Add ability to set drawing colour

src/lib.rs

@@ -235,7 +235,7 @@ impl Sprite {
 
 /// Game context.
 ///
-/// This should never actually be used; instead, just pass it around to the various cat-box functions such as [`Sprite::draw()`].
+/// In most cases, this should never actually be used; instead, just pass it around to the various cat-box functions such as [`Sprite::draw()`].
 pub struct Context {
     canvas: Canvas<Window>,
     texture_creator: TextureCreator<WindowContext>,
@@ -264,6 +264,11 @@ impl Context {
     fn clear(&mut self) {
         self.canvas.clear();
     }
+
+    /// Set the background colour. See [`Canvas::set_draw_color()`](sdl2::render::Canvas::set_draw_color()) for more info.
+    pub fn set_background_colour(&mut self, r: u8, g: u8, b: u8) {
+        self.canvas.set_draw_color(Color::RGB(r, g, b));
+    }
 }
 
 /// Representation of the game.

src/main.rs

@@ -8,6 +8,7 @@ fn main() {
     let mut s2 = Sprite::new("duck.png", 400, 500).unwrap();
     game.run(|ctx, event_pump| {
         i = (i + 1.0) % 360.0;
+        ctx.set_background_colour(i as u8, 64, 255);
 
         let (start_x, start_y) = s.position();
         let m = sdl2::mouse::MouseState::new(event_pump.as_ref());