1 files changed, 77 insertions, 0 deletions
diff --git a/src/image.rs b/src/image.rs
new file mode 100644
index 0000000..e24c14b
--- /dev/null
+++ b/src/image.rs
@@ -0,0 +1,77 @@
+use std::io::Write;
+
+use crate::vec3::Color;
+
+pub struct Image {
+    width: usize,
+    height: usize,
+    data: Vec<Pixel>,
+}
+
+#[derive(Clone)]
+struct Pixel {
+    color: Color,
+    sample_count: u32,
+}
+
+impl Image {
+    pub fn new(width: usize, height: usize) -> Image {
+        let data = vec![
+            Pixel {
+                color: Color {
+                    x: 0.0,
+                    y: 0.0,
+                    z: 0.0
+                },
+                sample_count: 0
+            };
+            width * height
+        ];
+        Image {
+            width,
+            height,
+            data,
+        }
+    }
+
+    pub fn add_sample(&mut self, x: usize, y: usize, color: Color) {
+        self.data
+            .get_mut((y * self.width) + x)
+            .unwrap()
+            .update(color);
+    }
+
+    pub fn write(&self, output: &mut impl Write) {
+        output.write_fmt(format_args!("P3\n{} {}\n255\n", self.width, self.height)).unwrap();
+        for y in (0..self.height).rev() {
+            for x in 0..self.width {
+                let pixel = self.data.get((y * self.width) + x).unwrap();
+                let mut r = pixel.color.x;
+                let mut g = pixel.color.y;
+                let mut b = pixel.color.z;
+
+                // Divide by the number of samples and perform gamma correction for gamma 2
+                let scale = 1.0 / pixel.sample_count as f64;
+                r = (r * scale).sqrt();
+                g = (g * scale).sqrt();
+                b = (b * scale).sqrt();
+
+                output
+                    .write_fmt(format_args!(
+                        "{} {} {}\n",
+                        (256.0 * r.clamp(0.0, 0.999)) as u32,
+                        (256.0 * g.clamp(0.0, 0.999)) as u32,
+                        (256.0 * b.clamp(0.0, 0.999)) as u32,
+                    ))
+                    .unwrap();
+            }
+        }
+    }
+}
+
+impl Pixel {
+    pub fn update(&mut self, color: Color) {
+        self.color += color;
+        self.sample_count += 1;
+    }
+}