const dropShadow = source => Filter.do(function *() {
const alpha = yield f.feColorMatrix({
in: source,
type: 'matrix',
values: `0 0 0 0 0
0 0 0 0 0
0 0 0 0 0
0 0 0 1 0`
});
const shadow = yield f.feGaussianBlur({
in: alpha,
stdDeviation: 2
});
const shifted = yield f.feOffset({
in: shadow,
dy: 5
});
const full = yield f.feBlend({
in: source,
in2: shifted,
mode: 'normal'
});
const blend = yield crossFade(full, source, 0.3);
return Filter.done(blend);
});
const crossFade = (x, y, amt) => Filter.do(function *() {
const attenuated = yield f.feColorMatrix({
in: x,
type: 'matrix',
values: `1 0 0 0 0
0 1 0 0 0
0 0 1 0 0
0 0 0 ${amt} 0`
});
const blend = yield f.feBlend({
in: attenuated,
in2: y,
mode: 'normal'
});
return Filter.done(blend);
});
});
const shifted = yield f.feOffset({
in: shadow,
dy: 5
});
const full = yield f.feBlend({
in: source,
in2: shifted,
mode: 'normal'
});
const blend = yield crossFade(full, source, 0.3);
return Filter.done(blend);
});
const program = Filter.do(function *() {
const source = yield f.sourceGraphic();
const shadow = yield dropShadow(source);
return Filter.done(shadow);
});
const filter = Filter(program, {
id: 'drop-shadow',
x0: '-50%',
y0: '-50%',
width: '200%',
height: '200%'
});
filter.create();