Finish PPM conversions and plot the projectile

ray-tracer/src/bin/projectile.rs

@@ -1,4 +1,5 @@
-use ray_tracer::types::*;
+use ray_tracer::{types::*, PPM};
+use std::{fs::File, io::Write};
 
 #[derive(Clone, Copy)]
 struct Projectile {
@@ -18,26 +19,35 @@ fn tick(env: &Environment, proj: &Projectile) -> Projectile {
 }
 
 fn main() {
+    let mut canvas = Canvas::new(900, 550);
+
     let start = Projectile {
         position: Point::new(0., 1., 0.),
-        velocity: Vector::new(1., 1., 0.).normalize() * 5.,
+        velocity: Vector::new(1., 5., 0.).normalize() * 5.,
     };
 
     let e = Environment {
         gravity: Vector::new(0., -0.1, 0.),
-        wind: Vector::new(-0.1, 0., 0.),
+        wind: Vector::new(-0.01, 0., 0.),
     };
 
     let mut p = start;
     while p.position.y() > 0. {
         p = tick(&e, &p);
+
+        let x = p.position.x().round() as usize;
+        let y = p.position.y().round() as usize;
+        if x > 1 && x < 900 && y > 1 && y < 550 {
+            *canvas.pixel_mut(x, 550 - y - 1) = Color::new(1., 1., 0.);
+            *canvas.pixel_mut(x+1, 550 - y - 1) = Color::new(1., 1., 0.);
+            *canvas.pixel_mut(x-1, 550 - y - 1) = Color::new(1., 1., 0.);
+            *canvas.pixel_mut(x, 550 - y) = Color::new(1., 1., 0.);
+            *canvas.pixel_mut(x, 550 - y - 2) = Color::new(1., 1., 0.);
+        }
     }
 
-    println!(
-        "distance travelled: [{}] {} {} {}",
-        (p.position - start.position).magnitude(),
-        p.position.x(),
-        p.position.y(),
-        p.position.z(),
-    );
+    let ppm = PPM::from(canvas);
+
+    let mut file = File::create("projectile.ppm").unwrap();
+    file.write(ppm.as_bytes()).unwrap();
 }

ray-tracer/src/lib.rs

@@ -1,2 +1,5 @@
-pub mod ppm;
+mod ppm;
+
 pub mod types;
+
+pub use ppm::PPM;

ray-tracer/src/ppm.rs

@@ -24,13 +24,11 @@ fn join_to_line_limit(data: impl IntoIterator<Item = String>) -> Vec<String> {
         lines.push(line);
     }
 
-    println!("{:?}", lines);
-
     lines
 }
 
 #[derive(Debug)]
-struct PPM(String);
+pub struct PPM(String);
 
 impl From<Canvas> for PPM {
     fn from(c: Canvas) -> Self {

ray-tracer/src/types/canvas.rs

@@ -36,7 +36,11 @@ impl Canvas {
 
     #[inline]
     fn addr(&self, y: usize, x: usize) -> usize {
-        y * self.width() + x
+        let val = y * self.width() + x;
+        if val >= self.pixels.len() {
+            eprintln!("[{val}] out of range: [{x}, {y}]");
+        }
+        val
     }
 }