Use Vec3 in main program.

rtiow/src/bin/vec3_ppm.rs

@@ -0,0 +1,20 @@
+extern crate rtiow;
+
+use rtiow::vec3::Vec3;
+
+fn main() -> Result<(), std::io::Error> {
+    let nx = 200;
+    let ny = 100;
+    println!("P3\n{} {}\n255", nx, ny);
+    for j in (0..ny).rev() {
+        for i in 0..nx {
+            let col = Vec3::new(i as f32 / nx as f32, j as f32 / ny as f32, 0.2);
+
+            let ir = (255.99 * col[0]) as u8;
+            let ig = (255.99 * col[1]) as u8;
+            let ib = (255.99 * col[2]) as u8;
+            println!("{} {} {}", ir, ig, ib);
+        }
+    }
+    Ok(())
+}