blob: 9868ca26920f69592c17f7a71091ef8a32b42331 [file] [log] [blame]
/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkMultiPictureDocument.h"
#include "SkMultiPictureDocumentPriv.h"
#include "SkNWayCanvas.h"
#include "SkPicture.h"
#include "SkPictureRecorder.h"
#include "SkStream.h"
#include "SkTArray.h"
#include <limits.h>
/*
File format:
BEGINNING_OF_FILE:
kMagic
uint32_t version_number (==2)
uint32_t page_count
{
float sizeX
float sizeY
} * page_count
skp file
*/
namespace {
// The unique file signature for this file type.
static constexpr char kMagic[] = "Skia Multi-Picture Doc\n\n";
static constexpr char kEndPage[] = "SkMultiPictureEndPage";
const uint32_t kVersion = 2;
static SkSize join(const SkTArray<SkSize>& sizes) {
SkSize joined = {0, 0};
for (SkSize s : sizes) {
joined = SkSize{SkTMax(joined.width(), s.width()), SkTMax(joined.height(), s.height())};
}
return joined;
}
static SkCanvas* trim(SkCanvas* canvas,
SkScalar w, SkScalar h,
const SkRect& trimBox) {
// Only trim if necessary.
if (trimBox != SkRect::MakeWH(w, h)) {
// All SkDocument implementations implement trimBox using a
// clip+translate.
canvas->clipRect(trimBox);
canvas->translate(trimBox.x(), trimBox.y());
}
return canvas;
}
struct MultiPictureDocument final : public SkDocument {
SkPictureRecorder fPictureRecorder;
SkSize fCurrentPageSize;
SkTArray<sk_sp<SkPicture>> fPages;
SkTArray<SkSize> fSizes;
MultiPictureDocument(SkWStream* s, void (*d)(SkWStream*, bool))
: SkDocument(s, d) {}
~MultiPictureDocument() override { this->close(); }
SkCanvas* onBeginPage(SkScalar w, SkScalar h, const SkRect& c) override {
fCurrentPageSize.set(w, h);
return trim(fPictureRecorder.beginRecording(w, h), w, h, c);
}
void onEndPage() override {
fSizes.push_back(fCurrentPageSize);
fPages.push_back(fPictureRecorder.finishRecordingAsPicture());
}
void onClose(SkWStream* wStream) override {
SkASSERT(wStream);
SkASSERT(wStream->bytesWritten() == 0);
wStream->writeText(kMagic);
wStream->write32(kVersion);
wStream->write32(SkToU32(fPages.count()));
for (SkSize s : fSizes) {
wStream->write(&s, sizeof(s));
}
SkSize bigsize = join(fSizes);
SkCanvas* c = fPictureRecorder.beginRecording(SkRect::MakeSize(bigsize));
for (const sk_sp<SkPicture>& page : fPages) {
c->drawPicture(page);
c->drawAnnotation(SkRect::MakeEmpty(), kEndPage, nullptr);
}
sk_sp<SkPicture> p = fPictureRecorder.finishRecordingAsPicture();
p->serialize(wStream);
fPages.reset();
fSizes.reset();
return;
}
void onAbort() override {
fPages.reset();
fSizes.reset();
}
};
}
sk_sp<SkDocument> SkMakeMultiPictureDocument(SkWStream* wStream) {
return sk_make_sp<MultiPictureDocument>(wStream, nullptr);
}
////////////////////////////////////////////////////////////////////////////////
int SkMultiPictureDocumentReadPageCount(SkStreamSeekable* stream) {
if (!stream) {
return 0;
}
stream->seek(0);
const size_t size = sizeof(kMagic) - 1;
char buffer[size];
if (size != stream->read(buffer, size) || 0 != memcmp(kMagic, buffer, size)) {
stream = nullptr;
return 0;
}
uint32_t versionNumber = stream->readU32();
if (versionNumber != kVersion) {
return 0;
}
uint32_t pageCount = stream->readU32();
if (pageCount > INT_MAX) {
return 0;
}
// leave stream position right here.
return (int)pageCount;
}
bool SkMultiPictureDocumentReadPageSizes(SkStreamSeekable* stream,
SkDocumentPage* dstArray,
int dstArrayCount) {
if (!dstArray || dstArrayCount < 1) {
return false;
}
int pageCount = SkMultiPictureDocumentReadPageCount(stream);
if (pageCount < 1 || pageCount != dstArrayCount) {
return false;
}
for (int i = 0; i < pageCount; ++i) {
SkSize& s = dstArray[i].fSize;
if (sizeof(s) != stream->read(&s, sizeof(s))) {
return false;
}
}
// leave stream position right here.
return true;
}
namespace {
struct PagerCanvas : public SkNWayCanvas {
SkPictureRecorder fRecorder;
SkDocumentPage* fDst;
int fCount;
int fIndex = 0;
PagerCanvas(SkISize wh, SkDocumentPage* dst, int count)
: SkNWayCanvas(wh.width(), wh.height()), fDst(dst), fCount(count) {
this->nextCanvas();
}
void nextCanvas() {
if (fIndex < fCount) {
SkRect bounds = SkRect::MakeSize(fDst[fIndex].fSize);
this->addCanvas(fRecorder.beginRecording(bounds));
}
}
void onDrawAnnotation(const SkRect& r, const char* key, SkData* d) override {
if (0 == strcmp(key, kEndPage)) {
this->removeAll();
if (fIndex < fCount) {
fDst[fIndex].fPicture = fRecorder.finishRecordingAsPicture();
++fIndex;
}
this->nextCanvas();
} else {
this->SkNWayCanvas::onDrawAnnotation(r, key, d);
}
}
};
} // namespace
bool SkMultiPictureDocumentRead(SkStreamSeekable* stream,
SkDocumentPage* dstArray,
int dstArrayCount) {
if (!SkMultiPictureDocumentReadPageSizes(stream, dstArray, dstArrayCount)) {
return false;
}
SkSize joined = {0.0f, 0.0f};
for (int i = 0; i < dstArrayCount; ++i) {
joined = SkSize{SkTMax(joined.width(), dstArray[i].fSize.width()),
SkTMax(joined.height(), dstArray[i].fSize.height())};
}
auto picture = SkPicture::MakeFromStream(stream);
PagerCanvas canvas(joined.toCeil(), dstArray, dstArrayCount);
// Must call playback(), not drawPicture() to reach
// PagerCanvas::onDrawAnnotation().
picture->playback(&canvas);
if (canvas.fIndex != dstArrayCount) {
SkDEBUGF(("Malformed SkMultiPictureDocument\n"));
}
return true;
}