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