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
14 class GrWindowRectangles {
15 public:
16 constexpr static int kMaxWindows = 8;
17
GrWindowRectangles()18 GrWindowRectangles() : fCount(0) {}
GrWindowRectangles(const GrWindowRectangles & that)19 GrWindowRectangles(const GrWindowRectangles& that) : fCount(0) { *this = that; }
~GrWindowRectangles()20 ~GrWindowRectangles() { SkSafeUnref(this->rec()); }
21
22 GrWindowRectangles makeOffset(int dx, int dy) const;
23
empty()24 bool empty() const { return !fCount; }
count()25 int count() const { return fCount; }
26 const SkIRect* data() const;
27
28 void reset();
29 GrWindowRectangles& operator=(const GrWindowRectangles&);
30
addWindow(const SkIRect & window)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
37 private:
38 constexpr static int kNumLocalWindows = 1;
39 struct Rec;
40
rec()41 const Rec* rec() const { return fCount <= kNumLocalWindows ? nullptr : fRec; }
42
43 int fCount;
44 union {
45 SkIRect fLocalWindows[kNumLocalWindows]; // If fCount <= kNumLocalWindows.
46 Rec* fRec; // If fCount > kNumLocalWindows.
47 };
48 };
49
50 struct GrWindowRectangles::Rec : public GrNonAtomicRef<Rec> {
RecRec51 Rec(const SkIRect* windows, int numWindows) {
52 SkASSERT(numWindows < kMaxWindows);
53 memcpy(fData, windows, sizeof(SkIRect) * numWindows);
54 }
55 Rec() = default;
56
57 SkIRect fData[kMaxWindows];
58 };
59
data()60 inline const SkIRect* GrWindowRectangles::data() const {
61 return fCount <= kNumLocalWindows ? fLocalWindows : fRec->fData;
62 }
63
reset()64 inline void GrWindowRectangles::reset() {
65 SkSafeUnref(this->rec());
66 fCount = 0;
67 }
68
69 inline GrWindowRectangles& GrWindowRectangles::operator=(const GrWindowRectangles& that) {
70 SkSafeUnref(this->rec());
71 fCount = that.fCount;
72 if (fCount <= kNumLocalWindows) {
73 memcpy(fLocalWindows, that.fLocalWindows, fCount * sizeof(SkIRect));
74 } else {
75 fRec = SkRef(that.fRec);
76 }
77 return *this;
78 }
79
makeOffset(int dx,int dy)80 inline GrWindowRectangles GrWindowRectangles::makeOffset(int dx, int dy) const {
81 if (!dx && !dy) {
82 return *this;
83 }
84 GrWindowRectangles result;
85 result.fCount = fCount;
86 SkIRect* windows;
87 if (result.fCount > kNumLocalWindows) {
88 result.fRec = new Rec();
89 windows = result.fRec->fData;
90 } else {
91 windows = result.fLocalWindows;
92 }
93 for (int i = 0; i < fCount; ++i) {
94 windows[i] = this->data()[i].makeOffset(dx, dy);
95 }
96 return result;
97 }
98
addWindow()99 inline SkIRect& GrWindowRectangles::addWindow() {
100 SkASSERT(fCount < kMaxWindows);
101 if (fCount < kNumLocalWindows) {
102 return fLocalWindows[fCount++];
103 }
104 if (fCount == kNumLocalWindows) {
105 fRec = new Rec(fLocalWindows, kNumLocalWindows);
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
113 inline bool GrWindowRectangles::operator==(const GrWindowRectangles& that) const {
114 if (fCount != that.fCount) {
115 return false;
116 }
117 if (fCount > kNumLocalWindows && fRec == that.fRec) {
118 return true;
119 }
120 return !fCount || !memcmp(this->data(), that.data(), sizeof(SkIRect) * fCount);
121 }
122
123 #endif
124