reorganize, add Azimuth

src/draw/layout.rs

@@ -0,0 +1,80 @@
+use crate::*;
+
+pub enum Layout<T: Screen, X: Into<Option<T::Unit>>, I: Draw<T>> {
+    __(PhantomData<T>),
+    MinW(X, I),
+    MinH(X, I),
+    MinWH(X, X, I),
+    MaxW(X, I),
+    MaxH(X, I),
+    MaxWH(X, X, I),
+    ExactW(X, I),
+    ExactH(X, I),
+    ExactWH(X, X, I),
+    ClipW(X, I),
+    ClipH(X, I),
+    ClipWH(X, X, I),
+}
+
+impl_draw!(<
+    T: Screen,
+    X: Into<Option<T::Unit>>,
+    I: Draw<T>,
+>|self: Layout<T, X, I>, to: T|{
+    use Layout::*;
+    match self {
+        __(_) => unreachable!(),
+        MinW(x, it) => {
+            let x = x.into();
+            it.draw(to)
+        },
+        MinH(y, it) => {
+            let y = y.into();
+            it.draw(to)
+        },
+        MinWH(x, y, it) => {
+            let x = x.into();
+            let y = y.into();
+            it.draw(to)
+        },
+        MaxW(x, it) => {
+            let x = x.into();
+            it.draw(to)
+        },
+        MaxH(y, it) => {
+            let y = y.into();
+            it.draw(to)
+        },
+        MaxWH(x, y, it) => {
+            let x = x.into();
+            let y = y.into();
+            it.draw(to)
+        },
+        ExactW(x, it) => {
+            let x = x.into();
+            it.draw(to)
+        },
+        ExactH(y, it) => {
+            let y = y.into();
+            it.draw(to)
+        },
+        ExactWH(x, y, it) => {
+            let x = x.into();
+            let y = y.into();
+            it.draw(to)
+        },
+        ClipW(x, it) => {
+            let x = x.into();
+            it.draw(to)
+        },
+        ClipH(y, it) => {
+            let y = y.into();
+            it.draw(to)
+        },
+        ClipWH(x, y, it) => {
+            let x = x.into();
+            let y = y.into();
+            it.draw(to)
+        },
+    }
+});