void onDraw(SkCanvas* canvas) override {
sk_sp<SkImage> image0(make_image(canvas));
const ImageFilterFactory factories[] = {
IFCCast([]{ return SkBlurImageFilter::Make(8, 8, nullptr); }),
IFCCast([]{ return SkDilateImageFilter::Make(8, 8, nullptr); }),
IFCCast([]{ return SkErodeImageFilter::Make(8, 8, nullptr); }),
IFCCast([]{ return SkOffsetImageFilter::Make(8, 8, nullptr); }),
};
const SkMatrix matrices[] = {
SkMatrix::MakeScale(SK_ScalarHalf, SK_ScalarHalf),
SkMatrix::MakeScale(2, 2),
SkMatrix::MakeTrans(10, 10)
};
const SkScalar spacer = image0->width() * 3.0f / 2;
canvas->translate(40, 40);
for (auto&& factory : factories) {
sk_sp<SkImageFilter> filter(factory());
canvas->save();
show_image(canvas, image0.get(), filter);
for (const auto& matrix : matrices) {
sk_sp<SkImageFilter> localFilter(filter->makeWithLocalMatrix(matrix));
canvas->translate(spacer, 0);
show_image(canvas, image0.get(), std::move(localFilter));
}
canvas->restore();
canvas->translate(0, spacer);
}
}
canvas->drawImage(image, 0, 0, &paint);
}
typedef sk_sp<SkImageFilter> (*ImageFilterFactory)();
// +[]{...} did not work on windows (VS)
// (ImageFilterFactory)[]{...} did not work on linux (gcc)
// hence this cast function
template <typename T> ImageFilterFactory IFCCast(T arg) { return arg; }
// Show the effect of localmatriximagefilter with various matrices, on various filters
DEF_SIMPLE_GM(localmatriximagefilter, canvas, 640, 640) {
sk_sp<SkImage> image0(make_image(canvas));
const ImageFilterFactory factories[] = {
IFCCast([]{ return SkBlurImageFilter::Make(8, 8, nullptr); }),
IFCCast([]{ return SkDilateImageFilter::Make(8, 8, nullptr); }),
IFCCast([]{ return SkErodeImageFilter::Make(8, 8, nullptr); }),
IFCCast([]{ return SkOffsetImageFilter::Make(8, 8, nullptr); }),
};
const SkMatrix matrices[] = {
SkMatrix::MakeScale(SK_ScalarHalf, SK_ScalarHalf),
SkMatrix::MakeScale(2, 2),
SkMatrix::MakeTrans(10, 10)
};
const SkScalar spacer = image0->width() * 3.0f / 2;
canvas->translate(40, 40);
for (auto&& factory : factories) {
