blob: 9b92270daa810989d138c4115472f7adad0875dd [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 "experimental/svg/model/SkSVGPattern.h"
#include "experimental/svg/model/SkSVGRenderContext.h"
#include "experimental/svg/model/SkSVGValue.h"
#include "include/core/SkPictureRecorder.h"
#include "include/core/SkShader.h"
SkSVGPattern::SkSVGPattern() : INHERITED(SkSVGTag::kPattern) {}
void SkSVGPattern::setX(const SkSVGLength& x) {
fAttributes.fX.set(x);
}
void SkSVGPattern::setY(const SkSVGLength& y) {
fAttributes.fY.set(y);
}
void SkSVGPattern::setWidth(const SkSVGLength& w) {
fAttributes.fWidth.set(w);
}
void SkSVGPattern::setHeight(const SkSVGLength& h) {
fAttributes.fHeight.set(h);
}
void SkSVGPattern::setHref(const SkSVGStringType& href) {
fHref = std::move(href);
}
void SkSVGPattern::setPatternTransform(const SkSVGTransformType& patternTransform) {
fAttributes.fPatternTransform.set(patternTransform);
}
void SkSVGPattern::onSetAttribute(SkSVGAttribute attr, const SkSVGValue& v) {
switch (attr) {
case SkSVGAttribute::kX:
if (const auto* x = v.as<SkSVGLengthValue>()) {
this->setX(*x);
}
break;
case SkSVGAttribute::kY:
if (const auto* y = v.as<SkSVGLengthValue>()) {
this->setY(*y);
}
break;
case SkSVGAttribute::kWidth:
if (const auto* w = v.as<SkSVGLengthValue>()) {
this->setWidth(*w);
}
break;
case SkSVGAttribute::kHeight:
if (const auto* h = v.as<SkSVGLengthValue>()) {
this->setHeight(*h);
}
break;
case SkSVGAttribute::kHref:
if (const auto* href = v.as<SkSVGStringValue>()) {
this->setHref(*href);
}
break;
case SkSVGAttribute::kPatternTransform:
if (const auto* t = v.as<SkSVGTransformValue>()) {
this->setPatternTransform(*t);
}
break;
default:
this->INHERITED::onSetAttribute(attr, v);
}
}
const SkSVGPattern* SkSVGPattern::hrefTarget(const SkSVGRenderContext& ctx) const {
if (fHref.value().isEmpty()) {
return nullptr;
}
const auto* href = ctx.findNodeById(fHref);
if (!href || href->tag() != SkSVGTag::kPattern) {
return nullptr;
}
return static_cast<const SkSVGPattern*>(href);
}
template <typename T>
bool inherit_if_needed(const SkTLazy<T>& src, SkTLazy<T>& dst) {
if (!dst.isValid()) {
dst = src;
return true;
}
return false;
}
/* https://www.w3.org/TR/SVG/pservers.html#PatternElementHrefAttribute
*
* Any attributes which are defined on the referenced element which are not defined on this element
* are inherited by this element. If this element has no children, and the referenced element does
* (possibly due to its own ‘xlink:href’ attribute), then this element inherits the children from
* the referenced element. Inheritance can be indirect to an arbitrary level; thus, if the
* referenced element inherits attributes or children due to its own ‘xlink:href’ attribute, then
* the current element can inherit those attributes or children.
*/
const SkSVGPattern* SkSVGPattern::resolveHref(const SkSVGRenderContext& ctx,
PatternAttributes* attrs) const {
const SkSVGPattern *currentNode = this,
*contentNode = this;
do {
// Bitwise OR to avoid short-circuiting.
const bool didInherit =
inherit_if_needed(currentNode->fAttributes.fX , attrs->fX) |
inherit_if_needed(currentNode->fAttributes.fY , attrs->fY) |
inherit_if_needed(currentNode->fAttributes.fWidth , attrs->fWidth) |
inherit_if_needed(currentNode->fAttributes.fHeight , attrs->fHeight) |
inherit_if_needed(currentNode->fAttributes.fPatternTransform, attrs->fPatternTransform);
if (!contentNode->hasChildren()) {
contentNode = currentNode;
}
if (contentNode->hasChildren() && !didInherit) {
// All attributes have been resolved, and a valid content node has been found.
// We can terminate the href chain early.
break;
}
// TODO: reference loop mitigation.
currentNode = currentNode->hrefTarget(ctx);
} while (currentNode);
return contentNode;
}
bool SkSVGPattern::onAsPaint(const SkSVGRenderContext& ctx, SkPaint* paint) const {
PatternAttributes attrs;
const auto* contentNode = this->resolveHref(ctx, &attrs);
const auto tile = ctx.lengthContext().resolveRect(
attrs.fX.isValid() ? *attrs.fX.get() : SkSVGLength(0),
attrs.fY.isValid() ? *attrs.fY.get() : SkSVGLength(0),
attrs.fWidth.isValid() ? *attrs.fWidth.get() : SkSVGLength(0),
attrs.fHeight.isValid() ? *attrs.fHeight.get() : SkSVGLength(0));
if (tile.isEmpty()) {
return false;
}
const SkMatrix* patternTransform = attrs.fPatternTransform.isValid()
? &attrs.fPatternTransform.get()->value()
: nullptr;
SkPictureRecorder recorder;
SkSVGRenderContext recordingContext(ctx, recorder.beginRecording(tile));
// Cannot call into INHERITED:: because SkSVGHiddenContainer skips rendering.
contentNode->SkSVGContainer::onRender(recordingContext);
paint->setShader(recorder.finishRecordingAsPicture()->makeShader(
SkTileMode::kRepeat,
SkTileMode::kRepeat,
patternTransform,
&tile));
return true;
}