Make ContourBuilder generic over the raster data type

Signed-off-by: netthier <lp@senselabs.de>

Author: netthier

Cargo.toml

@@ -14,11 +14,12 @@ license = "MIT OR Apache-2.0"
 
 [dependencies]
 geojson = { version = ">=0.16, <=0.24", optional = true }
-geo-types= { version = "0.7" }
+geo-types = { version = "0.7" }
 lazy_static = "1.0"
 serde_json = { version = "^1.0", optional = true }
 rustc-hash = "1.0"
 slab = "0.4"
+num-traits = "0.2"
 
 [dev-dependencies]
 serde_json = "^1.0"

src/area.rs

@@ -1,4 +1,4 @@
-use crate::{Float, Pt};
+use crate::{ContourValue, Float, Pt};
 
 #[allow(clippy::unnecessary_cast)]
 // Note that we need to disable the clippy warning about unnecessary casts

src/band.rs

@@ -1,32 +1,32 @@
-use crate::Float;
-use geo_types::MultiPolygon;
+use crate::{ContourValue, Float};
+use geo_types::{CoordFloat, MultiPolygon};
 
 /// An isoband has the geometry and min / max values of a contour ring, built by [`ContourBuilder`].
 #[derive(Debug, Clone)]
-pub struct Band {
+pub struct Band<V: ContourValue> {
     pub(crate) geometry: MultiPolygon<Float>,
-    pub(crate) min_v: Float,
-    pub(crate) max_v: Float,
+    pub(crate) min_v: V,
+    pub(crate) max_v: V,
 }
 
-impl Band {
+impl<V: ContourValue> Band<V> {
     /// Borrow the [`MultiPolygon`](geo_types::MultiPolygon) geometry of this contour.
     pub fn geometry(&self) -> &MultiPolygon<Float> {
         &self.geometry
     }
 
     /// Get the owned polygons and thresholds (min and max) of this band.
-    pub fn into_inner(self) -> (MultiPolygon<Float>, Float, Float) {
+    pub fn into_inner(self) -> (MultiPolygon<Float>, V, V) {
         (self.geometry, self.min_v, self.max_v)
     }
 
     /// Get the minimum value used to construct this band.
-    pub fn min_v(&self) -> Float {
+    pub fn min_v(&self) -> V {
         self.min_v
     }
 
     /// Get the maximum value used to construct this band.
-    pub fn max_v(&self) -> Float {
+    pub fn max_v(&self) -> V {
         self.max_v
     }
 

src/contour.rs

@@ -1,26 +1,26 @@
-use crate::Float;
-use geo_types::MultiPolygon;
+use crate::{ContourValue, Float};
+use geo_types::{CoordFloat, MultiPolygon};
 
 /// A contour has the geometry and threshold of a contour ring, built by [`ContourBuilder`].
 #[derive(Debug, Clone)]
-pub struct Contour {
+pub struct Contour<V: ContourValue> {
     pub(crate) geometry: MultiPolygon<Float>,
-    pub(crate) threshold: Float,
+    pub(crate) threshold: V,
 }
 
-impl Contour {
+impl<V: ContourValue> Contour<V> {
     /// Borrow the [`MultiPolygon`](geo_types::MultiPolygon) geometry of this contour.
     pub fn geometry(&self) -> &MultiPolygon<Float> {
         &self.geometry
     }
 
     /// Get the owned polygons and threshold of this contour.
-    pub fn into_inner(self) -> (MultiPolygon<Float>, Float) {
+    pub fn into_inner(self) -> (MultiPolygon<Float>, V) {
         (self.geometry, self.threshold)
     }
 
     /// Get the threshold used to construct this contour.
-    pub fn threshold(&self) -> Float {
+    pub fn threshold(&self) -> V {
         self.threshold
     }
 

src/contourbuilder.rs

@@ -1,8 +1,8 @@
 use crate::area::{area, contains};
 use crate::error::{new_error, ErrorKind, Result};
 use crate::isoringbuilder::IsoRingBuilder;
-use crate::{Band, Contour, Float, Line, Ring};
-use geo_types::{LineString, MultiLineString, MultiPolygon, Polygon};
+use crate::{Band, Contour, ContourValue, Float, Line, Ring};
+use geo_types::{CoordFloat, LineString, MultiLineString, MultiPolygon, Polygon};
 use rustc_hash::FxHashMap;
 
 /// Contours generator, using builder pattern, to
@@ -43,10 +43,10 @@ impl ContourBuilder {
             dx,
             dy,
             smooth,
-            x_origin: 0.,
-            y_origin: 0.,
-            x_step: 1.,
-            y_step: 1.,
+            x_origin: 0.0,
+            y_origin: 0.0,
+            x_step: 1.0,
+            y_step: 1.0,
         }
     }
 
@@ -74,7 +74,7 @@ impl ContourBuilder {
         self
     }
 
-    fn smooth_linear(&self, ring: &mut Ring, values: &[Float], value: Float) {
+    fn smooth_linear<V: ContourValue>(&self, ring: &mut Ring, values: &[V], value: V) {
         let dx = self.dx;
         let dy = self.dy;
         let len_values = values.len();
@@ -91,11 +91,11 @@ impl ContourBuilder {
                     let v1 = values[ix];
                     if x > 0.0 && x < (dx as Float) && (xt as Float - x).abs() < Float::EPSILON {
                         v0 = values[yt * dx + xt - 1];
-                        point.x = x + (value - v0) / (v1 - v0) - 0.5;
+                        point.x = x + num_traits::cast::<V, Float>( (value - v0) / (v1 - v0) - num_traits::cast(0.5).unwrap()).unwrap();
                     }
                     if y > 0.0 && y < (dy as Float) && (yt as Float - y).abs() < Float::EPSILON {
                         v0 = values[(yt - 1) * dx + xt];
-                        point.y = y + (value - v0) / (v1 - v0) - 0.5;
+                        point.y = y + num_traits::cast::<V, Float>((value - v0) / (v1 - v0) - num_traits::cast(0.5).unwrap()).unwrap();
                     }
                 }
             })
@@ -111,7 +111,7 @@ impl ContourBuilder {
     ///
     /// * `values` - The slice of values to be used.
     /// * `thresholds` - The slice of thresholds values to be used.
-    pub fn lines(&self, values: &[Float], thresholds: &[Float]) -> Result<Vec<Line>> {
+    pub fn lines<V: ContourValue>(&self, values: &[V], thresholds: &[V]) -> Result<Vec<Line<V>>> {
         if values.len() != self.dx * self.dy {
             return Err(new_error(ErrorKind::BadDimension));
         }
@@ -122,12 +122,12 @@ impl ContourBuilder {
             .collect()
     }
 
-    fn line(
+    fn line<V: ContourValue>(
         &self,
-        values: &[Float],
-        threshold: Float,
+        values: &[V],
+        threshold: V,
         isoring: &mut IsoRingBuilder,
-    ) -> Result<Line> {
+    ) -> Result<Line<V>> {
         let mut result = isoring.compute(values, threshold)?;
         let mut linestrings = Vec::new();
 
@@ -148,7 +148,7 @@ impl ContourBuilder {
             linestrings.push(LineString(ring));
         });
         Ok(Line {
-            geometry: MultiLineString::<Float>(linestrings),
+            geometry: MultiLineString(linestrings),
             threshold,
         })
     }
@@ -162,7 +162,7 @@ impl ContourBuilder {
     ///
     /// * `values` - The slice of values to be used.
     /// * `thresholds` - The slice of thresholds values to be used.
-    pub fn contours(&self, values: &[Float], thresholds: &[Float]) -> Result<Vec<Contour>> {
+    pub fn contours<V: ContourValue>(&self, values: &[V], thresholds: &[V]) -> Result<Vec<Contour<V>>> {
         if values.len() != self.dx * self.dy {
             return Err(new_error(ErrorKind::BadDimension));
         }
@@ -173,12 +173,12 @@ impl ContourBuilder {
             .collect()
     }
 
-    fn contour(
+    fn contour<V: ContourValue>(
         &self,
-        values: &[Float],
-        threshold: Float,
+        values: &[V],
+        threshold: V,
         isoring: &mut IsoRingBuilder,
-    ) -> Result<Contour> {
+    ) -> Result<Contour<V>> {
         let (mut polygons, mut holes) = (Vec::new(), Vec::new());
         let mut result = isoring.compute(values, threshold)?;
 
@@ -197,7 +197,7 @@ impl ContourBuilder {
                 });
             }
             if area(&ring) > 0.0 {
-                polygons.push(Polygon::<Float>::new(LineString::new(ring), vec![]))
+                polygons.push(Polygon::new(LineString::new(ring), vec![]))
             } else {
                 holes.push(LineString::new(ring));
             }
@@ -213,7 +213,7 @@ impl ContourBuilder {
         });
 
         Ok(Contour {
-            geometry: MultiPolygon::<Float>(polygons),
+            geometry: MultiPolygon(polygons),
             threshold,
         })
     }
@@ -228,7 +228,7 @@ impl ContourBuilder {
     /// * `values` - The slice of values to be used.
     /// * `thresholds` - The slice of thresholds values to be used
     ///                  (have to be equal to or greater than 2).
-    pub fn isobands(&self, values: &[Float], thresholds: &[Float]) -> Result<Vec<Band>> {
+    pub fn isobands<V: ContourValue>(&self, values: &[V], thresholds: &[V]) -> Result<Vec<Band<V>>> {
         // We will compute rings as previously, but we will
         // iterate over the contours in pairs and use the paths from the lower threshold
         // and the path from the upper threshold to create the isoband.
@@ -268,7 +268,7 @@ impl ContourBuilder {
                     .collect::<Vec<Ring>>();
                 Ok((rings, *threshold))
             })
-            .collect::<Result<Vec<(Vec<Ring>, Float)>>>()?;
+            .collect::<Result<Vec<(Vec<Ring>, V)>>>()?;
 
         // We now have the rings for each isolines for all the given thresholds,
         // we can iterate over them in pairs to compute the isobands.
@@ -281,7 +281,7 @@ impl ContourBuilder {
             })
             .collect::<Vec<_>>();
 
-        let mut bands: Vec<Band> = Vec::new();
+        let mut bands: Vec<Band<V>> = Vec::new();
         // Reconstruction of the polygons
         b.into_iter().for_each(|(rings, min_v, max_v)| {
             let mut rings_and_area = rings
@@ -314,7 +314,7 @@ impl ContourBuilder {
 
             for (i, (ring, _)) in rings_and_area.into_iter().enumerate() {
                 if *enclosed_by_n.get(&i).unwrap() % 2 == 0 {
-                    polygons.push(Polygon::<Float>::new(ring.into(), vec![]));
+                    polygons.push(Polygon::new(ring.into(), vec![]));
                 } else {
                     interior_rings.push(ring.into());
                 }
@@ -331,7 +331,7 @@ impl ContourBuilder {
             polygons.reverse();
 
             bands.push(Band {
-                geometry: MultiPolygon::<Float>(polygons),
+                geometry: MultiPolygon(polygons),
                 min_v: *min_v,
                 max_v: *max_v,
             });

src/isoringbuilder.rs

@@ -1,5 +1,6 @@
+use geo_types::{Coord, CoordFloat};
 use crate::error::{new_error, ErrorKind, Result};
-use crate::{Float, Pt, Ring};
+use crate::{ContourValue, Float, Pt, Ring};
 use lazy_static::lazy_static;
 use rustc_hash::FxHashMap;
 use slab::Slab;
@@ -49,12 +50,8 @@ struct Fragment {
 /// * `threshold` - The threshold value.
 /// * `dx` - The number of columns in the grid.
 /// * `dy` - The number of rows in the grid.
-pub fn contour_rings(
-    values: &[Float],
-    threshold: Float,
-    dx: usize,
-    dy: usize,
-) -> Result<Vec<Ring>> {
+
+pub fn contour_rings<V: ContourValue>(values: &[V], threshold: V, dx: usize, dy: usize) -> Result<Vec<Ring>> {
     let mut isoring = IsoRingBuilder::new(dx, dy);
     isoring.compute(values, threshold)
 }
@@ -94,7 +91,7 @@ impl IsoRingBuilder {
     ///
     /// * `values` - The slice of values to be used.
     /// * `threshold` - The threshold value to use.
-    pub fn compute(&mut self, values: &[Float], threshold: Float) -> Result<Vec<Ring>> {
+    pub fn compute<V: ContourValue>(&mut self, values: &[V], threshold: V) -> Result<Vec<Ring>> {
         macro_rules! case_stitch {
             ($ix:expr, $x:ident, $y:ident, $result:expr) => {
                 CASES[$ix]
@@ -177,11 +174,11 @@ impl IsoRingBuilder {
         y: i64,
         result: &mut Vec<Ring>,
     ) -> Result<()> {
-        let start = Pt {
+        let start = Coord {
             x: line[0][0] + x as Float,
             y: line[0][1] + y as Float,
         };
-        let end = Pt {
+        let end = Coord {
             x: line[1][0] + x as Float,
             y: line[1][1] + y as Float,
         };

src/lib.rs

@@ -63,17 +63,19 @@ mod error;
 mod isoringbuilder;
 mod line;
 
+pub trait ContourValue: PartialOrd + Copy + Num + NumCast{}
+impl<T> ContourValue for T where T: PartialOrd + Copy + Num + NumCast {}
+
 #[cfg(feature = "f32")]
 pub type Float = f32;
 #[cfg(not(feature = "f32"))]
 pub type Float = f64;
-#[cfg(feature = "f32")]
-pub type Pt = geo_types::Coord<f32>;
-#[cfg(not(feature = "f32"))]
-pub type Pt = geo_types::Coord;
 
+pub type Pt = geo_types::Coord<Float>;
 pub type Ring = Vec<Pt>;
 
+use geo_types::CoordNum;
+use num_traits::{Num, NumCast};
 pub use crate::band::Band;
 pub use crate::contour::Contour;
 pub use crate::contourbuilder::ContourBuilder;

src/line.rs

@@ -1,26 +1,26 @@
-use crate::Float;
-use geo_types::MultiLineString;
+use crate::{ContourValue, Float};
+use geo_types::{CoordFloat, MultiLineString};
 
 /// A line has the geometry and threshold of a contour ring, built by [`ContourBuilder`].
 #[derive(Debug, Clone)]
-pub struct Line {
+pub struct Line< V: ContourValue> {
     pub(crate) geometry: MultiLineString<Float>,
-    pub(crate) threshold: Float,
+    pub(crate) threshold: V,
 }
 
-impl Line {
+impl<V: ContourValue> Line<V> {
     /// Borrow the [`MultiLineString`](geo_types::MultiLineString) geometry of this contour.
     pub fn geometry(&self) -> &MultiLineString<Float> {
         &self.geometry
     }
 
     /// Get the owned lines and threshold of this contour.
-    pub fn into_inner(self) -> (MultiLineString<Float>, Float) {
+    pub fn into_inner(self) -> (MultiLineString<Float>, V) {
         (self.geometry, self.threshold)
     }
 
     /// Get the threshold used to construct this isoline.
-    pub fn threshold(&self) -> Float {
+    pub fn threshold(&self) -> V {
         self.threshold
     }