reduce number of space modules

src/space/split.rs

@@ -138,6 +138,157 @@ impl<E: Engine, X: Render<E>, Y: Render<E>> Render<E> for Bsp<E, X, Y> {
     }
 }
 
+pub struct Stack<
+    E: Engine,
+    F: Send + Sync + Fn(&mut dyn FnMut(&dyn Render<E>)->Usually<()>)->Usually<()>
+>(pub F, pub Direction, PhantomData<E>);
+
+impl<
+    E: Engine,
+    F: Send + Sync + Fn(&mut dyn FnMut(&dyn Render<E>)->Usually<()>)->Usually<()>
+> Stack<E, F> {
+    #[inline] pub fn new (direction: Direction, build: F) -> Self {
+        Self(build, direction, Default::default())
+    }
+    #[inline] pub fn right (build: F) -> Self {
+        Self::new(East, build)
+    }
+    #[inline] pub fn down (build: F) -> Self {
+        Self::new(South, build)
+    }
+    #[inline] pub fn up (build: F) -> Self {
+        Self::new(North, build)
+    }
+}
+
+impl<E: Engine, F> Render<E> for Stack<E, F>
+where
+    F: Send + Sync + Fn(&mut dyn FnMut(&dyn Render<E>)->Usually<()>)->Usually<()>
+{
+    fn min_size (&self, to: E::Size) -> Perhaps<E::Size> {
+        match self.1 {
+
+            South => {
+                let mut w: E::Unit = 0.into();
+                let mut h: E::Unit = 0.into();
+                (self.0)(&mut |component: &dyn Render<E>| {
+                    let max = to.h().minus(h);
+                    if max > E::Unit::zero() {
+                        let item = E::max_y(max, E::push_y(h, component));
+                        let size = item.min_size(to)?.map(|size|size.wh());
+                        if let Some([width, height]) = size {
+                            h = h + height.into();
+                            w = w.max(width);
+                        }
+                    }
+                    Ok(())
+                })?;
+                Ok(Some([w, h].into()))
+            },
+
+            East => {
+                let mut w: E::Unit = 0.into();
+                let mut h: E::Unit = 0.into();
+                (self.0)(&mut |component: &dyn Render<E>| {
+                    let max = to.w().minus(w);
+                    if max > E::Unit::zero() {
+                        let item = E::max_x(max, E::push_x(h, component));
+                        let size = item.min_size(to)?.map(|size|size.wh());
+                        if let Some([width, height]) = size {
+                            w = w + width.into();
+                            h = h.max(height);
+                        }
+                    }
+                    Ok(())
+                })?;
+                Ok(Some([w, h].into()))
+            },
+
+            North => {
+                let mut w: E::Unit = 0.into();
+                let mut h: E::Unit = 0.into();
+                (self.0)(&mut |component: &dyn Render<E>| {
+                    let max = to.h().minus(h);
+                    if max > E::Unit::zero() {
+                        let item = E::max_y(to.h() - h, component);
+                        let size = item.min_size(to)?.map(|size|size.wh());
+                        if let Some([width, height]) = size {
+                            h = h + height.into();
+                            w = w.max(width);
+                        }
+                    }
+                    Ok(())
+                })?;
+                Ok(Some([w, h].into()))
+            },
+
+            West => {
+                let w: E::Unit = 0.into();
+                let h: E::Unit = 0.into();
+                (self.0)(&mut |component: &dyn Render<E>| {
+                    if w < to.w() {
+                        todo!();
+                    }
+                    Ok(())
+                })?;
+                Ok(Some([w, h].into()))
+            },
+        }
+    }
+
+    fn render (&self, to: &mut E::Output) -> Usually<()> {
+        let area = to.area();
+        let mut w = 0.into();
+        let mut h = 0.into();
+        match self.1 {
+            South => {
+                (self.0)(&mut |item| {
+                    if h < area.h() {
+                        let item = E::max_y(area.h() - h, E::push_y(h, item));
+                        let show = item.min_size(area.wh().into())?.map(|s|s.wh());
+                        if let Some([width, height]) = show {
+                            item.render(to)?;
+                            h = h + height;
+                            if width > w { w = width }
+                        };
+                    }
+                    Ok(())
+                })?;
+            },
+            East => {
+                (self.0)(&mut |item| {
+                    if w < area.w() {
+                        let item = E::max_x(area.w() - w, E::push_x(w, item));
+                        let show = item.min_size(area.wh().into())?.map(|s|s.wh());
+                        if let Some([width, height]) = show {
+                            item.render(to)?;
+                            w = width + w;
+                            if height > h { h = height }
+                        };
+                    }
+                    Ok(())
+                })?;
+            },
+            North => {
+                (self.0)(&mut |item| {
+                    if h < area.h() {
+                        let show = item.min_size([area.w(), area.h().minus(h)].into())?.map(|s|s.wh());
+                        if let Some([width, height]) = show {
+                            E::shrink_y(height, E::push_y(area.h() - height, item))
+                                .render(to)?;
+                            h = h + height;
+                            if width > w { w = width }
+                        };
+                    }
+                    Ok(())
+                })?;
+            },
+            _ => todo!()
+        };
+        Ok(())
+    }
+}
+
 #[cfg(test)] #[test] fn test_bsp () {
     // TODO
 }