Rect.cpp revision f3e85d432749ca77ad707bec523b67d741d43e6e 
1/*
2 * Copyright (C) 2009 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#include <system/graphics.h>
18#include <ui/Rect.h>
19
20namespace android {
21
22static inline int32_t min(int32_t a, int32_t b) {
23    return (a < b) ? a : b;
24}
25
26static inline int32_t max(int32_t a, int32_t b) {
27    return (a > b) ? a : b;
28}
29
30void Rect::makeInvalid() {
31    left = 0;
32    top = 0;
33    right = -1;
34    bottom = -1;
35}
36
37bool Rect::operator <(const Rect& rhs) const {
38    if (top < rhs.top) {
39        return true;
40    } else if (top == rhs.top) {
41        if (left < rhs.left) {
42            return true;
43        } else if (left == rhs.left) {
44            if (bottom < rhs.bottom) {
45                return true;
46            } else if (bottom == rhs.bottom) {
47                if (right < rhs.right) {
48                    return true;
49                }
50            }
51        }
52    }
53    return false;
54}
55
56Rect& Rect::offsetTo(int32_t x, int32_t y) {
57    right -= left - x;
58    bottom -= top - y;
59    left = x;
60    top = y;
61    return *this;
62}
63
64Rect& Rect::offsetBy(int32_t x, int32_t y) {
65    left += x;
66    top += y;
67    right += x;
68    bottom += y;
69    return *this;
70}
71
72const Rect Rect::operator +(const Point& rhs) const {
73    const Rect result(left + rhs.x, top + rhs.y, right + rhs.x, bottom + rhs.y);
74    return result;
75}
76
77const Rect Rect::operator -(const Point& rhs) const {
78    const Rect result(left - rhs.x, top - rhs.y, right - rhs.x, bottom - rhs.y);
79    return result;
80}
81
82bool Rect::intersect(const Rect& with, Rect* result) const {
83    result->left = max(left, with.left);
84    result->top = max(top, with.top);
85    result->right = min(right, with.right);
86    result->bottom = min(bottom, with.bottom);
87    return !(result->isEmpty());
88}
89
90Rect Rect::transform(uint32_t xform, int32_t width, int32_t height) const {
91    Rect result(*this);
92    if (xform & HAL_TRANSFORM_FLIP_H) {
93        result = Rect(width - result.right, result.top, width - result.left,
94                result.bottom);
95    }
96    if (xform & HAL_TRANSFORM_FLIP_V) {
97        result = Rect(result.left, height - result.bottom, result.right,
98                height - result.top);
99    }
100    if (xform & HAL_TRANSFORM_ROT_90) {
101        int left = height - result.bottom;
102        int top = result.left;
103        int right = height - result.top;
104        int bottom = result.right;
105        result = Rect(left, top, right, bottom);
106    }
107    return result;
108}
109
110Rect Rect::reduce(const Rect& exclude) const {
111    Rect result;
112
113    uint32_t mask = 0;
114    mask |= (exclude.left   > left)   ? 1 : 0;
115    mask |= (exclude.top    > top)    ? 2 : 0;
116    mask |= (exclude.right  < right)  ? 4 : 0;
117    mask |= (exclude.bottom < bottom) ? 8 : 0;
118
119    if (mask == 0) {
120        // crop entirely covers us
121        result.clear();
122    } else {
123        result = *this;
124        if (!(mask & (mask - 1))) {
125            // power-of-2, i.e.: just one bit is set
126            if (mask & 1) {
127                result.right = exclude.left;
128            } else if (mask & 2) {
129                result.bottom = exclude.top;
130            } else if (mask & 4) {
131                result.left = exclude.right;
132            } else if (mask & 8) {
133                result.top = exclude.bottom;
134            }
135        }
136    }
137
138    return result;
139}
140
141}; // namespace android
142