Use Line32.intersection from pointy crate

src/geom.rs

@@ -15,28 +15,6 @@ pub fn float_lerp(a: f32, b: f32, t: f32) -> f32 {
     b + (a - b) * t
 }
 
-/// Calculate intersection point of two lines.
-///
-/// * `a0` First point on line a.
-/// * `a1` Second point on line a.
-/// * `b0` First point on line b.
-/// * `b1` Second point on line b.
-/// Returns None if the lines are colinear.
-pub fn intersection(a0: Pt32, a1: Pt32, b0: Pt32, b1: Pt32) -> Option<Pt32> {
-    let av = a0 - a1;
-    let bv = b0 - b1;
-    let den = av * bv;
-    if den != 0.0 {
-        let ca = a0 * a1;
-        let cb = b0 * b1;
-        let xn = bv.x() * ca - av.x() * cb;
-        let yn = bv.y() * ca - av.y() * cb;
-        Some(Pt32(xn / den, yn / den))
-    } else {
-        None
-    }
-}
-
 impl Default for WidePt {
     fn default() -> Self {
         WidePt(Pt32::default(), 1.0)

src/stroker.rs

@@ -2,10 +2,10 @@
 //
 // Copyright (c) 2017-2020  Douglas P Lau
 //
-use crate::geom::{intersection, WidePt};
+use crate::geom::WidePt;
 use crate::path::PathOp;
 use crate::vid::Vid;
-use pointy::Pt32;
+use pointy::{Line32, Pt32};
 use std::fmt;
 
 /// Style for stroke joins.
@@ -354,8 +354,10 @@ impl Stroke {
             let th = (a1 - a0).angle_rel(b0 - b1);
             let sm = (th / 2.0).sin().abs();
             if sm >= sm_min && sm < 1.0 {
+                let lna = Line32::new(a0, a1);
+                let lnb = Line32::new(b0, b1);
                 // Calculate miter point
-                if let Some(xp) = intersection(a0, a1, b0, b1) {
+                if let Some(xp) = lna.intersection(lnb) {
                     self.stroke_point(ops, xp);
                     return;
                 }