ClipArea.h revision a2a70723b8cbda4354d23f901f995623e819012c 
1/*
2 * Copyright (C) 2015 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#ifndef CLIPAREA_H
17#define CLIPAREA_H
18
19#include <SkRegion.h>
20
21#include "Matrix.h"
22#include "Rect.h"
23#include "utils/Pair.h"
24
25namespace android {
26namespace uirenderer {
27
28Rect transformAndCalculateBounds(const Rect& r, const Matrix4& transform);
29
30class TransformedRectangle {
31public:
32    TransformedRectangle();
33    TransformedRectangle(const Rect& bounds, const Matrix4& transform);
34
35    bool canSimplyIntersectWith(const TransformedRectangle& other) const;
36    void intersectWith(const TransformedRectangle& other);
37
38    bool isEmpty() const;
39
40    const Rect& getBounds() const {
41        return mBounds;
42    }
43
44    Rect transformedBounds() const {
45        Rect transformedBounds(transformAndCalculateBounds(mBounds, mTransform));
46        return transformedBounds;
47    }
48
49    const Matrix4& getTransform() const {
50        return mTransform;
51    }
52
53private:
54    Rect mBounds;
55    Matrix4 mTransform;
56};
57
58class RectangleList {
59public:
60    RectangleList();
61
62    bool isEmpty() const;
63    int getTransformedRectanglesCount() const;
64    const TransformedRectangle& getTransformedRectangle(int i) const;
65
66    void setEmpty();
67    void set(const Rect& bounds, const Matrix4& transform);
68    bool intersectWith(const Rect& bounds, const Matrix4& transform);
69
70    SkRegion convertToRegion(const SkRegion& clip) const;
71    Rect calculateBounds() const;
72
73private:
74    enum {
75        kMaxTransformedRectangles = 5
76    };
77
78    int mTransformedRectanglesCount;
79    TransformedRectangle mTransformedRectangles[kMaxTransformedRectangles];
80};
81
82class ClipArea {
83private:
84    enum class Mode {
85        Rectangle,
86        Region,
87        RectangleList
88    };
89
90public:
91    ClipArea();
92
93    void setViewportDimensions(int width, int height);
94
95    bool isEmpty() const {
96        return mClipRect.isEmpty();
97    }
98
99    void setEmpty();
100    void setClip(float left, float top, float right, float bottom);
101    void clipRectWithTransform(const Rect& r, const mat4* transform,
102            SkRegion::Op op);
103    void clipRegion(const SkRegion& region, SkRegion::Op op);
104    void clipPathWithTransform(const SkPath& path, const mat4* transform,
105            SkRegion::Op op);
106
107    const Rect& getClipRect() const {
108        return mClipRect;
109    }
110
111    const SkRegion& getClipRegion() const {
112        return mClipRegion;
113    }
114
115    const RectangleList& getRectangleList() const {
116        return mRectangleList;
117    }
118
119    bool isRegion() const {
120        return Mode::Region == mMode;
121    }
122
123    bool isSimple() const {
124        return mMode == Mode::Rectangle;
125    }
126
127    bool isRectangleList() const {
128        return mMode == Mode::RectangleList;
129    }
130
131private:
132    void enterRectangleMode();
133    void rectangleModeClipRectWithTransform(const Rect& r, const mat4* transform, SkRegion::Op op);
134
135    void enterRectangleListMode();
136    void rectangleListModeClipRectWithTransform(const Rect& r,
137            const mat4* transform, SkRegion::Op op);
138
139    void enterRegionModeFromRectangleMode();
140    void enterRegionModeFromRectangleListMode();
141    void enterRegionMode();
142    void regionModeClipRectWithTransform(const Rect& r, const mat4* transform,
143            SkRegion::Op op);
144
145    void ensureClipRegion();
146    void onClipRegionUpdated();
147
148    SkRegion createViewportRegion() {
149        return SkRegion(mViewportBounds.toSkIRect());
150    }
151
152    void regionFromPath(const SkPath& path, SkRegion& pathAsRegion) {
153        // TODO: this should not mask every path to the viewport - this makes it impossible to use
154        // paths to clip to larger areas (which is valid e.g. with SkRegion::kReplace_Op)
155        pathAsRegion.setPath(path, createViewportRegion());
156    }
157
158    Mode mMode;
159    Rect mViewportBounds;
160    Rect mClipRect;
161    SkRegion mClipRegion;
162    RectangleList mRectangleList;
163};
164
165} /* namespace uirenderer */
166} /* namespace android */
167
168#endif /* CLIPAREA_H_ */
169