some fiddling with documentation. Added Poly type

src/drawables/rect.rs

@@ -0,0 +1,57 @@
+use crate::canvas::canvas_frame::Drawable;
+use crate::util::vertex::{VertexTypes, ColorVertex3D};
+
+///
+#[derive(Debug, Clone)]
+pub struct Rect {
+
+    pub verts: VertexTypes,
+
+    position: (f32, f32),
+    size: (f32, f32),
+}
+
+/// Container class which implements drawable.
+impl Rect {
+
+    ///
+    pub fn new(position: (f32, f32),
+               size: (f32, f32),
+               depth: u32) -> Rect {
+
+        let normalized_depth = (depth as f32 / 255.0);
+
+        let verts = vec![
+            ColorVertex3D{
+                v_position: [position.0, position.1, normalized_depth],                   // top left
+                color: [0.0, 1.0, 1.0, 0.5] },
+            ColorVertex3D{
+                v_position: [position.0, position.1 + size.1, normalized_depth],          // bottom left
+                color: [1.0, 1.0, 1.0, 1.0] },
+            ColorVertex3D{
+                v_position: [position.0 + size.0, position.1 + size.1, normalized_depth], // bottom right
+                color: [1.0, 1.0, 1.0, 1.0] },
+            ColorVertex3D{
+                v_position: [position.0, position.1, normalized_depth],                   // top left
+                color: [1.0, 1.0, 1.0, 1.0] },
+            ColorVertex3D{
+                v_position: [position.0 + size.0, position.1 + size.1, normalized_depth], // bottom right
+                color: [1.0, 1.0, 1.0, 1.0] },
+            ColorVertex3D{
+                v_position: [position.0 + size.0, position.1, normalized_depth],          // top right
+                color: [1.0, 1.0, 1.0, 1.0] },
+        ];
+
+        Rect {
+            verts: VertexTypes::ColorType(verts),
+            position: position,
+            size: size,
+        }
+    }
+}
+impl Drawable for Rect {
+    fn get(&self) -> VertexTypes {
+        self.verts.clone()
+    }
+
+}