X-Git-Url: http://dolda2000.com/gitweb/?a=blobdiff_plain;f=src%2Fcommon%2Fgeometry.rs;h=540db53bff9568f488024837ac44857636c5eb34;hb=0c56b1f7a5568d6bfbebd196cf63ccef503cf959;hp=02f93b1efa29656561175cd37b61ba1005c8691a;hpb=e570927ad1703298a2c85599c7e25475c60b33d4;p=kaka%2Frust-sdl-test.git

diff --git a/src/common/geometry.rs b/src/common/geometry.rs
index 02f93b1..540db53 100644
--- a/src/common/geometry.rs
+++ b/src/common/geometry.rs
@@ -1,5 +1,7 @@
 use std::ops::{Add, AddAssign, Sub, SubAssign, Mul, MulAssign, Div, DivAssign, Neg};
 
+////////// POINT ///////////////////////////////////////////////////////////////
+
 #[macro_export]
 macro_rules! point {
     ( $x:expr, $y:expr ) => {
@@ -26,12 +28,8 @@ impl Point<f64> {
 	}
     }
 
-    pub fn to_radians(&self) -> Radians {
-	Radians(self.y.atan2(self.x))
-    }
-
-    pub fn to_degrees(&self) -> Degrees {
-	self.to_radians().to_degrees()
+    pub fn to_angle(&self) -> Angle {
+	self.y.atan2(self.x).radians()
     }
 
     pub fn to_i32(self) -> Point<i32> {
@@ -42,7 +40,7 @@ impl Point<f64> {
     }
 }
 
-macro_rules! point_op {
+macro_rules! impl_point_op {
     ($op:tt, $trait:ident($fn:ident), $trait_assign:ident($fn_assign:ident), $rhs:ident = $Rhs:ty => $x:expr, $y:expr) => {
         impl<T: $trait<Output = T>> $trait<$Rhs> for Point<T> {
             type Output = Self;
@@ -66,14 +64,16 @@ macro_rules! point_op {
     }
 }
 
-point_op!(+, Add(add), AddAssign(add_assign), rhs = Point<T> => rhs.x, rhs.y);
-point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = Point<T> => rhs.x, rhs.y);
-point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = Point<T> => rhs.x, rhs.y);
-point_op!(/, Div(div), DivAssign(div_assign), rhs = Point<T> => rhs.x, rhs.y);
-point_op!(+, Add(add), AddAssign(add_assign), rhs = (T, T) => rhs.0, rhs.1);
-point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = (T, T) => rhs.0, rhs.1);
-point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = (T, T) => rhs.0, rhs.1);
-point_op!(/, Div(div), DivAssign(div_assign), rhs = (T, T) => rhs.0, rhs.1);
+impl_point_op!(+, Add(add), AddAssign(add_assign), rhs = Point<T> => rhs.x, rhs.y);
+impl_point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = Point<T> => rhs.x, rhs.y);
+impl_point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = Point<T> => rhs.x, rhs.y);
+impl_point_op!(/, Div(div), DivAssign(div_assign), rhs = Point<T> => rhs.x, rhs.y);
+impl_point_op!(+, Add(add), AddAssign(add_assign), rhs = (T, T) => rhs.0, rhs.1);
+impl_point_op!(-, Sub(sub), SubAssign(sub_assign), rhs = (T, T) => rhs.0, rhs.1);
+impl_point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = (T, T) => rhs.0, rhs.1);
+impl_point_op!(/, Div(div), DivAssign(div_assign), rhs = (T, T) => rhs.0, rhs.1);
+impl_point_op!(*, Mul(mul), MulAssign(mul_assign), rhs = Dimension<T> => rhs.width, rhs.height);
+impl_point_op!(/, Div(div), DivAssign(div_assign), rhs = Dimension<T> => rhs.width, rhs.height);
 
 ////////// multiply point with scalar //////////////////////////////////////////
 impl<T: Mul<Output = T> + Copy> Mul<T> for Point<T> {
@@ -143,84 +143,272 @@ impl<T> From<Point<T>> for (T, T) {
     }
 }
 
-impl From<Degrees> for Point<f64> {
-    fn from(item: Degrees) -> Self {
-	let r = item.0.to_radians();
-        Point {
-            x: r.cos(),
-            y: r.sin(),
-        }
+impl From<Angle> for Point<f64> {
+    fn from(item: Angle) -> Self {
+	Point {
+	    x: item.0.cos(),
+	    y: item.0.sin(),
+	}
     }
 }
 
-impl From<Radians> for Point<f64> {
-    fn from(item: Radians) -> Self {
-        Point {
-            x: item.0.cos(),
-            y: item.0.sin(),
-        }
+////////// ANGLE ///////////////////////////////////////////////////////////////
+
+#[derive(Debug, Default, Clone, Copy)]
+pub struct Angle(pub f64);
+
+pub trait ToAngle {
+    fn radians(self) -> Angle;
+    fn degrees(self) -> Angle;
+}
+
+macro_rules! impl_angle {
+    ($($type:ty),*) => {
+	$(
+	    impl ToAngle for $type {
+		fn radians(self) -> Angle {
+		    Angle(self as f64)
+		}
+
+		fn degrees(self) -> Angle {
+		    Angle((self as f64).to_radians())
+		}
+	    }
+
+	    impl Mul<$type> for Angle {
+		type Output = Self;
+
+		fn mul(self, rhs: $type) -> Self {
+		    Angle(self.0 * (rhs as f64))
+		}
+	    }
+
+	    impl MulAssign<$type> for Angle {
+		fn mul_assign(&mut self, rhs: $type) {
+		    self.0 *= rhs as f64;
+		}
+	    }
+
+	    impl Div<$type> for Angle {
+		type Output = Self;
+
+		fn div(self, rhs: $type) -> Self {
+		    Angle(self.0 / (rhs as f64))
+		}
+	    }
+
+	    impl DivAssign<$type> for Angle {
+		fn div_assign(&mut self, rhs: $type) {
+		    self.0 /= rhs as f64;
+		}
+	    }
+	)*
     }
 }
 
-#[derive(Debug, Default, PartialEq, Clone, Copy)]
-pub struct Degrees(pub f64);
-#[derive(Debug, Default, PartialEq, Clone, Copy)]
-pub struct Radians(pub f64);
+impl_angle!(f32, f64, i8, i16, i32, i64, isize, u8, u16, u32, u64, usize);
 
-impl Degrees {
-    #[allow(dead_code)]
-    fn to_radians(&self) -> Radians {
-	Radians(self.0.to_radians())
+impl Angle {
+    pub fn to_radians(self) -> f64 {
+	self.0
+    }
+
+    pub fn to_degrees(self) -> f64 {
+	self.0.to_degrees()
+    }
+
+    /// Returns the reflection of the incident when mirrored along this angle.
+    pub fn mirror(&self, incidence: Angle) -> Angle {
+	Angle((std::f64::consts::PI + self.0 * 2.0 - incidence.0) % std::f64::consts::TAU)
     }
 }
 
-impl Radians {
-    #[allow(dead_code)]
-    fn to_degrees(&self) -> Degrees {
-	Degrees(self.0.to_degrees())
+impl PartialEq for Angle {
+    fn eq(&self, rhs: &Angle) -> bool {
+	self.0 % std::f64::consts::TAU == rhs.0 % std::f64::consts::TAU
+    }
+}
+
+// addition and subtraction of angles
+
+impl Add<Angle> for Angle {
+    type Output = Self;
+
+    fn add(self, rhs: Angle) -> Self {
+	Angle(self.0 + rhs.0)
+    }
+}
+
+impl AddAssign<Angle> for Angle {
+    fn add_assign(&mut self, rhs: Angle) {
+	self.0 += rhs.0;
+    }
+}
+
+impl Sub<Angle> for Angle {
+    type Output = Self;
+
+    fn sub(self, rhs: Angle) -> Self {
+	Angle(self.0 - rhs.0)
+    }
+}
+
+impl SubAssign<Angle> for Angle {
+    fn sub_assign(&mut self, rhs: Angle) {
+	self.0 -= rhs.0;
     }
 }
 
+////////// INTERSECTION ////////////////////////////////////////////////////////
+
+#[derive(Debug)]
+pub enum Intersection {
+    Point(Point<f64>),
+    //Line(Point<f64>, Point<f64>), // TODO: overlapping collinear
+    None,
+}
+
+impl Intersection {
+    pub fn lines(p1: Point<f64>, p2: Point<f64>, p3: Point<f64>, p4: Point<f64>) -> Intersection {
+	let s1 = p2 - p1;
+	let s2 = p4 - p3;
+
+	let denomimator = -s2.x * s1.y + s1.x * s2.y;
+	if denomimator != 0.0 {
+	    let s = (-s1.y * (p1.x - p3.x) + s1.x * (p1.y - p3.y)) / denomimator;
+	    let t = ( s2.x * (p1.y - p3.y) - s2.y * (p1.x - p3.x)) / denomimator;
+
+	    if (0.0..=1.0).contains(&s) && (0.0..=1.0).contains(&t) {
+		return Intersection::Point(p1 + (s1 * t))
+	    }
+	}
+
+	Intersection::None
+    }
+}
+
+////////// DIMENSION ///////////////////////////////////////////////////////////
+
 #[macro_export]
-macro_rules! rect {
-    ( $x:expr, $y:expr ) => {
-        Rect { x: $x, y: $y }
+macro_rules! dimen {
+    ( $w:expr, $h:expr ) => {
+        Dimension { width: $w, height: $h }
     };
 }
 
-#[derive(Default)]
-pub struct Rect<T> {
+#[derive(Debug, Default, Copy, Clone, PartialEq)]
+pub struct Dimension<T> {
     pub width: T,
     pub height: T,
 }
 
-impl<T: Mul<Output = T> + Copy> Rect<T> {
+impl<T: Mul<Output = T> + Copy> Dimension<T> {
     #[allow(dead_code)]
     pub fn area(&self) -> T {
         self.width * self.height
     }
 }
 
-impl<T> From<(T, T)> for Rect<T> {
+impl<T> From<(T, T)> for Dimension<T> {
     fn from(item: (T, T)) -> Self {
-        Rect {
+        Dimension {
             width: item.0,
             height: item.1,
         }
     }
 }
 
-#[macro_export]
-macro_rules! hashmap {
-    ($($k:expr => $v:expr),*) => {
-	{
-	    let mut map = std::collections::HashMap::new();
-	    $(map.insert($k, $v);)*
-	    map
+impl<T> From<Dimension<T>> for (T, T) {
+    fn from(item: Dimension<T>) -> Self {
+        (item.width, item.height)
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+#[allow(dead_code)]
+pub fn supercover_line_int(p1: Point<isize>, p2: Point<isize>) -> Vec<Point<isize>> {
+    let d = p2 - p1;
+    let n = point!(d.x.abs(), d.y.abs());
+    let step = point!(
+	if d.x > 0 { 1 } else { -1 },
+	if d.y > 0 { 1 } else { -1 }
+    );
+
+    let mut p = p1;
+    let mut points = vec!(point!(p.x as isize, p.y as isize));
+    let mut i = point!(0, 0);
+    while i.x < n.x || i.y < n.y {
+        let decision = (1 + 2 * i.x) * n.y - (1 + 2 * i.y) * n.x;
+        if decision == 0 { // next step is diagonal
+            p.x += step.x;
+            p.y += step.y;
+            i.x += 1;
+            i.y += 1;
+        } else if decision < 0 { // next step is horizontal
+            p.x += step.x;
+	    i.x += 1;
+        } else { // next step is vertical
+            p.y += step.y;
+            i.y += 1;
+        }
+        points.push(point!(p.x as isize, p.y as isize));
+    }
+
+    points
+}
+
+/// Calculates all points a line crosses, unlike Bresenham's line algorithm.
+/// There might be room for a lot of improvement here.
+pub fn supercover_line(mut p1: Point<f64>, mut p2: Point<f64>) -> Vec<Point<isize>> {
+    let mut delta = p2 - p1;
+    if (delta.x.abs() > delta.y.abs() && delta.x.is_sign_negative()) || (delta.x.abs() <= delta.y.abs() && delta.y.is_sign_negative()) {
+	std::mem::swap(&mut p1, &mut p2);
+	delta = -delta;
+    }
+
+    let mut last = point!(p1.x as isize, p1.y as isize);
+    let mut coords: Vec<Point<isize>> = vec!();
+    coords.push(last);
+
+    if delta.x.abs() > delta.y.abs() {
+	let k = delta.y / delta.x;
+	let m = p1.y as f64 - p1.x as f64 * k;
+	for x in (p1.x as isize + 1)..=(p2.x as isize) {
+	    let y = (k * x as f64 + m).floor();
+	    let next = point!(x as isize - 1, y as isize);
+	    if next != last {
+		coords.push(next);
+	    }
+	    let next = point!(x as isize, y as isize);
+	    coords.push(next);
+	    last = next;
+	}
+    } else {
+	let k = delta.x / delta.y;
+	let m = p1.x as f64 - p1.y as f64 * k;
+	for y in (p1.y as isize + 1)..=(p2.y as isize) {
+	    let x = (k * y as f64 + m).floor();
+	    let next = point!(x as isize, y as isize - 1);
+	    if next != last {
+		coords.push(next);
+	    }
+	    let next = point!(x as isize, y as isize);
+	    coords.push(next);
+	    last = next;
 	}
     }
+
+    let next = point!(p2.x as isize, p2.y as isize);
+    if next != last {
+	coords.push(next);
+    }
+
+    coords
 }
 
+////////// TESTS ///////////////////////////////////////////////////////////////
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -283,17 +471,59 @@ mod tests {
 
     #[test]
     fn angles() {
-	assert_eq!(Radians(0.0).to_degrees(), Degrees(0.0));
-	assert_eq!(Radians(std::f64::consts::PI).to_degrees(), Degrees(180.0));
-	assert_eq!(Degrees(180.0).to_radians(), Radians(std::f64::consts::PI));
-	assert!((Point::from(Degrees(90.0)) - point!(0.0, 1.0)).length() < 0.001);
-	assert!((Point::from(Radians(std::f64::consts::FRAC_PI_2)) - point!(0.0, 1.0)).length() < 0.001);
+	assert_eq!(0.radians(), 0.degrees());
+	assert_eq!(0.degrees(), 360.degrees());
+	assert_eq!(180.degrees(), std::f64::consts::PI.radians());
+	assert_eq!(std::f64::consts::PI.radians().to_degrees(), 180.0);
+	assert!((Point::from(90.degrees()) - point!(0.0, 1.0)).length() < 0.001);
+	assert!((Point::from(std::f64::consts::FRAC_PI_2.radians()) - point!(0.0, 1.0)).length() < 0.001);
     }
 
     #[test]
-    fn area_for_rect_of_multipliable_type() {
-        let r: Rect<_> = (30, 20).into(); // the Into trait uses the From trait
+    fn area_for_dimension_of_multipliable_type() {
+        let r: Dimension<_> = (30, 20).into(); // the Into trait uses the From trait
         assert_eq!(r.area(), 30 * 20);
-        // let a = Rect::from(("a".to_string(), "b".to_string())).area(); // this doesn't work, because area() is not implemented for String
+        // let a = Dimension::from(("a".to_string(), "b".to_string())).area(); // this doesn't work, because area() is not implemented for String
+    }
+
+    #[test]
+    fn intersection_of_lines() {
+        let p1 = point!(0.0, 0.0);
+        let p2 = point!(2.0, 2.0);
+        let p3 = point!(0.0, 2.0);
+        let p4 = point!(2.0, 0.0);
+	let r = Intersection::lines(p1, p2, p3, p4);
+	if let Intersection::Point(p) = r {
+            assert_eq!(p, point!(1.0, 1.0));
+	} else {
+	    panic!();
+	}
+    }
+
+    #[test]
+    fn some_coordinates_on_line() {
+	// horizontally up
+	let coords = supercover_line(point!(0.0, 0.0), point!(3.3, 2.2));
+	assert_eq!(coords.as_slice(), &[point!(0, 0), point!(1, 0), point!(1, 1), point!(2, 1), point!(2, 2), point!(3, 2)]);
+
+	// horizontally down
+	let coords = supercover_line(point!(0.0, 5.0), point!(3.3, 2.2));
+	assert_eq!(coords.as_slice(), &[point!(0, 5), point!(0, 4), point!(1, 4), point!(1, 3), point!(2, 3), point!(2, 2), point!(3, 2)]);
+
+	// vertically right
+	let coords = supercover_line(point!(0.0, 0.0), point!(2.2, 3.3));
+	assert_eq!(coords.as_slice(), &[point!(0, 0), point!(0, 1), point!(1, 1), point!(1, 2), point!(2, 2), point!(2, 3)]);
+
+	// vertically left
+	let coords = supercover_line(point!(5.0, 0.0), point!(3.0, 3.0));
+	assert_eq!(coords.as_slice(), &[point!(5, 0), point!(4, 0), point!(4, 1), point!(3, 1), point!(3, 2), point!(3, 3)]);
+
+	// negative
+	let coords = supercover_line(point!(0.0, 0.0), point!(-3.0, -2.0));
+	assert_eq!(coords.as_slice(), &[point!(-3, -2), point!(-2, -2), point!(-2, -1), point!(-1, -1), point!(-1, 0), point!(0, 0)]);
+
+	// 
+	let coords = supercover_line(point!(0.0, 0.0), point!(2.3, 1.1));
+	assert_eq!(coords.as_slice(), &[point!(0, 0), point!(1, 0), point!(2, 0), point!(2, 1)]);
     }
 }