mirror of
https://github.com/storytold/vectorcraft.git
synced 2026-10-25 02:07:09 -06:00
dwetscherandClaude Opus 5.5
b3ccdf01a7
- Overlays bake child-first: a group's overlay now lies over its children's (they used to be applied after it and win). Each one pays out of the import's overlay work budget. - Master page instances inside embedded documents are left out with a warning: their indices count the embedded document's masters, which aren't kept, and would show the outer document's. - A text outline's gradient stops and dashes are charged to the text attribute budget, like the fill's. Addresses CodeRabbit's second review on #3548. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
664 lines
26 KiB
Rust
664 lines
26 KiB
Rust
//! Colour and gradient overlays. VectorCraft has no such effect, so an overlay is baked into what
|
||
//! its node paints: fill, stroke and text colours, and pixels. The overlay lies over the node's
|
||
//! own paint in its blend mode at its opacity, inside the node's alpha (which it keeps).
|
||
//!
|
||
//! Blend modes follow the W3C Compositing and Blending formulas; the modes PDF lacks (Vivid
|
||
//! Light, Linear Light, Pin Light, Hard Mix, Add, Subtract, Average, Negation, Reflect, Glow,
|
||
//! Darker/Lighter Color) use their usual definitions.
|
||
|
||
use std::borrow::Cow;
|
||
|
||
use crate::model::{Affine, Blend, Effect, Image, Kind, Node, Pixels, Point};
|
||
use crate::paint::{Color, Gradient, GradientKind, Paint, Stop, Stroke};
|
||
|
||
/// Deepest subtree an overlay is baked into (the reader bounds trees well below this).
|
||
const MAX_DEPTH: usize = 256;
|
||
|
||
/// Most pixels an overlay is baked into per image.
|
||
const MAX_PIXELS: usize = 64 << 20;
|
||
|
||
/// Work the overlays of one import may take together: each overlay counts the nodes and pixels
|
||
/// of the subtree it is baked into (which is copied once more for them all). Nested overlays
|
||
/// and shared content would otherwise multiply it; past it, overlays are left out and said.
|
||
pub const MAX_WORK: u64 = 1 << 29;
|
||
|
||
#[derive(Clone, Copy)]
|
||
enum Source<'a> {
|
||
Solid(Color),
|
||
Gradient(&'a Gradient),
|
||
}
|
||
|
||
#[derive(Clone, Copy)]
|
||
struct Overlay<'a> {
|
||
source: Source<'a>,
|
||
opacity: f64,
|
||
blend: Blend,
|
||
}
|
||
|
||
/// `node` with its colour and gradient overlays baked in, and those of everything in it
|
||
/// (borrowed unchanged when `node` has none, or when what is left of `work`, see [`MAX_WORK`],
|
||
/// can't pay for copying it). `warn` hears what could only be approximated or was left out.
|
||
pub fn apply<'a>(node: &'a Node, work: &mut u64, warn: &mut dyn FnMut(&str)) -> Cow<'a, Node> {
|
||
if overlays(&node.effects).is_empty() {
|
||
return Cow::Borrowed(node);
|
||
}
|
||
let Some(left) = work.checked_sub(subtree_cost(node, *work, 0)) else {
|
||
warn("overlay effects beyond the work one import may take (left out)");
|
||
return Cow::Borrowed(node);
|
||
};
|
||
*work = left;
|
||
let mut out = node.clone();
|
||
bake_tree(&mut out, work, 0, warn);
|
||
Cow::Owned(out)
|
||
}
|
||
|
||
/// The visible colour and gradient overlays among `effects`.
|
||
fn overlays(effects: &[Effect]) -> Vec<Overlay<'_>> {
|
||
effects
|
||
.iter()
|
||
.filter_map(|e| match e {
|
||
Effect::ColorOverlay { color, opacity, blend } => Some(Overlay { source: Source::Solid(*color), opacity: *opacity, blend: *blend }),
|
||
Effect::GradientOverlay { gradient, opacity, blend } => {
|
||
Some(Overlay { source: Source::Gradient(gradient), opacity: *opacity, blend: *blend })
|
||
}
|
||
_ => None,
|
||
})
|
||
.filter(|o| o.opacity > 0.0)
|
||
.collect()
|
||
}
|
||
|
||
fn is_overlay(e: &Effect) -> bool {
|
||
matches!(e, Effect::ColorOverlay { .. } | Effect::GradientOverlay { .. })
|
||
}
|
||
|
||
/// Bakes the overlays of `node` and its subtree into their paint, innermost first: an overlay
|
||
/// lies over what its node shows, its children's overlays included. Each overlay pays for the
|
||
/// subtree it is baked into out of `work`; past it, it is left out (and said).
|
||
fn bake_tree(node: &mut Node, work: &mut u64, depth: usize, warn: &mut dyn FnMut(&str)) {
|
||
if depth > MAX_DEPTH {
|
||
return;
|
||
}
|
||
for c in &mut node.children {
|
||
bake_tree(c, work, depth + 1, warn);
|
||
}
|
||
if !node.effects.iter().any(is_overlay) {
|
||
return;
|
||
}
|
||
let (effects, rest): (Vec<Effect>, Vec<Effect>) = std::mem::take(&mut node.effects).into_iter().partition(is_overlay);
|
||
node.effects = rest;
|
||
let overlays = overlays(&effects);
|
||
if overlays.is_empty() {
|
||
return;
|
||
}
|
||
let count = u64::try_from(overlays.len()).unwrap_or(u64::MAX);
|
||
let cost = subtree_cost(node, *work / count, 0).saturating_mul(count);
|
||
let Some(left) = work.checked_sub(cost) else {
|
||
warn("overlay effects beyond the work one import may take (left out)");
|
||
return;
|
||
};
|
||
*work = left;
|
||
for o in &overlays {
|
||
if matches!(o.blend, Blend::Erase | Blend::PassThrough) {
|
||
warn("overlay effects in a blend mode VectorCraft doesn't have (imported as Normal)");
|
||
}
|
||
bake_node(node, o, 0, warn);
|
||
}
|
||
}
|
||
|
||
/// Nodes and pixels in `node`'s subtree, counted only until they pass `limit`.
|
||
fn subtree_cost(node: &Node, limit: u64, depth: usize) -> u64 {
|
||
if depth > MAX_DEPTH {
|
||
return 0;
|
||
}
|
||
let mut cost: u64 = match &node.kind {
|
||
Kind::Image(img) => (u64::from(img.width) * u64::from(img.height)).saturating_add(1),
|
||
Kind::Text(t) => u64::try_from(t.runs.len()).unwrap_or(u64::MAX).saturating_add(1),
|
||
Kind::Table(t) => u64::try_from(t.cells.len()).unwrap_or(u64::MAX).saturating_add(1),
|
||
_ => 1,
|
||
};
|
||
for c in &node.children {
|
||
if cost > limit {
|
||
break;
|
||
}
|
||
cost = cost.saturating_add(subtree_cost(c, limit - cost, depth + 1));
|
||
}
|
||
cost
|
||
}
|
||
|
||
fn bake_node(node: &mut Node, o: &Overlay, depth: usize, warn: &mut dyn FnMut(&str)) {
|
||
if depth > MAX_DEPTH {
|
||
return;
|
||
}
|
||
match &mut node.kind {
|
||
Kind::Shape { fills, strokes, .. } => {
|
||
for f in fills.iter_mut() {
|
||
*f = paint(f, o, warn);
|
||
}
|
||
strokes.iter_mut().for_each(|s| stroke(s, o, warn));
|
||
}
|
||
Kind::Artboard { background, strokes, .. } => {
|
||
for f in background.iter_mut() {
|
||
*f = paint(f, o, warn);
|
||
}
|
||
strokes.iter_mut().for_each(|s| stroke(s, o, warn));
|
||
}
|
||
Kind::Text(t) => {
|
||
for r in &mut t.runs {
|
||
r.fill = paint(&r.fill, o, warn);
|
||
if let Some(s) = &mut r.stroke {
|
||
stroke(s, o, warn);
|
||
}
|
||
}
|
||
}
|
||
Kind::Table(t) => {
|
||
for c in &mut t.cells {
|
||
for r in &mut c.runs {
|
||
r.fill = paint(&r.fill, o, warn);
|
||
if let Some(s) = &mut r.stroke {
|
||
stroke(s, o, warn);
|
||
}
|
||
}
|
||
}
|
||
for s in t.vertical.iter_mut().chain(t.horizontal.iter_mut()).flatten() {
|
||
stroke(s, o, warn);
|
||
}
|
||
}
|
||
Kind::Image(img) => {
|
||
if !pixels(img, o) {
|
||
warn("overlay effects on images too large to recolour (left out)");
|
||
}
|
||
}
|
||
Kind::Layer | Kind::Group | Kind::Unsupported | Kind::MasterInstance { .. } => {}
|
||
}
|
||
for e in &mut node.effects {
|
||
match e {
|
||
Effect::Outline { color, .. } => *color = over(*color, o.source.at_solid(), o),
|
||
Effect::DropShadow { .. } | Effect::InnerShadow { .. } | Effect::OuterGlow { .. } | Effect::Bevel { .. } => {}
|
||
Effect::ColorOverlay { .. } | Effect::GradientOverlay { .. } => {}
|
||
}
|
||
}
|
||
for c in &mut node.children {
|
||
bake_node(c, o, depth + 1, warn);
|
||
}
|
||
}
|
||
|
||
fn stroke(s: &mut Stroke, o: &Overlay, warn: &mut dyn FnMut(&str)) {
|
||
s.paint = paint(&s.paint, o, warn);
|
||
}
|
||
|
||
/// A paint with the overlay over it.
|
||
fn paint(p: &Paint, o: &Overlay, warn: &mut dyn FnMut(&str)) -> Paint {
|
||
match (p, o.source) {
|
||
(Paint::None, _) => Paint::None,
|
||
(Paint::Solid(c), Source::Solid(s)) => Paint::Solid(over(*c, s, o)),
|
||
(Paint::Gradient(g), Source::Solid(s)) => {
|
||
Paint::Gradient(Gradient { stops: g.stops.iter().map(|st| Stop { color: over(st.color, s, o), ..*st }).collect(), ..g.clone() })
|
||
}
|
||
// Over one colour, the result is the overlay's gradient with each stop laid over it.
|
||
(Paint::Solid(c), Source::Gradient(g)) => {
|
||
Paint::Gradient(Gradient { stops: g.stops.iter().map(|st| Stop { color: over(*c, st.color, o), ..*st }).collect(), ..g.clone() })
|
||
}
|
||
(Paint::Gradient(base), Source::Gradient(g)) => {
|
||
if !(o.blend == Blend::Normal && o.opacity >= 1.0) {
|
||
warn("gradient overlays on gradients (approximated)");
|
||
}
|
||
// Exact when the overlay covers it; otherwise over the base gradient's average colour.
|
||
let avg = average(base);
|
||
Paint::Gradient(Gradient { stops: g.stops.iter().map(|st| Stop { color: over(avg, st.color, o), ..*st }).collect(), ..g.clone() })
|
||
}
|
||
}
|
||
}
|
||
|
||
impl Source<'_> {
|
||
/// One colour for the source (a gradient's average) where only one fits.
|
||
fn at_solid(&self) -> Color {
|
||
match self {
|
||
Source::Solid(c) => *c,
|
||
Source::Gradient(g) => average(g),
|
||
}
|
||
}
|
||
}
|
||
|
||
fn average(g: &Gradient) -> Color {
|
||
let n = g.stops.len().max(1) as f64;
|
||
let (mut r, mut gr, mut b, mut a) = (0.0, 0.0, 0.0, 0.0);
|
||
for s in &g.stops {
|
||
let [sr, sg, sb] = rgb(s.color);
|
||
r += sr;
|
||
gr += sg;
|
||
b += sb;
|
||
a += s.color.alpha();
|
||
}
|
||
Color::Rgb { r: r / n, g: gr / n, b: b / n, a: a / n }
|
||
}
|
||
|
||
/// `source` laid over `base` in the overlay's mode and opacity; `base`'s alpha is kept.
|
||
fn over(base: Color, source: Color, o: &Overlay) -> Color {
|
||
let k = (o.opacity * source.alpha()).clamp(0.0, 1.0);
|
||
let alpha = base.alpha();
|
||
// Normal mixes within the colour model when both share it, so CMYK stays CMYK.
|
||
if matches!(o.blend, Blend::Normal | Blend::PassThrough | Blend::Erase) {
|
||
let mix = |a: f64, b: f64| a + (b - a) * k;
|
||
match (base, source) {
|
||
(Color::Cmyk { c, m, y, k: kk, .. }, Color::Cmyk { c: c2, m: m2, y: y2, k: k2, .. }) => {
|
||
return Color::Cmyk { c: mix(c, c2), m: mix(m, m2), y: mix(y, y2), k: mix(kk, k2), a: alpha };
|
||
}
|
||
(Color::Gray { v, .. }, Color::Gray { v: v2, .. }) => return Color::Gray { v: mix(v, v2), a: alpha },
|
||
(_, s) if k >= 1.0 => return with_alpha(s, alpha),
|
||
_ => {}
|
||
}
|
||
}
|
||
let b = rgb(base);
|
||
let s = rgb(source);
|
||
let blended = blend(o.blend, b, s);
|
||
let [r, g, bl] = [0, 1, 2].map(|i| b[i] + (blended[i] - b[i]) * k);
|
||
Color::Rgb { r, g, b: bl, a: alpha }
|
||
}
|
||
|
||
fn with_alpha(c: Color, a: f64) -> Color {
|
||
match c {
|
||
Color::Rgb { r, g, b, .. } => Color::Rgb { r, g, b, a },
|
||
Color::Cmyk { c, m, y, k, .. } => Color::Cmyk { c, m, y, k, a },
|
||
Color::Gray { v, .. } => Color::Gray { v, a },
|
||
Color::Lab { l, a: la, b, .. } => Color::Lab { l, a: la, b, alpha: a },
|
||
}
|
||
}
|
||
|
||
/// sRGB components (0..1) of a colour. CMYK uses the profile-free formula (the engine shows the
|
||
/// node's other CMYK colours through the document's profile), Lab its D50 sRGB colour.
|
||
fn rgb(c: Color) -> [f64; 3] {
|
||
let f = |v: f64| if v.is_finite() { v.clamp(0.0, 1.0) } else { 0.0 };
|
||
match c {
|
||
Color::Rgb { r, g, b, .. } => [f(r), f(g), f(b)],
|
||
Color::Gray { v, .. } => [f(v); 3],
|
||
Color::Cmyk { c, m, y, k, .. } => {
|
||
let w = 1.0 - f(k);
|
||
[(1.0 - f(c)) * w, (1.0 - f(m)) * w, (1.0 - f(y)) * w]
|
||
}
|
||
Color::Lab { l, a, b, .. } => lab_to_srgb(l, a, b).map(f),
|
||
}
|
||
}
|
||
|
||
/// CIE L*a*b* (D50) to sRGB, through XYZ and the Bradford adaptation to D65.
|
||
fn lab_to_srgb(l: f64, a: f64, b: f64) -> [f64; 3] {
|
||
let finite = |v: f64| if v.is_finite() { v } else { 0.0 };
|
||
let (l, a, b) = (finite(l), finite(a), finite(b));
|
||
let fy = (l + 16.0) / 116.0;
|
||
let (fx, fz) = (fy + a / 500.0, fy - b / 200.0);
|
||
let inv = |t: f64| if t > 6.0 / 29.0 { t * t * t } else { 3.0 * (6.0f64 / 29.0).powi(2) * (t - 4.0 / 29.0) };
|
||
// D50 white.
|
||
let (x, y, z) = (0.964_22 * inv(fx), inv(fy), 0.825_21 * inv(fz));
|
||
// XYZ (D50) to linear sRGB, Bradford-adapted.
|
||
let r = 3.133_856 * x - 1.616_867 * y - 0.490_615 * z;
|
||
let g = -0.978_768 * x + 1.916_142 * y + 0.033_454 * z;
|
||
let bl = 0.071_945 * x - 0.228_991 * y + 1.405_243 * z;
|
||
let gamma = |v: f64| if v <= 0.003_130_8 { 12.92 * v } else { 1.055 * v.max(0.0).powf(1.0 / 2.4) - 0.055 };
|
||
[gamma(r), gamma(g), gamma(bl)]
|
||
}
|
||
|
||
/// Bake the overlay into an image's pixels. False if they couldn't be read or are too many.
|
||
fn pixels(img: &mut Image, o: &Overlay) -> bool {
|
||
let Some(n) = (img.width as usize).checked_mul(img.height as usize).filter(|n| *n <= MAX_PIXELS) else { return false };
|
||
let Some(len) = n.checked_mul(4) else { return false };
|
||
let mut px = match &img.pixels {
|
||
Pixels::Rgba8(p) => match p.get(..len) {
|
||
Some(p) => p.to_vec(),
|
||
None => return false,
|
||
},
|
||
Pixels::Encoded(bytes) => match decode(bytes, img.width, img.height) {
|
||
Some(p) => p,
|
||
None => return false,
|
||
},
|
||
// An overlay is blended in RGB: CMYK pixels take the profile-free formula here.
|
||
Pixels::Cmyka8(p) => match p.get(..n.saturating_mul(5)) {
|
||
Some(p) if p.len() == n * 5 => p
|
||
.as_chunks::<5>()
|
||
.0
|
||
.iter()
|
||
.flat_map(|[c, m, y, k, a]| {
|
||
let w = 255 - u16::from(*k);
|
||
let ch = |v: u8| ((u16::from(255 - v) * w + 127) / 255) as u8;
|
||
[ch(*c), ch(*m), ch(*y), *a]
|
||
})
|
||
.collect(),
|
||
_ => return false,
|
||
},
|
||
};
|
||
let width = img.width.max(1) as usize;
|
||
// A solid source is converted once; a gradient is sampled at each pixel's centre.
|
||
let solid = match o.source {
|
||
Source::Solid(c) => Some((rgb(c), c.alpha())),
|
||
Source::Gradient(_) => None,
|
||
};
|
||
let to_unit = match o.source {
|
||
Source::Gradient(g) => match invert(g.transform) {
|
||
Some(m) => Some((img.transform.then(m), g)),
|
||
None => return false,
|
||
},
|
||
Source::Solid(_) => None,
|
||
};
|
||
for (i, p) in px.as_chunks_mut::<4>().0.iter_mut().enumerate() {
|
||
if p[3] == 0 {
|
||
continue;
|
||
}
|
||
let (s, sa) = match (solid, &to_unit) {
|
||
(Some(s), _) => s,
|
||
(None, Some((m, g))) => {
|
||
let q = m.apply(Point { x: (i % width) as f64 + 0.5, y: (i / width) as f64 + 0.5 });
|
||
let c = sample(g, q);
|
||
(rgb(c), c.alpha())
|
||
}
|
||
(None, None) => continue,
|
||
};
|
||
let k = (o.opacity * sa).clamp(0.0, 1.0);
|
||
let b = [p[0], p[1], p[2]].map(|v| f64::from(v) / 255.0);
|
||
let m = blend(o.blend, b, s);
|
||
for c in 0..3 {
|
||
p[c] = ((b[c] + (m[c] - b[c]) * k).clamp(0.0, 1.0) * 255.0).round() as u8;
|
||
}
|
||
}
|
||
img.pixels = Pixels::Rgba8(px);
|
||
true
|
||
}
|
||
|
||
/// An encoded original's RGBA pixels, decoded only if it is `width` × `height` as its layer says.
|
||
fn decode(bytes: &[u8], width: u32, height: u32) -> Option<Vec<u8>> {
|
||
let probe = image::ImageReader::new(std::io::Cursor::new(bytes)).with_guessed_format().ok()?;
|
||
if probe.into_dimensions().ok()? != (width, height) {
|
||
return None;
|
||
}
|
||
let mut reader = image::ImageReader::new(std::io::Cursor::new(bytes)).with_guessed_format().ok()?;
|
||
let mut limits = image::Limits::default();
|
||
limits.max_image_width = Some(width);
|
||
limits.max_image_height = Some(height);
|
||
limits.max_alloc = u64::try_from(MAX_PIXELS).ok().map(|n| n * 8);
|
||
reader.limits(limits);
|
||
Some(reader.decode().ok()?.into_rgba8().into_raw())
|
||
}
|
||
|
||
/// The gradient's colour at unit-space point `q`.
|
||
fn sample(g: &Gradient, q: Point) -> Color {
|
||
let t = match g.kind {
|
||
GradientKind::Linear => q.x,
|
||
GradientKind::Radial => q.x.hypot(q.y),
|
||
GradientKind::Conical => q.y.atan2(q.x).rem_euclid(std::f64::consts::TAU) / std::f64::consts::TAU,
|
||
};
|
||
let t = if t.is_finite() { t.clamp(0.0, 1.0) } else { 0.0 };
|
||
let (Some(first), Some(last)) = (g.stops.first(), g.stops.last()) else { return Color::Rgb { r: 0.0, g: 0.0, b: 0.0, a: 0.0 } };
|
||
if t <= first.offset {
|
||
return first.color;
|
||
}
|
||
for w in g.stops.windows(2) {
|
||
let [a, b] = [&w[0], &w[1]];
|
||
if t <= b.offset {
|
||
let span = b.offset - a.offset;
|
||
let u = if span > 1e-9 { (t - a.offset) / span } else { 1.0 };
|
||
// Affinity's midpoint bias (see `Stop::half_point`).
|
||
let k = 1.0 + 8.0 * (a.bias - 0.5).abs();
|
||
let u = if a.bias >= 0.5 { u.powf(k) } else { 1.0 - (1.0 - u).powf(k) };
|
||
let (x, y) = (rgb(a.color), rgb(b.color));
|
||
let [r, g, bl] = [0, 1, 2].map(|i| x[i] + (y[i] - x[i]) * u);
|
||
return Color::Rgb { r, g, b: bl, a: a.color.alpha() + (b.color.alpha() - a.color.alpha()) * u };
|
||
}
|
||
}
|
||
last.color
|
||
}
|
||
|
||
fn invert(m: Affine) -> Option<Affine> {
|
||
let [a, b, c, d, e, f] = m.0;
|
||
let det = a * d - b * c;
|
||
if !(det.is_finite() && det.abs() > 1e-12) {
|
||
return None;
|
||
}
|
||
let (ia, ib, ic, id) = (d / det, -b / det, -c / det, a / det);
|
||
Some(Affine([ia, ib, ic, id, -(ia * e + ic * f), -(ib * e + id * f)]))
|
||
}
|
||
|
||
/// The blend of backdrop `b` and source `s` (sRGB, 0..1).
|
||
fn blend(mode: Blend, b: [f64; 3], s: [f64; 3]) -> [f64; 3] {
|
||
use Blend::*;
|
||
let sep = |f: fn(f64, f64) -> f64| [0, 1, 2].map(|i| f(b[i], s[i]).clamp(0.0, 1.0));
|
||
match mode {
|
||
Normal | PassThrough | Erase => s,
|
||
Darken => sep(f64::min),
|
||
Lighten => sep(f64::max),
|
||
Multiply => sep(|b, s| b * s),
|
||
Screen => sep(screen),
|
||
ColorBurn => sep(burn),
|
||
ColorDodge => sep(dodge),
|
||
Blend::Overlay => sep(|b, s| hard_light(s, b)),
|
||
HardLight => sep(hard_light),
|
||
SoftLight => sep(soft_light),
|
||
Difference => sep(|b, s| (b - s).abs()),
|
||
Exclusion => sep(|b, s| b + s - 2.0 * b * s),
|
||
Add => sep(|b, s| b + s),
|
||
Subtract => sep(|b, s| b - s),
|
||
VividLight => sep(|b, s| if s <= 0.5 { burn(b, 2.0 * s) } else { dodge(b, 2.0 * s - 1.0) }),
|
||
LinearLight => sep(|b, s| b + 2.0 * s - 1.0),
|
||
PinLight => sep(|b, s| if s <= 0.5 { b.min(2.0 * s) } else { b.max(2.0 * s - 1.0) }),
|
||
HardMix => sep(|b, s| if b + s >= 1.0 { 1.0 } else { 0.0 }),
|
||
Average => sep(|b, s| (b + s) / 2.0),
|
||
Negation => sep(|b, s| 1.0 - (1.0 - b - s).abs()),
|
||
Reflect => sep(reflect),
|
||
Glow => sep(|b, s| reflect(s, b)),
|
||
DarkerColor => {
|
||
if lum(s) < lum(b) {
|
||
s
|
||
} else {
|
||
b
|
||
}
|
||
}
|
||
LighterColor => {
|
||
if lum(s) > lum(b) {
|
||
s
|
||
} else {
|
||
b
|
||
}
|
||
}
|
||
Hue => set_lum(set_sat(s, sat(b)), lum(b)),
|
||
Saturation => set_lum(set_sat(b, sat(s)), lum(b)),
|
||
Blend::Color => set_lum(s, lum(b)),
|
||
Luminosity => set_lum(b, lum(s)),
|
||
}
|
||
}
|
||
|
||
fn screen(b: f64, s: f64) -> f64 {
|
||
b + s - b * s
|
||
}
|
||
|
||
fn burn(b: f64, s: f64) -> f64 {
|
||
if b >= 1.0 {
|
||
1.0
|
||
} else if s <= 0.0 {
|
||
0.0
|
||
} else {
|
||
1.0 - ((1.0 - b) / s).min(1.0)
|
||
}
|
||
}
|
||
|
||
fn dodge(b: f64, s: f64) -> f64 {
|
||
if b <= 0.0 {
|
||
0.0
|
||
} else if s >= 1.0 {
|
||
1.0
|
||
} else {
|
||
(b / (1.0 - s)).min(1.0)
|
||
}
|
||
}
|
||
|
||
fn hard_light(b: f64, s: f64) -> f64 {
|
||
if s <= 0.5 { b * 2.0 * s } else { screen(b, 2.0 * s - 1.0) }
|
||
}
|
||
|
||
fn soft_light(b: f64, s: f64) -> f64 {
|
||
if s <= 0.5 {
|
||
b - (1.0 - 2.0 * s) * b * (1.0 - b)
|
||
} else {
|
||
let d = if b <= 0.25 { ((16.0 * b - 12.0) * b + 4.0) * b } else { b.sqrt() };
|
||
b + (2.0 * s - 1.0) * (d - b)
|
||
}
|
||
}
|
||
|
||
fn reflect(b: f64, s: f64) -> f64 {
|
||
if s >= 1.0 { 1.0 } else { (b * b / (1.0 - s)).min(1.0) }
|
||
}
|
||
|
||
fn lum(c: [f64; 3]) -> f64 {
|
||
0.3 * c[0] + 0.59 * c[1] + 0.11 * c[2]
|
||
}
|
||
|
||
fn clip_color(c: [f64; 3]) -> [f64; 3] {
|
||
let l = lum(c);
|
||
let n = c[0].min(c[1]).min(c[2]);
|
||
let x = c[0].max(c[1]).max(c[2]);
|
||
c.map(|v| {
|
||
let mut v = v;
|
||
if n < 0.0 && l - n > 1e-12 {
|
||
v = l + (v - l) * l / (l - n);
|
||
}
|
||
if x > 1.0 && x - l > 1e-12 {
|
||
v = l + (v - l) * (1.0 - l) / (x - l);
|
||
}
|
||
v.clamp(0.0, 1.0)
|
||
})
|
||
}
|
||
|
||
fn set_lum(c: [f64; 3], l: f64) -> [f64; 3] {
|
||
let d = l - lum(c);
|
||
clip_color(c.map(|v| v + d))
|
||
}
|
||
|
||
fn sat(c: [f64; 3]) -> f64 {
|
||
c[0].max(c[1]).max(c[2]) - c[0].min(c[1]).min(c[2])
|
||
}
|
||
|
||
fn set_sat(c: [f64; 3], s: f64) -> [f64; 3] {
|
||
let max = c[0].max(c[1]).max(c[2]);
|
||
let min = c[0].min(c[1]).min(c[2]);
|
||
if max - min <= 1e-12 {
|
||
return [0.0; 3];
|
||
}
|
||
c.map(|v| (v - min) * s / (max - min))
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod tests {
|
||
use super::*;
|
||
|
||
fn solid(c: Color, opacity: f64, blend: Blend) -> Node {
|
||
Node {
|
||
class: crate::stream::Tag::of(b"ShpN"),
|
||
name: String::new(),
|
||
visible: true,
|
||
locked: false,
|
||
opacity: 1.0,
|
||
blend: Blend::Normal,
|
||
kind: Kind::Shape {
|
||
path: Default::default(),
|
||
fills: vec![Paint::Solid(Color::Rgb { r: 1.0, g: 0.5, b: 0.0, a: 1.0 })],
|
||
strokes: vec![],
|
||
even_odd: false,
|
||
},
|
||
mask: None,
|
||
pixel_mask: None,
|
||
effects: vec![Effect::ColorOverlay { color: c, opacity, blend }],
|
||
children: vec![],
|
||
}
|
||
}
|
||
|
||
fn fill(n: &Node) -> Color {
|
||
match &n.kind {
|
||
Kind::Shape { fills, .. } => match fills.first() {
|
||
Some(Paint::Solid(c)) => *c,
|
||
other => panic!("{other:?}"),
|
||
},
|
||
other => panic!("{other:?}"),
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn a_full_colour_overlay_replaces_the_fill_and_keeps_its_alpha() {
|
||
let white = Color::Rgb { r: 1.0, g: 1.0, b: 1.0, a: 1.0 };
|
||
let n = apply(&solid(white, 1.0, Blend::Normal), &mut { MAX_WORK }, &mut |_| {}).into_owned();
|
||
assert_eq!(fill(&n), white);
|
||
assert!(n.effects.is_empty(), "the overlay is baked, not kept");
|
||
// Half way, mixed in RGB.
|
||
let n = apply(&solid(white, 0.5, Blend::Normal), &mut { MAX_WORK }, &mut |_| {}).into_owned();
|
||
assert_eq!(fill(&n), Color::Rgb { r: 1.0, g: 0.75, b: 0.5, a: 1.0 });
|
||
}
|
||
|
||
#[test]
|
||
fn blend_modes_follow_their_formulas() {
|
||
let b = [0.25, 0.5, 1.0];
|
||
assert_eq!(blend(Blend::Multiply, b, [0.5; 3]), [0.125, 0.25, 0.5]);
|
||
assert_eq!(blend(Blend::Screen, b, [0.5; 3]), [0.625, 0.75, 1.0]);
|
||
assert_eq!(blend(Blend::VividLight, [0.5; 3], [0.75; 3]), [1.0; 3]);
|
||
assert_eq!(blend(Blend::HardMix, [0.5; 3], [0.6; 3]), [1.0; 3]);
|
||
// Color keeps the backdrop's luminosity with the source's hue and saturation.
|
||
let c = blend(Blend::Color, [0.5; 3], [1.0, 0.0, 0.0]);
|
||
assert!((lum(c) - 0.5).abs() < 1e-9 && c[0] > c[1] && (c[1] - c[2]).abs() < 1e-9, "{c:?}");
|
||
}
|
||
|
||
#[test]
|
||
fn overlays_recolour_pixels_inside_their_alpha() {
|
||
let mut n = solid(Color::Rgb { r: 0.0, g: 0.0, b: 1.0, a: 1.0 }, 1.0, Blend::Normal);
|
||
n.kind = Kind::Image(Image { width: 2, height: 1, pixels: Pixels::Rgba8(vec![255, 0, 0, 255, 255, 0, 0, 0]), transform: Affine::IDENTITY });
|
||
let out = apply(&n, &mut { MAX_WORK }, &mut |_| {}).into_owned();
|
||
let Kind::Image(img) = &out.kind else { panic!() };
|
||
assert_eq!(img.pixels, Pixels::Rgba8(vec![0, 0, 255, 255, 255, 0, 0, 0]));
|
||
}
|
||
|
||
#[test]
|
||
fn a_gradient_overlay_over_one_colour_becomes_that_gradient() {
|
||
let g = Gradient {
|
||
kind: GradientKind::Linear,
|
||
stops: vec![
|
||
Stop { offset: 0.0, color: Color::Rgb { r: 0.0, g: 0.0, b: 0.0, a: 1.0 }, bias: 0.5 },
|
||
Stop { offset: 1.0, color: Color::Rgb { r: 1.0, g: 1.0, b: 1.0, a: 1.0 }, bias: 0.5 },
|
||
],
|
||
transform: Affine([10.0, 0.0, 0.0, 10.0, 0.0, 0.0]),
|
||
};
|
||
let mut n = solid(Color::Rgb { r: 0.0, g: 0.0, b: 0.0, a: 1.0 }, 1.0, Blend::Normal);
|
||
n.effects = vec![Effect::GradientOverlay { gradient: g.clone(), opacity: 1.0, blend: Blend::Normal }];
|
||
let out = apply(&n, &mut { MAX_WORK }, &mut |_| {}).into_owned();
|
||
let Kind::Shape { fills, .. } = &out.kind else { panic!() };
|
||
assert_eq!(fills.first(), Some(&Paint::Gradient(g)));
|
||
}
|
||
|
||
#[test]
|
||
fn a_group_overlay_lies_over_its_childrens_overlays() {
|
||
let red = Color::Rgb { r: 1.0, g: 0.0, b: 0.0, a: 1.0 };
|
||
let blue = Color::Rgb { r: 0.0, g: 0.0, b: 1.0, a: 1.0 };
|
||
let mut group = solid(red, 0.5, Blend::Normal);
|
||
group.kind = Kind::Group;
|
||
group.children = vec![solid(blue, 1.0, Blend::Normal)];
|
||
// The copy (2 nodes), the child's overlay (1) and the group's (2).
|
||
let mut work = 5;
|
||
let out = apply(&group, &mut work, &mut |_| {}).into_owned();
|
||
assert_eq!(work, 0);
|
||
let child = out.children.first().unwrap();
|
||
// Blue first, then half of the group's red over it.
|
||
assert_eq!(fill(child), Color::Rgb { r: 0.5, g: 0.0, b: 0.5, a: 1.0 });
|
||
assert!(out.effects.is_empty() && child.effects.is_empty(), "both overlays are baked");
|
||
// With no work left for the group's overlay, the child's still applies.
|
||
let mut warnings = Vec::new();
|
||
let out = apply(&group, &mut { 4 }, &mut |w| warnings.push(w.to_string())).into_owned();
|
||
assert_eq!(fill(out.children.first().unwrap()), blue);
|
||
assert!(warnings.iter().any(|w| w.contains("beyond the work")), "{warnings:?}");
|
||
}
|
||
|
||
#[test]
|
||
fn overlays_stop_at_the_work_one_import_may_take() {
|
||
let mut n = solid(Color::Rgb { r: 0.0, g: 0.0, b: 1.0, a: 1.0 }, 1.0, Blend::Normal);
|
||
n.kind = Kind::Image(Image { width: 4, height: 4, pixels: Pixels::Rgba8(vec![255; 64]), transform: Affine::IDENTITY });
|
||
// 16 pixels and the node, for the copy and for the overlay: 34.
|
||
let mut work = 40;
|
||
let mut warnings = Vec::new();
|
||
assert!(matches!(apply(&n, &mut work, &mut |w| warnings.push(w.to_string())), Cow::Owned(_)));
|
||
assert_eq!((work, warnings.len()), (6, 0));
|
||
assert!(matches!(apply(&n, &mut work, &mut |w| warnings.push(w.to_string())), Cow::Borrowed(_)));
|
||
assert_eq!(work, 6);
|
||
assert!(warnings.iter().any(|w| w.contains("beyond the work")), "{warnings:?}");
|
||
}
|
||
}
|