From 2ce55950e03a8da30248d9f8eca7c1955f68f281 Mon Sep 17 00:00:00 2001
From: Thomas Forgione <thomas@tforgione.fr>
Date: Mon, 5 Mar 2018 10:37:48 +0100
Subject: [PATCH] Initial commit

---
 .gitignore     |  4 +++
 Cargo.toml     | 12 +++++++
 src/example.rs | 21 ++++++++++++
 src/lib.rs     | 86 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 123 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Cargo.toml
 create mode 100644 src/example.rs
 create mode 100644 src/lib.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..143b1ca
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+
+/target/
+**/*.rs.bk
+Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..0faacfa
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "kdtree"
+version = "0.1.0"
+authors = ["Thomas Forgione <thomas@tforgione.fr>"]
+
+[dependencies]
+model-converter = { path = "../model-converter" }
+num = "*"
+
+[[bin]]
+name = "kdtree-example"
+path = "src/example.rs"
diff --git a/src/example.rs b/src/example.rs
new file mode 100644
index 0000000..658c274
--- /dev/null
+++ b/src/example.rs
@@ -0,0 +1,21 @@
+extern crate model_converter;
+extern crate kdtree;
+
+use model_converter::math::vector::Vector2;
+use kdtree::KdTree2;
+
+fn main() {
+    let mut points = vec![
+        Vector2::new(2.0, 3.0),
+        Vector2::new(5.0, 4.0),
+        Vector2::new(9.0, 6.0),
+        Vector2::new(4.0, 7.0),
+        Vector2::new(8.0, 1.0),
+        Vector2::new(7.0, 2.0),
+    ];
+
+    let kdtree = KdTree2::new(&mut points);
+
+    println!("{}", kdtree);
+
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..a5c37a6
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,86 @@
+extern crate num;
+extern crate model_converter;
+
+use std::fmt;
+
+use num::Zero;
+
+use model_converter::math::vector;
+
+macro_rules! define_kdtree {
+
+    ($name: ident, $vector_type: ty, $dimension: expr) => {
+
+        /// A 3-dimension kd tree
+        pub struct $name {
+            location: $vector_type,
+            left:  Option<Box<$name>>,
+            right: Option<Box<$name>>,
+        }
+
+        impl $name {
+            pub fn new(points: &mut [$vector_type]) -> $name {
+                $name::new_with_depth(points, 0)
+            }
+
+            fn new_with_depth(points: &mut [$vector_type], depth: usize) -> $name {
+
+                // Select axis to work on
+                let axis = depth % $dimension;
+
+                // Sort the points by axis
+                points.sort_by(|p1, p2| p1[axis].partial_cmp(&p2[axis]).unwrap());
+
+                // Find the median
+                let len = points.len();
+                let delimiter = points.len() / 2;
+                let median = points[delimiter];
+
+                let zero = Zero::zero();
+                let mut left = vec![zero; delimiter];
+                left.copy_from_slice(&points[0..delimiter]);
+
+                let right = &mut points[delimiter + 1 .. len];
+
+                if left.len() == 0 || right.len() == 0 {
+                    $name {
+                        location: median,
+                        left:  None,
+                        right: None,
+                    }
+                } else {
+                    $name {
+                        location: median,
+                        left:  Some(Box::new($name::new_with_depth(&mut left, depth + 1))),
+                        right: Some(Box::new($name::new_with_depth(right, depth + 1))),
+                    }
+                }
+            }
+
+            fn print(&self, formatter: &mut fmt::Formatter, indent: &str) -> fmt::Result {
+                writeln!(formatter, "{}{}", indent, self.location)?;
+
+                if let Some(left) = self.left.as_ref() {
+                    left.print(formatter, &format!("{}  ", indent))?;
+                }
+
+                if let Some(right) = self.right.as_ref() {
+                    right.print(formatter, &format!("{}  ", indent))?;
+                }
+
+                Ok(())
+            }
+        }
+
+        impl fmt::Display for $name {
+            fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+                self.print(formatter, "")
+            }
+
+        }
+    }
+}
+
+define_kdtree!(KdTree2, vector::Vector2<f64>, 2);
+define_kdtree!(KdTree3, vector::Vector3<f64>, 3);
+define_kdtree!(KdTree4, vector::Vector4<f64>, 4);