1 files changed, 178 insertions, 0 deletions
diff --git a/packages/svgbob/src/point.rs b/packages/svgbob/src/point.rs
new file mode 100644
index 0000000..08e0e12
--- /dev/null
+++ b/packages/svgbob/src/point.rs
@@ -0,0 +1,178 @@
+use crate::buffer::CellGrid;
+use crate::util;
+use crate::Cell;
+use nalgebra::coordinates::XY;
+use nalgebra::{Point2, Vector2};
+use std::{
+    cmp::Ordering,
+    fmt,
+    ops::{Add, Deref, Sub},
+};
+
+#[derive(Clone, Copy, Debug)]
+pub struct Point(Point2<f32>);
+
+impl Deref for Point {
+    type Target = Point2<f32>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl Point {
+    pub fn new(x: f32, y: f32) -> Self {
+        Point(Point2::new(x, y))
+    }
+
+    /// convert a point to vector
+    #[inline]
+    pub fn to_vector(&self) -> Vector2<f32> {
+        Vector2::new(self.x, self.y)
+    }
+
+    /// scale point
+    pub fn scale(&self, scale: f32) -> Self {
+        Point::new(self.x * scale, self.y * scale)
+    }
+
+    pub fn normalize(&self) -> Point {
+        let vector = self.to_vector().normalize();
+        Point::new(vector.x, vector.y)
+    }
+
+    pub fn distance(&self, other: &Self) -> f32 {
+        nalgebra::distance(&self.0, &other.0)
+    }
+
+    /// align x to 0.5
+    /// align y to odd number
+    pub fn align(&self) -> Self {
+        let x = self.x.round() + 0.5;
+        let y = if self.y.round().rem_euclid(2.0) == 0.0 {
+            self.y.round() + 1.0
+        } else {
+            self.y.round()
+        };
+        Point::new(x, y)
+    }
+
+    /// adjust x value by units specified
+    pub fn adjust_x(&self, units: f32) -> Self {
+        let t = units * CellGrid::unit_x();
+        Self::new(self.x + t, self.y)
+    }
+
+    /// adjust y value by units specified
+    pub fn adjust_y(&self, units: f32) -> Self {
+        let t = units * CellGrid::unit_y();
+        Self::new(self.x, self.y + t)
+    }
+
+    /// adjust both x and y value by units specified
+    pub fn adjust(&self, units_x: f32, units_y: f32) -> Self {
+        let t = units_x * CellGrid::unit_x();
+        let u = units_y * CellGrid::unit_y();
+        Self::new(self.x + t, self.y + u)
+    }
+
+    /// test if the point lie on an edge of a cell
+    /// that is the fractional part is 0.0
+    pub fn is_edge_x(&self) -> bool {
+        self.x.fract() == 0.0
+    }
+    pub fn is_edge_y(&self) -> bool {
+        (self.y / 2.0).fract() == 0.0
+    }
+    pub fn is_mid_x(&self) -> bool {
+        self.x.fract() == 0.5
+    }
+    pub fn is_mid_y(&self) -> bool {
+        (self.y / 2.0).fract() == 0.5
+    }
+
+    /// return the cell where this point fall to
+    pub fn cell(&self) -> Cell {
+        let (cell, _) = Cell::snap_point(*self);
+        cell
+    }
+}
+
+impl From<Point2<f32>> for Point {
+    fn from(point: Point2<f32>) -> Self {
+        Point(point)
+    }
+}
+
+impl From<Point2<i32>> for Point {
+    fn from(point: Point2<i32>) -> Self {
+        Point::new(point.x as f32, point.y as f32)
+    }
+}
+
+impl From<XY<i32>> for Point {
+    fn from(point: XY<i32>) -> Self {
+        Point::new(point.x as f32, point.y as f32)
+    }
+}
+
+impl From<XY<f32>> for Point {
+    fn from(point: XY<f32>) -> Self {
+        Point::new(point.x, point.y)
+    }
+}
+
+impl Add for Point {
+    type Output = Self;
+
+    fn add(self, other: Self) -> Self::Output {
+        Point::new(self.x + other.x, self.y + other.y)
+    }
+}
+
+impl Sub for Point {
+    type Output = Self;
+
+    fn sub(self, other: Self) -> Self::Output {
+        Point::new(self.x - other.x, self.y - other.y)
+    }
+}
+
+impl fmt::Display for Point {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "({},{})", self.x, self.y)
+    }
+}
+
+impl Eq for Point {}
+
+impl Ord for Point {
+    fn cmp(&self, other: &Self) -> Ordering {
+        util::ord(self.y, other.y).then(util::ord(self.x, other.x))
+    }
+}
+
+impl PartialOrd for Point {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl PartialEq for Point {
+    fn eq(&self, other: &Self) -> bool {
+        self.cmp(other) == Ordering::Equal
+    }
+}
+
+#[cfg(test)]
+mod tests {
+
+    use super::*;
+
+    #[test]
+    fn test_align() {
+        let p = Point::new(1.25, 2.0);
+        let p2 = p.align();
+        assert_eq!(p2, Point::new(1.5, 3.0));
+    }
+}