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 #include "SkMultiPictureDocument.h"
9 #include "SkMultiPictureDocumentPriv.h"
10 #include "SkNWayCanvas.h"
11 #include "SkPicture.h"
12 #include "SkPictureRecorder.h"
13 #include "SkStream.h"
14 #include "SkTArray.h"
15
16 #include <limits.h>
17
18 /*
19 File format:
20 BEGINNING_OF_FILE:
21 kMagic
22 uint32_t version_number (==2)
23 uint32_t page_count
24 {
25 float sizeX
26 float sizeY
27 } * page_count
28 skp file
29 */
30
31 namespace {
32 // The unique file signature for this file type.
33 static constexpr char kMagic[] = "Skia Multi-Picture Doc\n\n";
34
35 static constexpr char kEndPage[] = "SkMultiPictureEndPage";
36
37 const uint32_t kVersion = 2;
38
join(const SkTArray<SkSize> & sizes)39 static SkSize join(const SkTArray<SkSize>& sizes) {
40 SkSize joined = {0, 0};
41 for (SkSize s : sizes) {
42 joined = SkSize{SkTMax(joined.width(), s.width()), SkTMax(joined.height(), s.height())};
43 }
44 return joined;
45 }
46
47 struct MultiPictureDocument final : public SkDocument {
48 SkPictureRecorder fPictureRecorder;
49 SkSize fCurrentPageSize;
50 SkTArray<sk_sp<SkPicture>> fPages;
51 SkTArray<SkSize> fSizes;
MultiPictureDocument__anon4dea72130111::MultiPictureDocument52 MultiPictureDocument(SkWStream* s, void (*d)(SkWStream*, bool))
53 : SkDocument(s, d) {}
~MultiPictureDocument__anon4dea72130111::MultiPictureDocument54 ~MultiPictureDocument() override { this->close(); }
55
onBeginPage__anon4dea72130111::MultiPictureDocument56 SkCanvas* onBeginPage(SkScalar w, SkScalar h) override {
57 fCurrentPageSize.set(w, h);
58 return fPictureRecorder.beginRecording(w, h);
59 }
onEndPage__anon4dea72130111::MultiPictureDocument60 void onEndPage() override {
61 fSizes.push_back(fCurrentPageSize);
62 fPages.push_back(fPictureRecorder.finishRecordingAsPicture());
63 }
onClose__anon4dea72130111::MultiPictureDocument64 void onClose(SkWStream* wStream) override {
65 SkASSERT(wStream);
66 SkASSERT(wStream->bytesWritten() == 0);
67 wStream->writeText(kMagic);
68 wStream->write32(kVersion);
69 wStream->write32(SkToU32(fPages.count()));
70 for (SkSize s : fSizes) {
71 wStream->write(&s, sizeof(s));
72 }
73 SkSize bigsize = join(fSizes);
74 SkCanvas* c = fPictureRecorder.beginRecording(SkRect::MakeSize(bigsize));
75 for (const sk_sp<SkPicture>& page : fPages) {
76 c->drawPicture(page);
77 c->drawAnnotation(SkRect::MakeEmpty(), kEndPage, nullptr);
78 }
79 sk_sp<SkPicture> p = fPictureRecorder.finishRecordingAsPicture();
80 p->serialize(wStream);
81 fPages.reset();
82 fSizes.reset();
83 return;
84 }
onAbort__anon4dea72130111::MultiPictureDocument85 void onAbort() override {
86 fPages.reset();
87 fSizes.reset();
88 }
89 };
90 }
91
SkMakeMultiPictureDocument(SkWStream * wStream)92 sk_sp<SkDocument> SkMakeMultiPictureDocument(SkWStream* wStream) {
93 return sk_make_sp<MultiPictureDocument>(wStream, nullptr);
94 }
95
96 ////////////////////////////////////////////////////////////////////////////////
97
SkMultiPictureDocumentReadPageCount(SkStreamSeekable * stream)98 int SkMultiPictureDocumentReadPageCount(SkStreamSeekable* stream) {
99 if (!stream) {
100 return 0;
101 }
102 stream->seek(0);
103 const size_t size = sizeof(kMagic) - 1;
104 char buffer[size];
105 if (size != stream->read(buffer, size) || 0 != memcmp(kMagic, buffer, size)) {
106 stream = nullptr;
107 return 0;
108 }
109 uint32_t versionNumber = stream->readU32();
110 if (versionNumber != kVersion) {
111 return 0;
112 }
113 uint32_t pageCount = stream->readU32();
114 if (pageCount > INT_MAX) {
115 return 0;
116 }
117 // leave stream position right here.
118 return (int)pageCount;
119 }
120
SkMultiPictureDocumentReadPageSizes(SkStreamSeekable * stream,SkDocumentPage * dstArray,int dstArrayCount)121 bool SkMultiPictureDocumentReadPageSizes(SkStreamSeekable* stream,
122 SkDocumentPage* dstArray,
123 int dstArrayCount) {
124 if (!dstArray || dstArrayCount < 1) {
125 return false;
126 }
127 int pageCount = SkMultiPictureDocumentReadPageCount(stream);
128 if (pageCount < 1 || pageCount != dstArrayCount) {
129 return false;
130 }
131 for (int i = 0; i < pageCount; ++i) {
132 SkSize& s = dstArray[i].fSize;
133 if (sizeof(s) != stream->read(&s, sizeof(s))) {
134 return false;
135 }
136 }
137 // leave stream position right here.
138 return true;
139 }
140
141 namespace {
142 struct PagerCanvas : public SkNWayCanvas {
143 SkPictureRecorder fRecorder;
144 SkDocumentPage* fDst;
145 int fCount;
146 int fIndex = 0;
PagerCanvas__anon4dea72130211::PagerCanvas147 PagerCanvas(SkISize wh, SkDocumentPage* dst, int count)
148 : SkNWayCanvas(wh.width(), wh.height()), fDst(dst), fCount(count) {
149 this->nextCanvas();
150 }
nextCanvas__anon4dea72130211::PagerCanvas151 void nextCanvas() {
152 if (fIndex < fCount) {
153 SkRect bounds = SkRect::MakeSize(fDst[fIndex].fSize);
154 this->addCanvas(fRecorder.beginRecording(bounds));
155 }
156 }
onDrawAnnotation__anon4dea72130211::PagerCanvas157 void onDrawAnnotation(const SkRect& r, const char* key, SkData* d) override {
158 if (0 == strcmp(key, kEndPage)) {
159 this->removeAll();
160 if (fIndex < fCount) {
161 fDst[fIndex].fPicture = fRecorder.finishRecordingAsPicture();
162 ++fIndex;
163 }
164 this->nextCanvas();
165 } else {
166 this->SkNWayCanvas::onDrawAnnotation(r, key, d);
167 }
168 }
169 };
170 } // namespace
171
SkMultiPictureDocumentRead(SkStreamSeekable * stream,SkDocumentPage * dstArray,int dstArrayCount)172 bool SkMultiPictureDocumentRead(SkStreamSeekable* stream,
173 SkDocumentPage* dstArray,
174 int dstArrayCount) {
175 if (!SkMultiPictureDocumentReadPageSizes(stream, dstArray, dstArrayCount)) {
176 return false;
177 }
178 SkSize joined = {0.0f, 0.0f};
179 for (int i = 0; i < dstArrayCount; ++i) {
180 joined = SkSize{SkTMax(joined.width(), dstArray[i].fSize.width()),
181 SkTMax(joined.height(), dstArray[i].fSize.height())};
182 }
183
184 auto picture = SkPicture::MakeFromStream(stream);
185
186 PagerCanvas canvas(joined.toCeil(), dstArray, dstArrayCount);
187 // Must call playback(), not drawPicture() to reach
188 // PagerCanvas::onDrawAnnotation().
189 picture->playback(&canvas);
190 if (canvas.fIndex != dstArrayCount) {
191 SkDEBUGF(("Malformed SkMultiPictureDocument\n"));
192 }
193 return true;
194 }
195