From 8c6110a3884baa6b4c66906b44c4b0f7151c56ce Mon Sep 17 00:00:00 2001
From: Patrick Walton <pcwalton@mimiga.net>
Date: Mon, 2 Oct 2017 11:45:34 -0700
Subject: [PATCH] Remove the duplicated de Casteljau subdivision code in
 `partitioner::geometry`

---
 partitioner/src/geometry.rs    | 68 ----------------------------------
 partitioner/src/lib.rs         |  1 -
 partitioner/src/partitioner.rs | 30 +++++++--------
 3 files changed, 15 insertions(+), 84 deletions(-)
 delete mode 100644 partitioner/src/geometry.rs

diff --git a/partitioner/src/geometry.rs b/partitioner/src/geometry.rs
deleted file mode 100644
index 7ce159ed..00000000
--- a/partitioner/src/geometry.rs
+++ /dev/null
@@ -1,68 +0,0 @@
-// pathfinder/partitioner/src/geometry.rs
-//
-// Copyright © 2017 The Pathfinder Project Developers.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-use euclid::Point2D;
-use euclid::approxeq::ApproxEq;
-
-fn quadratic_bezier_axis_inflection_point(p0: f32, p1: f32, p2: f32) -> Option<f32> {
-    let t = (p0 - p1) / (p0 - 2.0 * p1 + p2);
-    if t > f32::approx_epsilon() && t < 1.0 - f32::approx_epsilon() {
-        Some(t)
-    } else {
-        None
-    }
-}
-
-#[derive(Clone, Copy, Debug)]
-pub struct QuadraticBezierInflectionPoints {
-    pub xt: Option<f32>,
-    pub yt: Option<f32>,
-}
-
-impl QuadraticBezierInflectionPoints {
-    pub fn calculate(p0: &Point2D<f32>, p1: &Point2D<f32>, p2: &Point2D<f32>)
-                     -> QuadraticBezierInflectionPoints {
-        if ((*p1 - *p0).length() + (*p2 - *p1).length()).abs() < f32::approx_epsilon() {
-            QuadraticBezierInflectionPoints {
-                xt: None,
-                yt: None,
-            }
-        } else {
-            QuadraticBezierInflectionPoints {
-                xt: quadratic_bezier_axis_inflection_point(p0.x, p1.x, p2.x),
-                yt: quadratic_bezier_axis_inflection_point(p0.y, p1.y, p2.y),
-            }
-        }
-    }
-}
-
-#[derive(Clone, Copy, Debug)]
-pub struct SubdividedQuadraticBezier {
-    pub ap0: Point2D<f32>,
-    pub ap1: Point2D<f32>,
-    pub ap2bp0: Point2D<f32>,
-    pub bp1: Point2D<f32>,
-    pub bp2: Point2D<f32>,
-}
-
-impl SubdividedQuadraticBezier {
-    pub fn new(t: f32, p0: &Point2D<f32>, p1: &Point2D<f32>, p2: &Point2D<f32>)
-               -> SubdividedQuadraticBezier {
-        let (ap1, bp1) = (p0.lerp(*p1, t), p1.lerp(*p2, t));
-        let ap2bp0 = ap1.lerp(bp1, t);
-        SubdividedQuadraticBezier {
-            ap0: *p0,
-            ap1: ap1,
-            ap2bp0: ap2bp0,
-            bp1: bp1,
-            bp2: *p2,
-        }
-    }
-}
diff --git a/partitioner/src/lib.rs b/partitioner/src/lib.rs
index 9e329c60..d6d4cff7 100644
--- a/partitioner/src/lib.rs
+++ b/partitioner/src/lib.rs
@@ -26,7 +26,6 @@ use pathfinder_path_utils::{Endpoint, Subpath};
 use std::u32;
 
 pub mod capi;
-pub mod geometry;
 pub mod partitioner;
 
 #[repr(C)]
diff --git a/partitioner/src/partitioner.rs b/partitioner/src/partitioner.rs
index 904cd0da..32ad4d13 100644
--- a/partitioner/src/partitioner.rs
+++ b/partitioner/src/partitioner.rs
@@ -11,7 +11,6 @@
 use bit_vec::BitVec;
 use euclid::approxeq::ApproxEq;
 use euclid::Point2D;
-use geometry::SubdividedQuadraticBezier;
 use log::LogLevel;
 use pathfinder_path_utils::PathBuffer;
 use pathfinder_path_utils::curve::Curve;
@@ -1064,33 +1063,34 @@ impl<'a> Partitioner<'a> {
             _ => {
                 let left_endpoint_position =
                     self.b_vertex_positions[active_edge.left_vertex_index as usize];
+                let control_point_position =
+                    self.b_vertex_positions[active_edge.control_point_vertex_index as usize];
                 let right_endpoint_position =
                     self.endpoints[active_edge.right_endpoint_index as usize].position;
-                let subdivided_quadratic_bezier = SubdividedQuadraticBezier::new(
-                    t,
-                    &left_endpoint_position,
-                    &self.b_vertex_positions[active_edge.control_point_vertex_index as usize],
-                    &right_endpoint_position);
+                let original_curve = Curve::new(&left_endpoint_position,
+                                                &control_point_position,
+                                                &right_endpoint_position);
+                let (left_curve, right_curve) = original_curve.subdivide(t);
 
                 left_curve_control_point_vertex_index = self.b_vertex_loop_blinn_data.len() as u32;
                 active_edge.left_vertex_index = left_curve_control_point_vertex_index + 1;
                 active_edge.control_point_vertex_index = left_curve_control_point_vertex_index + 2;
 
                 self.b_vertex_positions.extend([
-                    subdivided_quadratic_bezier.ap1,
-                    subdivided_quadratic_bezier.ap2bp0,
-                    subdivided_quadratic_bezier.bp1,
+                    left_curve.control_point,
+                    left_curve.endpoints[1],
+                    right_curve.control_point,
                 ].into_iter());
                 self.b_vertex_path_ids.extend(iter::repeat(self.path_id).take(3));
                 self.b_vertex_loop_blinn_data.extend([
-                    BVertexLoopBlinnData::control_point(&left_endpoint_position,
-                                                        &subdivided_quadratic_bezier.ap1,
-                                                        &subdivided_quadratic_bezier.ap2bp0,
+                    BVertexLoopBlinnData::control_point(&left_curve.endpoints[0],
+                                                        &left_curve.control_point,
+                                                        &left_curve.endpoints[1],
                                                         bottom),
                     BVertexLoopBlinnData::new(active_edge.endpoint_kind()),
-                    BVertexLoopBlinnData::control_point(&subdivided_quadratic_bezier.ap2bp0,
-                                                        &subdivided_quadratic_bezier.bp1,
-                                                        &right_endpoint_position,
+                    BVertexLoopBlinnData::control_point(&right_curve.endpoints[0],
+                                                        &right_curve.control_point,
+                                                        &right_curve.endpoints[1],
                                                         bottom),
                 ].into_iter());
             }