Add player movementHEADmain

1 files changed, 203 insertions, 0 deletions

diff --git a/src/math/rect.rs b/src/math/rect.rs
new file mode 100644
index 0000000..55e0b1c
--- /dev/null
+++ b/src/math/rect.rs
@@ -0,0 +1,203 @@
+//! Rectangles where the sides are parallel to the x and y-axes.
+
+use std::ops::{Add, AddAssign, Sub};
+
+//use alga::general::{Additive, Identity};
+use nalgebra::Scalar;
+use num_traits::sign::{self, Signed};
+use num_traits::Zero;
+use serde::{Deserialize, Serialize};
+
+use super::Vec2;
+
+/// Represents a Rectangle with the value type T.
+#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Rect<T: Scalar + Copy>
+{
+    /// The x coordinate, or leftmost coordinate of the Rect.
+    pub x: T,
+    /// The y coordinate, or rightmost coordinate of the Rect.
+    pub y: T,
+    /// The width of the Rect.
+    pub w: T,
+    /// The height of the Rect.
+    pub h: T,
+}
+
+impl<T: Scalar + Copy> Rect<T>
+{
+    /// Create a new Rectangle from the internal values, where it might be nicer
+    /// to use a function instead of setting the values directly.
+    pub fn new(x: T, y: T, w: T, h: T) -> Self { Self { x, y, w, h } }
+
+    /// Create a Rectangle from a slice. Indices are [x, y, w, h].
+    pub fn from_slice(slice: [T; 4]) -> Rect<T>
+    where
+        T: Copy,
+    {
+        Rect {
+            x: slice[0],
+            y: slice[1],
+            w: slice[2],
+            h: slice[3],
+        }
+    }
+
+    /// Move by the Vec provided.
+    pub fn translate(&mut self, by: Vec2<T>)
+    where
+        T: AddAssign,
+    {
+        self.x += by.x;
+        self.y += by.y;
+    }
+
+    /// Set the posiotien of the rectangle to the given one without changing its
+    /// size
+    pub fn set_pos(&mut self, pos: Vec2<T>)
+    {
+        self.x = pos.x;
+        self.y = pos.y;
+    }
+
+    /// Test if two rectangles intersect.
+    pub fn intersect<'a>(this: &'a Rect<T>, other: &'a Rect<T>) -> bool
+    where
+        T: Add<Output = T> + PartialOrd + Copy,
+    {
+        !(this.x > other.x + other.w
+            || this.x + this.w < other.x
+            || this.y > other.y + other.h
+            || this.y + this.h < other.y)
+    }
+
+    /// Function to calculate the bounding rectangle that is between two
+    /// vectors. The order of the vectors is irrelevent for this. As long as
+    /// they are diagonally opposite of each other, this function will work.
+    pub fn bounding_rect(pos1: Vec2<T>, pos2: Vec2<T>) -> Self
+    where
+        T: PartialOrd + Sub<Output = T>,
+    {
+        let vertices = [pos1, pos2];
+
+        Self::bounding_rect_n(&vertices)
+    }
+
+    /// Function to calculate the bounding rectangle of n vertices provided. The
+    /// order of them is not relevant and a point that is contained by the
+    /// vertices will not change the result.
+    ///
+    /// # Panics
+    /// If there is not at least one vertex in the vertices slice, the function
+    /// will panic, since it is impossible to calculate any bounds in such a
+    /// case.
+    pub fn bounding_rect_n(vertices: &[Vec2<T>]) -> Self
+    where
+        T: PartialOrd + Sub<Output = T>,
+    {
+        if vertices.is_empty() {
+            panic!("Cannot create bounding rectangle without any vertices");
+        }
+
+        let mut min = vertices[0];
+        let mut max = vertices[0];
+
+        for vertex in vertices.iter().skip(1) {
+            min.x = super::partial_min(min.x, vertex.x);
+            min.y = super::partial_min(min.y, vertex.y);
+            max.x = super::partial_max(max.x, vertex.x);
+            max.y = super::partial_max(max.y, vertex.y);
+        }
+
+        Self {
+            x: min.x,
+            y: min.y,
+            w: max.x - min.x,
+            h: max.y - min.y,
+        }
+    }
+
+    /// Get the shortest way that must be applied to this Rect to clear out of
+    /// another Rect of the same type so that they would not intersect any more.
+    pub fn shortest_way_out(&self, of: &Rect<T>) -> Vec2<T>
+    where
+        T: Add<Output = T> + Sub<Output = T> + Signed + PartialOrd,
+    {
+        // Check upwards
+        let mut move_y = of.y - self.y - self.h;
+        // Check downwards
+        let move_down = of.y + of.h - self.y;
+        if move_down < -move_y {
+            move_y = move_down;
+        }
+
+        // Check left
+        let mut move_x = of.x - self.x - self.w;
+        // Check right
+        let move_right = of.x + of.w - self.x;
+        if move_right < -move_x {
+            move_x = move_right;
+        }
+
+        if move_x.abs() < move_y.abs() {
+            Vec2::new(move_x, T::zero())
+        }
+        else {
+            Vec2::new(T::zero(), move_y)
+        }
+    }
+
+    /// Calculate the area of the rectangle.
+    pub fn area(&self) -> T
+    where
+        T: Signed,
+    {
+        sign::abs(self.w) * sign::abs(self.h)
+    }
+
+    fn contains_point(&self, point: &Vec2<T>) -> bool
+    where
+        T: Add<Output = T> + PartialOrd,
+    {
+        point.x >= self.x
+            && point.x <= self.x + self.w
+            && point.y >= self.y
+            && point.y <= self.y + self.h
+    }
+
+    fn contains_rect(&self, rect: &Rect<T>) -> bool
+    where
+        T: Add<Output = T> + Sub<Output = T> + Zero + PartialOrd,
+    {
+        /* True, if the rightmost x-coordinate of the called rectangle is further
+         * right or the same as the rightmost coordinate of the given rect.
+         */
+        let x_exceeds = self.x + self.w - rect.x - rect.w >= T::zero();
+        // The same for the y-coordinates
+        let y_exceeds = self.y + self.h - rect.y - rect.h >= T::zero();
+
+        x_exceeds && y_exceeds && self.x <= rect.x && self.y <= rect.y
+    }
+
+    fn is_inside_rect(&self, rect: &Rect<T>) -> bool
+    where
+        T: Add<Output = T> + Sub<Output = T> + Zero + PartialOrd,
+    {
+        rect.contains_rect(&self)
+    }
+}
+
+#[cfg(test)]
+mod test
+{
+    use super::*;
+
+    #[test]
+    fn test_intersect()
+    {
+        let a = Rect::from_slice([0, 0, 4, 4]);
+        let b = Rect::from_slice([-1, -1, 1, 1]);
+
+        assert!(Rect::intersect(&a, &b));
+    }
+}