refactor: switchable renderer

1 files changed, 48 insertions, 11 deletions

diff --git a/src/main.rs b/src/main.rs
index 06f041c..31d11ae 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,15 +4,56 @@ use std::io::Write;
 const IMG_WIDTH: usize = 256;
 const IMG_HEIGHT: usize = 256;
 
+#[derive(Debug, Copy, Clone)]
 struct Pixel {
     r: u8,
     g: u8,
     b: u8,
 }
 
-fn main() {
+impl Default for Pixel {
+    fn default() -> Self {
+        Pixel { r:0, g:0, b:0 }
+    }
+}
+
+struct View<'a> {
+    data: &'a[[Pixel; IMG_WIDTH]; IMG_HEIGHT],
+    renderer: fn(&[[Pixel; IMG_WIDTH]; IMG_HEIGHT]) -> Result<String, std::io::Error>,
+}
+
+impl<'a> View<'a> {
+    fn render(&self) {
+        let result = (self.renderer)(self.data);
+        match result {
+            Ok(success_msg) => {
+                println!("{}", success_msg);
+            },
+            Err(error_msg) => {
+                eprintln!("{}", error_msg);
+            }
+        }
+    }
+}
+
+fn ppm_renderer(data: &[[Pixel; IMG_WIDTH]; IMG_HEIGHT]) -> Result<String, std::io::Error> {
+    let file_name = "output.ppm";
+    let mut file = File::create(file_name)?;
+    // header
     let mut txt_data = String::from("P3\n");
     txt_data.push_str(format!("{} {}\n255\n", IMG_WIDTH, IMG_HEIGHT).as_str());
+    // data point
+    data.iter().for_each(|row| {
+        row.iter().for_each(|&pixel| {
+            txt_data.push_str(&format!("{} {} {}\n", pixel.r, pixel.g, pixel.b));
+        })
+    });
+    file.write_all(txt_data.as_bytes())?;
+    Ok(format!("Output rendered to file {}", file_name))
+}
+
+fn main() {
+    let mut data = [[Pixel::default(); IMG_WIDTH]; IMG_HEIGHT];
 
     (0..IMG_HEIGHT).for_each(|j| {
         (0..IMG_WIDTH).for_each(|i| {
@@ -24,17 +65,13 @@ fn main() {
             let ig = (255.999 * g) as u8;
             let ib = (255.999 * b) as u8;
 
-            txt_data.push_str(&format!("{} {} {}\n", ir, ig, ib));
+            data[i][j] = Pixel { r: ir, g: ig, b: ib};
         })
     });
 
-    match write_file("output.ppm", txt_data.as_str()) {
-        Ok(_) => {println!("PPM file writen")},
-        Err(e) => {println!("Error writing file {}", e)}
-    }
-}
-
-fn write_file(file_path:  &str, txt_data:  &str) -> Result<(), std::io::Error> {
-    let mut file = File::create(file_path)?;
-    file.write_all(txt_data.as_bytes())
+    let view = View {
+        data: &data,
+        renderer: ppm_renderer,
+    };
+    view.render();
 }