SkPDFFunctionShader* SkPDFFunctionShader::Create(
SkPDFCanon* canon, SkAutoTDelete<SkPDFShader::State>* autoState) {
const SkPDFShader::State& state = **autoState;
SkString (*codeFunction)(const SkShader::GradientInfo& info,
const SkMatrix& perspectiveRemover) = NULL;
SkPoint transformPoints[2];
// Depending on the type of the gradient, we want to transform the
// coordinate space in different ways.
const SkShader::GradientInfo* info = &state.fInfo;
transformPoints[0] = info->fPoint[0];
transformPoints[1] = info->fPoint[1];
switch (state.fType) {
case SkShader::kLinear_GradientType:
codeFunction = &linearCode;
break;
case SkShader::kRadial_GradientType:
transformPoints[1] = transformPoints[0];
transformPoints[1].fX += info->fRadius[0];
codeFunction = &radialCode;
break;
case SkShader::kRadial2_GradientType: {
// Bail out if the radii are the same.
if (info->fRadius[0] == info->fRadius[1]) {
return NULL;
}
transformPoints[1] = transformPoints[0];
SkScalar dr = info->fRadius[1] - info->fRadius[0];
transformPoints[1].fX += dr;
codeFunction = &twoPointRadialCode;
break;
}
case SkShader::kConical_GradientType: {
transformPoints[1] = transformPoints[0];
transformPoints[1].fX += SK_Scalar1;
codeFunction = &twoPointConicalCode;
break;
}
case SkShader::kSweep_GradientType:
transformPoints[1] = transformPoints[0];
transformPoints[1].fX += SK_Scalar1;
codeFunction = &sweepCode;
break;
case SkShader::kColor_GradientType:
case SkShader::kNone_GradientType:
default:
return NULL;
}
// Move any scaling (assuming a unit gradient) or translation
// (and rotation for linear gradient), of the final gradient from
// info->fPoints to the matrix (updating bbox appropriately). Now
// the gradient can be drawn on on the unit segment.
SkMatrix mapperMatrix;
unitToPointsMatrix(transformPoints, &mapperMatrix);
SkMatrix finalMatrix = state.fCanvasTransform;
finalMatrix.preConcat(state.fShaderTransform);
finalMatrix.preConcat(mapperMatrix);
// Preserves as much as posible in the final matrix, and only removes
// the perspective. The inverse of the perspective is stored in
// perspectiveInverseOnly matrix and has 3 useful numbers
// (p0, p1, p2), while everything else is either 0 or 1.
// In this way the shader will handle it eficiently, with minimal code.
SkMatrix perspectiveInverseOnly = SkMatrix::I();
if (finalMatrix.hasPerspective()) {
if (!split_perspective(finalMatrix,
&finalMatrix, &perspectiveInverseOnly)) {
return NULL;
}
}
SkRect bbox;
bbox.set(state.fBBox);
if (!inverse_transform_bbox(finalMatrix, &bbox)) {
return NULL;
}
SkAutoTUnref<SkPDFArray> domain(new SkPDFArray);
domain->reserve(4);
domain->appendScalar(bbox.fLeft);
domain->appendScalar(bbox.fRight);
domain->appendScalar(bbox.fTop);
domain->appendScalar(bbox.fBottom);
SkString functionCode;
// The two point radial gradient further references
// state.fInfo
// in translating from x, y coordinates to the t parameter. So, we have
// to transform the points and radii according to the calculated matrix.
if (state.fType == SkShader::kRadial2_GradientType) {
SkShader::GradientInfo twoPointRadialInfo = *info;
SkMatrix inverseMapperMatrix;
if (!mapperMatrix.invert(&inverseMapperMatrix)) {
return NULL;
}
inverseMapperMatrix.mapPoints(twoPointRadialInfo.fPoint, 2);
twoPointRadialInfo.fRadius[0] =
inverseMapperMatrix.mapRadius(info->fRadius[0]);
twoPointRadialInfo.fRadius[1] =
inverseMapperMatrix.mapRadius(info->fRadius[1]);
functionCode = codeFunction(twoPointRadialInfo, perspectiveInverseOnly);
} else {
functionCode = codeFunction(*info, perspectiveInverseOnly);
}
SkAutoTUnref<SkPDFDict> pdfShader(new SkPDFDict);
pdfShader->insertInt("ShadingType", 1);
pdfShader->insertName("ColorSpace", "DeviceRGB");
pdfShader->insert("Domain", domain.get());
SkAutoTUnref<SkPDFStream> function(
make_ps_function(functionCode, domain.get()));
pdfShader->insert("Function", new SkPDFObjRef(function))->unref();
SkAutoTUnref<SkPDFArray> matrixArray(
SkPDFUtils::MatrixToArray(finalMatrix));
SkPDFFunctionShader* pdfFunctionShader =
SkNEW_ARGS(SkPDFFunctionShader, (autoState->detach()));
pdfFunctionShader->insertInt("PatternType", 2);
pdfFunctionShader->insert("Matrix", matrixArray.get());
pdfFunctionShader->insert("Shading", pdfShader.get());
canon->addFunctionShader(pdfFunctionShader);
return pdfFunctionShader;
}
static SkPDFIndirectReference make_function_shader(SkPDFDocument* doc,
const SkPDFGradientShader::Key& state) {
SkPoint transformPoints[2];
const SkShader::GradientInfo& info = state.fInfo;
SkMatrix finalMatrix = state.fCanvasTransform;
finalMatrix.preConcat(state.fShaderTransform);
bool doStitchFunctions = (state.fType == SkShader::kLinear_GradientType ||
state.fType == SkShader::kRadial_GradientType ||
state.fType == SkShader::kConical_GradientType) &&
(SkTileMode)info.fTileMode == SkTileMode::kClamp &&
!finalMatrix.hasPerspective();
int32_t shadingType = 1;
auto pdfShader = SkPDFMakeDict();
// The two point radial gradient further references
// state.fInfo
// in translating from x, y coordinates to the t parameter. So, we have
// to transform the points and radii according to the calculated matrix.
if (doStitchFunctions) {
pdfShader->insertObject("Function", gradientStitchCode(info));
shadingType = (state.fType == SkShader::kLinear_GradientType) ? 2 : 3;
auto extend = SkPDFMakeArray();
extend->reserve(2);
extend->appendBool(true);
extend->appendBool(true);
pdfShader->insertObject("Extend", std::move(extend));
std::unique_ptr<SkPDFArray> coords;
if (state.fType == SkShader::kConical_GradientType) {
SkScalar r1 = info.fRadius[0];
SkScalar r2 = info.fRadius[1];
SkPoint pt1 = info.fPoint[0];
SkPoint pt2 = info.fPoint[1];
FixUpRadius(pt1, r1, pt2, r2);
coords = SkPDFMakeArray(pt1.x(),
pt1.y(),
r1,
pt2.x(),
pt2.y(),
r2);
} else if (state.fType == SkShader::kRadial_GradientType) {
const SkPoint& pt1 = info.fPoint[0];
coords = SkPDFMakeArray(pt1.x(),
pt1.y(),
0,
pt1.x(),
pt1.y(),
info.fRadius[0]);
} else {
const SkPoint& pt1 = info.fPoint[0];
const SkPoint& pt2 = info.fPoint[1];
coords = SkPDFMakeArray(pt1.x(),
pt1.y(),
pt2.x(),
pt2.y());
}
pdfShader->insertObject("Coords", std::move(coords));
} else {
// Depending on the type of the gradient, we want to transform the
// coordinate space in different ways.
transformPoints[0] = info.fPoint[0];
transformPoints[1] = info.fPoint[1];
switch (state.fType) {
case SkShader::kLinear_GradientType:
break;
case SkShader::kRadial_GradientType:
transformPoints[1] = transformPoints[0];
transformPoints[1].fX += info.fRadius[0];
break;
case SkShader::kConical_GradientType: {
transformPoints[1] = transformPoints[0];
transformPoints[1].fX += SK_Scalar1;
break;
}
case SkShader::kSweep_GradientType:
transformPoints[1] = transformPoints[0];
transformPoints[1].fX += SK_Scalar1;
break;
case SkShader::kColor_GradientType:
case SkShader::kNone_GradientType:
default:
return SkPDFIndirectReference();
}
// Move any scaling (assuming a unit gradient) or translation
// (and rotation for linear gradient), of the final gradient from
// info.fPoints to the matrix (updating bbox appropriately). Now
// the gradient can be drawn on on the unit segment.
SkMatrix mapperMatrix;
unit_to_points_matrix(transformPoints, &mapperMatrix);
finalMatrix.preConcat(mapperMatrix);
// Preserves as much as possible in the final matrix, and only removes
// the perspective. The inverse of the perspective is stored in
// perspectiveInverseOnly matrix and has 3 useful numbers
// (p0, p1, p2), while everything else is either 0 or 1.
// In this way the shader will handle it eficiently, with minimal code.
SkMatrix perspectiveInverseOnly = SkMatrix::I();
if (finalMatrix.hasPerspective()) {
if (!split_perspective(finalMatrix,
&finalMatrix, &perspectiveInverseOnly)) {
return SkPDFIndirectReference();
}
}
SkRect bbox;
bbox.set(state.fBBox);
if (!SkPDFUtils::InverseTransformBBox(finalMatrix, &bbox)) {
return SkPDFIndirectReference();
}
SkDynamicMemoryWStream functionCode;
SkShader::GradientInfo infoCopy = info;
if (state.fType == SkShader::kConical_GradientType) {
SkMatrix inverseMapperMatrix;
if (!mapperMatrix.invert(&inverseMapperMatrix)) {
return SkPDFIndirectReference();
}
inverseMapperMatrix.mapPoints(infoCopy.fPoint, 2);
infoCopy.fRadius[0] = inverseMapperMatrix.mapRadius(info.fRadius[0]);
infoCopy.fRadius[1] = inverseMapperMatrix.mapRadius(info.fRadius[1]);
}
switch (state.fType) {
case SkShader::kLinear_GradientType:
linearCode(infoCopy, perspectiveInverseOnly, &functionCode);
break;
case SkShader::kRadial_GradientType:
radialCode(infoCopy, perspectiveInverseOnly, &functionCode);
break;
case SkShader::kConical_GradientType:
twoPointConicalCode(infoCopy, perspectiveInverseOnly, &functionCode);
break;
case SkShader::kSweep_GradientType:
sweepCode(infoCopy, perspectiveInverseOnly, &functionCode);
break;
default:
SkASSERT(false);
}
pdfShader->insertObject(
"Domain", SkPDFMakeArray(bbox.left(), bbox.right(), bbox.top(), bbox.bottom()));
auto domain = SkPDFMakeArray(bbox.left(), bbox.right(), bbox.top(), bbox.bottom());
std::unique_ptr<SkPDFArray> rangeObject = SkPDFMakeArray(0, 1, 0, 1, 0, 1);
pdfShader->insertRef("Function",
make_ps_function(functionCode.detachAsStream(), std::move(domain),
std::move(rangeObject), doc));
}
pdfShader->insertInt("ShadingType", shadingType);
pdfShader->insertName("ColorSpace", "DeviceRGB");
SkPDFDict pdfFunctionShader("Pattern");
pdfFunctionShader.insertInt("PatternType", 2);
pdfFunctionShader.insertObject("Matrix", SkPDFUtils::MatrixToArray(finalMatrix));
pdfFunctionShader.insertObject("Shading", std::move(pdfShader));
return doc->emit(pdfFunctionShader);
}