| Flutter Impeller |

rect.h
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #pragma once
6
7 #include <array>
8 #include <optional>
9 #include <ostream>
10 #include <vector>
11
12 #include "impeller/geometry/matrix.h"
13 #include "impeller/geometry/point.h"
14 #include "impeller/geometry/scalar.h"
15 #include "impeller/geometry/size.h"
16
17 namespace impeller {
18
19 template <class T>
20 struct TRect {
21 using Type = T;
22
23 TPoint<Type> origin;
24 TSize<Type> size;
25
26 constexpr TRect() : origin({0, 0}), size({0, 0}) {}
27
28 constexpr TRect(TSize<Type> size) : origin({0.0, 0.0}), size(size) {}
29
30 constexpr TRect(TPoint<Type> origin, TSize<Type> size)
31 : origin(origin), size(size) {}
32
33 constexpr TRect(const Type components[4])
34 : origin(components[0], components[1]),
35 size(components[2], components[3]) {}
36
37 constexpr TRect(Type x, Type y, Type width, Type height)
38 : origin(x, y), size(width, height) {}
39
40 constexpr static TRect MakeLTRB(Type left,
41 Type top,
42 Type right,
43 Type bottom) {
44 return TRect(left, top, right - left, bottom - top);
45 }
46
47 constexpr static TRect MakeXYWH(Type x, Type y, Type width, Type height) {
48 return TRect(x, y, width, height);
49 }
50
51 template <class U>
52 constexpr static TRect MakeSize(const TSize<U>& size) {
53 return TRect(0.0, 0.0, size.width, size.height);
54 }
55
56 template <typename PointIter>
57 constexpr static std::optional<TRect> MakePointBounds(const PointIter first,
58 const PointIter last) {
59 if (first == last) {
60 return std::nullopt;
61 }
62 auto left = first->x;
63 auto top = first->y;
64 auto right = first->x;
65 auto bottom = first->y;
66 for (auto it = first + 1; it < last; ++it) {
67 left = std::min(left, it->x);
68 top = std::min(top, it->y);
69 right = std::max(right, it->x);
70 bottom = std::max(bottom, it->y);
71 }
72 return TRect::MakeLTRB(left, top, right, bottom);
73 }
74
75 constexpr static TRect MakeMaximum() {
76 return TRect::MakeLTRB(-std::numeric_limits<Type>::infinity(),
77 -std::numeric_limits<Type>::infinity(),
78 std::numeric_limits<Type>::infinity(),
79 std::numeric_limits<Type>::infinity());
80 }
81
82 template <class U>
83 constexpr explicit TRect(const TRect<U>& other)
84 : origin(static_cast<TPoint<Type>>(other.origin)),
85 size(static_cast<TSize<Type>>(other.size)) {}
86
87 constexpr TRect operator+(const TRect& r) const {
88 return TRect({origin.x + r.origin.x, origin.y + r.origin.y},
89 {size.width + r.size.width, size.height + r.size.height});
90 }
91
92 constexpr TRect operator-(const TRect& r) const {
93 return TRect({origin.x - r.origin.x, origin.y - r.origin.y},
94 {size.width - r.size.width, size.height - r.size.height});
95 }
96
97 constexpr TRect operator*(Type scale) const { return Scale(scale); }
98
99 constexpr TRect operator*(const TRect& r) const {
100 return TRect({origin.x * r.origin.x, origin.y * r.origin.y},
101 {size.width * r.size.width, size.height * r.size.height});
102 }
103
104 constexpr bool operator==(const TRect& r) const {
105 return origin == r.origin && size == r.size;
106 }
107
108 constexpr TRect Scale(Type scale) const {
109 return TRect({origin.x * scale, origin.y * scale},
110 {size.width * scale, size.height * scale});
111 }
112
113 constexpr TRect Scale(TPoint<T> scale) const {
114 return TRect({origin.x * scale.x, origin.y * scale.y},
115 {size.width * scale.x, size.height * scale.y});
116 }
117
118 constexpr TRect Scale(TSize<T> scale) const {
119 return Scale(TPoint<T>(scale));
120 }
121
122 constexpr bool Contains(const TPoint<Type>& p) const {
123 return p.x >= GetLeft() && p.x < GetRight() && p.y >= GetTop() &&
124 p.y < GetBottom();
125 }
126
127 constexpr bool Contains(const TRect& o) const {
128 return Union(o).size == size;
129 }
130
131 constexpr bool IsZero() const { return size.IsZero(); }
132
133 constexpr bool IsEmpty() const { return size.IsEmpty(); }
134
135 constexpr bool IsMaximum() const { return *this == MakeMaximum(); }
136
137 constexpr auto GetLeft() const {
138 if (IsMaximum()) {
139 return -std::numeric_limits<Type>::infinity();
140 }
141 return std::min(origin.x, origin.x + size.width);
142 }
143
144 constexpr auto GetTop() const {
145 if (IsMaximum()) {
146 return -std::numeric_limits<Type>::infinity();
147 }
148 return std::min(origin.y, origin.y + size.height);
149 }
150
151 constexpr auto GetRight() const {
152 if (IsMaximum()) {
153 return std::numeric_limits<Type>::infinity();
154 }
155 return std::max(origin.x, origin.x + size.width);
156 }
157
158 constexpr auto GetBottom() const {
159 if (IsMaximum()) {
160 return std::numeric_limits<Type>::infinity();
161 }
162 return std::max(origin.y, origin.y + size.height);
163 }
164
165 constexpr TPoint<T> GetLeftTop() const { return {GetLeft(), GetTop()}; }
166
167 constexpr TPoint<T> GetRightTop() const { return {GetRight(), GetTop()}; }
168
169 constexpr TPoint<T> GetLeftBottom() const { return {GetLeft(), GetBottom()}; }
170
171 constexpr TPoint<T> GetRightBottom() const {
172 return {GetRight(), GetBottom()};
173 }
174
175 constexpr std::array<T, 4> GetLTRB() const {
176 return {GetLeft(), GetTop(), GetRight(), GetBottom()};
177 }
178
179 /// @brief Get a version of this rectangle that has a non-negative size.
180 constexpr TRect GetPositive() const {
181 auto ltrb = GetLTRB();
182 return MakeLTRB(ltrb[0], ltrb[1], ltrb[2], ltrb[3]);
183 }
184
185 /// @brief Get the points that represent the 4 corners of this rectangle. The
186 /// order is: Top left, top right, bottom left, bottom right.
187 constexpr std::array<TPoint<T>, 4> GetPoints() const {
188 auto [left, top, right, bottom] = GetLTRB();
189 return {TPoint(left, top), TPoint(right, top), TPoint(left, bottom),
190 TPoint(right, bottom)};
191 }
192
193 constexpr std::array<TPoint<T>, 4> GetTransformedPoints(
194 const Matrix& transform) const {
195 auto points = GetPoints();
196 for (size_t i = 0; i < points.size(); i++) {
197 points[i] = transform * points[i];
198 }
199 return points;
200 }
201
202 /// @brief Creates a new bounding box that contains this transformed
203 /// rectangle.
204 constexpr TRect TransformBounds(const Matrix& transform) const {
205 auto points = GetTransformedPoints(transform);
206 return TRect::MakePointBounds(points.begin(), points.end()).value();
207 }
208
209 constexpr TRect Union(const TRect& o) const {
210 auto this_ltrb = GetLTRB();
211 auto other_ltrb = o.GetLTRB();
212 return TRect::MakeLTRB(std::min(this_ltrb[0], other_ltrb[0]), //
213 std::min(this_ltrb[1], other_ltrb[1]), //
214 std::max(this_ltrb[2], other_ltrb[2]), //
215 std::max(this_ltrb[3], other_ltrb[3]) //
216 );
217 }
218
219 constexpr std::optional<TRect<T>> Intersection(const TRect& o) const {
220 auto this_ltrb = GetLTRB();
221 auto other_ltrb = o.GetLTRB();
222 auto intersection =
223 TRect::MakeLTRB(std::max(this_ltrb[0], other_ltrb[0]), //
224 std::max(this_ltrb[1], other_ltrb[1]), //
225 std::min(this_ltrb[2], other_ltrb[2]), //
226 std::min(this_ltrb[3], other_ltrb[3]) //
227 );
228 if (intersection.size.IsEmpty()) {
229 return std::nullopt;
230 }
231 return intersection;
232 }
233
234 constexpr bool IntersectsWithRect(const TRect& o) const {
235 return Intersection(o).has_value();
236 }
237
238 /// @brief Returns the new boundary rectangle that would result from the
239 /// rectangle being cutout by a second rectangle.
240 constexpr std::optional<TRect<T>> Cutout(const TRect& o) const {
241 const auto& [a_left, a_top, a_right, a_bottom] = GetLTRB(); // Source rect.
242 const auto& [b_left, b_top, b_right, b_bottom] = o.GetLTRB(); // Cutout.
243 if (b_left <= a_left && b_right >= a_right) {
244 if (b_top <= a_top && b_bottom >= a_bottom) {
245 // Full cutout.
246 return std::nullopt;
247 }
248 if (b_top <= a_top && b_bottom > a_top) {
249 // Cuts off the top.
250 return TRect::MakeLTRB(a_left, b_bottom, a_right, a_bottom);
251 }
252 if (b_bottom >= a_bottom && b_top < a_bottom) {
253 // Cuts out the bottom.
254 return TRect::MakeLTRB(a_left, a_top, a_right, b_top);
255 }
256 }
257 if (b_top <= a_top && b_bottom >= a_bottom) {
258 if (b_left <= a_left && b_right > a_left) {
259 // Cuts out the left.
260 return TRect::MakeLTRB(b_right, a_top, a_right, a_bottom);
261 }
262 if (b_right >= a_right && b_left < a_right) {
263 // Cuts out the right.
264 return TRect::MakeLTRB(a_left, a_top, b_left, a_bottom);
265 }
266 }
267
268 return *this;
269 }
270
271 /// @brief Returns a new rectangle translated by the given offset.
272 constexpr TRect<T> Shift(TPoint<T> offset) const {
273 return TRect(origin.x + offset.x, origin.y + offset.y, size.width,
274 size.height);
275 }
276
277 /// @brief Returns a rectangle with expanded edges. Negative expansion
278 /// results in shrinking.
279 constexpr TRect<T> Expand(T left, T top, T right, T bottom) const {
280 return TRect(origin.x - left, //
281 origin.y - top, //
282 size.width + left + right, //
283 size.height + top + bottom);
284 }
285
286 /// @brief Returns a rectangle with expanded edges in all directions.
287 /// Negative expansion results in shrinking.
288 constexpr TRect<T> Expand(T amount) const {
289 return TRect(origin.x - amount, //
290 origin.y - amount, //
291 size.width + amount * 2, //
292 size.height + amount * 2);
293 }
294
295 /// @brief Returns a new rectangle that represents the projection of the
296 /// source rectangle onto this rectangle. In other words, the source
297 /// rectangle is redefined in terms of the corrdinate space of this
298 /// rectangle.
299 constexpr TRect<T> Project(TRect<T> source) const {
300 return source.Shift(-origin).Scale(
301 TSize<T>(1.0 / static_cast<Scalar>(size.width),
302 1.0 / static_cast<Scalar>(size.height)));
303 }
304 };
305
306 using Rect = TRect<Scalar>;
307 using IRect = TRect<int64_t>;
308
309 } // namespace impeller
310
311 namespace std {
312
313 template <class T>
314 inline std::ostream& operator<<(std::ostream& out,
315 const impeller::TRect<T>& r) {
316 out << "(" << r.origin << ", " << r.size << ")";
317 return out;
318 }
319
320 } // namespace std
impeller::TRect::GetLTRB
constexpr std::array< T, 4 > GetLTRB() const
Definition: rect.h:175
impeller::TRect::TRect
constexpr TRect(TSize< Type > size)
Definition: rect.h:28
impeller::TRect::size
TSize< Type > size
Definition: rect.h:24
point.h
impeller::TPoint::y
Type y
Definition: point.h:24
impeller::Scalar
float Scalar
Definition: scalar.h:15
impeller::TRect< Scalar >::Type
Scalar Type
Definition: rect.h:21
impeller::TRect::MakeXYWH
constexpr static TRect MakeXYWH(Type x, Type y, Type width, Type height)
Definition: rect.h:47
impeller::TRect::IsZero
constexpr bool IsZero() const
Definition: rect.h:131
impeller::TRect::Expand
constexpr TRect< T > Expand(T amount) const
Returns a rectangle with expanded edges in all directions. Negative expansion results in shrinking.
Definition: rect.h:288
impeller::TRect::operator-
constexpr TRect operator-(const TRect &r) const
Definition: rect.h:92
impeller::TRect::TransformBounds
constexpr TRect TransformBounds(const Matrix &transform) const
Creates a new bounding box that contains this transformed rectangle.
Definition: rect.h:204
impeller::TRect::IsMaximum
constexpr bool IsMaximum() const
Definition: rect.h:135
impeller::TRect::GetLeftTop
constexpr TPoint< T > GetLeftTop() const
Definition: rect.h:165
impeller::TRect::operator+
constexpr TRect operator+(const TRect &r) const
Definition: rect.h:87
std::operator<<
std::ostream & operator<<(std::ostream &out, const impeller::Color &c)
Definition: color.h:945
impeller::TRect::TRect
constexpr TRect()
Definition: rect.h:26
impeller::TRect::GetRightTop
constexpr TPoint< T > GetRightTop() const
Definition: rect.h:167
impeller::TRect::Contains
constexpr bool Contains(const TRect &o) const
Definition: rect.h:127
impeller::TRect::operator==
constexpr bool operator==(const TRect &r) const
Definition: rect.h:104
impeller::TRect::IntersectsWithRect
constexpr bool IntersectsWithRect(const TRect &o) const
Definition: rect.h:234
impeller::TRect::GetPoints
constexpr std::array< TPoint< T >, 4 > GetPoints() const
Get the points that represent the 4 corners of this rectangle. The order is: Top left,...
Definition: rect.h:187
impeller::TRect::IsEmpty
constexpr bool IsEmpty() const
Definition: rect.h:133
matrix.h
impeller::TRect::Scale
constexpr TRect Scale(TSize< T > scale) const
Definition: rect.h:118
impeller::TSize< Type >
impeller::TRect::Intersection
constexpr std::optional< TRect< T > > Intersection(const TRect &o) const
Definition: rect.h:219
impeller::TRect::GetLeft
constexpr auto GetLeft() const
Definition: rect.h:137
impeller::TRect::GetTransformedPoints
constexpr std::array< TPoint< T >, 4 > GetTransformedPoints(const Matrix &transform) const
Definition: rect.h:193
impeller::TRect::operator*
constexpr TRect operator*(Type scale) const
Definition: rect.h:97
impeller::TRect::GetLeftBottom
constexpr TPoint< T > GetLeftBottom() const
Definition: rect.h:169
impeller::TRect::TRect
constexpr TRect(Type x, Type y, Type width, Type height)
Definition: rect.h:37
impeller::TRect::Scale
constexpr TRect Scale(Type scale) const
Definition: rect.h:108
impeller::TRect::origin
TPoint< Type > origin
Definition: rect.h:23
impeller::TRect::MakePointBounds
constexpr static std::optional< TRect > MakePointBounds(const PointIter first, const PointIter last)
Definition: rect.h:57
impeller::TRect::Shift
constexpr TRect< T > Shift(TPoint< T > offset) const
Returns a new rectangle translated by the given offset.
Definition: rect.h:272
impeller::TRect::Scale
constexpr TRect Scale(TPoint< T > scale) const
Definition: rect.h:113
impeller::TSize::IsZero
constexpr bool IsZero() const
Definition: size.h:103
impeller::TSize::width
Type width
Definition: size.h:21
impeller::TRect::Contains
constexpr bool Contains(const TPoint< Type > &p) const
Definition: rect.h:122
impeller::TPoint::x
Type x
Definition: point.h:23
scalar.h
impeller::TRect::Cutout
constexpr std::optional< TRect< T > > Cutout(const TRect &o) const
Returns the new boundary rectangle that would result from the rectangle being cutout by a second rect...
Definition: rect.h:240
impeller::TRect::GetRight
constexpr auto GetRight() const
Definition: rect.h:151
impeller::TRect::MakeSize
constexpr static TRect MakeSize(const TSize< U > &size)
Definition: rect.h:52
std
Definition: comparable.h:98
impeller::TRect::operator*
constexpr TRect operator*(const TRect &r) const
Definition: rect.h:99
impeller::TRect::Project
constexpr TRect< T > Project(TRect< T > source) const
Returns a new rectangle that represents the projection of the source rectangle onto this rectangle....
Definition: rect.h:299
impeller::TPoint< Type >
impeller::TRect::MakeMaximum
constexpr static TRect MakeMaximum()
Definition: rect.h:75
impeller::TRect::TRect
constexpr TRect(TPoint< Type > origin, TSize< Type > size)
Definition: rect.h:30
impeller::TRect::TRect
constexpr TRect(const Type components[4])
Definition: rect.h:33
impeller::TRect::Union
constexpr TRect Union(const TRect &o) const
Definition: rect.h:209
impeller::TRect::GetBottom
constexpr auto GetBottom() const
Definition: rect.h:158
impeller::TSize::height
Type height
Definition: size.h:22
impeller::TRect::MakeLTRB
constexpr static TRect MakeLTRB(Type left, Type top, Type right, Type bottom)
Definition: rect.h:40
impeller::TSize::IsEmpty
constexpr bool IsEmpty() const
Definition: size.h:105
impeller::TRect::GetPositive
constexpr TRect GetPositive() const
Get a version of this rectangle that has a non-negative size.
Definition: rect.h:180
impeller::TRect::GetRightBottom
constexpr TPoint< T > GetRightBottom() const
Definition: rect.h:171
impeller
Definition: aiks_context.cc:10
impeller::TRect::TRect
constexpr TRect(const TRect< U > &other)
Definition: rect.h:83
impeller::TRect::GetTop
constexpr auto GetTop() const
Definition: rect.h:144
impeller::TRect
Definition: rect.h:20
impeller::Matrix
A 4x4 matrix using column-major storage.
Definition: matrix.h:36
size.h
impeller::TRect::Expand
constexpr TRect< T > Expand(T left, T top, T right, T bottom) const
Returns a rectangle with expanded edges. Negative expansion results in shrinking.
Definition: rect.h:279