1/*
2 * Copyright 2016 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef GrWindowRectangles_DEFINED
9#define GrWindowRectangles_DEFINED
10
11#include "include/core/SkRect.h"
12#include "src/gpu/GrNonAtomicRef.h"
13
14class GrWindowRectangles {
15public:
16 constexpr static int kMaxWindows = 8;
17
18 GrWindowRectangles() : fCount(0) {}
19 GrWindowRectangles(const GrWindowRectangles& that) : fCount(0) { *this = that; }
20 ~GrWindowRectangles() { SkSafeUnref(this->rec()); }
21
22 GrWindowRectangles makeOffset(int dx, int dy) const;
23
24 bool empty() const { return !fCount; }
25 int count() const { return fCount; }
26 const SkIRect* data() const;
27
28 void reset();
29 GrWindowRectangles& operator=(const GrWindowRectangles&);
30
31 SkIRect& addWindow(const SkIRect& window) { return this->addWindow() = window; }
32 SkIRect& addWindow();
33
34 bool operator!=(const GrWindowRectangles& that) const { return !(*this == that); }
35 bool operator==(const GrWindowRectangles&) const;
36
37private:
38 struct Rec;
39
40 const Rec* rec() const { return fCount <= 1 ? nullptr : fRec; }
41
42 int fCount;
43 union {
44 SkIRect fLocalWindow; // If fCount <= 1
45 Rec* fRec; // If fCount > 1.
46 };
47};
48
49struct GrWindowRectangles::Rec : public GrNonAtomicRef<Rec> {
50 Rec(const SkIRect* windows, int numWindows) {
51 SkASSERT(numWindows < kMaxWindows);
52 memcpy(fData, windows, sizeof(SkIRect) * numWindows);
53 }
54 Rec() = default;
55
56 SkIRect fData[kMaxWindows];
57};
58
59inline const SkIRect* GrWindowRectangles::data() const {
60 return fCount <= 1 ? &fLocalWindow : fRec->fData;
61}
62
63inline void GrWindowRectangles::reset() {
64 SkSafeUnref(this->rec());
65 fCount = 0;
66}
67
68inline GrWindowRectangles& GrWindowRectangles::operator=(const GrWindowRectangles& that) {
69 SkSafeUnref(this->rec());
70 fCount = that.fCount;
71 if (fCount <= 1) {
72 fLocalWindow = that.fLocalWindow;
73 } else {
74 fRec = SkRef(that.fRec);
75 }
76 return *this;
77}
78
79inline GrWindowRectangles GrWindowRectangles::makeOffset(int dx, int dy) const {
80 if (!dx && !dy) {
81 return *this;
82 }
83 GrWindowRectangles result;
84 result.fCount = fCount;
85 SkIRect* windows;
86 if (result.fCount > 1) {
87 result.fRec = new Rec();
88 windows = result.fRec->fData;
89 } else {
90 windows = &result.fLocalWindow;
91 }
92 for (int i = 0; i < fCount; ++i) {
93 windows[i] = this->data()[i].makeOffset(dx, dy);
94 }
95 return result;
96}
97
98inline SkIRect& GrWindowRectangles::addWindow() {
99 SkASSERT(fCount < kMaxWindows);
100 if (fCount == 0) {
101 fCount = 1;
102 return fLocalWindow;
103 }
104 if (fCount == 1) {
105 fRec = new Rec(&fLocalWindow, 1);
106 } else if (!fRec->unique()) { // Simple copy-on-write.
107 fRec->unref();
108 fRec = new Rec(fRec->fData, fCount);
109 }
110 return fRec->fData[fCount++];
111}
112
113inline bool GrWindowRectangles::operator==(const GrWindowRectangles& that) const {
114 if (fCount != that.fCount) {
115 return false;
116 }
117 if (fCount > 1 && fRec == that.fRec) {
118 return true;
119 }
120 return !fCount || !memcmp(this->data(), that.data(), sizeof(SkIRect) * fCount);
121}
122
123#endif
124