1 /*
2 * Copyright 2021 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "include/core/SkCanvas.h"
9 #include "include/core/SkImage.h"
10 #include "modules/svg/include/SkSVGAttributeParser.h"
11 #include "modules/svg/include/SkSVGImage.h"
12 #include "modules/svg/include/SkSVGRenderContext.h"
13 #include "modules/svg/include/SkSVGValue.h"
14 #include "src/utils/SkOSPath.h"
15
parseAndSetAttribute(const char * n,const char * v)16 bool SkSVGImage::parseAndSetAttribute(const char* n, const char* v) {
17 return INHERITED::parseAndSetAttribute(n, v) ||
18 this->setX(SkSVGAttributeParser::parse<SkSVGLength>("x", n, v)) ||
19 this->setY(SkSVGAttributeParser::parse<SkSVGLength>("y", n, v)) ||
20 this->setWidth(SkSVGAttributeParser::parse<SkSVGLength>("width", n, v)) ||
21 this->setHeight(SkSVGAttributeParser::parse<SkSVGLength>("height", n, v)) ||
22 this->setHref(SkSVGAttributeParser::parse<SkSVGIRI>("xlink:href", n, v)) ||
23 this->setPreserveAspectRatio(SkSVGAttributeParser::parse<SkSVGPreserveAspectRatio>(
24 "preserveAspectRatio", n, v));
25 }
26
onPrepareToRender(SkSVGRenderContext * ctx) const27 bool SkSVGImage::onPrepareToRender(SkSVGRenderContext* ctx) const {
28 // Width or height of 0 disables rendering per spec:
29 // https://www.w3.org/TR/SVG11/struct.html#ImageElement
30 return !fHref.iri().isEmpty() && fWidth.value() > 0 && fHeight.value() > 0 &&
31 INHERITED::onPrepareToRender(ctx);
32 }
33
LoadImage(const sk_sp<skresources::ResourceProvider> & rp,const SkSVGIRI & href)34 static sk_sp<SkImage> LoadImage(const sk_sp<skresources::ResourceProvider>& rp,
35 const SkSVGIRI& href) {
36 // TODO: It may be better to use the SVG 'id' attribute as the asset id, to allow
37 // clients to perform asset substitution based on element id.
38 sk_sp<skresources::ImageAsset> imageAsset;
39 switch (href.type()) {
40 case SkSVGIRI::Type::kDataURI:
41 imageAsset = rp->loadImageAsset("", href.iri().c_str(), "");
42 break;
43 case SkSVGIRI::Type::kNonlocal: {
44 const auto path = SkOSPath::Dirname(href.iri().c_str());
45 const auto name = SkOSPath::Basename(href.iri().c_str());
46 imageAsset = rp->loadImageAsset(path.c_str(), name.c_str(), /* id */ name.c_str());
47 break;
48 }
49 default:
50 SkDebugf("error loading image: unhandled iri type %d\n", href.type());
51 return nullptr;
52 }
53
54 return imageAsset ? imageAsset->getFrameData(0).image : nullptr;
55 }
56
LoadImage(const sk_sp<skresources::ResourceProvider> & rp,const SkSVGIRI & iri,const SkRect & viewPort,SkSVGPreserveAspectRatio par)57 SkSVGImage::ImageInfo SkSVGImage::LoadImage(const sk_sp<skresources::ResourceProvider>& rp,
58 const SkSVGIRI& iri,
59 const SkRect& viewPort,
60 SkSVGPreserveAspectRatio par) {
61 SkASSERT(rp);
62
63 // TODO: svg sources
64 sk_sp<SkImage> image = ::LoadImage(rp, iri);
65 if (!image) {
66 return {};
67 }
68
69 // Per spec: raster content has implicit viewbox of '0 0 width height'.
70 const SkRect viewBox = SkRect::Make(image->bounds());
71
72 // Map and place at x, y specified by viewport
73 const SkMatrix m = ComputeViewboxMatrix(viewBox, viewPort, par);
74 const SkRect dst = m.mapRect(viewBox).makeOffset(viewPort.fLeft, viewPort.fTop);
75
76 return {std::move(image), dst};
77 }
78
onRender(const SkSVGRenderContext & ctx) const79 void SkSVGImage::onRender(const SkSVGRenderContext& ctx) const {
80 // Per spec: x, w, width, height attributes establish the new viewport.
81 const SkSVGLengthContext& lctx = ctx.lengthContext();
82 const SkRect viewPort = lctx.resolveRect(fX, fY, fWidth, fHeight);
83
84 const auto imgInfo = LoadImage(ctx.resourceProvider(), fHref, viewPort, fPreserveAspectRatio);
85 if (!imgInfo.fImage) {
86 SkDebugf("can't render image: load image failed\n");
87 return;
88 }
89
90 // TODO: image-rendering property
91 ctx.canvas()->drawImageRect(
92 imgInfo.fImage, imgInfo.fDst, SkSamplingOptions(SkFilterMode::kLinear));
93 }
94
onAsPath(const SkSVGRenderContext &) const95 SkPath SkSVGImage::onAsPath(const SkSVGRenderContext&) const { return {}; }
96
onObjectBoundingBox(const SkSVGRenderContext & ctx) const97 SkRect SkSVGImage::onObjectBoundingBox(const SkSVGRenderContext& ctx) const {
98 const SkSVGLengthContext& lctx = ctx.lengthContext();
99 return lctx.resolveRect(fX, fY, fWidth, fHeight);
100 }
101