Rect.h revision f0a590781b2c3e34132b2011d3956135add73ae0 
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
22#include <utils/Log.h>
23
24#include "Vertex.h"
25
26namespace android {
27namespace uirenderer {
28
29#define RECT_STRING "%7.2f %7.2f %7.2f %7.2f"
30#define RECT_ARGS(r) \
31    (r).left, (r).top, (r).right, (r).bottom
32
33///////////////////////////////////////////////////////////////////////////////
34// Structs
35///////////////////////////////////////////////////////////////////////////////
36
37class Rect {
38public:
39    float left;
40    float top;
41    float right;
42    float bottom;
43
44    // Used by Region
45    typedef float value_type;
46
47    // we don't provide copy-ctor and operator= on purpose
48    // because we want the compiler generated versions
49
50    inline Rect():
51            left(0),
52            top(0),
53            right(0),
54            bottom(0) {
55    }
56
57    inline Rect(float left, float top, float right, float bottom):
58            left(left),
59            top(top),
60            right(right),
61            bottom(bottom) {
62    }
63
64    inline Rect(float width, float height):
65            left(0.0f),
66            top(0.0f),
67            right(width),
68            bottom(height) {
69    }
70
71    friend int operator==(const Rect& a, const Rect& b) {
72        return !memcmp(&a, &b, sizeof(a));
73    }
74
75    friend int operator!=(const Rect& a, const Rect& b) {
76        return memcmp(&a, &b, sizeof(a));
77    }
78
79    inline void clear() {
80        left = top = right = bottom = 0.0f;
81    }
82
83    inline bool isEmpty() const {
84        // this is written in such way this it'll handle NANs to return
85        // true (empty)
86        return !((left < right) && (top < bottom));
87    }
88
89    inline void setEmpty() {
90        left = top = right = bottom = 0.0f;
91    }
92
93    inline void set(float left, float top, float right, float bottom) {
94        this->left = left;
95        this->right = right;
96        this->top = top;
97        this->bottom = bottom;
98    }
99
100    inline void set(const Rect& r) {
101        set(r.left, r.top, r.right, r.bottom);
102    }
103
104    inline float getWidth() const {
105        return right - left;
106    }
107
108    inline float getHeight() const {
109        return bottom - top;
110    }
111
112    bool intersects(float l, float t, float r, float b) const {
113        return !intersectWith(l, t, r, b).isEmpty();
114    }
115
116    bool intersects(const Rect& r) const {
117        return intersects(r.left, r.top, r.right, r.bottom);
118    }
119
120    bool intersect(float l, float t, float r, float b) {
121        Rect tmp(l, t, r, b);
122        intersectWith(tmp);
123        if (!tmp.isEmpty()) {
124            set(tmp);
125            return true;
126        }
127        return false;
128    }
129
130    bool intersect(const Rect& r) {
131        return intersect(r.left, r.top, r.right, r.bottom);
132    }
133
134    inline bool contains(float l, float t, float r, float b) const {
135        return l >= left && t >= top && r <= right && b <= bottom;
136    }
137
138    inline bool contains(const Rect& r) const {
139        return contains(r.left, r.top, r.right, r.bottom);
140    }
141
142    bool unionWith(const Rect& r) {
143        if (r.left < r.right && r.top < r.bottom) {
144            if (left < right && top < bottom) {
145                if (left > r.left) left = r.left;
146                if (top > r.top) top = r.top;
147                if (right < r.right) right = r.right;
148                if (bottom < r.bottom) bottom = r.bottom;
149                return true;
150            } else {
151                left = r.left;
152                top = r.top;
153                right = r.right;
154                bottom = r.bottom;
155                return true;
156            }
157        }
158        return false;
159    }
160
161    void translate(float dx, float dy) {
162        left += dx;
163        right += dx;
164        top += dy;
165        bottom += dy;
166    }
167
168    void outset(float delta) {
169        left -= delta;
170        top -= delta;
171        right += delta;
172        bottom += delta;
173    }
174
175    /**
176     * Similar to snapToPixelBoundaries, but estimates bounds conservatively to handle GL rounding
177     * errors.
178     *
179     * This function should be used whenever estimating the damage rect of geometry already mapped
180     * into layer space.
181     */
182    void snapGeometryToPixelBoundaries(bool snapOut) {
183        if (snapOut) {
184            /* For AA geometry with a ramp perimeter, don't snap by rounding - AA geometry will have
185             * a 0.5 pixel perimeter not accounted for in its bounds. Instead, snap by
186             * conservatively rounding out the bounds with floor/ceil.
187             *
188             * In order to avoid changing integer bounds with floor/ceil due to rounding errors
189             * inset the bounds first by the fudge factor. Very small fraction-of-a-pixel errors
190             * from this inset will only incur similarly small errors in output, due to transparency
191             * in extreme outside of the geometry.
192             */
193            left = floorf(left + Vertex::gGeometryFudgeFactor);
194            top = floorf(top + Vertex::gGeometryFudgeFactor);
195            right = ceilf(right - Vertex::gGeometryFudgeFactor);
196            bottom = ceilf(bottom - Vertex::gGeometryFudgeFactor);
197        } else {
198            /* For other geometry, we do the regular rounding in order to snap, but also outset the
199             * bounds by a fudge factor. This ensures that ambiguous geometry (e.g. a non-AA Rect
200             * with top left at (0.5, 0.5)) will err on the side of a larger damage rect.
201             */
202            left = floorf(left + 0.5f - Vertex::gGeometryFudgeFactor);
203            top = floorf(top + 0.5f - Vertex::gGeometryFudgeFactor);
204            right = floorf(right + 0.5f + Vertex::gGeometryFudgeFactor);
205            bottom = floorf(bottom + 0.5f + Vertex::gGeometryFudgeFactor);
206        }
207    }
208
209    void snapToPixelBoundaries() {
210        left = floorf(left + 0.5f);
211        top = floorf(top + 0.5f);
212        right = floorf(right + 0.5f);
213        bottom = floorf(bottom + 0.5f);
214    }
215
216    void roundOut() {
217        left = floorf(left);
218        top = floorf(top);
219        right = ceilf(right);
220        bottom = ceilf(bottom);
221    }
222
223    void dump() const {
224        ALOGD("Rect[l=%f t=%f r=%f b=%f]", left, top, right, bottom);
225    }
226
227private:
228    void intersectWith(Rect& tmp) const {
229        tmp.left = fmaxf(left, tmp.left);
230        tmp.top = fmaxf(top, tmp.top);
231        tmp.right = fminf(right, tmp.right);
232        tmp.bottom = fminf(bottom, tmp.bottom);
233    }
234
235    Rect intersectWith(float l, float t, float r, float b) const {
236        Rect tmp;
237        tmp.left = fmaxf(left, l);
238        tmp.top = fmaxf(top, t);
239        tmp.right = fminf(right, r);
240        tmp.bottom = fminf(bottom, b);
241        return tmp;
242    }
243
244}; // class Rect
245
246}; // namespace uirenderer
247}; // namespace android
248
249#endif // ANDROID_HWUI_RECT_H
250