Vendor dependencies

Let's see how I like this workflow.

vendor/cassowary/tests/quadrilateral.rs

@@ -0,0 +1,106 @@
+extern crate cassowary;
+use cassowary::{ Solver, Variable };
+use cassowary::WeightedRelation::*;
+
+mod common;
+use common::new_values;
+
+#[test]
+fn test_quadrilateral() {
+    use cassowary::strength::{WEAK, STRONG, REQUIRED};
+    struct Point {
+        x: Variable,
+        y: Variable
+    }
+    impl Point {
+        fn new() -> Point {
+            Point {
+                x: Variable::new(),
+                y: Variable::new()
+            }
+        }
+    }
+    let (value_of, update_values) = new_values();
+
+    let points = [Point::new(),
+                  Point::new(),
+                  Point::new(),
+                  Point::new()];
+    let point_starts = [(10.0, 10.0), (10.0, 200.0), (200.0, 200.0), (200.0, 10.0)];
+    let midpoints = [Point::new(),
+                     Point::new(),
+                     Point::new(),
+                     Point::new()];
+    let mut solver = Solver::new();
+    let mut weight = 1.0;
+    let multiplier = 2.0;
+    for i in 0..4 {
+        solver.add_constraints(&[points[i].x |EQ(WEAK * weight)| point_starts[i].0,
+                                 points[i].y |EQ(WEAK * weight)| point_starts[i].1])
+            .unwrap();
+        weight *= multiplier;
+    }
+
+    for (start, end) in vec![(0, 1), (1, 2), (2, 3), (3, 0)] {
+        solver.add_constraints(&[midpoints[start].x |EQ(REQUIRED)| (points[start].x + points[end].x) / 2.0,
+                                 midpoints[start].y |EQ(REQUIRED)| (points[start].y + points[end].y) / 2.0])
+            .unwrap();
+    }
+
+    solver.add_constraints(&[points[0].x + 20.0 |LE(STRONG)| points[2].x,
+                             points[0].x + 20.0 |LE(STRONG)| points[3].x,
+
+                             points[1].x + 20.0 |LE(STRONG)| points[2].x,
+                             points[1].x + 20.0 |LE(STRONG)| points[3].x,
+
+                             points[0].y + 20.0 |LE(STRONG)| points[1].y,
+                             points[0].y + 20.0 |LE(STRONG)| points[2].y,
+
+                             points[3].y + 20.0 |LE(STRONG)| points[1].y,
+                             points[3].y + 20.0 |LE(STRONG)| points[2].y])
+        .unwrap();
+
+    for point in &points {
+        solver.add_constraints(&[point.x |GE(REQUIRED)| 0.0,
+                                 point.y |GE(REQUIRED)| 0.0,
+
+                                 point.x |LE(REQUIRED)| 500.0,
+                                 point.y |LE(REQUIRED)| 500.0]).unwrap()
+    }
+
+    update_values(solver.fetch_changes());
+
+    assert_eq!([(value_of(midpoints[0].x), value_of(midpoints[0].y)),
+                (value_of(midpoints[1].x), value_of(midpoints[1].y)),
+                (value_of(midpoints[2].x), value_of(midpoints[2].y)),
+                (value_of(midpoints[3].x), value_of(midpoints[3].y))],
+               [(10.0, 105.0),
+                (105.0, 200.0),
+                (200.0, 105.0),
+                (105.0, 10.0)]);
+
+    solver.add_edit_variable(points[2].x, STRONG).unwrap();
+    solver.add_edit_variable(points[2].y, STRONG).unwrap();
+    solver.suggest_value(points[2].x, 300.0).unwrap();
+    solver.suggest_value(points[2].y, 400.0).unwrap();
+
+    update_values(solver.fetch_changes());
+
+    assert_eq!([(value_of(points[0].x), value_of(points[0].y)),
+                (value_of(points[1].x), value_of(points[1].y)),
+                (value_of(points[2].x), value_of(points[2].y)),
+                (value_of(points[3].x), value_of(points[3].y))],
+               [(10.0, 10.0),
+                (10.0, 200.0),
+                (300.0, 400.0),
+                (200.0, 10.0)]);
+
+    assert_eq!([(value_of(midpoints[0].x), value_of(midpoints[0].y)),
+                (value_of(midpoints[1].x), value_of(midpoints[1].y)),
+                (value_of(midpoints[2].x), value_of(midpoints[2].y)),
+                (value_of(midpoints[3].x), value_of(midpoints[3].y))],
+               [(10.0, 105.0),
+                (155.0, 300.0),
+                (250.0, 205.0),
+                (105.0, 10.0)]);
+}