an @-sign in a box

1 files changed, 296 insertions, 0 deletions

diff --git a/src/types/mod.rs b/src/types/mod.rs
new file mode 100644
index 000000000000..331aa236e324
--- /dev/null
+++ b/src/types/mod.rs
@@ -0,0 +1,296 @@
+use std::cmp::Ordering;
+use std::ops;
+pub mod command;
+pub mod direction;
+pub use direction::Direction;
+pub use direction::Direction::{Down, Left, Right, Up};
+use proptest_derive::Arbitrary;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Arbitrary)]
+pub struct Dimensions {
+    #[proptest(strategy = "std::ops::Range::<u16>::from(0..100)")]
+    pub w: u16,
+
+    #[proptest(strategy = "std::ops::Range::<u16>::from(0..100)")]
+    pub h: u16,
+}
+
+pub const ZERO_DIMENSIONS: Dimensions = Dimensions { w: 0, h: 0 };
+pub const UNIT_DIMENSIONS: Dimensions = Dimensions { w: 1, h: 1 };
+
+impl ops::Sub<Dimensions> for Dimensions {
+    type Output = Dimensions;
+    fn sub(self, dims: Dimensions) -> Dimensions {
+        Dimensions {
+            w: self.w - dims.w,
+            h: self.h - dims.h,
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Arbitrary)]
+pub struct BoundingBox {
+    pub dimensions: Dimensions,
+    pub position: Position,
+}
+
+impl BoundingBox {
+    pub fn at_origin(dimensions: Dimensions) -> BoundingBox {
+        BoundingBox {
+            dimensions,
+            position: ORIGIN,
+        }
+    }
+
+    pub fn lr_corner(self) -> Position {
+        self.position
+            + (Position {
+                x: self.dimensions.w,
+                y: self.dimensions.h,
+            })
+    }
+
+    /// Returns a bounding box representing the *inside* of this box if it was
+    /// drawn on the screen.
+    pub fn inner(self) -> BoundingBox {
+        self + UNIT_POSITION - UNIT_DIMENSIONS - UNIT_DIMENSIONS
+    }
+}
+
+impl ops::Add<Position> for BoundingBox {
+    type Output = BoundingBox;
+    fn add(self, pos: Position) -> BoundingBox {
+        BoundingBox {
+            position: self.position + pos,
+            ..self
+        }
+    }
+}
+
+impl ops::Sub<Dimensions> for BoundingBox {
+    type Output = BoundingBox;
+    fn sub(self, dims: Dimensions) -> BoundingBox {
+        BoundingBox {
+            dimensions: self.dimensions - dims,
+            ..self
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Arbitrary)]
+pub struct Position {
+    /// x (horizontal) position
+    #[proptest(strategy = "std::ops::Range::<u16>::from(0..100)")]
+    pub x: u16,
+
+    #[proptest(strategy = "std::ops::Range::<u16>::from(0..100)")]
+    /// y (vertical) position
+    pub y: u16,
+}
+
+pub const ORIGIN: Position = Position { x: 0, y: 0 };
+pub const UNIT_POSITION: Position = Position { x: 1, y: 1 };
+
+impl Position {
+    /// Returns true if this position exists within the bounds of the given box,
+    /// inclusive
+    pub fn within(self, b: BoundingBox) -> bool {
+        (self > b.position - UNIT_POSITION) && self < (b.lr_corner())
+    }
+}
+
+impl PartialOrd for Position {
+    fn partial_cmp(&self, other: &Position) -> Option<Ordering> {
+        if self.x == other.x && self.y == other.y {
+            Some(Ordering::Equal)
+        } else if self.x > other.x && self.y > other.y {
+            Some(Ordering::Greater)
+        } else if self.x < other.x && self.y < other.y {
+            Some(Ordering::Less)
+        } else {
+            None
+        }
+    }
+}
+
+/// Implements (bounded) addition of a Dimension to a position.
+///
+/// # Examples
+///
+/// ```
+/// let pos = Position { x: 1, y: 10 }
+///
+/// let left_pos = pos + Direction::Left
+/// assert_eq!(left, Position { x: 0, y: 10 })
+///
+/// let right_pos = pos + Direction::Right
+/// assert_eq!(right_pos, Position { x: 0, y: 10 })
+/// ```
+impl ops::Add<Direction> for Position {
+    type Output = Position;
+    fn add(self, dir: Direction) -> Position {
+        match dir {
+            Left => {
+                if self.x > 0 {
+                    Position {
+                        x: self.x - 1,
+                        ..self
+                    }
+                } else {
+                    self
+                }
+            }
+            Right => {
+                if self.x < std::u16::MAX {
+                    Position {
+                        x: self.x + 1,
+                        ..self
+                    }
+                } else {
+                    self
+                }
+            }
+            Up => {
+                if self.y > 0 {
+                    Position {
+                        y: self.y - 1,
+                        ..self
+                    }
+                } else {
+                    self
+                }
+            }
+            Down => {
+                if self.y < std::u16::MAX {
+                    Position {
+                        y: self.y + 1,
+                        ..self
+                    }
+                } else {
+                    self
+                }
+            }
+        }
+    }
+}
+
+impl ops::Add<Position> for Position {
+    type Output = Position;
+    fn add(self, pos: Position) -> Position {
+        Position {
+            x: self.x + pos.x,
+            y: self.y + pos.y,
+        }
+    }
+}
+
+impl ops::Sub<Position> for Position {
+    type Output = Position;
+    fn sub(self, pos: Position) -> Position {
+        Position {
+            x: self.x - pos.x,
+            y: self.y - pos.y,
+        }
+    }
+}
+
+pub trait Positioned {
+    fn x(&self) -> u16 {
+        self.position().x
+    }
+
+    fn y(&self) -> u16 {
+        self.position().y
+    }
+
+    fn position(&self) -> Position {
+        Position {
+            x: self.x(),
+            y: self.y(),
+        }
+    }
+}
+
+macro_rules! positioned {
+    ($name:ident) => {
+        positioned!($name, position);
+    };
+    ($name:ident, $attr:ident) => {
+        impl crate::types::Positioned for $name {
+            fn position(&self) -> Position {
+                self.$attr
+            }
+        }
+    };
+}
+
+/// A number of ticks
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Arbitrary)]
+pub struct Ticks(pub u16);
+
+/// A number of tiles
+///
+/// Expressed in terms of a float to allow moving partial tiles in a number of
+/// ticks
+#[derive(Clone, Copy, Debug, PartialEq, Arbitrary)]
+pub struct Tiles(pub f32);
+
+/// The speed of an entity, expressed in ticks per tile
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Arbitrary)]
+pub struct Speed(pub u32);
+
+impl Speed {
+    pub fn ticks_to_tiles(self, ticks: Ticks) -> Tiles {
+        Tiles(ticks.0 as f32 / self.0 as f32)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use proptest::prelude::*;
+
+    proptest! {
+        #[test]
+        fn position_partialord_lt_transitive(
+            a: Position,
+            b: Position,
+            c: Position
+        ) {
+            if a < b && b < c {
+                assert!(a < c)
+            }
+        }
+
+        #[test]
+        fn position_partialord_eq_transitive(
+            a: Position,
+            b: Position,
+            c: Position
+        ) {
+            if a == b && b == c {
+                assert!(a == c)
+            }
+        }
+
+        #[test]
+        fn position_partialord_gt_transitive(
+            a: Position,
+            b: Position,
+            c: Position,
+        ) {
+            if a > b && b > c {
+                assert!(a > c)
+            }
+        }
+
+        #[test]
+        fn position_partialord_antisymmetric(a: Position, b: Position) {
+            if a < b {
+                assert!(!(a > b))
+            } else if a > b {
+                assert!(!(a < b))
+            }
+        }
+    }
+}