// https://www.w3.org/TR/SVG/pservers.html#LinearGradientElementHrefAttribute
void SkSVGLinearGradient::collectColorStops(const SkSVGRenderContext& ctx,
SkSTArray<2, SkScalar, true>* pos,
SkSTArray<2, SkColor, true>* 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(SkColorSetA(stop.stopColor(),
SkScalarRoundToInt(stop.stopOpacity() * 255)));
pos->push_back(SkTPin(ltx.resolve(stop.offset(), SkSVGLengthContext::LengthType::kOther),
0.f, 1.f));
}
SkASSERT(colors->count() == pos->count());
if (pos->empty() && !fHref.value().isEmpty()) {
const auto* ref = ctx.findNodeById(fHref);
if (ref && ref->tag() == SkSVGTag::kLinearGradient) {
static_cast<const SkSVGLinearGradient*>(ref)->collectColorStops(ctx, pos, colors);
}
}
}
bool SkSVGLinearGradient::onAsPaint(const SkSVGRenderContext& ctx, SkPaint* paint) const {
const auto& lctx = ctx.lengthContext();
const auto x1 = lctx.resolve(fX1, SkSVGLengthContext::LengthType::kHorizontal);
const auto y1 = lctx.resolve(fY1, SkSVGLengthContext::LengthType::kVertical);
const auto x2 = lctx.resolve(fX2, SkSVGLengthContext::LengthType::kHorizontal);
const auto y2 = lctx.resolve(fY2, SkSVGLengthContext::LengthType::kVertical);
const SkPoint pts[2] = { {x1, y1}, {x2, y2}};
SkSTArray<2, SkColor , true> colors;
SkSTArray<2, SkScalar, true> 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<SkShader::TileMode>(SkSVGSpreadMethod::Type::kPad) ==
SkShader::kClamp_TileMode, "SkSVGSpreadMethod::Type is out of sync");
static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kRepeat) ==
SkShader::kRepeat_TileMode, "SkSVGSpreadMethod::Type is out of sync");
static_assert(static_cast<SkShader::TileMode>(SkSVGSpreadMethod::Type::kReflect) ==
SkShader::kMirror_TileMode, "SkSVGSpreadMethod::Type is out of sync");
const auto tileMode = static_cast<SkShader::TileMode>(fSpreadMethod.type());
paint->setShader(SkGradientShader::MakeLinear(pts, colors.begin(), pos.begin(), colors.count(),
tileMode, 0, &fGradientTransform.value()));
return true;
}
SkPath SkSVGPath::onAsPath(const SkSVGRenderContext& ctx) const {
// the computed fillType follows inheritance rules and needs to be applied at draw time.
fPath.setFillType(FillRuleToFillType(*ctx.presentationContext().fInherited.fFillRule.get()));
SkPath path = fPath;
this->mapToParent(&path);
return path;
}
SkPath SkSVGPoly::onAsPath(const SkSVGRenderContext& ctx) const {
SkPath path = fPath;
// clip-rule can be inherited and needs to be applied at clip time.
path.setFillType(ctx.presentationContext().fInherited.fClipRule.get()->asFillType());
this->mapToParent(&path);
return path;
}
void SkSVGShape::onRender(const SkSVGRenderContext& ctx) const {
const auto fillType = ctx.presentationContext().fInherited.fFillRule.get()->asFillType();
// TODO: this approach forces duplicate geometry resolution in onDraw(); refactor to avoid.
if (const SkPaint* fillPaint = ctx.fillPaint()) {
this->onDraw(ctx.canvas(), ctx.lengthContext(), *fillPaint, fillType);
}
if (const SkPaint* strokePaint = ctx.strokePaint()) {
this->onDraw(ctx.canvas(), ctx.lengthContext(), *strokePaint, fillType);
}
}
void SkSVGPath::onRender(SkCanvas* canvas, const SkSVGRenderContext& ctx) const {
this->doRender(canvas, ctx.fillPaint());
this->doRender(canvas, ctx.strokePaint());
}
