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
// Copyright 2020 Yevhenii Reizner
//
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

use core::convert::TryFrom;

use crate::{FiniteF32, IntSize, LengthU32, PathBuilder, Point, SaturateRound, Size, Transform};

#[cfg(all(not(feature = "std"), feature = "no-std-float"))]
use crate::NoStdFloat;

/// An integer rectangle.
///
/// # Guarantees
///
/// - Width and height are in 1..=i32::MAX range.
/// - x+width and y+height does not overflow.
#[allow(missing_docs)]
#[derive(Copy, Clone, PartialEq, Debug)]
pub struct IntRect {
    x: i32,
    y: i32,
    width: LengthU32,
    height: LengthU32,
}

impl IntRect {
    /// Creates a new `IntRect`.
    pub fn from_xywh(x: i32, y: i32, width: u32, height: u32) -> Option<Self> {
        x.checked_add(i32::try_from(width).ok()?)?;
        y.checked_add(i32::try_from(height).ok()?)?;

        Some(IntRect {
            x,
            y,
            width: LengthU32::new(width)?,
            height: LengthU32::new(height)?,
        })
    }

    /// Creates a new `IntRect`.
    pub fn from_ltrb(left: i32, top: i32, right: i32, bottom: i32) -> Option<Self> {
        let width = u32::try_from(right.checked_sub(left)?).ok()?;
        let height = u32::try_from(bottom.checked_sub(top)?).ok()?;
        IntRect::from_xywh(left, top, width, height)
    }

    /// Returns rect's X position.
    pub fn x(&self) -> i32 {
        self.x
    }

    /// Returns rect's Y position.
    pub fn y(&self) -> i32 {
        self.y
    }

    /// Returns rect's width.
    pub fn width(&self) -> u32 {
        self.width.get()
    }

    /// Returns rect's height.
    pub fn height(&self) -> u32 {
        self.height.get()
    }

    /// Returns rect's left edge.
    pub fn left(&self) -> i32 {
        self.x
    }

    /// Returns rect's top edge.
    pub fn top(&self) -> i32 {
        self.y
    }

    /// Returns rect's right edge.
    pub fn right(&self) -> i32 {
        // No overflow is guaranteed by constructors.
        self.x + self.width.get() as i32
    }

    /// Returns rect's bottom edge.
    pub fn bottom(&self) -> i32 {
        // No overflow is guaranteed by constructors.
        self.y + self.height.get() as i32
    }

    /// Returns rect's size.
    pub fn size(&self) -> IntSize {
        IntSize::from_wh_safe(self.width, self.height)
    }

    /// Checks that the rect is completely includes `other` Rect.
    pub fn contains(&self, other: &Self) -> bool {
        self.x <= other.x
            && self.y <= other.y
            && self.right() >= other.right()
            && self.bottom() >= other.bottom()
    }

    /// Returns an intersection of two rectangles.
    ///
    /// Returns `None` otherwise.
    pub fn intersect(&self, other: &Self) -> Option<Self> {
        let left = self.x.max(other.x);
        let top = self.y.max(other.y);

        let right = self.right().min(other.right());
        let bottom = self.bottom().min(other.bottom());

        let w = u32::try_from(right.checked_sub(left)?).ok()?;
        let h = u32::try_from(bottom.checked_sub(top)?).ok()?;

        IntRect::from_xywh(left, top, w, h)
    }

    /// Insets the rectangle.
    pub fn inset(&self, dx: i32, dy: i32) -> Option<Self> {
        IntRect::from_ltrb(
            self.left() + dx,
            self.top() + dy,
            self.right() - dx,
            self.bottom() - dy,
        )
    }

    /// Outsets the rectangle.
    pub fn make_outset(&self, dx: i32, dy: i32) -> Option<Self> {
        IntRect::from_ltrb(
            self.left().saturating_sub(dx),
            self.top().saturating_sub(dy),
            self.right().saturating_add(dx),
            self.bottom().saturating_add(dy),
        )
    }

    /// Translates the rect by the specified offset.
    pub fn translate(&self, tx: i32, ty: i32) -> Option<Self> {
        IntRect::from_xywh(self.x() + tx, self.y() + ty, self.width(), self.height())
    }

    /// Translates the rect to the specified position.
    pub fn translate_to(&self, x: i32, y: i32) -> Option<Self> {
        IntRect::from_xywh(x, y, self.width(), self.height())
    }

    /// Converts into `Rect`.
    pub fn to_rect(&self) -> Rect {
        // Can't fail, because `IntRect` is always valid.
        Rect::from_ltrb(
            self.x as f32,
            self.y as f32,
            self.x as f32 + self.width.get() as f32,
            self.y as f32 + self.height.get() as f32,
        )
        .unwrap()
    }
}

#[cfg(test)]
mod int_rect_tests {
    use super::*;

    #[test]
    fn tests() {
        assert_eq!(IntRect::from_xywh(0, 0, 0, 0), None);
        assert_eq!(IntRect::from_xywh(0, 0, 1, 0), None);
        assert_eq!(IntRect::from_xywh(0, 0, 0, 1), None);

        assert_eq!(IntRect::from_xywh(0, 0, u32::MAX, u32::MAX), None);
        assert_eq!(IntRect::from_xywh(0, 0, 1, u32::MAX), None);
        assert_eq!(IntRect::from_xywh(0, 0, u32::MAX, 1), None);

        assert_eq!(IntRect::from_xywh(i32::MAX, 0, 1, 1), None);
        assert_eq!(IntRect::from_xywh(0, i32::MAX, 1, 1), None);

        {
            // No intersection.
            let r1 = IntRect::from_xywh(1, 2, 3, 4).unwrap();
            let r2 = IntRect::from_xywh(11, 12, 13, 14).unwrap();
            assert_eq!(r1.intersect(&r2), None);
        }

        {
            // Second inside the first one.
            let r1 = IntRect::from_xywh(1, 2, 30, 40).unwrap();
            let r2 = IntRect::from_xywh(11, 12, 13, 14).unwrap();
            assert_eq!(r1.intersect(&r2), IntRect::from_xywh(11, 12, 13, 14));
        }

        {
            // Partial overlap.
            let r1 = IntRect::from_xywh(1, 2, 30, 40).unwrap();
            let r2 = IntRect::from_xywh(11, 12, 50, 60).unwrap();
            assert_eq!(r1.intersect(&r2), IntRect::from_xywh(11, 12, 20, 30));
        }
    }
}

/// A rectangle defined by left, top, right and bottom edges.
///
/// Can have zero width and/or height. But not a negative one.
///
/// # Guarantees
///
/// - All values are finite.
/// - Left edge is <= right.
/// - Top edge is <= bottom.
/// - Width and height are <= f32::MAX.
#[allow(missing_docs)]
#[derive(Copy, Clone, PartialEq)]
pub struct Rect {
    left: FiniteF32,
    top: FiniteF32,
    right: FiniteF32,
    bottom: FiniteF32,
}

impl core::fmt::Debug for Rect {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        f.debug_struct("Rect")
            .field("left", &self.left.get())
            .field("top", &self.top.get())
            .field("right", &self.right.get())
            .field("bottom", &self.bottom.get())
            .finish()
    }
}

impl Rect {
    /// Creates new `Rect`.
    pub fn from_ltrb(left: f32, top: f32, right: f32, bottom: f32) -> Option<Self> {
        let left = FiniteF32::new(left)?;
        let top = FiniteF32::new(top)?;
        let right = FiniteF32::new(right)?;
        let bottom = FiniteF32::new(bottom)?;

        if left.get() <= right.get() && top.get() <= bottom.get() {
            // Width and height must not overflow.
            checked_f32_sub(right.get(), left.get())?;
            checked_f32_sub(bottom.get(), top.get())?;

            Some(Rect {
                left,
                top,
                right,
                bottom,
            })
        } else {
            None
        }
    }

    /// Creates new `Rect`.
    pub fn from_xywh(x: f32, y: f32, w: f32, h: f32) -> Option<Self> {
        Rect::from_ltrb(x, y, w + x, h + y)
    }

    /// Returns the left edge.
    pub fn left(&self) -> f32 {
        self.left.get()
    }

    /// Returns the top edge.
    pub fn top(&self) -> f32 {
        self.top.get()
    }

    /// Returns the right edge.
    pub fn right(&self) -> f32 {
        self.right.get()
    }

    /// Returns the bottom edge.
    pub fn bottom(&self) -> f32 {
        self.bottom.get()
    }

    /// Returns rect's X position.
    pub fn x(&self) -> f32 {
        self.left.get()
    }

    /// Returns rect's Y position.
    pub fn y(&self) -> f32 {
        self.top.get()
    }

    /// Returns rect's width.
    #[inline]
    pub fn width(&self) -> f32 {
        self.right.get() - self.left.get()
    }

    /// Returns rect's height.
    #[inline]
    pub fn height(&self) -> f32 {
        self.bottom.get() - self.top.get()
    }

    /// Converts into an `IntRect` by adding 0.5 and discarding the fractional portion.
    ///
    /// Width and height are guarantee to be >= 1.
    pub fn round(&self) -> Option<IntRect> {
        IntRect::from_xywh(
            i32::saturate_round(self.x()),
            i32::saturate_round(self.y()),
            core::cmp::max(1, i32::saturate_round(self.width()) as u32),
            core::cmp::max(1, i32::saturate_round(self.height()) as u32),
        )
    }

    /// Converts into an `IntRect` rounding outwards.
    ///
    /// Width and height are guarantee to be >= 1.
    pub fn round_out(&self) -> Option<IntRect> {
        IntRect::from_xywh(
            i32::saturate_floor(self.x()),
            i32::saturate_floor(self.y()),
            core::cmp::max(1, i32::saturate_ceil(self.width()) as u32),
            core::cmp::max(1, i32::saturate_ceil(self.height()) as u32),
        )
    }

    /// Returns an intersection of two rectangles.
    ///
    /// Returns `None` otherwise.
    pub fn intersect(&self, other: &Self) -> Option<Self> {
        let left = self.x().max(other.x());
        let top = self.y().max(other.y());

        let right = self.right().min(other.right());
        let bottom = self.bottom().min(other.bottom());

        Rect::from_ltrb(left, top, right, bottom)
    }

    /// Creates a Rect from Point array.
    ///
    /// Returns None if count is zero or if Point array contains an infinity or NaN.
    pub fn from_points(points: &[Point]) -> Option<Self> {
        use crate::f32x4_t::f32x4;

        if points.is_empty() {
            return None;
        }

        let mut offset = 0;
        let mut min;
        let mut max;
        if points.len() & 1 != 0 {
            let pt = points[0];
            min = f32x4([pt.x, pt.y, pt.x, pt.y]);
            max = min;
            offset += 1;
        } else {
            let pt0 = points[0];
            let pt1 = points[1];
            min = f32x4([pt0.x, pt0.y, pt1.x, pt1.y]);
            max = min;
            offset += 2;
        }

        let mut accum = f32x4::default();
        while offset != points.len() {
            let pt0 = points[offset + 0];
            let pt1 = points[offset + 1];
            let xy = f32x4([pt0.x, pt0.y, pt1.x, pt1.y]);

            accum *= xy;
            min = min.min(xy);
            max = max.max(xy);
            offset += 2;
        }

        let all_finite = accum * f32x4::default() == f32x4::default();
        let min: [f32; 4] = min.0;
        let max: [f32; 4] = max.0;
        if all_finite {
            Rect::from_ltrb(
                min[0].min(min[2]),
                min[1].min(min[3]),
                max[0].max(max[2]),
                max[1].max(max[3]),
            )
        } else {
            None
        }
    }

    /// Insets the rectangle by the specified offset.
    pub fn inset(&self, dx: f32, dy: f32) -> Option<Self> {
        Rect::from_ltrb(
            self.left() + dx,
            self.top() + dy,
            self.right() - dx,
            self.bottom() - dy,
        )
    }

    /// Outsets the rectangle by the specified offset.
    pub fn outset(&self, dx: f32, dy: f32) -> Option<Self> {
        self.inset(-dx, -dy)
    }

    /// Transforms the rect using the provided `Transform`.
    ///
    /// This method is expensive.
    pub fn transform(&self, ts: Transform) -> Option<Self> {
        if !ts.is_identity() {
            // TODO: remove allocation
            let mut path = PathBuilder::from_rect(*self);
            path = path.transform(ts)?;
            Some(path.bounds())
        } else {
            Some(*self)
        }
    }

    /// Applies a bounding box transform.
    pub fn bbox_transform(&self, bbox: NonZeroRect) -> Self {
        let x = self.x() * bbox.width() + bbox.x();
        let y = self.y() * bbox.height() + bbox.y();
        let w = self.width() * bbox.width();
        let h = self.height() * bbox.height();
        Self::from_xywh(x, y, w, h).unwrap()
    }

    /// Converts into [`NonZeroRect`].
    pub fn to_non_zero_rect(&self) -> Option<NonZeroRect> {
        NonZeroRect::from_xywh(self.x(), self.y(), self.width(), self.height())
    }
}

fn checked_f32_sub(a: f32, b: f32) -> Option<f32> {
    debug_assert!(a.is_finite());
    debug_assert!(b.is_finite());

    let n = a as f64 - b as f64;
    // Not sure if this is perfectly correct.
    if n > f32::MIN as f64 && n < f32::MAX as f64 {
        Some(n as f32)
    } else {
        None
    }
}

#[cfg(test)]
mod rect_tests {
    use super::*;

    #[test]
    fn tests() {
        assert_eq!(Rect::from_ltrb(10.0, 10.0, 5.0, 10.0), None);
        assert_eq!(Rect::from_ltrb(10.0, 10.0, 10.0, 5.0), None);
        assert_eq!(Rect::from_ltrb(f32::NAN, 10.0, 10.0, 10.0), None);
        assert_eq!(Rect::from_ltrb(10.0, f32::NAN, 10.0, 10.0), None);
        assert_eq!(Rect::from_ltrb(10.0, 10.0, f32::NAN, 10.0), None);
        assert_eq!(Rect::from_ltrb(10.0, 10.0, 10.0, f32::NAN), None);
        assert_eq!(Rect::from_ltrb(10.0, 10.0, 10.0, f32::INFINITY), None);

        let rect = Rect::from_ltrb(10.0, 20.0, 30.0, 40.0).unwrap();
        assert_eq!(rect.left(), 10.0);
        assert_eq!(rect.top(), 20.0);
        assert_eq!(rect.right(), 30.0);
        assert_eq!(rect.bottom(), 40.0);
        assert_eq!(rect.width(), 20.0);
        assert_eq!(rect.height(), 20.0);

        let rect = Rect::from_ltrb(-30.0, 20.0, -10.0, 40.0).unwrap();
        assert_eq!(rect.width(), 20.0);
        assert_eq!(rect.height(), 20.0);
    }

    #[test]
    fn round_overflow() {
        // minimum value that cause overflow
        // because i32::MAX has no exact conversion to f32
        let x = 128.0;
        // maximum width
        let width = i32::MAX as f32;

        let rect = Rect::from_xywh(x, 0.0, width, 1.0).unwrap();
        assert_eq!(rect.round(), None);
        assert_eq!(rect.round_out(), None);
    }
}

/// A rectangle defined by left, top, right and bottom edges.
///
/// Similar to [`Rect`], but width and height guarantee to be non-zero and positive.
///
/// # Guarantees
///
/// - All values are finite.
/// - Left edge is < right.
/// - Top edge is < bottom.
/// - Width and height are <= f32::MAX.
/// - Width and height are > 0.0
#[allow(missing_docs)]
#[derive(Copy, Clone, PartialEq)]
pub struct NonZeroRect {
    left: FiniteF32,
    top: FiniteF32,
    right: FiniteF32,
    bottom: FiniteF32,
}

impl core::fmt::Debug for NonZeroRect {
    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
        f.debug_struct("NonZeroRect")
            .field("left", &self.left.get())
            .field("top", &self.top.get())
            .field("right", &self.right.get())
            .field("bottom", &self.bottom.get())
            .finish()
    }
}

impl NonZeroRect {
    /// Creates new `NonZeroRect`.
    pub fn from_ltrb(left: f32, top: f32, right: f32, bottom: f32) -> Option<Self> {
        let left = FiniteF32::new(left)?;
        let top = FiniteF32::new(top)?;
        let right = FiniteF32::new(right)?;
        let bottom = FiniteF32::new(bottom)?;

        if left.get() < right.get() && top.get() < bottom.get() {
            // Width and height must not overflow.
            checked_f32_sub(right.get(), left.get())?;
            checked_f32_sub(bottom.get(), top.get())?;

            Some(Self {
                left,
                top,
                right,
                bottom,
            })
        } else {
            None
        }
    }

    /// Creates new `NonZeroRect`.
    pub fn from_xywh(x: f32, y: f32, w: f32, h: f32) -> Option<Self> {
        Self::from_ltrb(x, y, w + x, h + y)
    }

    /// Returns the left edge.
    pub fn left(&self) -> f32 {
        self.left.get()
    }

    /// Returns the top edge.
    pub fn top(&self) -> f32 {
        self.top.get()
    }

    /// Returns the right edge.
    pub fn right(&self) -> f32 {
        self.right.get()
    }

    /// Returns the bottom edge.
    pub fn bottom(&self) -> f32 {
        self.bottom.get()
    }

    /// Returns rect's X position.
    pub fn x(&self) -> f32 {
        self.left.get()
    }

    /// Returns rect's Y position.
    pub fn y(&self) -> f32 {
        self.top.get()
    }

    /// Returns rect's width.
    pub fn width(&self) -> f32 {
        self.right.get() - self.left.get()
    }

    /// Returns rect's height.
    pub fn height(&self) -> f32 {
        self.bottom.get() - self.top.get()
    }

    /// Returns rect's size.
    pub fn size(&self) -> Size {
        Size::from_wh(self.width(), self.height()).unwrap()
    }

    /// Translates the rect to the specified position.
    pub fn translate_to(&self, x: f32, y: f32) -> Option<Self> {
        Self::from_xywh(x, y, self.width(), self.height())
    }

    /// Transforms the rect using the provided `Transform`.
    ///
    /// This method is expensive.
    pub fn transform(&self, ts: Transform) -> Option<Self> {
        if !ts.is_identity() {
            // TODO: remove allocation
            let mut path = PathBuilder::from_rect(self.to_rect());
            path = path.transform(ts)?;
            path.bounds().to_non_zero_rect()
        } else {
            Some(*self)
        }
    }

    /// Applies a bounding box transform.
    pub fn bbox_transform(&self, bbox: NonZeroRect) -> Self {
        let x = self.x() * bbox.width() + bbox.x();
        let y = self.y() * bbox.height() + bbox.y();
        let w = self.width() * bbox.width();
        let h = self.height() * bbox.height();
        Self::from_xywh(x, y, w, h).unwrap()
    }

    /// Converts into [`Rect`].
    pub fn to_rect(&self) -> Rect {
        Rect::from_xywh(self.x(), self.y(), self.width(), self.height()).unwrap()
    }

    /// Converts into [`IntRect`].
    pub fn to_int_rect(&self) -> IntRect {
        IntRect::from_xywh(
            self.x().floor() as i32,
            self.y().floor() as i32,
            core::cmp::max(1, self.width().ceil() as u32),
            core::cmp::max(1, self.height().ceil() as u32),
        )
        .unwrap()
    }
}