Rect.h revision 3f085429fd47ebd32ac2463b3eae2a5a6c17be25 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_HWUI_RECT_H
18#define ANDROID_HWUI_RECT_H
19
20#include <cmath>
21#include <SkRect.h>
22
23#include <utils/Log.h>
24
25#include "Vertex.h"
26
27namespace android {
28namespace uirenderer {
29
30#define RECT_STRING "%7.2f %7.2f %7.2f %7.2f"
31#define RECT_ARGS(r) \
32    (r).left, (r).top, (r).right, (r).bottom
33#define SK_RECT_ARGS(r) \
34    (r).left(), (r).top(), (r).right(), (r).bottom()
35
36///////////////////////////////////////////////////////////////////////////////
37// Structs
38///////////////////////////////////////////////////////////////////////////////
39
40class Rect {
41public:
42    float left;
43    float top;
44    float right;
45    float bottom;
46
47    // Used by Region
48    typedef float value_type;
49
50    // we don't provide copy-ctor and operator= on purpose
51    // because we want the compiler generated versions
52
53    inline Rect():
54            left(0),
55            top(0),
56            right(0),
57            bottom(0) {
58    }
59
60    inline Rect(float left, float top, float right, float bottom):
61            left(left),
62            top(top),
63            right(right),
64            bottom(bottom) {
65    }
66
67    inline Rect(float width, float height):
68            left(0.0f),
69            top(0.0f),
70            right(width),
71            bottom(height) {
72    }
73
74    inline Rect(const SkRect& rect):
75            left(rect.fLeft),
76            top(rect.fTop),
77            right(rect.fRight),
78            bottom(rect.fBottom) {
79    }
80
81    friend int operator==(const Rect& a, const Rect& b) {
82        return !memcmp(&a, &b, sizeof(a));
83    }
84
85    friend int operator!=(const Rect& a, const Rect& b) {
86        return memcmp(&a, &b, sizeof(a));
87    }
88
89    inline void clear() {
90        left = top = right = bottom = 0.0f;
91    }
92
93    inline bool isEmpty() const {
94        // this is written in such way this it'll handle NANs to return
95        // true (empty)
96        return !((left < right) && (top < bottom));
97    }
98
99    inline void setEmpty() {
100        left = top = right = bottom = 0.0f;
101    }
102
103    inline void set(float left, float top, float right, float bottom) {
104        this->left = left;
105        this->right = right;
106        this->top = top;
107        this->bottom = bottom;
108    }
109
110    inline void set(const Rect& r) {
111        set(r.left, r.top, r.right, r.bottom);
112    }
113
114    inline float getWidth() const {
115        return right - left;
116    }
117
118    inline float getHeight() const {
119        return bottom - top;
120    }
121
122    bool intersects(float l, float t, float r, float b) const {
123        return !intersectWith(l, t, r, b).isEmpty();
124    }
125
126    bool intersects(const Rect& r) const {
127        return intersects(r.left, r.top, r.right, r.bottom);
128    }
129
130    bool intersect(float l, float t, float r, float b) {
131        Rect tmp(l, t, r, b);
132        intersectWith(tmp);
133        if (!tmp.isEmpty()) {
134            set(tmp);
135            return true;
136        }
137        return false;
138    }
139
140    bool intersect(const Rect& r) {
141        return intersect(r.left, r.top, r.right, r.bottom);
142    }
143
144    inline bool contains(float l, float t, float r, float b) const {
145        return l >= left && t >= top && r <= right && b <= bottom;
146    }
147
148    inline bool contains(const Rect& r) const {
149        return contains(r.left, r.top, r.right, r.bottom);
150    }
151
152    bool unionWith(const Rect& r) {
153        if (r.left < r.right && r.top < r.bottom) {
154            if (left < right && top < bottom) {
155                if (left > r.left) left = r.left;
156                if (top > r.top) top = r.top;
157                if (right < r.right) right = r.right;
158                if (bottom < r.bottom) bottom = r.bottom;
159                return true;
160            } else {
161                left = r.left;
162                top = r.top;
163                right = r.right;
164                bottom = r.bottom;
165                return true;
166            }
167        }
168        return false;
169    }
170
171    void translate(float dx, float dy) {
172        left += dx;
173        right += dx;
174        top += dy;
175        bottom += dy;
176    }
177
178    void outset(float delta) {
179        left -= delta;
180        top -= delta;
181        right += delta;
182        bottom += delta;
183    }
184
185    /**
186     * Similar to snapToPixelBoundaries, but estimates bounds conservatively to handle GL rounding
187     * errors.
188     *
189     * This function should be used whenever estimating the damage rect of geometry already mapped
190     * into layer space.
191     */
192    void snapGeometryToPixelBoundaries(bool snapOut) {
193        if (snapOut) {
194            /* For AA geometry with a ramp perimeter, don't snap by rounding - AA geometry will have
195             * a 0.5 pixel perimeter not accounted for in its bounds. Instead, snap by
196             * conservatively rounding out the bounds with floor/ceil.
197             *
198             * In order to avoid changing integer bounds with floor/ceil due to rounding errors
199             * inset the bounds first by the fudge factor. Very small fraction-of-a-pixel errors
200             * from this inset will only incur similarly small errors in output, due to transparency
201             * in extreme outside of the geometry.
202             */
203            left = floorf(left + Vertex::GeometryFudgeFactor());
204            top = floorf(top + Vertex::GeometryFudgeFactor());
205            right = ceilf(right - Vertex::GeometryFudgeFactor());
206            bottom = ceilf(bottom - Vertex::GeometryFudgeFactor());
207        } else {
208            /* For other geometry, we do the regular rounding in order to snap, but also outset the
209             * bounds by a fudge factor. This ensures that ambiguous geometry (e.g. a non-AA Rect
210             * with top left at (0.5, 0.5)) will err on the side of a larger damage rect.
211             */
212            left = floorf(left + 0.5f - Vertex::GeometryFudgeFactor());
213            top = floorf(top + 0.5f - Vertex::GeometryFudgeFactor());
214            right = floorf(right + 0.5f + Vertex::GeometryFudgeFactor());
215            bottom = floorf(bottom + 0.5f + Vertex::GeometryFudgeFactor());
216        }
217    }
218
219    void snapToPixelBoundaries() {
220        left = floorf(left + 0.5f);
221        top = floorf(top + 0.5f);
222        right = floorf(right + 0.5f);
223        bottom = floorf(bottom + 0.5f);
224    }
225
226    void roundOut() {
227        left = floorf(left);
228        top = floorf(top);
229        right = ceilf(right);
230        bottom = ceilf(bottom);
231    }
232
233    void dump() const {
234        ALOGD("Rect[l=%f t=%f r=%f b=%f]", left, top, right, bottom);
235    }
236
237private:
238    void intersectWith(Rect& tmp) const {
239        tmp.left = fmaxf(left, tmp.left);
240        tmp.top = fmaxf(top, tmp.top);
241        tmp.right = fminf(right, tmp.right);
242        tmp.bottom = fminf(bottom, tmp.bottom);
243    }
244
245    Rect intersectWith(float l, float t, float r, float b) const {
246        Rect tmp;
247        tmp.left = fmaxf(left, l);
248        tmp.top = fmaxf(top, t);
249        tmp.right = fminf(right, r);
250        tmp.bottom = fminf(bottom, b);
251        return tmp;
252    }
253
254}; // class Rect
255
256}; // namespace uirenderer
257}; // namespace android
258
259#endif // ANDROID_HWUI_RECT_H
260