1/*
2 * Copyright 2012 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef SkRRect_DEFINED
9#define SkRRect_DEFINED
10
11#include "include/core/SkPoint.h"
12#include "include/core/SkRect.h"
13#include "include/core/SkScalar.h"
14#include "include/core/SkTypes.h"
15
16#include <cstdint>
17#include <cstring>
18
19class SkMatrix;
20class SkString;
21
22/** \class SkRRect
23 SkRRect describes a rounded rectangle with a bounds and a pair of radii for each corner.
24 The bounds and radii can be set so that SkRRect describes: a rectangle with sharp corners;
25 a circle; an oval; or a rectangle with one or more rounded corners.
26
27 SkRRect allows implementing CSS properties that describe rounded corners.
28 SkRRect may have up to eight different radii, one for each axis on each of its four
29 corners.
30
31 SkRRect may modify the provided parameters when initializing bounds and radii.
32 If either axis radii is zero or less: radii are stored as zero; corner is square.
33 If corner curves overlap, radii are proportionally reduced to fit within bounds.
34*/
35class SK_API SkRRect {
36public:
37
38 /** Initializes bounds at (0, 0), the origin, with zero width and height.
39 Initializes corner radii to (0, 0), and sets type of kEmpty_Type.
40
41 @return empty SkRRect
42 */
43 SkRRect() = default;
44
45 /** Initializes to copy of rrect bounds and corner radii.
46
47 @param rrect bounds and corner to copy
48 @return copy of rrect
49 */
50 SkRRect(const SkRRect& rrect) = default;
51
52 /** Copies rrect bounds and corner radii.
53
54 @param rrect bounds and corner to copy
55 @return copy of rrect
56 */
57 SkRRect& operator=(const SkRRect& rrect) = default;
58
59 /** \enum SkRRect::Type
60 Type describes possible specializations of SkRRect. Each Type is
61 exclusive; a SkRRect may only have one type.
62
63 Type members become progressively less restrictive; larger values of
64 Type have more degrees of freedom than smaller values.
65 */
66 enum Type {
67 kEmpty_Type, //!< zero width or height
68 kRect_Type, //!< non-zero width and height, and zeroed radii
69 kOval_Type, //!< non-zero width and height filled with radii
70 kSimple_Type, //!< non-zero width and height with equal radii
71 kNinePatch_Type, //!< non-zero width and height with axis-aligned radii
72 kComplex_Type, //!< non-zero width and height with arbitrary radii
73 kLastType = kComplex_Type, //!< largest Type value
74 };
75
76 Type getType() const {
77 SkASSERT(this->isValid());
78 return static_cast<Type>(fType);
79 }
80
81 Type type() const { return this->getType(); }
82
83 inline bool isEmpty() const { return kEmpty_Type == this->getType(); }
84 inline bool isRect() const { return kRect_Type == this->getType(); }
85 inline bool isOval() const { return kOval_Type == this->getType(); }
86 inline bool isSimple() const { return kSimple_Type == this->getType(); }
87 inline bool isNinePatch() const { return kNinePatch_Type == this->getType(); }
88 inline bool isComplex() const { return kComplex_Type == this->getType(); }
89
90 /** Returns span on the x-axis. This does not check if result fits in 32-bit float;
91 result may be infinity.
92
93 @return rect().fRight minus rect().fLeft
94 */
95 SkScalar width() const { return fRect.width(); }
96
97 /** Returns span on the y-axis. This does not check if result fits in 32-bit float;
98 result may be infinity.
99
100 @return rect().fBottom minus rect().fTop
101 */
102 SkScalar height() const { return fRect.height(); }
103
104 /** Returns top-left corner radii. If type() returns kEmpty_Type, kRect_Type,
105 kOval_Type, or kSimple_Type, returns a value representative of all corner radii.
106 If type() returns kNinePatch_Type or kComplex_Type, at least one of the
107 remaining three corners has a different value.
108
109 @return corner radii for simple types
110 */
111 SkVector getSimpleRadii() const {
112 return fRadii[0];
113 }
114
115 /** Sets bounds to zero width and height at (0, 0), the origin. Sets
116 corner radii to zero and sets type to kEmpty_Type.
117 */
118 void setEmpty() { *this = SkRRect(); }
119
120 /** Sets bounds to sorted rect, and sets corner radii to zero.
121 If set bounds has width and height, and sets type to kRect_Type;
122 otherwise, sets type to kEmpty_Type.
123
124 @param rect bounds to set
125 */
126 void setRect(const SkRect& rect) {
127 if (!this->initializeRect(rect)) {
128 return;
129 }
130
131 memset(s: fRadii, c: 0, n: sizeof(fRadii));
132 fType = kRect_Type;
133
134 SkASSERT(this->isValid());
135 }
136
137 /** Initializes bounds at (0, 0), the origin, with zero width and height.
138 Initializes corner radii to (0, 0), and sets type of kEmpty_Type.
139
140 @return empty SkRRect
141 */
142 static SkRRect MakeEmpty() { return SkRRect(); }
143
144 /** Initializes to copy of r bounds and zeroes corner radii.
145
146 @param r bounds to copy
147 @return copy of r
148 */
149 static SkRRect MakeRect(const SkRect& r) {
150 SkRRect rr;
151 rr.setRect(r);
152 return rr;
153 }
154
155 /** Sets bounds to oval, x-axis radii to half oval.width(), and all y-axis radii
156 to half oval.height(). If oval bounds is empty, sets to kEmpty_Type.
157 Otherwise, sets to kOval_Type.
158
159 @param oval bounds of oval
160 @return oval
161 */
162 static SkRRect MakeOval(const SkRect& oval) {
163 SkRRect rr;
164 rr.setOval(oval);
165 return rr;
166 }
167
168 /** Sets to rounded rectangle with the same radii for all four corners.
169 If rect is empty, sets to kEmpty_Type.
170 Otherwise, if xRad and yRad are zero, sets to kRect_Type.
171 Otherwise, if xRad is at least half rect.width() and yRad is at least half
172 rect.height(), sets to kOval_Type.
173 Otherwise, sets to kSimple_Type.
174
175 @param rect bounds of rounded rectangle
176 @param xRad x-axis radius of corners
177 @param yRad y-axis radius of corners
178 @return rounded rectangle
179 */
180 static SkRRect MakeRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad) {
181 SkRRect rr;
182 rr.setRectXY(rect, xRad, yRad);
183 return rr;
184 }
185
186 /** Sets bounds to oval, x-axis radii to half oval.width(), and all y-axis radii
187 to half oval.height(). If oval bounds is empty, sets to kEmpty_Type.
188 Otherwise, sets to kOval_Type.
189
190 @param oval bounds of oval
191 */
192 void setOval(const SkRect& oval);
193
194 /** Sets to rounded rectangle with the same radii for all four corners.
195 If rect is empty, sets to kEmpty_Type.
196 Otherwise, if xRad or yRad is zero, sets to kRect_Type.
197 Otherwise, if xRad is at least half rect.width() and yRad is at least half
198 rect.height(), sets to kOval_Type.
199 Otherwise, sets to kSimple_Type.
200
201 @param rect bounds of rounded rectangle
202 @param xRad x-axis radius of corners
203 @param yRad y-axis radius of corners
204
205 example: https://fiddle.skia.org/c/@RRect_setRectXY
206 */
207 void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad);
208
209 /** Sets bounds to rect. Sets radii to (leftRad, topRad), (rightRad, topRad),
210 (rightRad, bottomRad), (leftRad, bottomRad).
211
212 If rect is empty, sets to kEmpty_Type.
213 Otherwise, if leftRad and rightRad are zero, sets to kRect_Type.
214 Otherwise, if topRad and bottomRad are zero, sets to kRect_Type.
215 Otherwise, if leftRad and rightRad are equal and at least half rect.width(), and
216 topRad and bottomRad are equal at least half rect.height(), sets to kOval_Type.
217 Otherwise, if leftRad and rightRad are equal, and topRad and bottomRad are equal,
218 sets to kSimple_Type. Otherwise, sets to kNinePatch_Type.
219
220 Nine patch refers to the nine parts defined by the radii: one center rectangle,
221 four edge patches, and four corner patches.
222
223 @param rect bounds of rounded rectangle
224 @param leftRad left-top and left-bottom x-axis radius
225 @param topRad left-top and right-top y-axis radius
226 @param rightRad right-top and right-bottom x-axis radius
227 @param bottomRad left-bottom and right-bottom y-axis radius
228 */
229 void setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad,
230 SkScalar rightRad, SkScalar bottomRad);
231
232 /** Sets bounds to rect. Sets radii array for individual control of all for corners.
233
234 If rect is empty, sets to kEmpty_Type.
235 Otherwise, if one of each corner radii are zero, sets to kRect_Type.
236 Otherwise, if all x-axis radii are equal and at least half rect.width(), and
237 all y-axis radii are equal at least half rect.height(), sets to kOval_Type.
238 Otherwise, if all x-axis radii are equal, and all y-axis radii are equal,
239 sets to kSimple_Type. Otherwise, sets to kNinePatch_Type.
240
241 @param rect bounds of rounded rectangle
242 @param radii corner x-axis and y-axis radii
243
244 example: https://fiddle.skia.org/c/@RRect_setRectRadii
245 */
246 void setRectRadii(const SkRect& rect, const SkVector radii[4]);
247
248 /** \enum SkRRect::Corner
249 The radii are stored: top-left, top-right, bottom-right, bottom-left.
250 */
251 enum Corner {
252 kUpperLeft_Corner, //!< index of top-left corner radii
253 kUpperRight_Corner, //!< index of top-right corner radii
254 kLowerRight_Corner, //!< index of bottom-right corner radii
255 kLowerLeft_Corner, //!< index of bottom-left corner radii
256 };
257
258 /** Returns bounds. Bounds may have zero width or zero height. Bounds right is
259 greater than or equal to left; bounds bottom is greater than or equal to top.
260 Result is identical to getBounds().
261
262 @return bounding box
263 */
264 const SkRect& rect() const { return fRect; }
265
266 /** Returns scalar pair for radius of curve on x-axis and y-axis for one corner.
267 Both radii may be zero. If not zero, both are positive and finite.
268
269 @return x-axis and y-axis radii for one corner
270 */
271 SkVector radii(Corner corner) const { return fRadii[corner]; }
272
273 /** Returns bounds. Bounds may have zero width or zero height. Bounds right is
274 greater than or equal to left; bounds bottom is greater than or equal to top.
275 Result is identical to rect().
276
277 @return bounding box
278 */
279 const SkRect& getBounds() const { return fRect; }
280
281 /** Returns true if bounds and radii in a are equal to bounds and radii in b.
282
283 a and b are not equal if either contain NaN. a and b are equal if members
284 contain zeroes with different signs.
285
286 @param a SkRect bounds and radii to compare
287 @param b SkRect bounds and radii to compare
288 @return true if members are equal
289 */
290 friend bool operator==(const SkRRect& a, const SkRRect& b) {
291 return a.fRect == b.fRect && SkScalarsEqual(a: &a.fRadii[0].fX, b: &b.fRadii[0].fX, n: 8);
292 }
293
294 /** Returns true if bounds and radii in a are not equal to bounds and radii in b.
295
296 a and b are not equal if either contain NaN. a and b are equal if members
297 contain zeroes with different signs.
298
299 @param a SkRect bounds and radii to compare
300 @param b SkRect bounds and radii to compare
301 @return true if members are not equal
302 */
303 friend bool operator!=(const SkRRect& a, const SkRRect& b) {
304 return a.fRect != b.fRect || !SkScalarsEqual(a: &a.fRadii[0].fX, b: &b.fRadii[0].fX, n: 8);
305 }
306
307 /** Copies SkRRect to dst, then insets dst bounds by dx and dy, and adjusts dst
308 radii by dx and dy. dx and dy may be positive, negative, or zero. dst may be
309 SkRRect.
310
311 If either corner radius is zero, the corner has no curvature and is unchanged.
312 Otherwise, if adjusted radius becomes negative, pins radius to zero.
313 If dx exceeds half dst bounds width, dst bounds left and right are set to
314 bounds x-axis center. If dy exceeds half dst bounds height, dst bounds top and
315 bottom are set to bounds y-axis center.
316
317 If dx or dy cause the bounds to become infinite, dst bounds is zeroed.
318
319 @param dx added to rect().fLeft, and subtracted from rect().fRight
320 @param dy added to rect().fTop, and subtracted from rect().fBottom
321 @param dst insets bounds and radii
322
323 example: https://fiddle.skia.org/c/@RRect_inset
324 */
325 void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const;
326
327 /** Insets bounds by dx and dy, and adjusts radii by dx and dy. dx and dy may be
328 positive, negative, or zero.
329
330 If either corner radius is zero, the corner has no curvature and is unchanged.
331 Otherwise, if adjusted radius becomes negative, pins radius to zero.
332 If dx exceeds half bounds width, bounds left and right are set to
333 bounds x-axis center. If dy exceeds half bounds height, bounds top and
334 bottom are set to bounds y-axis center.
335
336 If dx or dy cause the bounds to become infinite, bounds is zeroed.
337
338 @param dx added to rect().fLeft, and subtracted from rect().fRight
339 @param dy added to rect().fTop, and subtracted from rect().fBottom
340 */
341 void inset(SkScalar dx, SkScalar dy) {
342 this->inset(dx, dy, dst: this);
343 }
344
345 /** Outsets dst bounds by dx and dy, and adjusts radii by dx and dy. dx and dy may be
346 positive, negative, or zero.
347
348 If either corner radius is zero, the corner has no curvature and is unchanged.
349 Otherwise, if adjusted radius becomes negative, pins radius to zero.
350 If dx exceeds half dst bounds width, dst bounds left and right are set to
351 bounds x-axis center. If dy exceeds half dst bounds height, dst bounds top and
352 bottom are set to bounds y-axis center.
353
354 If dx or dy cause the bounds to become infinite, dst bounds is zeroed.
355
356 @param dx subtracted from rect().fLeft, and added to rect().fRight
357 @param dy subtracted from rect().fTop, and added to rect().fBottom
358 @param dst outset bounds and radii
359 */
360 void outset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
361 this->inset(dx: -dx, dy: -dy, dst);
362 }
363
364 /** Outsets bounds by dx and dy, and adjusts radii by dx and dy. dx and dy may be
365 positive, negative, or zero.
366
367 If either corner radius is zero, the corner has no curvature and is unchanged.
368 Otherwise, if adjusted radius becomes negative, pins radius to zero.
369 If dx exceeds half bounds width, bounds left and right are set to
370 bounds x-axis center. If dy exceeds half bounds height, bounds top and
371 bottom are set to bounds y-axis center.
372
373 If dx or dy cause the bounds to become infinite, bounds is zeroed.
374
375 @param dx subtracted from rect().fLeft, and added to rect().fRight
376 @param dy subtracted from rect().fTop, and added to rect().fBottom
377 */
378 void outset(SkScalar dx, SkScalar dy) {
379 this->inset(dx: -dx, dy: -dy, dst: this);
380 }
381
382 /** Translates SkRRect by (dx, dy).
383
384 @param dx offset added to rect().fLeft and rect().fRight
385 @param dy offset added to rect().fTop and rect().fBottom
386 */
387 void offset(SkScalar dx, SkScalar dy) {
388 fRect.offset(dx, dy);
389 }
390
391 /** Returns SkRRect translated by (dx, dy).
392
393 @param dx offset added to rect().fLeft and rect().fRight
394 @param dy offset added to rect().fTop and rect().fBottom
395 @return SkRRect bounds offset by (dx, dy), with unchanged corner radii
396 */
397 [[nodiscard]] SkRRect makeOffset(SkScalar dx, SkScalar dy) const {
398 return SkRRect(fRect.makeOffset(dx, dy), fRadii, fType);
399 }
400
401 /** Returns true if rect is inside the bounds and corner radii, and if
402 SkRRect and rect are not empty.
403
404 @param rect area tested for containment
405 @return true if SkRRect contains rect
406
407 example: https://fiddle.skia.org/c/@RRect_contains
408 */
409 bool contains(const SkRect& rect) const;
410
411 /** Returns true if bounds and radii values are finite and describe a SkRRect
412 SkRRect::Type that matches getType(). All SkRRect methods construct valid types,
413 even if the input values are not valid. Invalid SkRRect data can only
414 be generated by corrupting memory.
415
416 @return true if bounds and radii match type()
417
418 example: https://fiddle.skia.org/c/@RRect_isValid
419 */
420 bool isValid() const;
421
422 static constexpr size_t kSizeInMemory = 12 * sizeof(SkScalar);
423
424 /** Writes SkRRect to buffer. Writes kSizeInMemory bytes, and returns
425 kSizeInMemory, the number of bytes written.
426
427 @param buffer storage for SkRRect
428 @return bytes written, kSizeInMemory
429
430 example: https://fiddle.skia.org/c/@RRect_writeToMemory
431 */
432 size_t writeToMemory(void* buffer) const;
433
434 /** Reads SkRRect from buffer, reading kSizeInMemory bytes.
435 Returns kSizeInMemory, bytes read if length is at least kSizeInMemory.
436 Otherwise, returns zero.
437
438 @param buffer memory to read from
439 @param length size of buffer
440 @return bytes read, or 0 if length is less than kSizeInMemory
441
442 example: https://fiddle.skia.org/c/@RRect_readFromMemory
443 */
444 size_t readFromMemory(const void* buffer, size_t length);
445
446 /** Transforms by SkRRect by matrix, storing result in dst.
447 Returns true if SkRRect transformed can be represented by another SkRRect.
448 Returns false if matrix contains transformations that are not axis aligned.
449
450 Asserts in debug builds if SkRRect equals dst.
451
452 @param matrix SkMatrix specifying the transform
453 @param dst SkRRect to store the result
454 @return true if transformation succeeded.
455
456 example: https://fiddle.skia.org/c/@RRect_transform
457 */
458 bool transform(const SkMatrix& matrix, SkRRect* dst) const;
459
460 /** Writes text representation of SkRRect to standard output.
461 Set asHex true to generate exact binary representations
462 of floating point numbers.
463
464 @param asHex true if SkScalar values are written as hexadecimal
465
466 example: https://fiddle.skia.org/c/@RRect_dump
467 */
468 void dump(bool asHex) const;
469 SkString dumpToString(bool asHex) const;
470
471 /** Writes text representation of SkRRect to standard output. The representation
472 may be directly compiled as C++ code. Floating point values are written
473 with limited precision; it may not be possible to reconstruct original
474 SkRRect from output.
475 */
476 void dump() const { this->dump(asHex: false); }
477
478 /** Writes text representation of SkRRect to standard output. The representation
479 may be directly compiled as C++ code. Floating point values are written
480 in hexadecimal to preserve their exact bit pattern. The output reconstructs the
481 original SkRRect.
482 */
483 void dumpHex() const { this->dump(asHex: true); }
484
485private:
486 static bool AreRectAndRadiiValid(const SkRect&, const SkVector[4]);
487
488 SkRRect(const SkRect& rect, const SkVector radii[4], int32_t type)
489 : fRect(rect)
490 , fRadii{radii[0], radii[1], radii[2], radii[3]}
491 , fType(type) {}
492
493 /**
494 * Initializes fRect. If the passed in rect is not finite or empty the rrect will be fully
495 * initialized and false is returned. Otherwise, just fRect is initialized and true is returned.
496 */
497 bool initializeRect(const SkRect&);
498
499 void computeType();
500 bool checkCornerContainment(SkScalar x, SkScalar y) const;
501 // Returns true if the radii had to be scaled to fit rect
502 bool scaleRadii();
503
504 SkRect fRect = SkRect::MakeEmpty();
505 // Radii order is UL, UR, LR, LL. Use Corner enum to index into fRadii[]
506 SkVector fRadii[4] = {{.fX: 0, .fY: 0}, {.fX: 0, .fY: 0}, {.fX: 0,.fY: 0}, {.fX: 0,.fY: 0}};
507 // use an explicitly sized type so we're sure the class is dense (no uninitialized bytes)
508 int32_t fType = kEmpty_Type;
509 // TODO: add padding so we can use memcpy for flattening and not copy uninitialized data
510
511 // to access fRadii directly
512 friend class SkPath;
513 friend class SkRRectPriv;
514};
515
516#endif
517

source code of flutter_engine/third_party/skia/include/core/SkRRect.h