xref: /aosp_15_r20/external/skia/modules/svg/src/SkSVGFeImage.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
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 "modules/svg/include/SkSVGFeImage.h"
9 
10 #include "include/core/SkImage.h"
11 #include "include/core/SkImageFilter.h"
12 #include "include/core/SkRect.h"
13 #include "include/core/SkSamplingOptions.h"
14 #include "include/effects/SkImageFilters.h"
15 #include "modules/svg/include/SkSVGAttributeParser.h"
16 #include "modules/svg/include/SkSVGFilterContext.h"
17 #include "modules/svg/include/SkSVGImage.h"
18 #include "modules/svg/include/SkSVGRenderContext.h"
19 
parseAndSetAttribute(const char * n,const char * v)20 bool SkSVGFeImage::parseAndSetAttribute(const char* n, const char* v) {
21     return INHERITED::parseAndSetAttribute(n, v) ||
22            this->setHref(SkSVGAttributeParser::parse<SkSVGIRI>("xlink:href", n, v)) ||
23            this->setPreserveAspectRatio(SkSVGAttributeParser::parse<SkSVGPreserveAspectRatio>(
24                    "preserveAspectRatio", n, v));
25 }
26 
onMakeImageFilter(const SkSVGRenderContext & ctx,const SkSVGFilterContext & fctx) const27 sk_sp<SkImageFilter> SkSVGFeImage::onMakeImageFilter(const SkSVGRenderContext& ctx,
28                                                      const SkSVGFilterContext& fctx) const {
29     // Load image and map viewbox (image bounds) to viewport (filter effects subregion).
30     const SkRect viewport = this->resolveFilterSubregion(ctx, fctx);
31     const auto imgInfo =
32             SkSVGImage::LoadImage(ctx.resourceProvider(), fHref, viewport, fPreserveAspectRatio);
33     if (!imgInfo.fImage) {
34         return nullptr;
35     }
36 
37     // Create the image filter mapped according to aspect ratio
38     const SkRect srcRect = SkRect::Make(imgInfo.fImage->bounds());
39     const SkRect& dstRect = imgInfo.fDst;
40     // TODO: image-rendering property
41     auto imgfilt = SkImageFilters::Image(imgInfo.fImage, srcRect, dstRect,
42                                          SkSamplingOptions(SkFilterMode::kLinear,
43                                                            SkMipmapMode::kNearest));
44 
45     // Aspect ratio mapping may end up drawing content outside of the filter effects region,
46     // so perform an explicit crop.
47     return SkImageFilters::Merge(&imgfilt, 1, fctx.filterEffectsRegion());
48 }
49