all: can render basic things

src/main.rs

@@ -1,11 +1,14 @@
 extern crate getopts;
+extern crate image;
 
 use std::io::Read;
 use std::fs::File;
 
 pub mod css;
+pub mod display;
 pub mod dom;
 pub mod html;
+pub mod layout;
 pub mod styling;
 
 fn read_source(filename: String) -> String {
@@ -17,14 +20,40 @@ fn read_source(filename: String) -> String {
 fn main() {
     let mut opts = getopts::Options::new();
     opts.optopt("h", "html", "HTML document", "FILENAME");
+    opts.optopt("o", "out", "PNG output", "FILENAME");
 
     let matches = opts.parse(std::env::args().skip(1)).unwrap();
     let str_arg = |flag: &str, default: &str| -> String {
         matches.opt_str(flag).unwrap_or(default.to_string())
     };
 
+    let initial_block = layout::Dim {
+        content: layout::Rect { x: 0.0, y: 0.0, width: 800.0, height: 600.0 },
+        padding: Default::default(),
+        border: Default::default(),
+        margin: Default::default(),
+    };
+
     let html = read_source(str_arg("h", "examples/test.html"));
     let node = html::parse(html);
+    let style = dom::find_style(&node).unwrap();
+    let styled_node = styling::style_tree(&node, &style);
 
-    println!("{}", node)
+    let layout = layout::layout_tree(&styled_node, initial_block);
+    let canvas = display::paint(&layout, initial_block.content);
+
+    let filename = str_arg("o", "out.png");
+    let mut file = File::create(&filename).unwrap();
+
+    let (w, h) = (canvas.width as u32, canvas.height as u32);
+    let img = image::ImageBuffer::from_fn(w, h, move |x, y| {
+        let color = canvas.pixels[(y * w + x) as usize];
+        image::Pixel::from_channels(color.r, color.g, color.b, color.a)
+    });
+
+    let result = image::ImageRgba8(img).save(&mut file, image::PNG);
+    match result {
+        Ok(_) => println!("Saved output as {}", filename),
+        Err(_) => println!("Error saving output as {}", filename)
+    }
 }