Проектная работа - WIP

snake-game/src/gameplay.rs

@@ -83,6 +83,40 @@ fn find_grid_bound(old: f32, new: f32, grid: f32) -> f32 {
     }
 }
 
+/// Разбиение изменения координаты по границам сетки
+fn split_by_grid(src: f32, dst: f32, grid: f32) -> Vec<(f32, f32)> {
+    if grid <= 0.0 {
+        return Vec::default();
+    };
+
+    let old_grid = src / grid;
+    let new_grid = dst / grid;
+
+    let old_grid_right = old_grid.ceil();
+    let new_grid_right = new_grid.ceil();
+
+    let mut output = Vec::with_capacity(2);
+    if src < dst {
+        let mut src: f32 = src;
+        for step in old_grid_right as i32..new_grid_right as i32 {
+            let step = step as f32 * grid;
+            output.push((step, step - src));
+            src = step;
+        }
+        output.push((dst, dst - src));
+    } else {
+        let mut dst: f32 = dst;
+        for step in new_grid_right as i32..old_grid_right as i32 {
+            let step = step as f32 * grid;
+            output.push((dst, dst - step));
+            dst = step;
+        }
+        output.push((dst, dst - src));
+        output.reverse();
+    }
+    output
+}
+
 #[cfg(test)]
 mod test {
     use crate::gameplay::*;
@@ -126,4 +160,51 @@ mod test {
         assert!(find_grid_bound(1.0, 2.0, -0.0).is_nan());
         assert!(find_grid_bound(1.0, 2.0, -0.1).is_nan());
     }
+
+    #[test]
+    fn test_split_by_grid() {
+        // движение вправо
+        assert_eq!(split_by_grid(1.0, 4.0, 5.0), vec![(4.0, 3.0)]);
+        assert_eq!(split_by_grid(3.0, 5.0, 5.0), vec![(5.0, 2.0)]);
+        assert_eq!(split_by_grid(3.0, 6.0, 5.0), vec![(5.0, 2.0), (6.0, 1.0)]);
+        assert_eq!(split_by_grid(3.0, 10.0, 5.0), vec![(5.0, 2.0), (10.0, 5.0)]);
+        assert_eq!(
+            split_by_grid(3.0, 11.0, 5.0),
+            vec![(5.0, 2.0), (10.0, 5.0), (11.0, 1.0)]
+        );
+        assert_eq!(split_by_grid(-2.0, 3.0, 5.0), vec![(0.0, 2.0), (3.0, 3.0)]);
+        assert_eq!(
+            split_by_grid(-6.0, 7.0, 5.0),
+            vec![(-5.0, 1.0), (0.0, 5.0), (5.0, 5.0), (7.0, 2.0)]
+        );
+        assert_eq!(
+            split_by_grid(-6.0, -2.0, 5.0),
+            vec![(-5.0, 1.0), (-2.0, 3.0)]
+        );
+
+        // движение влево
+        assert_eq!(split_by_grid(4.0, 1.0, 5.0), vec![(1.0, -3.0)]);
+        assert_eq!(split_by_grid(5.0, 3.0, 5.0), vec![(3.0, -2.0)]);
+        assert_eq!(split_by_grid(6.0, 3.0, 5.0), vec![(5.0, -1.0), (3.0, -2.0)]);
+        assert_eq!(
+            split_by_grid(10.0, 3.0, 5.0),
+            vec![(5.0, -5.0), (3.0, -2.0)]
+        );
+        assert_eq!(
+            split_by_grid(11.0, 3.0, 5.0),
+            vec![(10.0, -1.0), (5.0, -5.0), (3.0, -2.0)]
+        );
+        assert_eq!(
+            split_by_grid(3.0, -2.0, 5.0),
+            vec![(0.0, -3.0), (-2.0, -2.0)]
+        );
+        assert_eq!(
+            split_by_grid(7.0, -6.0, 5.0),
+            vec![(5.0, -2.0), (0.0, -5.0), (-5.0, -5.0), (-6.0, -1.0)]
+        );
+        assert_eq!(
+            split_by_grid(-2.0, -6.0, 5.0),
+            vec![(-5.0, -3.0), (-6.0, -1.0)]
+        );
+    }
 }

snake-game/tests/rust_learning.rs

@@ -36,3 +36,10 @@ fn test_floor() {
 fn test_zero() {
     dbg!(-0.0_f32 == 0.0_f32);
 }
+
+#[test]
+fn test_ranges() {
+    for x in 0..5 {
+        dbg!(x);
+    }
+}