: u32,
+
+    img: Vec<u8>,
+}
+
+impl World {
+    fn render(&mut self) {
+        info!(
+            "Rendering world {}x{} w/ {} subsampling and {} ambient occlusion sampling",
+            self.width, self.height, self.n_subsamples, self.n_aosamples
+        );
+        for y in 0..self.height {
+            for x in 0..self.width {
+                self.img[(x + y * self.width) * 3 + 0] = (x % 256) as u8;
+                self.img[(x + y * self.width) * 3 + 1] = (y % 256) as u8;
+                self.img[(x + y * self.width) * 3 + 2] = ((x * y) % 256) as u8;
+            }
+        }
+    }
+
+    fn save(&self, path: &str) -> std::io::Result<()> {
+        info!("Saving scene to {}", path);
+        let mut buf = File::create(path)?;
+        writeln!(&buf, "P6\n{} {}\n255", self.width, self.height)?;
+        buf.write_all(&self.img)
+    }
+}
+
+fn init_scene() -> World {
+    let w: usize = 512;
+    let h: usize = 512;
+
+    World {
+        spheres: vec![
+            Sphere {
+                center: Vector {
+                    x: -2.0,
+                    y: 0.0,
+                    z: -3.5,
+                },
+                radius: 0.5,
+            },
+            Sphere {
+                center: Vector {
+                    x: -0.5,
+                    y: 0.0,
+                    z: -3.0,
+                },
+                radius: 0.5,
+            },
+            Sphere {
+                center: Vector {
+                    x: 1.0,
+                    y: 0.0,
+                    z: -2.2,
+                },
+                radius: 0.5,
+            },
+        ],
+        plane: Plane {
+            p: Vector {
+                x: 0.0,
+                y: -0.5,
+                z: 0.0,
+            },
+            n: Vector {
+                x: 0.0,
+                y: 1.0,
+                z: 0.0,
+            },
+        },
+        width: w,
+        height: h,
+        n_subsamples: 2,
+        n_aosamples: 8,
+
+        img: vec![0; w * h * 3],
+    }
+}
+
+fn main() -> std::io::Result<()> {
+    stderrlog::new().verbosity(3).init().unwrap();
+
+    let mut w = init_scene();
+    w.render();
+    w.save("ao.ppm")
+}