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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkData.h"
#include "SkOncePtr.h"
#include "SkPDFCanon.h"
#include "SkPDFFormXObject.h"
#include "SkPDFGraphicState.h"
#include "SkPDFUtils.h"
#include "SkTypes.h"
static const char* as_blend_mode(SkXfermode::Mode mode) {
switch (mode) {
case SkXfermode::kSrcOver_Mode:
return "Normal";
case SkXfermode::kMultiply_Mode:
return "Multiply";
case SkXfermode::kScreen_Mode:
return "Screen";
case SkXfermode::kOverlay_Mode:
return "Overlay";
case SkXfermode::kDarken_Mode:
return "Darken";
case SkXfermode::kLighten_Mode:
return "Lighten";
case SkXfermode::kColorDodge_Mode:
return "ColorDodge";
case SkXfermode::kColorBurn_Mode:
return "ColorBurn";
case SkXfermode::kHardLight_Mode:
return "HardLight";
case SkXfermode::kSoftLight_Mode:
return "SoftLight";
case SkXfermode::kDifference_Mode:
return "Difference";
case SkXfermode::kExclusion_Mode:
return "Exclusion";
case SkXfermode::kHue_Mode:
return "Hue";
case SkXfermode::kSaturation_Mode:
return "Saturation";
case SkXfermode::kColor_Mode:
return "Color";
case SkXfermode::kLuminosity_Mode:
return "Luminosity";
// These are handled in SkPDFDevice::setUpContentEntry.
case SkXfermode::kClear_Mode:
case SkXfermode::kSrc_Mode:
case SkXfermode::kDst_Mode:
case SkXfermode::kDstOver_Mode:
case SkXfermode::kSrcIn_Mode:
case SkXfermode::kDstIn_Mode:
case SkXfermode::kSrcOut_Mode:
case SkXfermode::kDstOut_Mode:
case SkXfermode::kSrcATop_Mode:
case SkXfermode::kDstATop_Mode:
case SkXfermode::kModulate_Mode:
return "Normal";
// TODO(vandebo): Figure out if we can support more of these modes.
case SkXfermode::kXor_Mode:
case SkXfermode::kPlus_Mode:
return nullptr;
}
return nullptr;
}
// If a SkXfermode is unsupported in PDF, this function returns
// SrcOver, otherwise, it returns that Xfermode as a Mode.
static SkXfermode::Mode mode_for_pdf(const SkXfermode* xfermode) {
SkXfermode::Mode mode = SkXfermode::kSrcOver_Mode;
if (xfermode) {
xfermode->asMode(&mode);
}
switch (mode) {
case SkXfermode::kSrcOver_Mode:
case SkXfermode::kMultiply_Mode:
case SkXfermode::kScreen_Mode:
case SkXfermode::kOverlay_Mode:
case SkXfermode::kDarken_Mode:
case SkXfermode::kLighten_Mode:
case SkXfermode::kColorDodge_Mode:
case SkXfermode::kColorBurn_Mode:
case SkXfermode::kHardLight_Mode:
case SkXfermode::kSoftLight_Mode:
case SkXfermode::kDifference_Mode:
case SkXfermode::kExclusion_Mode:
case SkXfermode::kHue_Mode:
case SkXfermode::kSaturation_Mode:
case SkXfermode::kColor_Mode:
case SkXfermode::kLuminosity_Mode:
// Mode is suppported and handled by pdf graphics state.
return mode;
default:
return SkXfermode::kSrcOver_Mode; // Default mode.
}
}
SkPDFGraphicState::SkPDFGraphicState(const SkPaint& p)
: fStrokeWidth(p.getStrokeWidth())
, fStrokeMiter(p.getStrokeMiter())
, fAlpha(p.getAlpha())
, fStrokeCap(SkToU8(p.getStrokeCap()))
, fStrokeJoin(SkToU8(p.getStrokeJoin()))
, fMode(SkToU8(mode_for_pdf(p.getXfermode()))) {}
// static
SkPDFGraphicState* SkPDFGraphicState::GetGraphicStateForPaint(
SkPDFCanon* canon, const SkPaint& paint) {
SkASSERT(canon);
SkPDFGraphicState key(paint);
if (const SkPDFGraphicState* canonGS = canon->findGraphicState(key)) {
// The returned SkPDFGraphicState must be made non-const,
// since the emitObject() interface is non-const. But We
// promise that there is no way to mutate this object from
// here on out.
return SkRef(const_cast<SkPDFGraphicState*>(canonGS));
}
SkPDFGraphicState* pdfGraphicState = new SkPDFGraphicState(paint);
canon->addGraphicState(pdfGraphicState);
return pdfGraphicState;
}
static SkPDFObject* create_invert_function() {
// Acrobat crashes if we use a type 0 function, kpdf crashes if we use
// a type 2 function, so we use a type 4 function.
SkAutoTUnref<SkPDFArray> domainAndRange(new SkPDFArray);
domainAndRange->reserve(2);
domainAndRange->appendInt(0);
domainAndRange->appendInt(1);
static const char psInvert[] = "{1 exch sub}";
// Do not copy the trailing '\0' into the SkData.
SkAutoTUnref<SkData> psInvertStream(
SkData::NewWithoutCopy(psInvert, strlen(psInvert)));
SkPDFStream* invertFunction = new SkPDFStream(psInvertStream.get());
invertFunction->insertInt("FunctionType", 4);
invertFunction->insertObject("Domain", SkRef(domainAndRange.get()));
invertFunction->insertObject("Range", domainAndRange.detach());
return invertFunction;
}
SK_DECLARE_STATIC_ONCE_PTR(SkPDFObject, invertFunction);
// static
SkPDFDict* SkPDFGraphicState::GetSMaskGraphicState(SkPDFFormXObject* sMask,
bool invert,
SkPDFSMaskMode sMaskMode) {
// The practical chances of using the same mask more than once are unlikely
// enough that it's not worth canonicalizing.
SkAutoTUnref<SkPDFDict> sMaskDict(new SkPDFDict("Mask"));
if (sMaskMode == kAlpha_SMaskMode) {
sMaskDict->insertName("S", "Alpha");
} else if (sMaskMode == kLuminosity_SMaskMode) {
sMaskDict->insertName("S", "Luminosity");
}
sMaskDict->insertObjRef("G", SkRef(sMask));
if (invert) {
sMaskDict->insertObjRef("TR", SkRef(invertFunction.get(create_invert_function)));
}
SkPDFDict* result = new SkPDFDict("ExtGState");
result->insertObject("SMask", sMaskDict.detach());
return result;
}
static SkPDFDict* create_no_smask_graphic_state() {
SkPDFDict* noSMaskGS = new SkPDFDict("ExtGState");
noSMaskGS->insertName("SMask", "None");
return noSMaskGS;
}
SK_DECLARE_STATIC_ONCE_PTR(SkPDFDict, noSMaskGraphicState);
// static
SkPDFDict* SkPDFGraphicState::GetNoSMaskGraphicState() {
return SkRef(noSMaskGraphicState.get(create_no_smask_graphic_state));
}
void SkPDFGraphicState::emitObject(
SkWStream* stream,
const SkPDFObjNumMap& objNumMap,
const SkPDFSubstituteMap& substitutes) const {
SkAutoTUnref<SkPDFDict> dict(new SkPDFDict("ExtGState"));
dict->insertName("Type", "ExtGState");
SkScalar alpha = SkIntToScalar(fAlpha) / 0xFF;
dict->insertScalar("CA", alpha);
dict->insertScalar("ca", alpha);
SkPaint::Cap strokeCap = (SkPaint::Cap)fStrokeCap;
SkPaint::Join strokeJoin = (SkPaint::Join)fStrokeJoin;
SkXfermode::Mode xferMode = (SkXfermode::Mode)fMode;
static_assert(SkPaint::kButt_Cap == 0, "paint_cap_mismatch");
static_assert(SkPaint::kRound_Cap == 1, "paint_cap_mismatch");
static_assert(SkPaint::kSquare_Cap == 2, "paint_cap_mismatch");
static_assert(SkPaint::kCapCount == 3, "paint_cap_mismatch");
SkASSERT(strokeCap >= 0 && strokeCap <= 2);
dict->insertInt("LC", strokeCap);
static_assert(SkPaint::kMiter_Join == 0, "paint_join_mismatch");
static_assert(SkPaint::kRound_Join == 1, "paint_join_mismatch");
static_assert(SkPaint::kBevel_Join == 2, "paint_join_mismatch");
static_assert(SkPaint::kJoinCount == 3, "paint_join_mismatch");
SkASSERT(strokeJoin >= 0 && strokeJoin <= 2);
dict->insertInt("LJ", strokeJoin);
dict->insertScalar("LW", fStrokeWidth);
dict->insertScalar("ML", fStrokeMiter);
dict->insertBool("SA", true); // SA = Auto stroke adjustment.
dict->insertName("BM", as_blend_mode(xferMode));
dict->emitObject(stream, objNumMap, substitutes);
}