Can create canvas

canvas/src/lib.rs

@@ -0,0 +1,36 @@
+use color::Color;
+
+struct Canvas {
+    width: usize,
+    height: usize,
+    pixels: Vec<Vec<Color>>,
+}
+
+impl Canvas {
+    fn new(width: usize, height: usize) -> Canvas {
+        Canvas {
+            width,
+            height,
+            pixels : vec![vec![Color::new(0.0, 0.0, 0.0); width]; height],
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn create_canvas() {
+        let c = Canvas::new(10, 20);
+        assert_eq!(10, c.width);
+        assert_eq!(20, c.height);
+
+        let black = Color::new(0.0, 0.0, 0.0);
+        for row in c.pixels {
+            for pixel in row {
+                assert_eq!(black, pixel);
+            }
+        }
+    }
+}