Rect.h revision af6f7ed8dd4288a41d0a07a1f0f0be7d6d035b33 
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
34///////////////////////////////////////////////////////////////////////////////
35// Structs
36///////////////////////////////////////////////////////////////////////////////
37
38class Rect {
39public:
40    float left;
41    float top;
42    float right;
43    float bottom;
44
45    // Used by Region
46    typedef float value_type;
47
48    // we don't provide copy-ctor and operator= on purpose
49    // because we want the compiler generated versions
50
51    inline Rect():
52            left(0),
53            top(0),
54            right(0),
55            bottom(0) {
56    }
57
58    inline Rect(float left, float top, float right, float bottom):
59            left(left),
60            top(top),
61            right(right),
62            bottom(bottom) {
63    }
64
65    inline Rect(float width, float height):
66            left(0.0f),
67            top(0.0f),
68            right(width),
69            bottom(height) {
70    }
71
72    inline Rect(const SkRect& rect):
73            left(rect.fLeft),
74            top(rect.fTop),
75            right(rect.fRight),
76            bottom(rect.fBottom) {
77    }
78
79    friend int operator==(const Rect& a, const Rect& b) {
80        return !memcmp(&a, &b, sizeof(a));
81    }
82
83    friend int operator!=(const Rect& a, const Rect& b) {
84        return memcmp(&a, &b, sizeof(a));
85    }
86
87    inline void clear() {
88        left = top = right = bottom = 0.0f;
89    }
90
91    inline bool isEmpty() const {
92        // this is written in such way this it'll handle NANs to return
93        // true (empty)
94        return !((left < right) && (top < bottom));
95    }
96
97    inline void setEmpty() {
98        left = top = right = bottom = 0.0f;
99    }
100
101    inline void set(float left, float top, float right, float bottom) {
102        this->left = left;
103        this->right = right;
104        this->top = top;
105        this->bottom = bottom;
106    }
107
108    inline void set(const Rect& r) {
109        set(r.left, r.top, r.right, r.bottom);
110    }
111
112    inline float getWidth() const {
113        return right - left;
114    }
115
116    inline float getHeight() const {
117        return bottom - top;
118    }
119
120    bool intersects(float l, float t, float r, float b) const {
121        return !intersectWith(l, t, r, b).isEmpty();
122    }
123
124    bool intersects(const Rect& r) const {
125        return intersects(r.left, r.top, r.right, r.bottom);
126    }
127
128    bool intersect(float l, float t, float r, float b) {
129        Rect tmp(l, t, r, b);
130        intersectWith(tmp);
131        if (!tmp.isEmpty()) {
132            set(tmp);
133            return true;
134        }
135        return false;
136    }
137
138    bool intersect(const Rect& r) {
139        return intersect(r.left, r.top, r.right, r.bottom);
140    }
141
142    inline bool contains(float l, float t, float r, float b) const {
143        return l >= left && t >= top && r <= right && b <= bottom;
144    }
145
146    inline bool contains(const Rect& r) const {
147        return contains(r.left, r.top, r.right, r.bottom);
148    }
149
150    bool unionWith(const Rect& r) {
151        if (r.left < r.right && r.top < r.bottom) {
152            if (left < right && top < bottom) {
153                if (left > r.left) left = r.left;
154                if (top > r.top) top = r.top;
155                if (right < r.right) right = r.right;
156                if (bottom < r.bottom) bottom = r.bottom;
157                return true;
158            } else {
159                left = r.left;
160                top = r.top;
161                right = r.right;
162                bottom = r.bottom;
163                return true;
164            }
165        }
166        return false;
167    }
168
169    void translate(float dx, float dy) {
170        left += dx;
171        right += dx;
172        top += dy;
173        bottom += dy;
174    }
175
176    void outset(float delta) {
177        left -= delta;
178        top -= delta;
179        right += delta;
180        bottom += delta;
181    }
182
183    /**
184     * Similar to snapToPixelBoundaries, but estimates bounds conservatively to handle GL rounding
185     * errors.
186     *
187     * This function should be used whenever estimating the damage rect of geometry already mapped
188     * into layer space.
189     */
190    void snapGeometryToPixelBoundaries(bool snapOut) {
191        if (snapOut) {
192            /* For AA geometry with a ramp perimeter, don't snap by rounding - AA geometry will have
193             * a 0.5 pixel perimeter not accounted for in its bounds. Instead, snap by
194             * conservatively rounding out the bounds with floor/ceil.
195             *
196             * In order to avoid changing integer bounds with floor/ceil due to rounding errors
197             * inset the bounds first by the fudge factor. Very small fraction-of-a-pixel errors
198             * from this inset will only incur similarly small errors in output, due to transparency
199             * in extreme outside of the geometry.
200             */
201            left = floorf(left + Vertex::GeometryFudgeFactor());
202            top = floorf(top + Vertex::GeometryFudgeFactor());
203            right = ceilf(right - Vertex::GeometryFudgeFactor());
204            bottom = ceilf(bottom - Vertex::GeometryFudgeFactor());
205        } else {
206            /* For other geometry, we do the regular rounding in order to snap, but also outset the
207             * bounds by a fudge factor. This ensures that ambiguous geometry (e.g. a non-AA Rect
208             * with top left at (0.5, 0.5)) will err on the side of a larger damage rect.
209             */
210            left = floorf(left + 0.5f - Vertex::GeometryFudgeFactor());
211            top = floorf(top + 0.5f - Vertex::GeometryFudgeFactor());
212            right = floorf(right + 0.5f + Vertex::GeometryFudgeFactor());
213            bottom = floorf(bottom + 0.5f + Vertex::GeometryFudgeFactor());
214        }
215    }
216
217    void snapToPixelBoundaries() {
218        left = floorf(left + 0.5f);
219        top = floorf(top + 0.5f);
220        right = floorf(right + 0.5f);
221        bottom = floorf(bottom + 0.5f);
222    }
223
224    void roundOut() {
225        left = floorf(left);
226        top = floorf(top);
227        right = ceilf(right);
228        bottom = ceilf(bottom);
229    }
230
231    void dump() const {
232        ALOGD("Rect[l=%f t=%f r=%f b=%f]", left, top, right, bottom);
233    }
234
235private:
236    void intersectWith(Rect& tmp) const {
237        tmp.left = fmaxf(left, tmp.left);
238        tmp.top = fmaxf(top, tmp.top);
239        tmp.right = fminf(right, tmp.right);
240        tmp.bottom = fminf(bottom, tmp.bottom);
241    }
242
243    Rect intersectWith(float l, float t, float r, float b) const {
244        Rect tmp;
245        tmp.left = fmaxf(left, l);
246        tmp.top = fmaxf(top, t);
247        tmp.right = fminf(right, r);
248        tmp.bottom = fminf(bottom, b);
249        return tmp;
250    }
251
252}; // class Rect
253
254}; // namespace uirenderer
255}; // namespace android
256
257#endif // ANDROID_HWUI_RECT_H
258