blob: cf09ee5c17aa74d7c4c6a169c6bd824b1a40105d [file] [log] [blame]
/*
* Copyright 2017 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "include/private/SkTPin.h"
#include "modules/svg/include/SkSVGGradient.h"
#include "modules/svg/include/SkSVGRenderContext.h"
#include "modules/svg/include/SkSVGStop.h"
#include "modules/svg/include/SkSVGValue.h"
bool SkSVGGradient::parseAndSetAttribute(const char* name, const char* value) {
return INHERITED::parseAndSetAttribute(name, value) ||
this->setGradientTransform(SkSVGAttributeParser::parse<SkSVGTransformType>(
"gradientTransform", name, value)) ||
this->setHref(SkSVGAttributeParser::parse<SkSVGIRI>("xlink:href", name, value)) ||
this->setSpreadMethod(
SkSVGAttributeParser::parse<SkSVGSpreadMethod>("spreadMethod", name, value)) ||
this->setGradientUnits(SkSVGAttributeParser::parse<SkSVGObjectBoundingBoxUnits>(
"gradientUnits", name, value));
}
// https://www.w3.org/TR/SVG11/pservers.html#LinearGradientElementHrefAttribute
void SkSVGGradient::collectColorStops(const SkSVGRenderContext& ctx,
StopPositionArray* pos,
StopColorArray* colors) const {
// Used to resolve percentage offsets.
const SkSVGLengthContext ltx(SkSize::Make(1, 1));
for (const auto& child : fChildren) {
if (child->tag() != SkSVGTag::kStop) {
continue;
}
const auto& stop = static_cast<const SkSVGStop&>(*child);
colors->push_back(this->resolveStopColor(ctx, stop));
pos->push_back(SkTPin(ltx.resolve(stop.getOffset(), SkSVGLengthContext::LengthType::kOther),
0.f, 1.f));
}
SkASSERT(colors->count() == pos->count());
if (pos->empty() && !fHref.iri().isEmpty()) {
const auto ref = ctx.findNodeById(fHref);
if (ref && (ref->tag() == SkSVGTag::kLinearGradient ||
ref->tag() == SkSVGTag::kRadialGradient)) {
static_cast<const SkSVGGradient*>(ref.get())->collectColorStops(ctx, pos, colors);
}
}
}
SkColor4f SkSVGGradient::resolveStopColor(const SkSVGRenderContext& ctx,
const SkSVGStop& stop) const {
const auto& stopColor = stop.getStopColor();
const auto& stopOpacity = stop.getStopOpacity();
// Uninherited presentation attrs should have a concrete value at this point.
if (!stopColor.isValue() || !stopOpacity.isValue()) {
SkDebugf("unhandled: stop-color or stop-opacity has no value\n");
return SkColors::kBlack;
}
const auto color = SkColor4f::FromColor(ctx.resolveSvgColor(*stopColor));
return { color.fR, color.fG, color.fB, *stopOpacity };
}
bool SkSVGGradient::onAsPaint(const SkSVGRenderContext& ctx, SkPaint* paint) const {
StopColorArray colors;
StopPositionArray pos;
this->collectColorStops(ctx, &pos, &colors);
// TODO:
// * stop (lazy?) sorting
// * href loop detection
// * href attribute inheritance (not just color stops)
// * objectBoundingBox units support
static_assert(static_cast<SkTileMode>(SkSVGSpreadMethod::Type::kPad) ==
SkTileMode::kClamp, "SkSVGSpreadMethod::Type is out of sync");
static_assert(static_cast<SkTileMode>(SkSVGSpreadMethod::Type::kRepeat) ==
SkTileMode::kRepeat, "SkSVGSpreadMethod::Type is out of sync");
static_assert(static_cast<SkTileMode>(SkSVGSpreadMethod::Type::kReflect) ==
SkTileMode::kMirror, "SkSVGSpreadMethod::Type is out of sync");
const auto tileMode = static_cast<SkTileMode>(fSpreadMethod.type());
const auto obbt = ctx.transformForCurrentOBB(fGradientUnits);
const auto localMatrix = SkMatrix::Translate(obbt.offset.x, obbt.offset.y)
* SkMatrix::Scale(obbt.scale.x, obbt.scale.y)
* fGradientTransform;
paint->setShader(this->onMakeShader(ctx, colors.begin(), pos.begin(), colors.count(), tileMode,
localMatrix));
return true;
}
// https://www.w3.org/TR/SVG11/pservers.html#LinearGradientElementSpreadMethodAttribute
template <>
bool SkSVGAttributeParser::parse(SkSVGSpreadMethod* spread) {
static const struct {
SkSVGSpreadMethod::Type fType;
const char* fName;
} gSpreadInfo[] = {
{ SkSVGSpreadMethod::Type::kPad , "pad" },
{ SkSVGSpreadMethod::Type::kReflect, "reflect" },
{ SkSVGSpreadMethod::Type::kRepeat , "repeat" },
};
bool parsedValue = false;
for (size_t i = 0; i < SK_ARRAY_COUNT(gSpreadInfo); ++i) {
if (this->parseExpectedStringToken(gSpreadInfo[i].fName)) {
*spread = SkSVGSpreadMethod(gSpreadInfo[i].fType);
parsedValue = true;
break;
}
}
return parsedValue && this->parseEOSToken();
}