From ca88af2b5f271c5c8be324cbe0574e99ece07bf2 Mon Sep 17 00:00:00 2001 From: arnav-hiwarkar Date: Wed, 21 Oct 2026 21:34:45 +0530 Subject: [PATCH] Fractal Noise: resolve the Blending Mode once per layer, not per pixel `crates/effects/src/noise3.rs` only: - a `blend_mode(u32) -> Option` helper, which the CPU and GPU paths now share; - the CPU `render` resolves the mode once and passes `Option` to the per-pixel `composite`. The semantics are unchanged: None means the noise alone, and an unknown index means Normal. Co-Authored-By: Claude Opus 5.5 --- crates/effects/src/noise3.rs | 54 ++++++++++++++++++++++++++++-------- 1 file changed, 43 insertions(+), 11 deletions(-) diff --git a/crates/effects/src/noise3.rs b/crates/effects/src/noise3.rs index 88a5c01d..0ea63dfe 100644 --- a/crates/effects/src/noise3.rs +++ b/crates/effects/src/noise3.rs @@ -406,15 +406,20 @@ pub fn fractal_gpu(ctx: &EffectCtx, offset: [f64; 2], scale: f64, turbulent: boo sub_rotation: fr.sub_rotation != 0.0, norm, octaves, - mode: match ctx.params.get("blendingMode").map(Value::as_enum).unwrap_or(BLEND_NONE) { - BLEND_NONE => None, - m => Some(BLEND_MODES.get(m as usize).and_then(|l| BlendMode::from_name(l)).unwrap_or(BlendMode::Normal)), - }, + mode: blend_mode(ctx.params.get("blendingMode").map(Value::as_enum).unwrap_or(BLEND_NONE)), opacity: (ctx.params.f("opacity") as f32 / 100.0).clamp(0.0, 1.0), blend: ctx.params.f("blend") as f32 / 100.0, } } +/// Resolve a Blending Mode index: None → `None`, unknown → Normal. +fn blend_mode(m: u32) -> Option { + match m { + BLEND_NONE => None, + m => Some(BLEND_MODES.get(m as usize).and_then(|l| BlendMode::from_name(l)).unwrap_or(BlendMode::Normal)), + } +} + /// Map a value by an [`OVERFLOWS`] option. pub fn overflow(v: f32, mode: u32) -> f32 { match mode { @@ -431,14 +436,11 @@ pub fn overflow(v: f32, mode: u32) -> f32 { /// Composite grey noise `val` over the original pixel by Blending Mode, Opacity and (ours) Blend /// With Original. The noise stays inside the layer's alpha, so a masked solid shows it only within /// its masks (#939). -pub(crate) fn composite(orig: [f32; 4], val: f32, opacity: f32, mode: u32, blend_orig: f32) -> [f32; 4] { +pub(crate) fn composite(orig: [f32; 4], val: f32, opacity: f32, mode: Option, blend_orig: f32) -> [f32; 4] { let src = [val * opacity, val * opacity, val * opacity, opacity]; let out = match mode { - BLEND_NONE => src, - m => { - let bm = BLEND_MODES.get(m as usize).and_then(|l| BlendMode::from_name(l)).unwrap_or(BlendMode::Normal); - blend_pixel(bm, orig, src, 0.5) - } + None => src, + Some(bm) => blend_pixel(bm, orig, src, 0.5), }; let k = 1.0 - blend_orig; [0, 1, 2, 3].map(|c| orig[c] * blend_orig + out[c] * orig[3] * k) @@ -447,7 +449,7 @@ pub(crate) fn composite(orig: [f32; 4], val: f32, opacity: f32, mode: u32, blend fn render(ctx: &EffectCtx, mut b: Buf, turbulent: bool) -> Buf { let fr = Fractal::from_params(ctx, &b, turbulent); let opacity = (ctx.params.f("opacity") as f32 / 100.0).clamp(0.0, 1.0); - let mode = ctx.params.get("blendingMode").map(Value::as_enum).unwrap_or(BLEND_NONE); + let mode = blend_mode(ctx.params.get("blendingMode").map(Value::as_enum).unwrap_or(BLEND_NONE)); let blend = ctx.params.f("blend") as f32 / 100.0; b.img.rows_mut().for_each(|(y, row)| { for (x, px) in row.iter_mut().enumerate() { @@ -665,4 +667,34 @@ mod tests { } assert!(axis / diag < 1.15, "gradient along the axes / along the diagonals: {}", axis / diag); } + + /// The base composite, resolving the Blending Mode by name on every call, kept only to prove + /// the hoisted lookup changes nothing. + fn old_composite(orig: [f32; 4], val: f32, opacity: f32, mode: u32, blend_orig: f32) -> [f32; 4] { + let src = [val * opacity, val * opacity, val * opacity, opacity]; + let out = match mode { + BLEND_NONE => src, + m => { + let bm = BLEND_MODES.get(m as usize).and_then(|l| BlendMode::from_name(l)).unwrap_or(BlendMode::Normal); + blend_pixel(bm, orig, src, 0.5) + } + }; + let k = 1.0 - blend_orig; + [0, 1, 2, 3].map(|c| orig[c] * blend_orig + out[c] * orig[3] * k) + } + + #[test] + fn resolved_blend_matches_per_pixel_lookup() { + for m in (0..BLEND_MODES.len() as u32).chain([24, 999]) { + for orig in [[0.2, 0.4, 0.6, 1.0], [0.9, 0.1, 0.5, 0.5], [0.0, 0.0, 0.0, 0.0]] { + for val in [0.0, 0.3, 0.75, 1.0] { + for (op, bl) in [(1.0, 0.0), (0.6, 0.25)] { + assert_eq!(composite(orig, val, op, blend_mode(m), bl), old_composite(orig, val, op, m, bl), "mode {m}"); + } + } + } + } + assert_eq!(blend_mode(BLEND_NONE), None); + assert_eq!(blend_mode(999), Some(BlendMode::Normal)); + } }