mirror of
https://github.com/storytold/designcraft.git
synced 2026-11-02 14:47:05 -06:00
PiMinusMaxandClaude Opus 5.5
13013b09d0
On a frame holding a graphic, Inner Shadow, Inner Glow (from the edges) and Bevel and Emboss are built from what the object paints instead of the frame's path: the colour everywhere but under the painted pixels moved by the offset, blurred, and kept only where the object paints. A transparent part of an image is outside the object, so the effect lines the image's opaque edge; before, it lined the frame and nothing marked the image's own edge. Frames without a graphic draw as before. Satin and a centred Inner Glow still follow the frame. Fixes #1622. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
557 lines
27 KiB
Rust
557 lines
27 KiB
Rust
//! Soft object effects (Effects panel): drop shadow, outer glow, inner shadow and basic feather,
|
||
//! drawn with vello filter layers.
|
||
//!
|
||
//! vello_cpu only supports filter layers in single-threaded contexts, so on the multithreaded
|
||
//! pipeline each effect is rendered into an offscreen single-threaded context cropped to its
|
||
//! reach and composited back as an image ([`Renderer::with_filters`]); single-threaded contexts
|
||
//! draw directly. A very wide blur goes offscreen in both, at a lower resolution; the object
|
||
//! itself and the clip to its shape stay at full resolution.
|
||
//!
|
||
//! - Drop shadow / outer glow: the object's silhouette (everything it paints: fill, image, text,
|
||
//! stroke) in a `DropShadowOnly` layer under the object. `size` sets the blur (σ = size / 2),
|
||
//! `spread`/`choke` (percent of size) grow the silhouette instead of blurring it. The shadow's
|
||
//! opacity rides on the filter colour's alpha.
|
||
//! - Inner shadow: the inverse of the offset shape, blurred, clipped to the shape, on top.
|
||
//! - Inner glow, bevel and emboss, satin: built like the inner shadow (an offset inverse of the
|
||
//! shape, blurred and clipped) with screen / multiply blending; satin XORs two offset copies.
|
||
//! - Feather: the object is masked by its shape inset by half the width and blurred, so the
|
||
//! edge fades from ~0 at the path to full strength `width` inside.
|
||
|
||
use designcraft_doc::Item;
|
||
use designcraft_geom::{Affine, BezPath, Rect, Shape, Vec2};
|
||
use vello_common::filter_effects::{EdgeMode, Filter, FilterPrimitive};
|
||
use vello_cpu::peniko::{self, BlendMode, Compose, Mix};
|
||
use vello_cpu::{RenderContext, kurbo};
|
||
|
||
use crate::{Frame, Renderer, color_of};
|
||
use designcraft_compose::ShownOn;
|
||
|
||
/// Shadow offset (spread units) for an InDesign angle (degrees, light direction) and distance.
|
||
pub(crate) fn offset(angle: f64, distance: f64) -> Vec2 {
|
||
let a = angle.to_radians();
|
||
Vec2::new(-a.cos() * distance, a.sin() * distance)
|
||
}
|
||
|
||
/// How far (points) the effects of `it` reach outside its geometry.
|
||
pub(crate) fn outset(it: &Item) -> f64 {
|
||
let e = &it.effects;
|
||
let mut o: f64 = 0.0;
|
||
if e.drop_shadow.on {
|
||
o = o.max(e.drop_shadow.distance.abs() + e.drop_shadow.size.abs() * 1.6 + 1.0);
|
||
}
|
||
if e.outer_glow.on {
|
||
o = o.max(e.outer_glow.size.abs() * 1.6 + 1.0);
|
||
}
|
||
o
|
||
}
|
||
|
||
/// (blur σ, growth) in points for an effect `size` with `pct` percent hardened.
|
||
fn split(size: f64, pct: f64) -> (f64, f64) {
|
||
let size = size.max(0.0);
|
||
let p = (pct / 100.0).clamp(0.0, 1.0);
|
||
(size * (1.0 - p) / 2.0, size * p)
|
||
}
|
||
|
||
fn blur(sigma: f64) -> Filter {
|
||
Filter::from_primitive(FilterPrimitive::GaussianBlur { std_deviation: sigma.max(0.0) as f32, edge_mode: EdgeMode::None })
|
||
}
|
||
|
||
fn shadow(sigma: f64, color: peniko::Color) -> Filter {
|
||
Filter::from_primitive(FilterPrimitive::DropShadowOnly {
|
||
dx: 0.0,
|
||
dy: 0.0,
|
||
std_deviation: sigma.max(0.0) as f32,
|
||
color,
|
||
edge_mode: EdgeMode::None,
|
||
})
|
||
}
|
||
|
||
/// Keep what was drawn in the current layer as much as `it`'s gradient feather says. Cover the
|
||
/// whole viewport: strokes, text and child effects can extend arbitrarily past the geometry,
|
||
/// and past the gradient's ends its end opacities carry on.
|
||
pub(crate) fn gradient_feather_mask(ctx: &mut RenderContext, f: &Frame, it: &Item, xf: Affine) {
|
||
let gf = &it.effects.gradient_feather;
|
||
let (p0, p1) = gf.points(it.feather_bounds());
|
||
let stop = |o: f32, a: f32| peniko::ColorStop::from((o, peniko::Color::from_rgba8(0, 0, 0, (a.clamp(0.0, 1.0) * 255.0).round() as u8)));
|
||
let stops = [stop(0.0, gf.start), stop(1.0, gf.end)];
|
||
let grad = if gf.radial {
|
||
peniko::Gradient::new_radial(p0, (p1 - p0).hypot().max(1e-3) as f32).with_stops(stops.as_slice())
|
||
} else {
|
||
peniko::Gradient::new_linear(p0, p1).with_stops(stops.as_slice())
|
||
};
|
||
ctx.set_transform(Affine::IDENTITY);
|
||
ctx.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::DestIn)), None, None, None);
|
||
ctx.set_paint(grad);
|
||
ctx.set_paint_transform(f.view * xf);
|
||
ctx.fill_rect(&Rect::new(0.0, 0.0, f64::from(ctx.width()), f64::from(ctx.height())));
|
||
ctx.reset_paint_transform();
|
||
ctx.pop_layer();
|
||
}
|
||
|
||
impl Renderer {
|
||
/// Draw an item with soft effects: below-effects, the (feathered) body, inner shadow.
|
||
pub(crate) fn draw_item_fx(&mut self, ctx: &mut RenderContext, f: &Frame, it: &Item, bp: &BezPath, xf: Affine, page: ShownOn) {
|
||
let doc = f.doc;
|
||
let e = &it.effects;
|
||
let sw = if it.stroke.is_none() { 0.0 } else { it.stroke.extent() };
|
||
// Spread-space reach of what the object paints.
|
||
let reach = xf.transform_rect_bbox(bp.bounding_box()).inflate(sw + 1.0, sw + 1.0);
|
||
// The silhouette is the shape when the object paints its area (fill / image); text frames
|
||
// without a fill cast the shadow of their text only, which can't be grown.
|
||
let solid = !it.fill.is_none() || matches!(it.content, designcraft_doc::Content::Graphic(_)) || it.has_nested_items();
|
||
let mut below = vec![];
|
||
if e.outer_glow.on {
|
||
let g = &e.outer_glow;
|
||
below.push((Vec2::ZERO, g.size, g.spread, g.color.clone(), g.opacity));
|
||
}
|
||
if e.drop_shadow.on {
|
||
let d = &e.drop_shadow;
|
||
below.push((offset(doc.light_angle(d.angle, d.global_light), d.distance), d.size, d.spread, d.color.clone(), d.opacity));
|
||
}
|
||
for (off, size, pct, color, opacity) in below {
|
||
let Some(c) = doc.resolve_color(&color, 1.0) else { continue };
|
||
let (sigma, grow) = split(size, pct);
|
||
let filter = shadow(sigma, color_of(&c, opacity.clamp(0.0, 1.0)));
|
||
// The offset moves the geometry, not the filter: vello drops layer content that lies
|
||
// entirely outside the viewport before filtering.
|
||
let r = (reach + off).inflate(grow, grow);
|
||
self.with_filters(ctx, f, r, sigma, None, |me, c, fr| {
|
||
let moved = Frame { view: fr.view * Affine::translate(off), ..*fr };
|
||
c.set_transform(moved.view);
|
||
c.push_layer(None, None, None, None, Some(filter));
|
||
me.draw_body(c, &moved, it, bp, xf, page);
|
||
if grow > 0.0 && solid {
|
||
c.set_transform(moved.view * xf);
|
||
c.set_paint(peniko::Color::BLACK);
|
||
c.set_stroke(kurbo::Stroke::new(grow * 2.0).with_join(kurbo::Join::Round));
|
||
c.stroke_path(bp);
|
||
}
|
||
c.pop_layer();
|
||
});
|
||
}
|
||
// Gradient feather: the object (feathered or not) drawn in its own layer, then kept as
|
||
// much as the opacity gradient says.
|
||
let gf = &e.gradient_feather;
|
||
let directional = e.directional_feather.on && e.directional_feather.widths.iter().any(|w| *w > 0.0);
|
||
if gf.on || directional {
|
||
ctx.set_transform(Affine::IDENTITY);
|
||
ctx.push_layer(None, None, None, None, None);
|
||
}
|
||
// The object, feathered or not. Choke keeps that much of the width opaque (a shorter
|
||
// fade); Sharp and Rounded corners follow the inset shape more tightly than Diffused.
|
||
if e.feather > 0.0 && it.path.is_closed() {
|
||
let fo = &e.feather_options;
|
||
let w = e.feather * (1.0 - fo.choke.clamp(0.0, 100.0) / 100.0).max(0.01);
|
||
let (sigma, join) = match fo.corners {
|
||
designcraft_doc::FeatherCorners::Diffused => (w / 4.0, kurbo::Join::Round),
|
||
designcraft_doc::FeatherCorners::Rounded => (w / 3.0, kurbo::Join::Round),
|
||
designcraft_doc::FeatherCorners::Sharp => (w / 6.0, kurbo::Join::Miter),
|
||
};
|
||
// The body and its clip stay at device resolution; only the blurred mask may be drawn
|
||
// offscreen at a lower one.
|
||
ctx.set_transform(f.view * xf);
|
||
ctx.push_clip_layer(bp);
|
||
self.draw_body(ctx, f, it, bp, xf, page);
|
||
// Keep the body where the blurred inset silhouette is.
|
||
ctx.set_transform(Affine::IDENTITY);
|
||
ctx.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::DestIn)), None, None, None);
|
||
self.with_filters(ctx, f, reach, sigma, None, |_, c, fr| {
|
||
c.set_transform(fr.view);
|
||
c.push_layer(None, None, None, None, Some(blur(sigma)));
|
||
c.set_transform(fr.view * xf);
|
||
c.set_paint(peniko::Color::BLACK);
|
||
c.fill_path(bp);
|
||
c.set_transform(Affine::IDENTITY);
|
||
c.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::DestOut)), None, None, None);
|
||
c.set_transform(fr.view * xf);
|
||
c.set_stroke(kurbo::Stroke::new(w).with_join(join));
|
||
c.stroke_path(bp);
|
||
c.pop_layer();
|
||
c.pop_layer();
|
||
});
|
||
ctx.pop_layer();
|
||
ctx.pop_layer();
|
||
} else {
|
||
self.draw_body(ctx, f, it, bp, xf, page);
|
||
}
|
||
// Directional feather: one fading ramp per side, multiplied in.
|
||
let df = &e.directional_feather;
|
||
if df.on && df.widths.iter().any(|w| *w > 0.0) {
|
||
let b = it.inner_bounds();
|
||
let area = if xf.determinant().abs() > 1e-12 { xf.inverse().transform_rect_bbox(reach) } else { b };
|
||
let ramps = [
|
||
(df.widths[0], kurbo::Point::new(b.x0, b.y0), kurbo::Point::new(b.x0, b.y0 + df.widths[0])),
|
||
(df.widths[1], kurbo::Point::new(b.x0, b.y0), kurbo::Point::new(b.x0 + df.widths[1], b.y0)),
|
||
(df.widths[2], kurbo::Point::new(b.x0, b.y1), kurbo::Point::new(b.x0, b.y1 - df.widths[2])),
|
||
(df.widths[3], kurbo::Point::new(b.x1, b.y0), kurbo::Point::new(b.x1 - df.widths[3], b.y0)),
|
||
];
|
||
for (w, p0, p1) in ramps {
|
||
if w <= 0.0 {
|
||
continue;
|
||
}
|
||
let stops = [
|
||
peniko::ColorStop::from((0.0, peniko::Color::from_rgba8(0, 0, 0, 0))),
|
||
peniko::ColorStop::from((1.0, peniko::Color::from_rgba8(0, 0, 0, 255))),
|
||
];
|
||
ctx.set_transform(Affine::IDENTITY);
|
||
ctx.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::DestIn)), None, None, None);
|
||
ctx.set_transform(f.view * xf);
|
||
ctx.set_paint(peniko::Gradient::new_linear(p0, p1).with_stops(stops.as_slice()));
|
||
ctx.fill_rect(&area.inflate(4.0, 4.0));
|
||
ctx.reset_paint_transform();
|
||
ctx.pop_layer();
|
||
}
|
||
}
|
||
if gf.on {
|
||
gradient_feather_mask(ctx, f, it, xf);
|
||
}
|
||
if gf.on || directional {
|
||
ctx.pop_layer();
|
||
}
|
||
if !it.path.is_closed() {
|
||
return;
|
||
}
|
||
// An image's edge is where it is opaque, not the frame: inner shadows, glows and bevels
|
||
// follow what is painted when the frame holds a graphic.
|
||
let painted = matches!(it.content, designcraft_doc::Content::Graphic(_)).then_some((it, page));
|
||
// Inner shadow, clipped to the shape.
|
||
if e.inner_shadow.on
|
||
&& let Some(c) = doc.resolve_color(&e.inner_shadow.color, 1.0)
|
||
{
|
||
let s = &e.inner_shadow;
|
||
let (sigma, choke) = split(s.size, s.choke);
|
||
let off = offset(doc.light_angle(s.angle, s.global_light), s.distance);
|
||
self.inner_edge(ctx, f, reach, bp, xf, off, sigma, choke, color_of(&c, s.opacity.clamp(0.0, 1.0)), Mix::Normal, painted);
|
||
}
|
||
// Inner glow: from the edges inwards (or out from the centre), screened over the object.
|
||
if e.inner_glow.on
|
||
&& let Some(c) = doc.resolve_color(&e.inner_glow.color, 1.0)
|
||
{
|
||
let g = &e.inner_glow;
|
||
let (sigma, choke) = split(g.size, g.choke);
|
||
// Precise keeps the glow close to the edge: a tighter blur.
|
||
let sigma = if g.technique == designcraft_doc::GlowTechnique::Precise { sigma * 0.4 } else { sigma };
|
||
let mix = crate::blend_mode(g.mode).mix;
|
||
let paint = color_of(&c, g.opacity.clamp(0.0, 1.0));
|
||
if g.center {
|
||
self.with_blended_filters(ctx, f, reach, sigma, mix, (bp, xf), |_, c, fr| {
|
||
c.set_transform(fr.view);
|
||
c.push_layer(None, None, None, None, Some(blur(sigma)));
|
||
c.set_transform(fr.view * xf);
|
||
c.set_paint(paint);
|
||
c.fill_path(bp);
|
||
// Fade towards the edge: cut a band of the glow's size away.
|
||
c.set_transform(Affine::IDENTITY);
|
||
c.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::DestOut)), None, None, None);
|
||
c.set_transform(fr.view * xf);
|
||
c.set_paint(peniko::Color::BLACK);
|
||
c.set_stroke(kurbo::Stroke::new((g.size - choke).max(0.5) * 2.0).with_join(kurbo::Join::Round));
|
||
c.stroke_path(bp);
|
||
c.pop_layer();
|
||
c.pop_layer();
|
||
});
|
||
} else {
|
||
self.inner_edge(ctx, f, reach, bp, xf, Vec2::ZERO, sigma, choke, paint, mix, painted);
|
||
}
|
||
}
|
||
// Satin: the shape shifted both ways along the angle, blurred, where exactly one covers.
|
||
if e.satin.on
|
||
&& let Some(c) = doc.resolve_color(&e.satin.color, 1.0)
|
||
{
|
||
let st = &e.satin;
|
||
let off = offset(st.angle, st.distance / 2.0);
|
||
let sigma = st.size.max(0.0) / 2.0;
|
||
let paint = color_of(&c, st.opacity.clamp(0.0, 1.0));
|
||
let invert = st.invert;
|
||
self.with_blended_filters(ctx, f, reach, sigma, Mix::Multiply, (bp, xf), |_, c, fr| {
|
||
c.set_transform(fr.view);
|
||
c.push_layer(None, None, None, None, Some(blur(sigma)));
|
||
if invert {
|
||
c.set_transform(fr.view * xf);
|
||
c.set_paint(paint);
|
||
c.fill_path(bp);
|
||
}
|
||
c.set_transform(Affine::IDENTITY);
|
||
c.push_layer(None, Some(BlendMode::new(Mix::Normal, if invert { Compose::DestOut } else { Compose::SrcOver })), None, None, None);
|
||
c.set_transform(fr.view * Affine::translate(off) * xf);
|
||
c.set_paint(paint);
|
||
c.fill_path(bp);
|
||
c.set_transform(Affine::IDENTITY);
|
||
c.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::Xor)), None, None, None);
|
||
c.set_transform(fr.view * Affine::translate(-off) * xf);
|
||
c.fill_path(bp);
|
||
c.pop_layer();
|
||
c.pop_layer();
|
||
c.pop_layer();
|
||
});
|
||
}
|
||
// Bevel and Emboss (inner bevel): highlight from the lit side, shadow from the other.
|
||
if e.bevel.on {
|
||
let b = &e.bevel;
|
||
let off = offset(doc.light_angle(b.angle, b.global_light), b.size * (b.depth / 100.0).clamp(0.01, 10.0) * 0.5);
|
||
let sigma = b.size.max(0.0) / 2.0;
|
||
if let Some(c) = doc.resolve_color(&b.highlight, 1.0) {
|
||
// The inverse shape moved away from the light lights the edges facing it.
|
||
self.inner_edge(ctx, f, reach, bp, xf, off, sigma, 0.0, color_of(&c, b.highlight_opacity.clamp(0.0, 1.0)), Mix::Screen, painted);
|
||
}
|
||
if let Some(c) = doc.resolve_color(&b.shadow, 1.0) {
|
||
self.inner_edge(ctx, f, reach, bp, xf, -off, sigma, 0.0, color_of(&c, b.shadow_opacity.clamp(0.0, 1.0)), Mix::Multiply, painted);
|
||
}
|
||
}
|
||
}
|
||
|
||
/// An inner shadow-like edge: everything outside the shape moved by `off`, blurred by
|
||
/// `sigma`, clipped to the shape and blended with `mix`. With `painted` (an object and the
|
||
/// page it shows on), the shape is what the object paints, so a transparent part of an image
|
||
/// is outside it: the edge runs along the image's opaque pixels, not the frame.
|
||
#[allow(clippy::too_many_arguments)]
|
||
fn inner_edge(
|
||
&mut self,
|
||
ctx: &mut RenderContext,
|
||
f: &Frame,
|
||
reach: Rect,
|
||
bp: &BezPath,
|
||
xf: Affine,
|
||
off: Vec2,
|
||
sigma: f64,
|
||
choke: f64,
|
||
paint: peniko::Color,
|
||
mix: Mix,
|
||
painted: Option<(&Item, ShownOn)>,
|
||
) {
|
||
if let Some((it, page)) = painted {
|
||
self.with_blended_filters(ctx, f, reach, sigma, mix, (bp, xf), |me, c, fr| {
|
||
let pad = sigma * 4.0 + choke + off.hypot() + 4.0 * fr.px;
|
||
let area = reach.inflate(pad, pad);
|
||
// The colour everywhere but under the painted pixels moved by `off`, blurred, ...
|
||
c.set_transform(fr.view);
|
||
c.push_layer(None, None, None, None, None);
|
||
c.push_layer(None, None, None, None, Some(blur(sigma)));
|
||
c.set_paint(paint);
|
||
c.fill_rect(&area);
|
||
c.set_transform(Affine::IDENTITY);
|
||
c.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::DestOut)), None, None, None);
|
||
let moved = Frame { view: fr.view * Affine::translate(off), ..*fr };
|
||
me.draw_body(c, &moved, it, bp, xf, page);
|
||
c.pop_layer();
|
||
c.pop_layer();
|
||
// ... kept only where the object paints.
|
||
c.set_transform(Affine::IDENTITY);
|
||
c.push_layer(None, Some(BlendMode::new(Mix::Normal, Compose::DestIn)), None, None, None);
|
||
me.draw_body(c, fr, it, bp, xf, page);
|
||
c.pop_layer();
|
||
c.pop_layer();
|
||
});
|
||
return;
|
||
}
|
||
self.with_blended_filters(ctx, f, reach, sigma, mix, (bp, xf), |_, c, fr| {
|
||
c.set_transform(fr.view);
|
||
c.push_layer(None, None, None, None, Some(blur(sigma)));
|
||
// Everything outside the offset shape, so the colour bleeds in from the edges.
|
||
let m = Affine::translate(off) * xf;
|
||
let pad = sigma * 4.0 + choke + off.hypot() + 4.0 * fr.px;
|
||
let mut inv = m.transform_rect_bbox(bp.bounding_box()).inflate(pad, pad).to_path(0.1);
|
||
let mut shape = bp.clone();
|
||
shape.apply_affine(m);
|
||
inv.extend(shape.iter());
|
||
c.set_paint(paint);
|
||
c.set_fill_rule(peniko::Fill::EvenOdd);
|
||
c.fill_path(&inv);
|
||
c.set_fill_rule(peniko::Fill::NonZero);
|
||
if choke > 0.0 {
|
||
c.set_stroke(kurbo::Stroke::new(choke * 2.0).with_join(kurbo::Join::Round));
|
||
c.stroke_path(&shape);
|
||
}
|
||
c.pop_layer();
|
||
});
|
||
}
|
||
|
||
/// [`Renderer::with_filters`] clipped to `clip` (a path and its spread transform), blended with
|
||
/// `mix`. The effect's blend must see the object's backdrop, outside its clipping and offscreen
|
||
/// filter layers. Putting it inside the clip blends with transparent pixels instead.
|
||
#[allow(clippy::too_many_arguments)]
|
||
fn with_blended_filters(
|
||
&mut self,
|
||
ctx: &mut RenderContext,
|
||
f: &Frame,
|
||
reach: Rect,
|
||
sigma: f64,
|
||
mix: Mix,
|
||
clip: (&BezPath, Affine),
|
||
draw: impl FnOnce(&mut Self, &mut RenderContext, &Frame),
|
||
) {
|
||
if mix != Mix::Normal {
|
||
ctx.set_transform(Affine::IDENTITY);
|
||
ctx.push_layer(None, Some(BlendMode::new(mix, Compose::SrcOver)), None, None, None);
|
||
}
|
||
self.with_filters(ctx, f, reach, sigma, Some(clip), draw);
|
||
if mix != Mix::Normal {
|
||
ctx.pop_layer();
|
||
}
|
||
}
|
||
|
||
/// Run `draw`, which pushes filter layers. Single-threaded contexts draw directly. On a
|
||
/// multithreaded context, or for a blur wider than [`MAX_BLUR_SPREAD`], the layer is drawn into
|
||
/// an offscreen single-threaded context covering `reach` (spread space) plus the blur's spread,
|
||
/// then composited back. `clip` (a path and its spread transform) clips what `draw` paints;
|
||
/// at a lower resolution it clips the composited image on `ctx`, so its edge stays sharp.
|
||
pub(crate) fn with_filters(
|
||
&mut self,
|
||
ctx: &mut RenderContext,
|
||
f: &Frame,
|
||
reach: Rect,
|
||
sigma: f64,
|
||
clip: Option<(&BezPath, Affine)>,
|
||
draw: impl FnOnce(&mut Self, &mut RenderContext, &Frame),
|
||
) {
|
||
// 3σ of the Gaussian in pixels, plus a pixel of antialiasing.
|
||
let spread = sigma.max(0.0) * 3.0 / f.px + 2.0;
|
||
if !f.mt && spread <= MAX_BLUR_SPREAD {
|
||
push_clip(ctx, f, clip);
|
||
draw(self, ctx, f);
|
||
pop_clip(ctx, clip);
|
||
return;
|
||
}
|
||
let Some(o) = offscreen(f.view.transform_rect_bbox(reach), spread, ctx.width(), ctx.height()) else { return };
|
||
let mut off = RenderContext::new_with(o.width, o.height, vello_cpu::RenderSettings { num_threads: 0, ..Default::default() });
|
||
let view = Affine::scale(1.0 / o.scale) * Affine::translate((-o.x0, -o.y0)) * f.view;
|
||
let shifted = Frame { mt: false, view, px: f.px * o.scale, ..*f };
|
||
// Clip where the result is at full resolution: offscreen unless that is reduced.
|
||
let (inner, outer) = if o.scale > 1.0 { (None, clip) } else { (clip, None) };
|
||
push_clip(&mut off, &shifted, inner);
|
||
draw(self, &mut off, &shifted);
|
||
pop_clip(&mut off, inner);
|
||
off.flush();
|
||
let mut pm = vello_cpu::Pixmap::new(o.width, o.height);
|
||
off.render(&mut pm, &mut self.resources);
|
||
push_clip(ctx, f, outer);
|
||
ctx.set_transform(Affine::translate((o.x0, o.y0)) * Affine::scale(o.scale));
|
||
ctx.set_paint(vello_cpu::Image { image: vello_cpu::ImageSource::Pixmap(std::sync::Arc::new(pm)), sampler: peniko::ImageSampler::default() });
|
||
ctx.fill_rect(&Rect::new(0.0, 0.0, f64::from(o.width), f64::from(o.height)));
|
||
pop_clip(ctx, outer);
|
||
ctx.set_transform(Affine::IDENTITY);
|
||
}
|
||
}
|
||
|
||
fn push_clip(ctx: &mut RenderContext, f: &Frame, clip: Option<(&BezPath, Affine)>) {
|
||
if let Some((bp, xf)) = clip {
|
||
ctx.set_transform(f.view * xf);
|
||
ctx.push_clip_layer(bp);
|
||
}
|
||
}
|
||
|
||
fn pop_clip(ctx: &mut RenderContext, clip: Option<(&BezPath, Affine)>) {
|
||
if clip.is_some() {
|
||
ctx.pop_layer();
|
||
}
|
||
}
|
||
|
||
/// The widest blur (3σ, device pixels) drawn at full resolution. vello pads a filter layer by the
|
||
/// blur's width on every side, so a wide blur needs gigabytes; it is drawn at a lower resolution
|
||
/// instead, where it is this wide, and has no detail to lose there.
|
||
const MAX_BLUR_SPREAD: f64 = 1024.0;
|
||
|
||
/// An offscreen image for [`Renderer::with_filters`]: where it goes on the device, how many device
|
||
/// pixels one of its pixels covers, and its size.
|
||
#[derive(Debug, PartialEq)]
|
||
struct Offscreen {
|
||
x0: f64,
|
||
y0: f64,
|
||
scale: f64,
|
||
width: u16,
|
||
height: u16,
|
||
}
|
||
|
||
/// The offscreen image an effect is drawn in: `reach` (device pixels) widened by the blur's
|
||
/// `spread`, within the window widened the same way, at a resolution that keeps the blur within
|
||
/// [`MAX_BLUR_SPREAD`], at most `MAX_SIDE` a side. `None` when none of it shows.
|
||
fn offscreen(reach: Rect, spread: f64, width: u16, height: u16) -> Option<Offscreen> {
|
||
let screen = Rect::new(0.0, 0.0, f64::from(width), f64::from(height)).inflate(spread, spread);
|
||
let r = reach.inflate(spread, spread).intersect(screen);
|
||
let (x0, y0) = (r.x0.floor(), r.y0.floor());
|
||
let scale = (spread / MAX_BLUR_SPREAD).max(1.0);
|
||
let side = |len: f64| (len / scale).ceil().min(crate::MAX_SIDE as f64);
|
||
let (w, h) = (side(r.x1.ceil() - x0), side(r.y1.ceil() - y0));
|
||
(w >= 1.0 && h >= 1.0).then_some(Offscreen { x0, y0, scale, width: w as u16, height: h as u16 })
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod tests {
|
||
use super::*;
|
||
|
||
#[test]
|
||
fn a_wide_blur_is_drawn_offscreen_at_a_lower_resolution() {
|
||
let object = Rect::new(150.0, 150.0, 350.0, 350.0);
|
||
let small = Offscreen { x0: 140.0, y0: 140.0, scale: 1.0, width: 220, height: 220 };
|
||
assert_eq!(offscreen(object, 10.0, 1440, 900), Some(small));
|
||
// A 10,000 pt drop shadow at 100%: 3σ is 15,000 px, which asked for 30,204 px a side and as
|
||
// much padding again inside vello's filter layer. Drawn at 1/14.65 it is 1,024 px wide.
|
||
let wide = Offscreen { x0: -14852.0, y0: -14852.0, scale: 15_002.0 / 1024.0, width: 2062, height: 2062 };
|
||
assert_eq!(offscreen(object, 15_002.0, 1440, 900), Some(wide));
|
||
}
|
||
|
||
/// An inner shadow on a frame holding an image whose left half is transparent: the shadow
|
||
/// lines the image's opaque part (its edge in the middle of the frame), not only the frame.
|
||
#[test]
|
||
fn an_inner_shadow_follows_a_transparent_images_edge() {
|
||
use designcraft_doc::build::NewDocument;
|
||
use designcraft_doc::{Document, SpreadRef};
|
||
let mut d = Document::new(&NewDocument::default());
|
||
let lid = d.default_layer();
|
||
// 20 × 20: transparent left half, opaque white right half.
|
||
let img = image::RgbaImage::from_fn(20, 20, |x, _| if x < 10 { image::Rgba([0, 0, 0, 0]) } else { image::Rgba([255, 255, 255, 255]) });
|
||
let mut png = Vec::new();
|
||
img.write_to(&mut std::io::Cursor::new(&mut png), image::ImageFormat::Png).unwrap();
|
||
let aid = designcraft_doc::AssetId(d.alloc());
|
||
d.assets.insert(
|
||
aid,
|
||
std::sync::Arc::new(designcraft_doc::Asset {
|
||
id: aid,
|
||
name: "half.png".into(),
|
||
mime: "image/png".into(),
|
||
data: std::sync::Arc::new(png),
|
||
pixels: Some((20, 20)),
|
||
..Default::default()
|
||
}),
|
||
);
|
||
let mut it = Item::new(
|
||
designcraft_doc::ItemId(d.alloc()),
|
||
lid,
|
||
designcraft_doc::Shape::Rectangle,
|
||
designcraft_geom::shapes::rectangle(Rect::new(100.0, 100.0, 300.0, 300.0)),
|
||
);
|
||
it.content = designcraft_doc::Content::Graphic(designcraft_doc::Graphic {
|
||
layer_options: None,
|
||
asset: aid,
|
||
size: (200.0, 200.0),
|
||
xf: Affine::translate((100.0, 100.0)),
|
||
clip: None,
|
||
auto_fit: Default::default(),
|
||
fit_align: 4,
|
||
crop: [0.0; 4],
|
||
wrap: Default::default(),
|
||
fill: Default::default(),
|
||
});
|
||
let s = &mut it.effects.inner_shadow;
|
||
s.on = true;
|
||
s.color = "[Black]".into();
|
||
s.opacity = 1.0;
|
||
s.distance = 0.0;
|
||
s.size = 20.0;
|
||
d.insert_item(SpreadRef::Doc(0), it, None).unwrap();
|
||
let cache = crate::Cache::new();
|
||
let mut r = Renderer::new();
|
||
r.threads = 0;
|
||
let page = r.render_page(&d, &cache, 0, 1.0, false, &crate::RenderOptions::default()).unwrap();
|
||
let lum = |x: u32| {
|
||
let p = page.pixel(x, 200);
|
||
u32::from(p[0]) + u32::from(p[1]) + u32::from(p[2])
|
||
};
|
||
// The image's opaque part starts at x = 200: just inside it the shadow darkens it; in its
|
||
// middle (x = 250, 50 pt from every edge but the frame's right one) it stays light.
|
||
assert!(lum(204) + 60 < lum(250), "shadow at the image's own edge: {} vs {}", lum(204), lum(250));
|
||
// The transparent half shows the page: no shadow painted there.
|
||
assert!(lum(150) > 700, "nothing over the transparent part: {}", lum(150));
|
||
}
|
||
}
|