Merge pull request #981 from storytold/feat/distort-effects

Part of gap 2: Effect › Distort (Diffuse Glow, Glass, Ocean Ripple)

crates/effects/src/lib.rs

@@ -146,6 +146,7 @@ const SHAPE: &[&str] = &["Effect", "Convert to Shape"];
 const STYLIZE: &[&str] = &["Effect", "Stylize"];
 const WARP: &[&str] = &["Effect", "Warp"];
 const BLUR: &[&str] = &["Effect", "Blur"];
+const DISTORT: &[&str] = &["Effect", "Distort"];
 const SHARPEN: &[&str] = &["Effect", "Sharpen"];
 const PIXELATE: &[&str] = &["Effect", "Pixelate"];
 const TEXTURE: &[&str] = &["Effect", "Texture"];
@@ -295,6 +296,27 @@ pub fn effect_catalog() -> Vec<EffectInfo> {
             "{radius: pt 0.1..100 (3), threshold: levels 0.1..100 (25; only colours closer than this blur together, so edges stay sharp), quality: \"low\"|\"medium\"|\"high\" (\"medium\"; 5, 7 or 9 samples across)} (Normal mode)",
             json!({"radius": 3.0, "threshold": 25.0, "quality": "medium"}),
         ),
+        r(
+            "distort.diffuseGlow",
+            "Diffuse Glow…",
+            DISTORT,
+            "{graininess: 0..10 (6; white grain, thicker in the glow), glowAmount: 0..20 (10), clearAmount: 0..20 (15; the higher, the more of the image stays clear of glow)} renders the object as if seen through a soft diffusion filter: its highlights glow white under see-through white grain",
+            json!({"graininess": 6.0, "glowAmount": 10.0, "clearAmount": 15.0}),
+        ),
+        r(
+            "distort.glass",
+            "Glass…",
+            DISTORT,
+            "{distortion: 0..20 (5), smoothness: 1..15 (3), texture: \"blocks\"|\"canvas\"|\"frosted\"|\"tinyLens\" (\"frosted\"; surfaces made in code), scaling: % 50..200 (100), invert: bool (false; turns the surface's heights over)} makes the object look as if seen through glass",
+            json!({"distortion": 5.0, "smoothness": 3.0, "texture": "frosted", "scaling": 100.0, "invert": false}),
+        ),
+        r(
+            "distort.oceanRipple",
+            "Ocean Ripple…",
+            DISTORT,
+            "{rippleSize: 1..15 (9), rippleMagnitude: 0..20 (9)} adds randomly spaced ripples, as if the object were under water",
+            json!({"rippleSize": 9.0, "rippleMagnitude": 9.0}),
+        ),
         r(
             "sharpen.unsharpMask",
             "Unsharp Mask…",

crates/effects/src/pixel/distort.rs

@@ -0,0 +1,200 @@
+//! Effect › Distort (Diffuse Glow, Glass, Ocean Ripple).
+//!
+//! Glass and Ocean Ripple move each pixel's content by a shift that a surface decides (the slope
+//! of Glass's texture, smooth noise for the ripples), sampling the object bilinearly. The shift is
+//! capped, so the object reaches no farther than [`glass_shift`] or [`ripple_shift`] past its
+//! bounds. Diffuse Glow brightens the object's highlights towards white and sprinkles it with
+//! white grain. Every surface lies in document space around the object's centre, as the Texture
+//! filters' do.
+
+use vectorcraft_geom::{Point, Vec2};
+
+use super::pixelate::{Place, value_noise};
+use super::texture::{Texture, cell_noise, luma, premultiply, smooth_noise, straight};
+use super::{PixelSpace, blur_plane, pick};
+
+const SALT_GLOW: u64 = 120;
+const SALT_FROST: u64 = 128;
+const SALT_RIPPLE: u64 = 136;
+
+/// Glass's surfaces, in its Texture menu's order: (label, parameter value).
+pub const GLASS_TEXTURES: [(&str, &str); 4] = [("Blocks", "blocks"), ("Canvas", "canvas"), ("Frosted", "frosted"), ("Tiny Lens", "tinyLens")];
+
+/// A Glass surface.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub enum GlassTexture {
+    Blocks,
+    Canvas,
+    Frosted,
+    TinyLens,
+}
+
+impl GlassTexture {
+    const ALL: [GlassTexture; 4] = [GlassTexture::Blocks, GlassTexture::Canvas, GlassTexture::Frosted, GlassTexture::TinyLens];
+
+    /// The surface of `value` (a [`GLASS_TEXTURES`] value, any case); Frosted otherwise.
+    pub fn parse(value: &str) -> Self {
+        pick(&GLASS_TEXTURES, &Self::ALL, value, GlassTexture::Frosted)
+    }
+
+    /// The surface's height at `p` (points at 100 %), in points: slopes of about 1 at most.
+    fn height(self, p: Point) -> f64 {
+        match self {
+            GlassTexture::Blocks => blocks(p),
+            GlassTexture::Canvas => Texture::Canvas.height(p),
+            GlassTexture::Frosted => frosted(p),
+            GlassTexture::TinyLens => tiny_lens(p),
+        }
+    }
+}
+
+/// Square glass blocks 10 points across, flat on top with 2.5-point bevels.
+fn blocks(p: Point) -> f64 {
+    const SIZE: f64 = 10.0;
+    const BEVEL: f64 = 2.5;
+    let to_edge = |v: f64| {
+        let t = v.rem_euclid(SIZE);
+        t.min(SIZE - t)
+    };
+    to_edge(p.x).min(to_edge(p.y)).min(BEVEL)
+}
+
+/// Frosted glass: two octaves of fine smooth noise (1.2 and 0.5 points).
+fn frosted(p: Point) -> f64 {
+    0.8 * value_noise(SALT_FROST, p.x / 1.2, p.y / 1.2) + 0.2 * value_noise(SALT_FROST + 1, p.x / 0.5, p.y / 0.5)
+}
+
+/// Tiny lenses 4 points across in rows and columns, each a shallow dome.
+fn tiny_lens(p: Point) -> f64 {
+    const SIZE: f64 = 4.0;
+    let r = 0.5 * SIZE;
+    let off = |v: f64| v.rem_euclid(SIZE) - r;
+    let d2 = off(p.x).powi(2) + off(p.y).powi(2);
+    0.5 * r * (1.0 - d2 / (r * r)).max(0.0)
+}
+
+/// The longest shift (points) Glass gives at `distortion` (0..20).
+pub(super) fn glass_shift(distortion: f64) -> f64 {
+    0.5 * distortion.clamp(0.0, 20.0)
+}
+
+/// The ripples' size (points) for Ripple Size `size` (1..15).
+fn ripple_wave(size: f64) -> f64 {
+    2.0 + size.clamp(1.0, 15.0)
+}
+
+/// The longest shift (points) Ocean Ripple gives for Ripple Size `size` (1..15) and Ripple
+/// Magnitude `magnitude` (0..20).
+pub(super) fn ripple_shift(size: f64, magnitude: f64) -> f64 {
+    0.03 * magnitude.clamp(0.0, 20.0) * ripple_wave(size)
+}
+
+/// How far (points) Diffuse Glow spreads the highlights (the σ of their blur).
+pub(super) const GLOW_SPREAD: f64 = 2.0;
+
+/// Glass: the object seen through a `texture` surface scaled by `scaling` (0.5..2), bent by
+/// `distortion` (0..20) and smoothed by `smoothness` (1..15); `invert` turns the surface's heights
+/// over.
+#[allow(clippy::too_many_arguments)] // the effect's five options
+pub(super) fn glass(
+    px: &mut [[u8; 4]],
+    w: usize,
+    h: usize,
+    space: &PixelSpace,
+    distortion: f64,
+    smoothness: f64,
+    texture: GlassTexture,
+    scaling: f64,
+    invert: bool,
+) {
+    let Some(place) = Place::new(space, w, h) else { return };
+    if !(scaling.is_finite() && scaling > 0.0 && smoothness.is_finite()) {
+        return;
+    }
+    // Slopes over a quarter point of the surface per step of Smoothness, or half a pixel where
+    // pixels are larger: a smoother glass bends the image more gently.
+    let step = (0.25 * smoothness.clamp(1.0, 15.0)).max(0.5 * place.px / scaling);
+    let gain = 0.25 * distortion.clamp(0.0, 20.0) * if invert { -1.0 } else { 1.0 };
+    displace(px, w, h, &place, glass_shift(distortion), |q| {
+        let t = Point::new(q.x / scaling, q.y / scaling);
+        let at = |dx: f64, dy: f64| texture.height(Point::new(t.x + dx, t.y + dy));
+        Vec2::new(at(step, 0.0) - at(-step, 0.0), at(0.0, step) - at(0.0, -step)) * (gain / (2.0 * step))
+    });
+}
+
+/// Ocean Ripple: the object as if under rippling water, ripples about `size` (1..15) points plus
+/// two across, shifting it by up to [`ripple_shift`].
+pub(super) fn ocean_ripple(px: &mut [[u8; 4]], w: usize, h: usize, space: &PixelSpace, size: f64, magnitude: f64) {
+    let Some(place) = Place::new(space, w, h) else { return };
+    let (wave, most) = (ripple_wave(size), ripple_shift(size, magnitude));
+    displace(px, w, h, &place, most, |q| {
+        let n = |salt: u64| 0.7 * smooth_noise(salt, q, wave) + 0.3 * smooth_noise(salt + 2, q, 0.5 * wave);
+        Vec2::new(n(SALT_RIPPLE), n(SALT_RIPPLE + 1)) * most
+    });
+}
+
+/// Diffuse Glow: the object as seen through a soft diffusion filter. Its highlights, softened over
+/// [`GLOW_SPREAD`], glow white as strongly as `glow` (0..20) says, from the brightness that
+/// `clear` (0..20) leaves clear of glow; white grain as dense as `graininess` (0..10) says is
+/// sprinkled over it, thicker in the glow.
+pub(super) fn diffuse_glow(px: &mut [[u8; 4]], w: usize, h: usize, space: &PixelSpace, graininess: f64, glow: f64, clear: f64) {
+    let Some(place) = Place::new(space, w, h) else { return };
+    let mut light: Vec<f32> = px.iter().map(|p| luma(straight(*p)) * f32::from(p[3]) / 255.0).collect();
+    blur_plane(&mut light, w, h, GLOW_SPREAD / place.px);
+    let amount = (glow / 20.0).clamp(0.0, 1.0) as f32;
+    let from = (0.9 * clear / 20.0).clamp(0.0, 0.9) as f32;
+    let grain = (graininess / 10.0).clamp(0.0, 1.0);
+    place.each(px, |x, y, p| {
+        if p[3] == 0 {
+            return;
+        }
+        let g = ((light.get(y * w + x).copied().unwrap_or(0.0) - from) / (1.0 - from)).clamp(0.0, 1.0);
+        let chance = 0.5 * (cell_noise(SALT_GLOW, place.at(x, y), 1.0, 0) + 1.0);
+        let dot = if chance < grain * (0.08 + 0.32 * f64::from(g)) { 0.55 } else { 0.0 };
+        let white = (amount * g + dot).min(1.0);
+        *p = premultiply(straight(*p).map(|v| v + (1.0 - v) * white), f32::from(p[3]) / 255.0);
+    });
+}
+
+/// Move the object's content by `shift(q)` (document units; `q` a pixel's centre relative to the
+/// object's centre, its length capped at `most`): each pixel takes the colour `shift` away from it,
+/// interpolated between pixels, transparent beyond the raster.
+fn displace(px: &mut [[u8; 4]], w: usize, h: usize, place: &Place, most: f64, shift: impl Fn(Point) -> Vec2) {
+    if !(most.is_finite() && most > 0.0) {
+        return;
+    }
+    let src = px.to_vec();
+    place.each(px, |x, y, p| {
+        let q = place.at(x, y);
+        let d = shift(q);
+        if !(d.x.is_finite() && d.y.is_finite()) {
+            return;
+        }
+        let len = d.hypot();
+        let d = if len > most { d * (most / len) } else { d };
+        let s = place.to_px * (q + d);
+        *p = sample(&src, w, h, s.x - 0.5, s.y - 0.5);
+    });
+}
+
+/// The premultiplied colour at (`x`, `y`) of `w` × `h` pixels (pixel centres at whole
+/// coordinates), interpolated between the four around it, transparent outside.
+fn sample(src: &[[u8; 4]], w: usize, h: usize, x: f64, y: f64) -> [u8; 4] {
+    if !(x.is_finite() && y.is_finite()) {
+        return [0; 4];
+    }
+    let (x0, y0) = (x.floor(), y.floor());
+    let (fx, fy) = (x - x0, y - y0);
+    let at = |i: f64, j: f64| -> [f64; 4] {
+        if i < 0.0 || j < 0.0 || i >= w as f64 || j >= h as f64 {
+            return [0.0; 4];
+        }
+        src.get(j as usize * w + i as usize).map_or([0.0; 4], |p| p.map(f64::from))
+    };
+    let (a, b, c, d) = (at(x0, y0), at(x0 + 1.0, y0), at(x0, y0 + 1.0), at(x0 + 1.0, y0 + 1.0));
+    std::array::from_fn(|k| {
+        let top = a[k] + (b[k] - a[k]) * fx;
+        let bottom = c[k] + (d[k] - c[k]) * fx;
+        (top + (bottom - top) * fy).round().clamp(0.0, 255.0) as u8
+    })
+}

crates/effects/src/pixel/mod.rs

@@ -1,5 +1,6 @@
-//! Photoshop-style raster effects (Effect › Blur › Radial Blur and Smart Blur, Pixelate › Color
-//! Halftone, Crystallize, Mezzotint and Pointillize, Sharpen › Unsharp Mask, Stylize › Glowing
+//! Photoshop-style raster effects (Effect › Blur › Radial Blur and Smart Blur, Distort › Diffuse
+//! Glow, Glass and Ocean Ripple, Pixelate › Color Halftone, Crystallize, Mezzotint and Pointillize,
+//! Sharpen › Unsharp Mask, Stylize › Glowing
 //! Edges, Texture › Craquelure, Grain, Mosaic Tiles, Patchwork, Stained Glass and Texturizer, and
 //! Video › De-Interlace and NTSC Colors): filters over premultiplied RGBA8 pixels.
 //!
@@ -11,6 +12,7 @@
 //! - Beyond the raster's edges is transparency.
 
 mod blur;
+mod distort;
 mod edges;
 mod pixelate;
 mod sharpen;
@@ -22,13 +24,17 @@ use vectorcraft_geom::{Affine, Point, Rect};
 
 use crate::util::{flag, num, text};
 
+pub use distort::{GLASS_TEXTURES, GlassTexture};
 pub use pixelate::{MEZZOTINT_TYPES, Mezzotint};
 pub use texture::{GRAIN_TYPES, Grain, LIGHT_DIRECTIONS, Light, TEXTURES, Texture};
 
 /// The Photoshop-style effect ids (all raster effects, see [`crate::is_raster`]).
-pub const PIXEL_EFFECTS: [&str; 16] = [
+pub const PIXEL_EFFECTS: [&str; 19] = [
     "blur.radial",
     "blur.smart",
+    "distort.diffuseGlow",
+    "distort.glass",
+    "distort.oceanRipple",
     "pixelate.colorHalftone",
     "pixelate.crystallize",
     "pixelate.mezzotint",
@@ -56,6 +62,16 @@ pub enum PixelFx {
     /// whose colour differs from its own by no more than `threshold` levels, over a grid of
     /// `samples` × `samples` neighbours at most.
     SmartBlur { radius: f64, threshold: f64, samples: u32 },
+    /// Distort › Diffuse Glow: the highlights glow white as strongly as `glow` (0..20), from the
+    /// brightness `clear` (0..20) leaves clear, under white grain as dense as `graininess` (0..10).
+    DiffuseGlow { graininess: f64, glow: f64, clear: f64 },
+    /// Distort › Glass: the object seen through a `texture` surface scaled by `scaling` (0.5..2),
+    /// bent by `distortion` (0..20), smoothed by `smoothness` (1..15), its heights turned over when
+    /// `invert`.
+    Glass { distortion: f64, smoothness: f64, texture: GlassTexture, scaling: f64, invert: bool },
+    /// Distort › Ocean Ripple: the object under ripples of `size` (1..15) shifting it as much as
+    /// `magnitude` (0..20) says.
+    OceanRipple { size: f64, magnitude: f64 },
     /// Sharpen › Unsharp Mask: colours pushed away from a Gaussian blur of σ = `radius` by `amount`
     /// (1 = 100 %), where they differ from it by at least `threshold` levels.
     UnsharpMask { amount: f64, radius: f64, threshold: f64 },
@@ -149,6 +165,21 @@ pub(crate) fn parse(id: &str, p: &Value) -> Option<PixelFx> {
             threshold: num(p, "threshold", 25.0).clamp(0.1, 100.0),
             samples: quality([("low", 5), ("medium", 7), ("high", 9)], 7),
         },
+        "distort.diffuseGlow" => PixelFx::DiffuseGlow {
+            graininess: num(p, "graininess", 6.0).clamp(0.0, 10.0),
+            glow: num(p, "glowAmount", 10.0).clamp(0.0, 20.0),
+            clear: num(p, "clearAmount", 15.0).clamp(0.0, 20.0),
+        },
+        "distort.glass" => PixelFx::Glass {
+            distortion: num(p, "distortion", 5.0).clamp(0.0, 20.0),
+            smoothness: num(p, "smoothness", 3.0).clamp(1.0, 15.0),
+            texture: GlassTexture::parse(text(p, "texture", "frosted")),
+            scaling: num(p, "scaling", 100.0).clamp(50.0, 200.0) / 100.0,
+            invert: flag(p, "invert", false),
+        },
+        "distort.oceanRipple" => {
+            PixelFx::OceanRipple { size: num(p, "rippleSize", 9.0).clamp(1.0, 15.0), magnitude: num(p, "rippleMagnitude", 9.0).clamp(0.0, 20.0) }
+        }
         "sharpen.unsharpMask" => PixelFx::UnsharpMask {
             amount: num(p, "amount", 50.0).clamp(1.0, 500.0) / 100.0,
             radius: num(p, "radius", 1.0).clamp(0.1, 250.0),
@@ -217,6 +248,10 @@ impl PixelFx {
             PixelFx::RadialBlur { zoom: false, .. } => (far - near).max(0.0),
             PixelFx::RadialBlur { amount, zoom: true, .. } => far * (blur::zoom_extent(amount).exp() - 1.0),
             PixelFx::SmartBlur { radius, .. } => radius,
+            PixelFx::DiffuseGlow { .. } => 0.0,
+            // Content shifted outwards reaches past the bounds by as much as the shift.
+            PixelFx::Glass { distortion, .. } => distort::glass_shift(distortion),
+            PixelFx::OceanRipple { size, magnitude } => distort::ripple_shift(size, magnitude),
             PixelFx::UnsharpMask { .. } => 0.0,
             PixelFx::GlowingEdges { width, smoothness, .. } => width.max(smoothness * 3.0),
             PixelFx::ColorHalftone { .. }
@@ -240,6 +275,9 @@ impl PixelFx {
         match *self {
             PixelFx::RadialBlur { .. } => None,
             PixelFx::SmartBlur { radius, .. } => Some(radius),
+            PixelFx::DiffuseGlow { .. } => Some(3.0 * distort::GLOW_SPREAD),
+            PixelFx::Glass { distortion, .. } => Some(distort::glass_shift(distortion)),
+            PixelFx::OceanRipple { size, magnitude } => Some(distort::ripple_shift(size, magnitude)),
             PixelFx::UnsharpMask { radius, .. } => Some(3.0 * radius),
             PixelFx::GlowingEdges { width, smoothness, .. } => Some(width.max(smoothness * 3.0)),
             // The cells around the pixel's, and the cells around theirs.
@@ -268,6 +306,11 @@ impl PixelFx {
         match *self {
             PixelFx::RadialBlur { amount, zoom, passes } => blur::radial(px, w, h, space, amount, zoom, passes),
             PixelFx::SmartBlur { radius, threshold, samples } => blur::smart(px, w, h, to_px(radius), threshold, samples),
+            PixelFx::DiffuseGlow { graininess, glow, clear } => distort::diffuse_glow(px, w, h, space, graininess, glow, clear),
+            PixelFx::Glass { distortion, smoothness, texture, scaling, invert } => {
+                distort::glass(px, w, h, space, distortion, smoothness, texture, scaling, invert)
+            }
+            PixelFx::OceanRipple { size, magnitude } => distort::ocean_ripple(px, w, h, space, size, magnitude),
             PixelFx::UnsharpMask { amount, radius, threshold } => sharpen::unsharp(px, w, h, amount, to_px(radius), threshold),
             PixelFx::GlowingEdges { width, brightness, smoothness } => edges::glow(px, w, h, to_px(width), brightness, to_px(smoothness)),
             PixelFx::ColorHalftone { max_radius, angles } => pixelate::color_halftone(px, w, h, space, max_radius, angles),

crates/effects/src/pixel/tests.rs

@@ -826,3 +826,159 @@ fn texture_patterns_follow_the_object_at_any_resolution() {
         assert_eq!(shifted, one, "{id}");
     }
 }
+
+#[test]
+fn distort_params_take_defaults_and_stay_in_range() {
+    assert_eq!(fx("distort.diffuseGlow", json!({})), PixelFx::DiffuseGlow { graininess: 6.0, glow: 10.0, clear: 15.0 });
+    assert_eq!(
+        fx("distort.diffuseGlow", json!({"graininess": 1e9, "glowAmount": -3, "clearAmount": "x"})),
+        PixelFx::DiffuseGlow { graininess: 10.0, glow: 0.0, clear: 15.0 }
+    );
+    assert_eq!(
+        fx("distort.glass", json!({})),
+        PixelFx::Glass { distortion: 5.0, smoothness: 3.0, texture: GlassTexture::Frosted, scaling: 1.0, invert: false }
+    );
+    assert_eq!(
+        fx("distort.glass", json!({"distortion": 1e308, "smoothness": 0, "texture": "TINYLENS", "scaling": 1, "invert": true})),
+        PixelFx::Glass { distortion: 20.0, smoothness: 1.0, texture: GlassTexture::TinyLens, scaling: 0.5, invert: true }
+    );
+    assert_eq!(fx("distort.glass", json!({"texture": "bubbles"})), fx("distort.glass", json!({})));
+    assert_eq!(fx("distort.oceanRipple", json!({})), PixelFx::OceanRipple { size: 9.0, magnitude: 9.0 });
+    assert_eq!(fx("distort.oceanRipple", json!({"rippleSize": 99, "rippleMagnitude": -1})), PixelFx::OceanRipple { size: 15.0, magnitude: 0.0 });
+    // Shifted content reaches past the bounds by the longest shift, and comes from as far.
+    let b = Rect::new(0.0, 0.0, 100.0, 50.0);
+    let glass = fx("distort.glass", json!({"distortion": 20}));
+    assert_eq!((glass.outset(b), glass.reach()), (10.0, Some(10.0)));
+    let ripple = fx("distort.oceanRipple", json!({}));
+    assert!((ripple.outset(b) - 0.03 * 9.0 * 11.0).abs() < 1e-9 && ripple.reach() == Some(ripple.outset(b)));
+    assert_eq!(fx("distort.diffuseGlow", json!({})).outset(b), 0.0);
+}
+
+/// Vertical stripes 5 points wide (out of step with every glass surface), alternately light and
+/// dark, over the whole raster.
+fn stripes(w: usize, h: usize) -> Vec<u8> {
+    image(w, h, |x, _| if (x / 5) % 2 == 0 { [230, 200, 60, 255] } else { [20, 40, 120, 255] })
+}
+
+#[test]
+fn glass_bends_the_image_by_its_texture() {
+    let (w, h) = (48, 40);
+    let src = stripes(w, h);
+    let run = |p: serde_json::Value| {
+        let mut d = src.clone();
+        fx("distort.glass", p).apply(&mut d, w, h, &space(w, h));
+        d
+    };
+    // No distortion, no change.
+    assert_eq!(run(json!({"distortion": 0})), src);
+    let mut seen = vec![];
+    for (_, texture) in GLASS_TEXTURES {
+        let bent = run(json!({"texture": texture, "distortion": 12}));
+        assert_ne!(bent, src, "{texture}");
+        assert!(!seen.contains(&bent), "{texture} differs from the other textures");
+        assert_ne!(run(json!({"texture": texture, "distortion": 12, "invert": true})), bent, "{texture} inverted");
+        // A colour moves; none is invented: every pixel blends two neighbouring stripes at most
+        // (those within a shift of the raster's edges also take in the transparency beyond it).
+        for (x, y) in (6..w - 6).flat_map(|x| (6..h - 6).map(move |y| (x, y))) {
+            let p = at(&bent, w, x, y);
+            assert!(p[3] == 255 && p[0] >= 20 && p[0] <= 230, "{texture} at ({x}, {y}): {p:?}");
+        }
+        seen.push(bent);
+    }
+    // Smoother glass bends the stripes differently (more gently).
+    assert_ne!(run(json!({"distortion": 12, "smoothness": 15})), run(json!({"distortion": 12, "smoothness": 1})));
+}
+
+#[test]
+fn ocean_ripple_moves_content_no_farther_than_its_magnitude() {
+    let (w, h) = (64, 32);
+    // The left half white, the right half transparent.
+    let src = image(w, h, |x, _| if x < 32 { grey(255) } else { [0; 4] });
+    let mut d = src.clone();
+    fx("distort.oceanRipple", json!({"rippleMagnitude": 0})).apply(&mut d, w, h, &space(w, h));
+    assert_eq!(d, src, "no magnitude, no ripples");
+    let f = fx("distort.oceanRipple", json!({"rippleSize": 6, "rippleMagnitude": 20}));
+    let most = f.reach().unwrap();
+    let mut d = src.clone();
+    f.apply(&mut d, w, h, &space(w, h));
+    assert_ne!(d, src);
+    // Away from the white's edge, and from the raster's (beyond which is transparency), nothing
+    // changes.
+    let inside = |v: usize, n: usize| (v as f64 + 0.5).min(n as f64 - v as f64 - 0.5) > most + 1.0;
+    for y in (0..h).filter(|y| inside(*y, h)) {
+        for x in (0..w).filter(|x| inside(*x, w)) {
+            let to_edge = (x as f64 + 0.5 - 32.0).abs();
+            if to_edge > most + 1.0 {
+                assert_eq!(at(&d, w, x, y), at(&src, w, x, y), "({x}, {y}) is {to_edge} from the edge, past {most}");
+            }
+        }
+    }
+    // The edge wanders: some rows reach farther right than others.
+    let ends: Vec<usize> = (0..h).map(|y| (0..w).filter(|x| at(&d, w, *x, y)[3] > 127).count()).collect();
+    assert!(ends.iter().min() != ends.iter().max(), "{ends:?}");
+}
+
+#[test]
+fn diffuse_glow_whitens_the_highlights_and_sprinkles_grain() {
+    let (w, h) = (48, 48);
+    // Dark on the left, light on the right, a transparent margin round them.
+    let src = image(w, h, |x, y| {
+        if !(4..44).contains(&x) || !(4..44).contains(&y) {
+            [0; 4]
+        } else if x < 24 {
+            [30, 30, 60, 255]
+        } else {
+            [200, 190, 170, 255]
+        }
+    });
+    let run = |p: serde_json::Value| {
+        let mut d = src.clone();
+        fx("distort.diffuseGlow", p).apply(&mut d, w, h, &space(w, h));
+        d
+    };
+    let clean = run(json!({"graininess": 0}));
+    // Transparency stays; the shadows stay clear; the highlights glow.
+    for (a, b) in clean.as_chunks::<4>().0.iter().zip(src.as_chunks::<4>().0) {
+        assert_eq!(a[3], b[3]);
+    }
+    assert_eq!(at(&clean, w, 10, 24), at(&src, w, 10, 24));
+    let (lit, before) = (at(&clean, w, 36, 24), at(&src, w, 36, 24));
+    assert!((0..3).all(|c| lit[c] > before[c]), "{lit:?} brighter than {before:?}");
+    // More Clear Amount leaves more of the image clear of glow.
+    assert!(at(&run(json!({"graininess": 0, "clearAmount": 20})), w, 36, 24)[0] < lit[0]);
+    assert_eq!(run(json!({"graininess": 0, "glowAmount": 0})), src);
+    // Grain: white specks, in the shadows too.
+    let grainy = run(json!({"graininess": 10}));
+    let specks = (4..24).flat_map(|x| (4..44).map(move |y| (x, y))).filter(|(x, y)| at(&grainy, w, *x, *y)[0] > 100).count();
+    assert!(specks > 10, "{specks} white specks in the shadows");
+}
+
+#[test]
+fn distort_patterns_follow_the_object_at_any_resolution() {
+    let (w, h) = (48, 48);
+    let art = |x: f64, y: f64| -> [u8; 4] {
+        if (8.0..40.0).contains(&x) && (8.0..40.0).contains(&y) { [(x * 5.0) as u8, (y * 5.0) as u8, 120, 255] } else { [0; 4] }
+    };
+    for (id, p) in [
+        ("distort.diffuseGlow", json!({"clearAmount": 5})),
+        ("distort.glass", json!({"texture": "blocks", "distortion": 8})),
+        ("distort.oceanRipple", json!({"rippleMagnitude": 12})),
+    ] {
+        let f = fx(id, p);
+        let mut one = image(w, h, |x, y| art(x as f64 + 0.5, y as f64 + 0.5));
+        f.apply(&mut one, w, h, &space(w, h));
+        let mut two = image(2 * w, 2 * h, |x, y| art((x as f64 + 0.5) / 2.0, (y as f64 + 0.5) / 2.0));
+        let fine = PixelSpace { to_doc: Affine::scale(0.5), px: 0.5, ..space(w, h) };
+        f.apply(&mut two, 2 * w, 2 * h, &fine);
+        let down = image(w, h, |x, y| {
+            let q = [(0, 0), (1, 0), (0, 1), (1, 1)].map(|(dx, dy)| at(&two, 2 * w, 2 * x + dx, 2 * y + dy));
+            std::array::from_fn(|c| (q.iter().map(|p| u32::from(p[c])).sum::<u32>() / 4) as u8)
+        });
+        let diff = one.iter().zip(&down).map(|(a, b)| f64::from(a.abs_diff(*b))).sum::<f64>() / one.len() as f64;
+        assert!(diff < 12.0, "{id}: {diff}");
+        let moved = PixelSpace { to_doc: Affine::translate((7.0, 3.0)), center: Point::new(31.0, 27.0), ..space(w, h) };
+        let mut shifted = image(w, h, |x, y| art(x as f64 + 0.5, y as f64 + 0.5));
+        f.apply(&mut shifted, w, h, &moved);
+        assert_eq!(shifted, one, "{id}");
+    }
+}

crates/effects/src/pixel/texture.rs

@@ -83,7 +83,7 @@ impl Texture {
     }
 
     /// The surface's height at `p` (points at 100 %), in points: slopes of about 1 at most.
-    fn height(self, p: Point) -> f64 {
+    pub(super) fn height(self, p: Point) -> f64 {
         match self {
             Texture::Brick => brick(p),
             Texture::Burlap => weave(p, 7.0, true),
@@ -155,13 +155,13 @@ const SALT_SURFACE: u64 = 112;
 pub(super) const CONTOUR_SOFTNESS: f64 = 1.0 / 6.0;
 
 /// A pixel's straight colour (0..1).
-fn straight(p: [u8; 4]) -> [f32; 3] {
+pub(super) fn straight(p: [u8; 4]) -> [f32; 3] {
     let a = f32::from(p[3]);
     [p[0], p[1], p[2]].map(|v| if a > 0.0 { (f32::from(v) / a).min(1.0) } else { 0.0 })
 }
 
 /// The pixel of straight colour `c` at coverage `alpha` (0..1), premultiplied.
-fn premultiply(c: [f32; 3], alpha: f32) -> [u8; 4] {
+pub(super) fn premultiply(c: [f32; 3], alpha: f32) -> [u8; 4] {
     let a = (alpha.clamp(0.0, 1.0) * 255.0).round();
     let [r, g, b] = c.map(|v| (v.clamp(0.0, 1.0) * a).round().min(a) as u8);
     [r, g, b, a as u8]
@@ -185,7 +185,7 @@ fn cover(d: f64, px: f64) -> f64 {
 }
 
 /// The luma of colour `c` (Rec. 601 weights).
-fn luma(c: [f32; 3]) -> f32 {
+pub(super) fn luma(c: [f32; 3]) -> f32 {
     0.299 * c[0] + 0.587 * c[1] + 0.114 * c[2]
 }
 
@@ -308,7 +308,7 @@ pub(super) fn craquelure(px: &mut [[u8; 4]], w: usize, h: usize, space: &PixelSp
 }
 
 /// A random value in [-1, 1) for the `size`-point cell holding `q`; `k` picks one of several.
-fn cell_noise(salt: u64, q: Point, size: f64, k: u64) -> f64 {
+pub(super) fn cell_noise(salt: u64, q: Point, size: f64, k: u64) -> f64 {
     match (cell(q.x / size), cell(q.y / size)) {
         (Some(i), Some(j)) => 2.0 * rand(salt, i, j, k) - 1.0,
         _ => 0.0,
@@ -316,7 +316,7 @@ fn cell_noise(salt: u64, q: Point, size: f64, k: u64) -> f64 {
 }
 
 /// [`value_noise`] in [-1, 1) over cells `size` points wide.
-fn smooth_noise(salt: u64, q: Point, size: f64) -> f64 {
+pub(super) fn smooth_noise(salt: u64, q: Point, size: f64) -> f64 {
     2.0 * value_noise(salt, q.x / size, q.y / size) - 1.0
 }
 

crates/engine/src/tests_rasterfilters.rs

@@ -1,5 +1,5 @@
-//! The Photoshop-style raster effects (Effect › Blur › Radial Blur and Smart Blur, Pixelate ›
-//! Color Halftone, Crystallize, Mezzotint and Pointillize, Sharpen › Unsharp Mask, Texture ›
+//! The Photoshop-style raster effects (Effect › Blur › Radial Blur and Smart Blur, Distort ›
+//! Diffuse Glow, Glass and Ocean Ripple, Pixelate › Color Halftone, Crystallize, Mezzotint and Pointillize, Sharpen › Unsharp Mask, Texture ›
 //! Craquelure, Grain, Mosaic Tiles, Patchwork, Stained Glass and Texturizer, Video): applied and
 //! edited as commands, listed in the catalogue, drawn on the canvas, and written to PDF and SVG
 //! as images of the effected object.
@@ -18,6 +18,11 @@ const EFFECTS: [(&str, &str); 3] = [
     ("sharpen.unsharpMask", r#"{"amount": 300, "radius": 3}"#),
 ];
 
+/// Effect › Distort (Diffuse Glow with its highlights glowing from a low brightness up, as the
+/// striped art's reds are dark).
+const DISTORT: [(&str, &str); 3] =
+    [("distort.diffuseGlow", r#"{"clearAmount": 0, "glowAmount": 20}"#), ("distort.glass", "{}"), ("distort.oceanRipple", "{}")];
+
 /// Effect › Pixelate, at their defaults.
 const PIXELATE: [(&str, &str); 4] =
     [("pixelate.colorHalftone", "{}"), ("pixelate.crystallize", "{}"), ("pixelate.mezzotint", "{}"), ("pixelate.pointillize", "{}")];
@@ -73,6 +78,7 @@ fn listed_applied_edited_and_undone() {
         EFFECTS.iter().map(|(id, _)| list["catalog"].as_array().unwrap().iter().find(|e| e["id"] == *id).unwrap()["menu"].clone()).collect();
     assert_eq!(menus, [json!(["Effect", "Blur"]), json!(["Effect", "Blur"]), json!(["Effect", "Sharpen"])]);
     for (group, menu) in [
+        (DISTORT.as_slice(), "Distort"),
         (PIXELATE.as_slice(), "Pixelate"),
         (TEXTURE.as_slice(), "Texture"),
         (VIDEO.as_slice(), "Video"),
@@ -102,7 +108,7 @@ fn listed_applied_edited_and_undone() {
 
 #[test]
 fn each_effect_changes_the_canvas_and_draws_the_same_twice() {
-    for (id, params) in EFFECTS.into_iter().chain(PIXELATE).chain(TEXTURE).chain(VIDEO) {
+    for (id, params) in EFFECTS.into_iter().chain(DISTORT).chain(PIXELATE).chain(TEXTURE).chain(VIDEO) {
         let (mut s, g) = striped();
         let plain = render(&s);
         let params: Value = serde_json::from_str(params).unwrap();
@@ -131,7 +137,7 @@ fn spin_blur_reaches_past_the_corners() {
 
 #[test]
 fn pdf_and_svg_write_the_effected_object_as_an_image() {
-    for (id, params) in EFFECTS.into_iter().chain(PIXELATE).chain(TEXTURE).chain(VIDEO) {
+    for (id, params) in EFFECTS.into_iter().chain(DISTORT).chain(PIXELATE).chain(TEXTURE).chain(VIDEO) {
         let (mut s, g) = striped();
         let params: Value = serde_json::from_str(params).unwrap();
         s.execute("effect.apply", &json!({"effect": id, "ids": [g], "params": params})).unwrap();

crates/engine/tests/command_sweep.rs

@@ -307,6 +307,9 @@ fn structured_junk() {
         ),
         ("effect.apply", json!({"effect": "video.deinterlace", "params": {"eliminate": 7, "create": ["x"]}})),
         ("effect.apply", json!({"effect": "video.ntscColors", "params": {"junk": 1e308}})),
+        ("effect.apply", json!({"effect": "distort.diffuseGlow", "params": {"graininess": "x", "glowAmount": 1e308, "clearAmount": -1e308}})),
+        ("effect.apply", json!({"effect": "distort.glass", "params": {"distortion": 1e308, "smoothness": "NaN", "texture": 3, "scaling": -1}})),
+        ("effect.apply", json!({"effect": "distort.oceanRipple", "params": {"rippleSize": [1], "rippleMagnitude": 1e308}})),
         ("effect.apply", json!({"effect": "no.such.effect"})),
         ("effect.remove", json!({"index": 99})),
         ("effect.setParams", json!({"index": 0, "params": null})),

crates/ui-egui/src/dialogs/effect.rs

@@ -159,6 +159,7 @@ fn choices(effect: &str, key: &str) -> Option<form::Choices> {
         ("blur.radial", "method") => Some(&[("Spin", "spin"), ("Zoom", "zoom")]),
         ("blur.radial", "quality") => Some(&[("Draft", "draft"), ("Good", "good"), ("Best", "best")]),
         ("blur.smart", "quality") => Some(&[("Low", "low"), ("Medium", "medium"), ("High", "high")]),
+        ("distort.glass", "texture") => Some(&vectorcraft_effects::pixel::GLASS_TEXTURES),
         ("pixelate.mezzotint", "type") => Some(&vectorcraft_effects::pixel::MEZZOTINT_TYPES),
         ("texture.grain", "grainType") => Some(&vectorcraft_effects::pixel::GRAIN_TYPES),
         ("texture.texturizer", "texture") => Some(&vectorcraft_effects::pixel::TEXTURES),

crates/ui-egui/src/i18n/cs.tsv

@@ -674,3 +674,7 @@
 	Texturizer…	Texturovač…
 	System Title Bar	Systémové záhlaví okna
 	Exit	Ukončit
+	Distort	Zkreslení
+	Diffuse Glow…	Rozptýlená záře…
+	Glass…	Sklo…
+	Ocean Ripple…	Vlnky na hladině…

crates/ui-egui/src/i18n/de.tsv

@@ -3938,3 +3938,19 @@ theme	Appearance	Erscheinungsbild
 	On Both Sides	Auf beiden Seiten
 	Short	Kurz
 	Full Width	Volle Breite
+	Distort	Verzerren
+	Diffuse Glow…	Weiches Licht…
+	Glass…	Glas…
+	Ocean Ripple…	Ozeanwellen…
+	Diffuse Glow	Weiches Licht
+	Glass	Glas
+	Ocean Ripple	Ozeanwellen
+	Graininess	Körnung
+	Glow Amount	Lichtmenge
+	Clear Amount	Klarer Bereich
+	Ripple Size	Wellengröße
+	Ripple Magnitude	Wellenstärke
+	Blocks	Blöcke
+	Frosted	Mattiert
+	Tiny Lens	Kleine Linsen
+	Canvas	Leinwand

crates/ui-egui/src/i18n/es.tsv

@@ -3982,3 +3982,18 @@ axis	Both	Ambos
 	On Both Sides	En ambos lados
 	Short	Corta
 	Full Width	Ancho completo
+	Distort	Distorsionar
+	Diffuse Glow…	Resplandor difuso…
+	Glass…	Vidrio…
+	Ocean Ripple…	Rizo oceánico…
+	Diffuse Glow	Resplandor difuso
+	Glass	Vidrio
+	Ocean Ripple	Rizo oceánico
+	Graininess	Granulosidad
+	Glow Amount	Cantidad de resplandor
+	Clear Amount	Cantidad de claridad
+	Ripple Size	Tamaño de rizo
+	Ripple Magnitude	Magnitud de rizo
+	Blocks	Bloques
+	Frosted	Esmerilado
+	Tiny Lens	Lente pequeña

crates/ui-egui/src/i18n/fr.tsv

@@ -3994,3 +3994,18 @@ effect	Soft	Doux
 	On Both Sides	Des deux côtés
 	Short	Courte
 	Full Width	Toute la largeur
+	Distort	Déformation
+	Diffuse Glow…	Diffusion lumineuse…
+	Glass…	Verre…
+	Ocean Ripple…	Ondulation océanique…
+	Diffuse Glow	Diffusion lumineuse
+	Glass	Verre
+	Ocean Ripple	Ondulation océanique
+	Graininess	Granularité
+	Glow Amount	Intensité de la lueur
+	Clear Amount	Zone claire
+	Ripple Size	Taille de l'ondulation
+	Ripple Magnitude	Amplitude de l'ondulation
+	Blocks	Blocs
+	Frosted	Dépoli
+	Tiny Lens	Petites lentilles

crates/ui-egui/src/i18n/it.tsv

@@ -3984,3 +3984,18 @@ effect	Regular	Normale
 	On Both Sides	Su entrambi i lati
 	Short	Breve
 	Full Width	Larghezza intera
+	Distort	Distorsione
+	Diffuse Glow…	Bagliore diffuso…
+	Glass…	Vetro…
+	Ocean Ripple…	Increspatura oceanica…
+	Diffuse Glow	Bagliore diffuso
+	Glass	Vetro
+	Ocean Ripple	Increspatura oceanica
+	Graininess	Granulosità
+	Glow Amount	Quantità di bagliore
+	Clear Amount	Quantità di chiarezza
+	Ripple Size	Dimensione increspatura
+	Ripple Magnitude	Ampiezza increspatura
+	Blocks	Blocchi
+	Frosted	Smerigliato
+	Tiny Lens	Lente piccola

crates/ui-egui/src/i18n/ja.tsv

@@ -3977,3 +3977,18 @@ effect	Vertical	垂直
 	On Both Sides	両側
 	Short	短い
 	Full Width	全幅
+	Distort	変形
+	Diffuse Glow…	光彩拡散…
+	Glass…	ガラス…
+	Ocean Ripple…	海の波紋…
+	Diffuse Glow	光彩拡散
+	Glass	ガラス
+	Ocean Ripple	海の波紋
+	Graininess	粒子
+	Glow Amount	光彩の量
+	Clear Amount	クリア量
+	Ripple Size	波紋のサイズ
+	Ripple Magnitude	波紋の強さ
+	Blocks	ブロック
+	Frosted	すりガラス
+	Tiny Lens	小さなレンズ

crates/ui-egui/src/i18n/pt-br.tsv

@@ -2734,3 +2734,7 @@
 	Texturizer…	Texturizador…
 	System Title Bar	Barra de título do sistema
 	Exit	Sair
+	Distort	Distorcer
+	Diffuse Glow…	Brilho difuso…
+	Glass…	Vidro…
+	Ocean Ripple…	Ondulação oceânica…

crates/ui-egui/src/i18n/ru.tsv

@@ -3980,3 +3980,18 @@ axis	Both	Оба
 	On Both Sides	С обеих сторон
 	Short	Короткие
 	Full Width	Во всю ширину
+	Distort	Искажение
+	Diffuse Glow…	Рассеянное свечение…
+	Glass…	Стекло…
+	Ocean Ripple…	Океанские волны…
+	Diffuse Glow	Рассеянное свечение
+	Glass	Стекло
+	Ocean Ripple	Океанские волны
+	Graininess	Зернистость
+	Glow Amount	Сила свечения
+	Clear Amount	Чистые области
+	Ripple Size	Размер волн
+	Ripple Magnitude	Сила волн
+	Blocks	Блоки
+	Frosted	Матовое
+	Tiny Lens	Мелкие линзы

crates/ui-egui/src/i18n/uk.tsv

@@ -3965,3 +3965,18 @@ axis	Both	Обидві
 	On Both Sides	З обох боків
 	Short	Короткі
 	Full Width	На всю ширину
+	Distort	Спотворення
+	Diffuse Glow…	Розсіяне світіння…
+	Glass…	Скло…
+	Ocean Ripple…	Океанські хвилі…
+	Diffuse Glow	Розсіяне світіння
+	Glass	Скло
+	Ocean Ripple	Океанські хвилі
+	Graininess	Зернистість
+	Glow Amount	Сила світіння
+	Clear Amount	Чисті ділянки
+	Ripple Size	Розмір хвиль
+	Ripple Magnitude	Сила хвиль
+	Blocks	Блоки
+	Frosted	Матове
+	Tiny Lens	Дрібні лінзи

crates/ui-egui/src/i18n/zh-hans.tsv

@@ -3613,3 +3613,18 @@ effect	Vertical	垂直
 	On Both Sides	两侧
 	Short	短
 	Full Width	全宽
+	Distort	扭曲
+	Diffuse Glow…	扩散亮光…
+	Glass…	玻璃…
+	Ocean Ripple…	海洋波纹…
+	Diffuse Glow	扩散亮光
+	Glass	玻璃
+	Ocean Ripple	海洋波纹
+	Graininess	颗粒
+	Glow Amount	发光量
+	Clear Amount	清除数量
+	Ripple Size	波纹大小
+	Ripple Magnitude	波纹幅度
+	Blocks	块状
+	Frosted	磨砂
+	Tiny Lens	小镜头

crates/ui-egui/src/i18n/zh-hant.tsv

@@ -3394,3 +3394,18 @@ effect	Soft	柔和
 	On Both Sides	兩側
 	Short	短
 	Full Width	全寬
+	Distort	扭曲
+	Diffuse Glow…	擴散光暈…
+	Glass…	玻璃…
+	Ocean Ripple…	海洋波紋…
+	Diffuse Glow	擴散光暈
+	Glass	玻璃
+	Ocean Ripple	海洋波紋
+	Graininess	顆粒
+	Glow Amount	光暈量
+	Clear Amount	清除量
+	Ripple Size	波紋大小
+	Ripple Magnitude	波紋強度
+	Blocks	塊狀
+	Frosted	磨砂
+	Tiny Lens	小鏡頭

crates/ui-egui/src/menus.rs

@@ -3297,8 +3297,9 @@ fn font_items(english_names: bool) -> Vec<Item> {
 
 /// The raster effects' submenus of the Effect menu (the Photoshop-style effects, below the
 /// vector effects): (submenu, the catalogue's menu path of its effects).
-const RASTER_MENUS: [(&str, &[&str]); 5] = [
+const RASTER_MENUS: [(&str, &[&str]); 6] = [
     ("Blur", &["Effect", "Blur"]),
+    ("Distort", &["Effect", "Distort"]),
     ("Pixelate", &["Effect", "Pixelate"]),
     ("Sharpen", &["Effect", "Sharpen"]),
     ("Texture", &["Effect", "Texture"]),

crates/ui-egui/src/tests_labels.rs

@@ -78,6 +78,23 @@ fn effect_menu_lists_the_video_filters_last() {
     assert!(at("Sharpen") < at("Video"));
 }
 
+/// Effect › Distort, between Blur and Pixelate: each filter opens its dialog.
+#[test]
+fn effect_menu_lists_the_distort_filters_between_blur_and_pixelate() {
+    let app = app();
+    let entries = menus::menu_entries(&app);
+    let distort: Vec<_> = entries.iter().filter(|e| e.path == ["Effect", "Distort"]).collect();
+    let labels: Vec<&str> = distort.iter().map(|e| e.label.as_str()).collect();
+    assert_eq!(labels, ["Diffuse Glow…", "Glass…", "Ocean Ripple…"]);
+    assert!(distort.iter().all(|e| e.command.as_deref() == Some("effect.dialog")));
+    let raster: Vec<&str> =
+        entries.iter().filter_map(|e| e.path.get(1).filter(|_| e.path.len() == 2 && e.path[0] == "Effect")).map(String::as_str).collect();
+    let at = |name: &str| raster.iter().position(|s| *s == name).unwrap();
+    assert!(at("Blur") < at("Distort") && at("Distort") < at("Pixelate"));
+    // The vector Distort & Transform stays its own submenu.
+    assert!(raster.contains(&"Distort & Transform"));
+}
+
 /// Effect › Texture, between Sharpen and Video: each filter opens its dialog.
 #[test]
 fn effect_menu_lists_the_texture_filters_between_sharpen_and_video() {