Empty segments & points (#1585)

* Made from_points and from_segments return Option

* Updated models

* Fixed doctests

crates/fj/src/group.rs

@@ -10,8 +10,8 @@ use crate::Shape;
 /// Convenient syntax for this operation is available through [`crate::syntax`].
 ///
 /// ``` rust
-/// # let a = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]);
-/// # let b = fj::Sketch::from_points(vec![[2., 0.], [3., 0.], [2., 1.]]);
+/// # let a = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]).unwrap();
+/// # let b = fj::Sketch::from_points(vec![[2., 0.], [3., 0.], [2., 1.]]).unwrap();
 /// use fj::syntax::*;
 ///
 /// // `a` and `b` can be anything that converts to `fj::Shape`

crates/fj/src/shape_2d.rs

@@ -29,8 +29,8 @@ impl Shape2d {
 /// Convenient syntax for this operation is available through [`crate::syntax`].
 ///
 /// ``` rust
-/// # let a = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]);
-/// # let b = fj::Sketch::from_points(vec![[2., 0.], [3., 0.], [2., 1.]]);
+/// # let a = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]).unwrap();
+/// # let b = fj::Sketch::from_points(vec![[2., 0.], [3., 0.], [2., 1.]]).unwrap();
 /// use fj::syntax::*;
 ///
 /// // `a` and `b` can be anything that converts to `fj::Shape2d`
@@ -102,18 +102,28 @@ pub struct Sketch {
 
 impl Sketch {
     /// Create a sketch made of sketch segments
-    pub fn from_segments(segments: Vec<SketchSegment>) -> Self {
-        Self {
-            chain: Chain::PolyChain(PolyChain::from_segments(segments)),
-            color: [255, 0, 0, 255],
+    pub fn from_segments(segments: Vec<SketchSegment>) -> Option<Self> {
+        // TODO Returning an option is just a temporary solution, see: https://github.com/hannobraun/Fornjot/issues/1507
+        if segments.is_empty() {
+            None
+        } else {
+            Some(Self {
+                chain: Chain::PolyChain(PolyChain::from_segments(segments)),
+                color: [255, 0, 0, 255],
+            })
         }
     }
 
     /// Create a sketch made of straight lines from a bunch of points
-    pub fn from_points(points: Vec<[f64; 2]>) -> Self {
-        Self {
-            chain: Chain::PolyChain(PolyChain::from_points(points)),
-            color: [255, 0, 0, 255],
+    pub fn from_points(points: Vec<[f64; 2]>) -> Option<Self> {
+        if points.is_empty() {
+            // TODO Returning an option is just a temporary solution, see: https://github.com/hannobraun/Fornjot/issues/1507
+            None
+        } else {
+            Some(Self {
+                chain: Chain::PolyChain(PolyChain::from_points(points)),
+                color: [255, 0, 0, 255],
+            })
         }
     }
 

crates/fj/src/sweep.rs

@@ -7,7 +7,7 @@ use crate::{Shape, Shape2d};
 /// Convenient syntax for this operation is available through [`crate::syntax`].
 ///
 /// ``` rust
-/// # let shape = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]);
+/// # let shape = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]).unwrap();
 /// use fj::syntax::*;
 ///
 /// // `shape` can be anything that converts to `fj::Shape2d`

crates/fj/src/syntax.rs

@@ -69,7 +69,7 @@ where
     T: AsRef<[[f64; 2]]>,
 {
     fn sketch(&self) -> crate::Sketch {
-        crate::Sketch::from_points(self.as_ref().to_vec())
+        crate::Sketch::from_points(self.as_ref().to_vec()).unwrap()
     }
 }
 

crates/fj/src/transform.rs

@@ -7,7 +7,7 @@ use crate::{Angle, Shape};
 /// Convenient syntax for this operation is available through [`crate::syntax`].
 ///
 /// ``` rust
-/// # let shape = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]);
+/// # let shape = fj::Sketch::from_points(vec![[0., 0.], [1., 0.], [0., 1.]]).unwrap();
 /// use fj::syntax::*;
 ///
 /// // `shape` can be anything that converts to `fj::Shape`

models/cuboid/src/lib.rs

@@ -10,7 +10,7 @@ pub fn model(
         [ x / 2., -y / 2.],
         [ x / 2.,  y / 2.],
         [-x / 2.,  y / 2.],
-    ]).with_color([100,255,0,200]);
+    ]).unwrap().with_color([100,255,0,200]);
 
     let cuboid = fj::Sweep::from_path(rectangle.into(), [0., 0., z]);
 

models/star/src/lib.rs

@@ -29,8 +29,8 @@ pub fn model(
         inner.push([x / 2., y / 2.]);
     }
 
-    let outer = fj::Sketch::from_points(outer);
-    let inner = fj::Sketch::from_points(inner);
+    let outer = fj::Sketch::from_points(outer).unwrap();
+    let inner = fj::Sketch::from_points(inner).unwrap();
 
     let footprint = fj::Difference2d::from_shapes([outer.into(), inner.into()]);
 

models/test/src/lib.rs

@@ -69,8 +69,8 @@ fn star(
         }
     }
 
-    let outer = fj::Sketch::from_segments(outer).with_color(color);
-    let inner = fj::Sketch::from_segments(inner);
+    let outer = fj::Sketch::from_segments(outer).unwrap().with_color(color);
+    let inner = fj::Sketch::from_segments(inner).unwrap();
 
     let footprint = fj::Difference2d::from_shapes([outer.into(), inner.into()]);