1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
//! The rectangle primitive.

mod points;

use crate::{
    geometry::{AnchorPoint, Dimensions, Point, Size},
    primitives::PointsIter,
};
use az::SaturatingAs;
use core::{
    cmp::min,
    ops::{Range, RangeInclusive},
};
pub use points::Points;

/// Rectangle primitive
///
/// # Examples
///
/// ## Create some rectangles with different styles
///
/// ```rust
/// use embedded_graphics::{
///     pixelcolor::Rgb565, prelude::*, primitives::{Rectangle, PrimitiveStyleBuilder},
/// };
/// # use embedded_graphics::mock_display::MockDisplay;
/// # let mut display = MockDisplay::default();
///
/// // Rectangle with red 3 pixel wide stroke and green fill with the top left corner at (30, 20) and
/// // a size of (10, 15)
/// let style = PrimitiveStyleBuilder::new()
///     .stroke_color(Rgb565::RED)
///     .stroke_width(3)
///     .fill_color(Rgb565::GREEN)
///     .build();
///
/// Rectangle::new(Point::new(30, 20), Size::new(10, 15))
///     .into_styled(style)
///     .draw(&mut display)?;
///
/// // Rectangle with translation applied
/// Rectangle::new(Point::new(30, 20), Size::new(10, 15))
///     .translate(Point::new(-20, -10))
///     .into_styled(style)
///     .draw(&mut display)?;
/// # Ok::<(), core::convert::Infallible>(())
/// ```
#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Default)]
pub struct Rectangle {
    /// Top left point of the rectangle.
    pub top_left: Point,

    /// Size of the rectangle.
    pub size: Size,
}

impl Dimensions for Rectangle {
    fn bounding_box(&self) -> Rectangle {
        *self
    }
}

impl PointsIter for Rectangle {
    type Iter = Points;

    fn points(&self) -> Self::Iter {
        self::Points::new(self)
    }
}

/// Returns the center offset.
///
/// The center offset is defined as the offset between the top left corner and
/// the center point of a rectangle with the given size.
fn center_offset(size: Size) -> Size {
    size.saturating_sub(Size::new_equal(1)) / 2
}

impl Rectangle {
    /// Creates a new rectangle from the top left point and the size.
    pub const fn new(top_left: Point, size: Size) -> Self {
        Rectangle { top_left, size }
    }

    /// Creates a new rectangle from two corners.
    pub fn with_corners(corner_1: Point, corner_2: Point) -> Self {
        let left = min(corner_1.x, corner_2.x);
        let top = min(corner_1.y, corner_2.y);

        Rectangle {
            top_left: Point::new(left, top),
            size: Size::from_bounding_box(corner_1, corner_2),
        }
    }

    /// Creates a new rectangle from the center point and the size.
    ///
    /// For rectangles with even width and/or height the top left corner doesn't
    /// align with the pixel grid. Because of this the coordinates of the top left
    /// corner will be rounded up to the nearest integer coordinate.
    pub fn with_center(center: Point, size: Size) -> Self {
        Rectangle {
            top_left: center - center_offset(size),
            size,
        }
    }

    /// Returns a zero sized rectangle.
    pub const fn zero() -> Rectangle {
        Rectangle::new(Point::zero(), Size::zero())
    }

    /// Returns the center of this rectangle.
    ///
    /// For rectangles with even width and/or height the returned value is rounded down
    /// to the nearest integer coordinate.
    pub fn center(&self) -> Point {
        self.top_left + center_offset(self.size)
    }

    /// Returns the bottom right corner of this rectangle.
    ///
    /// Because the smallest rectangle that can be represented by its corners
    /// has a size of 1 x 1 pixels, this function returns `None` if the width or
    /// height of the rectangle is zero.
    pub fn bottom_right(&self) -> Option<Point> {
        if self.size.width > 0 && self.size.height > 0 {
            Some(self.top_left + self.size - Point::new(1, 1))
        } else {
            None
        }
    }

    /// Return whether the rectangle contains a given point.
    pub fn contains(&self, point: Point) -> bool {
        if point.x >= self.top_left.x && point.y >= self.top_left.y {
            self.bottom_right().map_or(false, |bottom_right| {
                point.x <= bottom_right.x && point.y <= bottom_right.y
            })
        } else {
            false
        }
    }

    /// Returns a new `Rectangle` containing the intersection of `self` and `other`.
    ///
    /// If no intersection is present, this method will return a zero sized rectangle.
    ///
    /// # Examples
    ///
    /// ## Intersection
    ///
    /// This example draws two rectangles to a mock display using the `.` character, along with
    /// their intersection shown with `#` characters.
    ///
    /// ```rust
    /// use embedded_graphics::{
    ///     mock_display::MockDisplay, pixelcolor::BinaryColor, prelude::*,
    ///     primitives::{Rectangle, PrimitiveStyle},
    /// };
    ///
    /// let mut display = MockDisplay::new();
    /// # display.set_allow_overdraw(true);
    ///
    /// let rect1 = Rectangle::new(Point::zero(), Size::new(7, 8));
    /// let rect2 = Rectangle::new(Point::new(2, 3), Size::new(10, 7));
    ///
    /// let intersection = rect1.intersection(&rect2);
    ///
    /// rect1
    ///     .into_styled(PrimitiveStyle::with_stroke(BinaryColor::Off, 1))
    ///     .draw(&mut display)?;
    ///
    /// rect2
    ///     .into_styled(PrimitiveStyle::with_stroke(BinaryColor::Off, 1))
    ///     .draw(&mut display)?;
    ///
    /// intersection
    ///     .into_styled(PrimitiveStyle::with_stroke(BinaryColor::On, 1))
    ///     .draw(&mut display)?;
    ///
    /// display.assert_pattern(&[
    ///     ".......     ",
    ///     ".     .     ",
    ///     ".     .     ",
    ///     ". #####.....",
    ///     ". #   #    .",
    ///     ". #   #    .",
    ///     ". #   #    .",
    ///     "..#####    .",
    ///     "  .        .",
    ///     "  ..........",
    /// ]);
    /// # Ok::<(), core::convert::Infallible>(())
    /// ```
    ///
    /// ## No intersection
    ///
    /// This example creates two rectangles with no intersection between them. In this case,
    /// `intersection` returns a zero-sized rectangle.
    ///
    /// ```rust
    /// use embedded_graphics::{prelude::*, primitives::{Rectangle, PrimitiveStyle}};
    ///
    /// let rect1 = Rectangle::new(Point::zero(), Size::new(7, 8));
    /// let rect2 = Rectangle::new(Point::new(10, 15), Size::new(10, 7));
    ///
    /// let intersection = rect1.intersection(&rect2);
    ///
    /// assert!(intersection.is_zero_sized());
    /// # Ok::<(), core::convert::Infallible>(())
    /// ```
    pub fn intersection(&self, other: &Rectangle) -> Rectangle {
        match (other.bottom_right(), self.bottom_right()) {
            (Some(other_bottom_right), Some(self_bottom_right)) => {
                if overlaps(
                    self.top_left.x..=self_bottom_right.x,
                    other.top_left.x..=other_bottom_right.x,
                ) && overlaps(
                    self.top_left.y..=self_bottom_right.y,
                    other.top_left.y..=other_bottom_right.y,
                ) {
                    return Rectangle::with_corners(
                        self.top_left.component_max(other.top_left),
                        self_bottom_right.component_min(other_bottom_right),
                    );
                }
            }
            (Some(_other_bottom_right), None) => {
                // Check if zero sized self is inside other
                if other.contains(self.top_left) {
                    return *self;
                }
            }
            (None, Some(_self_bottom_right)) => {
                // Check if zero sized other is inside self
                if self.contains(other.top_left) {
                    return *other;
                }
            }
            (None, None) => (),
        };

        // No overlap present
        Rectangle::zero()
    }

    /// Returns a resized copy of this rectangle.
    ///
    /// The rectangle is resized relative to the given anchor point.
    ///
    /// # Examples
    ///
    /// ```
    /// use embedded_graphics::{
    ///     prelude::*,
    ///     primitives::rectangle::Rectangle,
    ///     geometry::AnchorPoint,
    /// };
    ///
    /// let rect = Rectangle::new(Point::new(20, 20), Size::new(10, 20));
    /// let resized = rect.resized(Size::new(20, 10), AnchorPoint::Center);
    ///
    /// assert_eq!(
    ///     resized,
    ///     Rectangle::new(Point::new(15, 25), Size::new(20, 10))
    /// );
    /// ```
    pub fn resized(&self, size: Size, anchor_point: AnchorPoint) -> Self {
        // Assume size = 1 for zero sized dimensions.
        let one = Size::new_equal(1);
        let delta = Point::zero() + self.size.component_max(one) - size.component_max(one);

        let top_left = self.top_left
            + match anchor_point {
                AnchorPoint::TopLeft => Point::zero(),
                AnchorPoint::TopCenter => delta.x_axis() / 2,
                AnchorPoint::TopRight => delta.x_axis(),
                AnchorPoint::CenterLeft => delta.y_axis() / 2,
                AnchorPoint::Center => delta / 2,
                AnchorPoint::CenterRight => Point::new(delta.x, delta.y / 2),
                AnchorPoint::BottomLeft => delta.y_axis(),
                AnchorPoint::BottomCenter => Point::new(delta.x / 2, delta.y),
                AnchorPoint::BottomRight => delta,
            };

        Self::new(top_left, size)
    }

    /// Offset the rectangle by a given value.
    ///
    /// Negative values will shrink the rectangle.
    pub fn offset(&self, offset: i32) -> Self {
        let size = if offset >= 0 {
            self.size.saturating_add(Size::new_equal(offset as u32 * 2))
        } else {
            self.size
                .saturating_sub(Size::new_equal((-offset) as u32 * 2))
        };

        Self::with_center(self.center(), size)
    }

    /// Returns an anchor point.
    ///
    /// # Examples
    /// ```
    /// use embedded_graphics::{
    ///     prelude::*,
    ///     primitives::rectangle::Rectangle,
    ///     geometry::AnchorPoint,
    /// };
    ///
    /// let mut rect = Rectangle::new(Point::new(20, 20), Size::new(11, 21));
    ///
    /// assert_eq!(rect.anchor_point(AnchorPoint::TopLeft), Point::new(20, 20));
    /// assert_eq!(
    ///     rect.anchor_point(AnchorPoint::BottomCenter),
    ///     Point::new(25, 40)
    /// );
    /// ```
    pub fn anchor_point(&self, anchor_point: AnchorPoint) -> Point {
        // Assume size = 1 for zero sized dimensions.
        let one = Size::new_equal(1);
        let delta = Point::zero() + self.size.component_max(one) - one;

        self.top_left
            + match anchor_point {
                AnchorPoint::TopLeft => Point::zero(),
                AnchorPoint::TopCenter => delta.x_axis() / 2,
                AnchorPoint::TopRight => delta.x_axis(),
                AnchorPoint::CenterLeft => delta.y_axis() / 2,
                AnchorPoint::Center => delta / 2,
                AnchorPoint::CenterRight => Point::new(delta.x, delta.y / 2),
                AnchorPoint::BottomLeft => delta.y_axis(),
                AnchorPoint::BottomCenter => Point::new(delta.x / 2, delta.y),
                AnchorPoint::BottomRight => delta,
            }
    }

    /// Returns the range of Y coordinates in this rectangle.
    ///
    /// # Examples
    ///
    /// ```
    /// use embedded_graphics::{prelude::*, primitives::Rectangle};
    ///
    /// let rect = Rectangle::new(Point::new(10, 20), Size::new(3, 4));
    /// assert_eq!(rect.rows(), 20..24);
    /// ```
    ///
    /// By combining this method with [`columns`] it is possible to iterate over all pixels inside
    /// the rectangle. This can be more flexible than using the [`points`] iterator, for example,
    /// if a different iteration order is required or some operations should be called once per row.
    ///
    /// ```
    /// use embedded_graphics::{prelude::*, primitives::Rectangle};
    ///
    /// let rect = Rectangle::new(Point::new(10, 20), Size::new(3, 4));
    ///
    /// // Iterate over the y coordinates of the rows in reverse order.
    /// for y in rect.rows().rev() {
    ///     for x in rect.columns() {
    ///         // use x, y coordinates
    ///     }
    /// }
    /// ```
    ///
    /// [`columns`]: #method.columns
    /// [`points`]: ../trait.PointsIter.html#tymethod.points
    pub fn rows(&self) -> Range<i32> {
        self.top_left.y
            ..self
                .top_left
                .y
                .saturating_add(self.size.height.saturating_as())
    }

    /// Returns the range of X coordinates in this rectangle.
    ///
    /// # Examples
    ///
    /// ```
    /// use embedded_graphics::{prelude::*, primitives::Rectangle};
    ///
    /// let rect = Rectangle::new(Point::new(10, 20), Size::new(3, 4));
    ///
    /// assert_eq!(rect.columns(), 10..13);
    /// ```
    ///
    /// By combining this method with [`rows`] it is possible to iterator over all pixels inside
    /// the rectangle. This can be more flexible than using the [`points`] iterator, for example,
    /// if a different iteration order is required or some operations should be called once per row.
    ///
    /// ```
    /// use embedded_graphics::{prelude::*, primitives::Rectangle};
    ///
    /// let rect = Rectangle::new(Point::new(10, 20), Size::new(3, 4));
    ///
    /// // Iterate over all points starting from the top right corner and advancing downwards.
    /// for x in rect.columns().rev() {
    ///     for y in rect.rows() {
    ///         // use x, y coordinates
    ///     }
    /// }
    /// ```
    ///
    /// [`rows`]: #method.rows
    /// [`points`]: ../trait.PointsIter.html#tymethod.points
    pub fn columns(&self) -> Range<i32> {
        self.top_left.x
            ..self
                .top_left
                .x
                .saturating_add(self.size.width.saturating_as())
    }

    /// Returns `true` is the rectangle is zero sized.
    ///
    /// A rectangle is zero sized if the width or height are zero.
    ///
    /// # Examples
    /// ```
    /// use embedded_graphics::{prelude::*, primitives::Rectangle};
    ///
    /// let rect = Rectangle::new(Point::new(10, 20), Size::new(10, 20));
    /// assert_eq!(rect.is_zero_sized(), false);
    ///
    /// let rect = Rectangle::new(Point::new(10, 20), Size::zero());
    /// assert_eq!(rect.is_zero_sized(), true);
    /// ```
    // MSRV: Add const when upgrading to at least 1.46.0
    pub fn is_zero_sized(&self) -> bool {
        self.size.height == 0 || self.size.width == 0
    }
}

/// Checks if the two ranges overlap.
fn overlaps(first: RangeInclusive<i32>, second: RangeInclusive<i32>) -> bool {
    second.contains(first.start())
        || second.contains(first.end())
        || first.start() < second.start() && first.end() > second.end()
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::geometry::{Dimensions, Point, Size};

    #[test]
    fn dimensions() {
        let rect = Rectangle::new(Point::new(5, 10), Size::new(10, 20));

        assert_eq!(
            rect.bounding_box(),
            Rectangle::new(Point::new(5, 10), Size::new(10, 20))
        );
    }

    #[test]
    fn center() {
        let odd = Rectangle::new(Point::new(10, 20), Size::new(5, 7));
        assert_eq!(odd.center(), Point::new(12, 23));

        let even = Rectangle::new(Point::new(20, 30), Size::new(4, 8));
        assert_eq!(even.center(), Point::new(21, 33));
    }

    #[test]
    fn bottom_right() {
        let zero = Rectangle::new(Point::new(10, 20), Size::zero());
        assert_eq!(zero.bottom_right(), None);

        let odd = Rectangle::new(Point::new(10, 20), Size::new(5, 7));
        assert_eq!(odd.bottom_right(), Some(Point::new(14, 26)));

        let even = Rectangle::new(Point::new(20, 30), Size::new(4, 8));
        assert_eq!(even.bottom_right(), Some(Point::new(23, 37)));
    }

    #[test]
    fn rectangle_intersection() {
        let rect1 = Rectangle::new(Point::new_equal(10), Size::new(20, 30));
        let rect2 = Rectangle::new(Point::new_equal(25), Size::new(30, 40));

        assert_eq!(
            rect1.intersection(&rect2),
            Rectangle::new(Point::new_equal(25), Size::new(5, 15))
        );
    }

    #[test]
    fn rectangle_no_intersection() {
        let rect1 = Rectangle::new(Point::new_equal(10), Size::new(20, 30));
        let rect2 = Rectangle::new(Point::new_equal(35), Size::new(30, 40));

        assert_eq!(
            rect1.intersection(&rect2),
            Rectangle::new(Point::zero(), Size::zero())
        );
    }

    #[test]
    fn rectangle_complete_intersection() {
        let rect1 = Rectangle::new(Point::new_equal(10), Size::new(20, 30));
        let rect2 = rect1;

        assert_eq!(rect1.intersection(&rect2), rect1);
    }

    #[test]
    fn rectangle_contained_intersection() {
        let rect1 = Rectangle::with_corners(Point::new_equal(10), Point::new(20, 30));
        let rect2 = Rectangle::with_corners(Point::new_equal(5), Point::new(30, 40));

        assert_eq!(rect1.intersection(&rect2), rect1);
    }

    #[test]
    fn zero_sized_intersection() {
        let rect1 = Rectangle::new(Point::new(1, 2), Size::new(0, 0));
        let rect2 = Rectangle::new(Point::new(-10, -10), Size::new(20, 20));

        assert_eq!(rect1.intersection(&rect2), rect1);

        let rect1 = Rectangle::new(Point::new(-10, -10), Size::new(20, 20));
        let rect2 = Rectangle::new(Point::new(2, 3), Size::new(0, 0));

        assert_eq!(rect1.intersection(&rect2), rect2);
    }

    /// Test for issue #452
    ///
    /// Rectangles can intersect even if no corner of any rectangle is contained inside the other
    /// rectangle.
    ///
    /// Example:
    ///
    ///     ****
    ///     *  *
    /// ############
    /// #   *  *   #
    /// #   *  *   #
    /// ############
    ///     *  *
    ///     ****
    #[test]
    fn issue_452_broken_intersection_check() {
        let rect1 = Rectangle::new(Point::new(50, 0), Size::new(75, 200));
        let rect2 = Rectangle::new(Point::new(0, 75), Size::new(200, 50));

        let expected = Rectangle::new(Point::new(50, 75), Size::new(75, 50));

        assert_eq!(rect1.intersection(&rect2), expected);
        assert_eq!(rect2.intersection(&rect1), expected);
    }

    #[test]
    fn offset() {
        let center = Point::new(10, 20);
        let rect = Rectangle::with_center(center, Size::new(3, 4));

        assert_eq!(rect.offset(0), rect);

        assert_eq!(
            rect.offset(1),
            Rectangle::with_center(center, Size::new(5, 6))
        );
        assert_eq!(
            rect.offset(2),
            Rectangle::with_center(center, Size::new(7, 8))
        );

        assert_eq!(
            rect.offset(-1),
            Rectangle::with_center(center, Size::new(1, 2))
        );
        assert_eq!(
            rect.offset(-2),
            Rectangle::with_center(center, Size::new(0, 0))
        );
        assert_eq!(
            rect.offset(-3),
            Rectangle::with_center(center, Size::new(0, 0))
        );
    }

    #[test]
    fn resized_smaller() {
        let rect = Rectangle::new(Point::new(10, 20), Size::new(30, 40));

        for &(anchor_point, expected_top_left) in &[
            (AnchorPoint::TopLeft, Point::new(10, 20)),
            (AnchorPoint::TopCenter, Point::new(20, 20)),
            (AnchorPoint::TopRight, Point::new(30, 20)),
            (AnchorPoint::CenterLeft, Point::new(10, 30)),
            (AnchorPoint::Center, Point::new(20, 30)),
            (AnchorPoint::CenterRight, Point::new(30, 30)),
            (AnchorPoint::BottomLeft, Point::new(10, 40)),
            (AnchorPoint::BottomCenter, Point::new(20, 40)),
            (AnchorPoint::BottomRight, Point::new(30, 40)),
        ] {
            let resized = rect.resized(Size::new(10, 20), anchor_point);

            assert_eq!(
                resized,
                Rectangle::new(expected_top_left, Size::new(10, 20)),
                "{:?}",
                anchor_point,
            );
        }
    }

    #[test]
    fn resized_larger() {
        let rect = Rectangle::new(Point::new(10, 20), Size::new(30, 40));

        for &(anchor_point, expected_top_left) in &[
            (AnchorPoint::TopLeft, Point::new(10, 20)),
            (AnchorPoint::TopCenter, Point::new(5, 20)),
            (AnchorPoint::TopRight, Point::new(0, 20)),
            (AnchorPoint::CenterLeft, Point::new(10, 15)),
            (AnchorPoint::Center, Point::new(5, 15)),
            (AnchorPoint::CenterRight, Point::new(0, 15)),
            (AnchorPoint::BottomLeft, Point::new(10, 10)),
            (AnchorPoint::BottomCenter, Point::new(5, 10)),
            (AnchorPoint::BottomRight, Point::new(0, 10)),
        ] {
            let resized = rect.resized(Size::new(40, 50), anchor_point);

            assert_eq!(
                resized,
                Rectangle::new(expected_top_left, Size::new(40, 50)),
                "{:?}",
                anchor_point,
            );
        }
    }

    #[test]
    fn resized_zero_sized() {
        let rect = Rectangle::new(Point::new(10, 20), Size::zero());

        for &(anchor_point, expected_top_left) in &[
            (AnchorPoint::TopLeft, Point::new(10, 20)),
            (AnchorPoint::TopCenter, Point::new(8, 20)),
            (AnchorPoint::TopRight, Point::new(6, 20)),
            (AnchorPoint::CenterLeft, Point::new(10, 17)),
            (AnchorPoint::Center, Point::new(8, 17)),
            (AnchorPoint::CenterRight, Point::new(6, 17)),
            (AnchorPoint::BottomLeft, Point::new(10, 14)),
            (AnchorPoint::BottomCenter, Point::new(8, 14)),
            (AnchorPoint::BottomRight, Point::new(6, 14)),
        ] {
            let resized = rect.resized(Size::new(5, 7), anchor_point);

            assert_eq!(
                resized,
                Rectangle::new(expected_top_left, Size::new(5, 7)),
                "{:?}",
                anchor_point,
            );
        }
    }

    #[test]
    fn resized_to_zero_sized() {
        let rect = Rectangle::new(Point::new(10, 20), Size::new(21, 31));

        for &(anchor_point, expected_top_left) in &[
            (AnchorPoint::TopLeft, Point::new(10, 20)),
            (AnchorPoint::TopCenter, Point::new(20, 20)),
            (AnchorPoint::TopRight, Point::new(30, 20)),
            (AnchorPoint::CenterLeft, Point::new(10, 35)),
            (AnchorPoint::Center, Point::new(20, 35)),
            (AnchorPoint::CenterRight, Point::new(30, 35)),
            (AnchorPoint::BottomLeft, Point::new(10, 50)),
            (AnchorPoint::BottomCenter, Point::new(20, 50)),
            (AnchorPoint::BottomRight, Point::new(30, 50)),
        ] {
            let resized = rect.resized(Size::zero(), anchor_point);

            assert_eq!(
                resized,
                Rectangle::new(expected_top_left, Size::zero()),
                "{:?}",
                anchor_point,
            );
        }
    }

    #[test]
    fn anchor_point() {
        let rect = Rectangle::new(Point::new(10, 20), Size::new(21, 31));

        for &(anchor_point, expected) in &[
            (AnchorPoint::TopLeft, Point::new(10, 20)),
            (AnchorPoint::TopCenter, Point::new(20, 20)),
            (AnchorPoint::TopRight, Point::new(30, 20)),
            (AnchorPoint::CenterLeft, Point::new(10, 35)),
            (AnchorPoint::Center, Point::new(20, 35)),
            (AnchorPoint::CenterRight, Point::new(30, 35)),
            (AnchorPoint::BottomLeft, Point::new(10, 50)),
            (AnchorPoint::BottomCenter, Point::new(20, 50)),
            (AnchorPoint::BottomRight, Point::new(30, 50)),
        ] {
            assert_eq!(
                rect.anchor_point(anchor_point),
                expected,
                "{:?}",
                anchor_point,
            );
        }
    }

    #[test]
    fn rows_and_columns_zero_sized() {
        let rect = Rectangle::zero();

        assert_eq!(
            rect.rows().next(),
            None,
            "the rows iterator for a zero sized rectangle shouldn't return any items"
        );

        assert_eq!(
            rect.columns().next(),
            None,
            "the columns iterator for a zero sized rectangle shouldn't return any items"
        );
    }
}