Files
effectcraft/crates/raster/src/warp.rs
T
Brandon ThomasandClaude Opus 5.5 a2ff724ac2 M12.1: render cache + parallel compositing fast paths
- render: LayerCache (content-keyed processed-layer cache: source -> masks ->
  effects, keyed by a hash of the layer's non-transform props evaluated at the
  frame time, solid item, switches, scale; time folded in for clock-driven
  effects / wiggle paths). Static and transform-only layers render once;
  edits only re-render the edited layer. Session + UI frame jobs share it.
- effects: TIME_DEPENDENT list + test that every clock-reading effect is listed.
- raster: affine composite fast path (per-row span clipping, unchecked interior
  bilinear, integer-translation copies, inlined Normal blend), checked against
  composite_warp_reference; box/Gaussian blur without transposes, two
  ping-pong buffers; accumulate_warp so motion blur sums into one buffer
  instead of one full-frame image per sub-sample.
- ui: viewer frame is urgent and jumps the prefetch queue; stale-revision jobs
  are dropped; paused prefetch waits for the viewer frame; "Frame Render Time"
  reports viewer frames only; parallel f32 -> Color32 conversion.
- cli: `frame --bench N` (per-layer/per-effect timings, wall + CPU time) and
  `frame --bench-play N` (consecutive frames with/without the layer cache).
- tests: cache transparency (scrub, edits of values/keys/effects/masks/
  solids/text/timing), hit/miss accounting, time-dependent effects, demo
  cached == uncached, fast warp/blur/accumulate == reference.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-01 21:34:33 -04:00

431 lines
16 KiB
Rust

//! Projective warps composited straight into a destination (the layer transform step).
use effectcraft_color::{BlendMode, blend_pixel};
use effectcraft_geom::{Mat3, Rect, vec2};
use rayon::prelude::*;
use crate::{Image, Px, hash_noise};
#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
pub enum Sampling {
Nearest,
#[default]
Bilinear,
Bicubic,
}
#[derive(Clone, Copy, Debug)]
pub struct WarpOpts {
pub sampling: Sampling,
pub opacity: f32,
pub mode: BlendMode,
pub seed: u32,
/// Only touch destination pixels inside this rect (dst pixel coords).
pub clip: Option<Rect>,
}
impl Default for WarpOpts {
fn default() -> Self {
WarpOpts { sampling: Sampling::Bilinear, opacity: 1.0, mode: BlendMode::Normal, seed: 0, clip: None }
}
}
/// Box-filter halving (for minification).
fn half(src: &Image) -> Image {
let w = src.width.div_ceil(2).max(1);
let h = src.height.div_ceil(2).max(1);
let mut out = Image::new(w, h);
out.rows_mut().for_each(|(y, row)| {
for (x, px) in row.iter_mut().enumerate() {
let (sx, sy) = (2 * x as i64, 2 * y as i64);
let mut acc = [0.0f32; 4];
for (dx, dy) in [(0, 0), (1, 0), (0, 1), (1, 1)] {
let p = src.get_clamped(sx + dx, sy + dy);
for c in 0..4 {
acc[c] += p[c];
}
}
*px = acc.map(|v| v * 0.25);
}
});
out
}
/// Draw `src` transformed by `m` (src pixel space → dst pixel space) onto `dst` with blending.
///
/// Affine transforms with non-stencil modes take a fast path (per-row span clipping, interior
/// bilinear without bounds checks, integer-translation copies, inlined Normal blending); it
/// matches [`composite_warp_reference`] to float rounding.
pub fn composite_warp(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts) {
composite_warp_impl(dst, src, m, opts, true, None);
}
/// `dst += warp(src) · weight` (plain sum, no blending): motion-blur sub-samples accumulate
/// straight into one buffer instead of one full-size image per sample.
pub fn accumulate_warp(dst: &mut Image, src: &Image, m: &Mat3, sampling: Sampling, weight: f32) {
let opts = WarpOpts { sampling, ..Default::default() };
if m.is_affine() && m.inverse().is_some_and(|i| i.is_affine()) {
composite_warp_impl(dst, src, m, &opts, true, Some(weight));
return;
}
let mut tmp = Image::new(dst.width, dst.height);
composite_warp(&mut tmp, src, m, &opts);
dst.data.par_iter_mut().zip(tmp.data.par_iter()).for_each(|(d, s)| {
for c in 0..4 {
d[c] += s[c] * weight;
}
});
}
/// The straightforward per-pixel implementation (reference for the fast path's tests).
pub fn composite_warp_reference(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts) {
composite_warp_impl(dst, src, m, opts, false, None);
}
/// Bilinear blend of four taps (same operation order as [`Image::sample_bilinear`]).
#[inline(always)]
fn bilerp(a: Px, b: Px, c: Px, d: Px, tx: f32, ty: f32) -> Px {
let mut o = [0.0; 4];
for i in 0..4 {
let top = a[i] + (b[i] - a[i]) * tx;
let bot = c[i] + (d[i] - c[i]) * tx;
o[i] = top + (bot - top) * ty;
}
o
}
/// Bilinear sample with an unchecked interior fast path.
#[inline(always)]
fn sample_bilinear_fast(img: &Image, x: f64, y: f64) -> Px {
let fx = x - 0.5;
let fy = y - 0.5;
let x0 = fx.floor();
let y0 = fy.floor();
let (xi, yi) = (x0 as i64, y0 as i64);
let (w, h) = (img.width as i64, img.height as i64);
if xi >= 0 && yi >= 0 && xi + 1 < w && yi + 1 < h {
let tx = (fx - x0) as f32;
let ty = (fy - y0) as f32;
let i = yi as usize * w as usize + xi as usize;
let row0 = &img.data[i..i + 2];
let row1 = &img.data[i + w as usize..i + w as usize + 2];
return bilerp(row0[0], row0[1], row1[0], row1[1], tx, ty);
}
img.sample_bilinear(x, y)
}
/// Index range `[lo, hi)` of `i` in `0..n` for which `p0 + i·s` may lie in `[min, max]`
/// (conservative by one step on each side; callers still check per pixel).
fn span(p0: f64, s: f64, min: f64, max: f64, n: usize) -> (usize, usize) {
if s.abs() < 1e-12 {
return if p0 >= min - 1e-9 && p0 <= max + 1e-9 { (0, n) } else { (0, 0) };
}
let (a, b) = ((min - p0) / s, (max - p0) / s);
let (a, b) = if a < b { (a, b) } else { (b, a) };
let lo = (a.floor() - 1.0).max(0.0);
let hi = (b.ceil() + 2.0).min(n as f64);
if hi <= lo { (0, 0) } else { (lo as usize, hi as usize) }
}
/// Fast affine rows: `blend(dst, src, x, y)` is only called for visible source pixels.
#[allow(clippy::too_many_arguments)]
fn affine_rows(
dst: &mut Image,
img: &Image,
inv: &Mat3,
sampling: Sampling,
op: f32,
x0: usize,
x1: usize,
y0: usize,
y1: usize,
blend: impl Fn(Px, Px, u32, u32) -> Px + Sync,
) {
let w = dst.width as usize;
let m = inv.0;
let (iw, ih) = (img.width as f64, img.height as f64);
let step = vec2(m[0][0], m[1][0]);
// Pure integer translation: every sample lands on a pixel centre, so all filters return the
// source pixel itself (bicubic still clamps negatives, as in the reference).
let int_tx = m[0][0] == 1.0 && m[1][1] == 1.0 && m[0][1] == 0.0 && m[1][0] == 0.0 && m[0][2].fract() == 0.0 && m[1][2].fract() == 0.0;
dst.data.par_chunks_mut(w).enumerate().skip(y0).take(y1 - y0).for_each(|(y, row)| {
let fy = y as f64 + 0.5;
let p0 = vec2(m[0][0] * (x0 as f64 + 0.5) + m[0][1] * fy + m[0][2], m[1][0] * (x0 as f64 + 0.5) + m[1][1] * fy + m[1][2]);
let n = x1 - x0;
let (ax, bx) = span(p0.x, step.x, -1.0, iw + 1.0, n);
let (ay, by) = span(p0.y, step.y, -1.0, ih + 1.0, n);
let (lo, hi) = (ax.max(ay), bx.min(by));
if lo >= hi {
return;
}
if int_tx {
let sy = y as i64 + m[1][2] as i64;
if sy < 0 || sy >= img.height as i64 {
return;
}
let dx = m[0][2] as i64;
let srow = &img.data[sy as usize * img.width as usize..(sy as usize + 1) * img.width as usize];
let xa = (x0 as i64 + lo as i64).max(-dx).max(0) as usize;
let xb = ((x0 + hi) as i64).min(img.width as i64 - dx).max(0) as usize;
for x in xa..xb.max(xa) {
let mut s = srow[(x as i64 + dx) as usize];
if sampling == Sampling::Bicubic {
s = [s[0].max(0.0), s[1].max(0.0), s[2].max(0.0), s[3].max(0.0)];
}
if s[3] <= 0.0 {
continue;
}
if op < 1.0 {
for c in s.iter_mut() {
*c *= op;
}
}
row[x] = blend(row[x], s, x as u32, y as u32);
}
return;
}
for i in lo..hi {
let x = x0 + i;
let p = vec2(p0.x + step.x * i as f64, p0.y + step.y * i as f64);
if p.x < -1.0 || p.y < -1.0 || p.x > iw + 1.0 || p.y > ih + 1.0 {
continue;
}
let mut s = match sampling {
Sampling::Nearest => img.get(p.x.floor() as i64, p.y.floor() as i64),
Sampling::Bilinear => sample_bilinear_fast(img, p.x, p.y),
Sampling::Bicubic => img.sample_bicubic(p.x, p.y),
};
if s[3] <= 0.0 {
continue;
}
if op < 1.0 {
for c in s.iter_mut() {
*c *= op;
}
}
row[x] = blend(row[x], s, x as u32, y as u32);
}
});
}
fn composite_warp_impl(dst: &mut Image, src: &Image, m: &Mat3, opts: &WarpOpts, allow_fast: bool, accumulate: Option<f32>) {
if src.is_empty() || dst.is_empty() || opts.opacity <= 0.0 {
return;
}
let Some(inv) = m.inverse() else { return };
// Minification: pick a pre-filtered level so sampling doesn't alias.
let scale = m.mean_scale();
let mut level_img;
let mut img = src;
let mut inv = inv;
if scale < 0.5 && m.is_affine() {
let mut s = scale;
let mut f = 1.0;
level_img = half(src);
f *= 0.5;
s *= 2.0;
while s < 0.5 && level_img.width > 1 && level_img.height > 1 {
level_img = half(&level_img);
f *= 0.5;
s *= 2.0;
}
img = &level_img;
inv = Mat3::scale(vec2(f, f)) * inv;
}
let bounds = m.map_rect(&Rect::from_size(src.width as f64, src.height as f64)).inflate(1.0).round_out();
let full = Rect::from_size(dst.width as f64, dst.height as f64);
let mut area = bounds.intersect(&full);
if let Some(c) = opts.clip {
area = area.intersect(&c);
}
if area.is_empty() {
return;
}
let (x0, x1) = (area.x0.max(0.0) as usize, area.x1.min(dst.width as f64) as usize);
let (y0, y1) = (area.y0.max(0.0) as usize, area.y1.min(dst.height as f64) as usize);
let w = dst.width as usize;
let affine = inv.is_affine();
let mode = opts.mode;
let op = opts.opacity;
if let Some(k) = accumulate
&& affine
{
affine_rows(dst, img, &inv, opts.sampling, 1.0, x0, x1, y0, y1, |d, s, _, _| [d[0] + s[0] * k, d[1] + s[1] * k, d[2] + s[2] * k, d[3] + s[3] * k]);
return;
}
if allow_fast && affine && !mode.is_stencil() {
match mode {
BlendMode::Normal => affine_rows(dst, img, &inv, opts.sampling, op, x0, x1, y0, y1, |d, s, _, _| {
let k = 1.0 - s[3];
[s[0] + d[0] * k, s[1] + d[1] * k, s[2] + d[2] * k, s[3] + d[3] * k]
}),
BlendMode::Dissolve | BlendMode::DancingDissolve => {
let seed = opts.seed;
affine_rows(dst, img, &inv, opts.sampling, op, x0, x1, y0, y1, |d, s, x, y| blend_pixel(mode, d, s, hash_noise(x, y, seed)))
}
_ => affine_rows(dst, img, &inv, opts.sampling, op, x0, x1, y0, y1, |d, s, _, _| blend_pixel(mode, d, s, 0.5)),
}
return;
}
dst.data.par_chunks_mut(w).enumerate().skip(y0).take(y1 - y0).for_each(|(y, row)| {
let fy = y as f64 + 0.5;
let mut sp = inv.apply(vec2(x0 as f64 + 0.5, fy));
let step = inv.apply_vec(vec2(1.0, 0.0));
for x in x0..x1 {
let p = if affine {
let p = sp;
sp += step;
p
} else {
inv.apply(vec2(x as f64 + 0.5, fy))
};
if p.x < -1.0 || p.y < -1.0 || p.x > img.width as f64 + 1.0 || p.y > img.height as f64 + 1.0 {
if mode.is_stencil() {
row[x] = blend_pixel(mode, row[x], [0.0; 4], 0.5);
}
continue;
}
let mut s = match opts.sampling {
Sampling::Nearest => img.get(p.x.floor() as i64, p.y.floor() as i64),
Sampling::Bilinear => img.sample_bilinear(p.x, p.y),
Sampling::Bicubic => img.sample_bicubic(p.x, p.y),
};
if s[3] <= 0.0 && !mode.is_stencil() {
continue;
}
if op < 1.0 {
for c in s.iter_mut() {
*c *= op;
}
}
let n = if matches!(mode, BlendMode::Dissolve | BlendMode::DancingDissolve) { hash_noise(x as u32, y as u32, opts.seed) } else { 0.5 };
row[x] = blend_pixel(mode, row[x], s, n);
}
});
// Stencil modes also clear everything outside the layer bounds.
if mode.is_stencil() && matches!(mode, BlendMode::StencilAlpha | BlendMode::StencilLuma) {
for (y, row) in dst.data.chunks_mut(w).enumerate() {
for (x, px) in row.iter_mut().enumerate() {
if x < x0 || x >= x1 || y < y0 || y >= y1 {
*px = [0.0; 4];
}
}
}
}
}
/// Resize with bilinear filtering (box pre-filter when shrinking).
pub fn resample(src: &Image, w: u32, h: u32) -> Image {
let mut out = Image::new(w, h);
if src.is_empty() || w == 0 || h == 0 {
return out;
}
let m = Mat3::scale(vec2(w as f64 / src.width as f64, h as f64 / src.height as f64));
composite_warp(&mut out, src, &m, &WarpOpts::default());
out
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn identity_warp_copies() {
let mut src = Image::new(4, 4);
src.set(1, 2, [0.5, 0.5, 0.5, 1.0]);
let mut dst = Image::new(4, 4);
composite_warp(&mut dst, &src, &Mat3::IDENTITY, &WarpOpts::default());
assert_eq!(dst.get(1, 2), [0.5, 0.5, 0.5, 1.0]);
assert_eq!(dst.get(0, 0), [0.0; 4]);
}
#[test]
fn translate_by_integer() {
let mut src = Image::new(4, 4);
src.set(0, 0, [1.0; 4]);
let mut dst = Image::new(8, 8);
composite_warp(&mut dst, &src, &Mat3::translate(vec2(3.0, 2.0)), &WarpOpts::default());
assert_eq!(dst.get(3, 2), [1.0; 4]);
}
fn test_image(w: u32, h: u32, seed: u32) -> Image {
let mut img = Image::new(w, h);
for y in 0..h {
for x in 0..w {
let a = if (x + y) % 7 == 0 { 0.0 } else { hash_noise(x, y, seed) };
img.set(x, y, [hash_noise(x, y, seed + 1) * a, hash_noise(x, y, seed + 2) * a, hash_noise(x, y, seed + 3) * a, a]);
}
}
img
}
/// The fast affine path equals the reference per-pixel path (modes, filters, transforms).
#[test]
fn fast_path_matches_reference() {
let src = test_image(37, 23, 5);
let mats = [
Mat3::IDENTITY,
Mat3::translate(vec2(5.0, -3.0)),
Mat3::translate(vec2(-40.0, 2.0)),
Mat3::translate(vec2(3.25, 7.5)),
Mat3::translate(vec2(20.0, 10.0)) * Mat3::rotate_deg(23.0) * Mat3::scale(vec2(1.3, 0.8)),
Mat3::translate(vec2(30.0, 5.0)) * Mat3::rotate_deg(-120.0) * Mat3::scale(vec2(0.7, 0.7)),
Mat3::translate(vec2(10.0, 10.0)) * Mat3::scale(vec2(-1.0, 1.0)),
Mat3::scale(vec2(0.3, 0.3)),
];
let modes = [BlendMode::Normal, BlendMode::Add, BlendMode::Multiply, BlendMode::Screen, BlendMode::Dissolve, BlendMode::Overlay];
for (mi, m) in mats.iter().enumerate() {
for mode in modes {
for sampling in [Sampling::Nearest, Sampling::Bilinear, Sampling::Bicubic] {
for opacity in [1.0, 0.6] {
let opts = WarpOpts { sampling, opacity, mode, seed: 9, clip: None };
let mut a = test_image(48, 40, 77);
let mut b = a.clone();
composite_warp(&mut a, &src, m, &opts);
composite_warp_reference(&mut b, &src, m, &opts);
for (i, (p, q)) in a.data.iter().zip(&b.data).enumerate() {
for c in 0..4 {
assert!((p[c] - q[c]).abs() < 1e-4, "mat {mi} {mode:?} {sampling:?} op {opacity} px {i}: {p:?} vs {q:?}");
}
}
}
}
}
}
}
/// Accumulating sub-samples equals warping each into its own image and summing.
#[test]
fn accumulate_matches_per_sample_images() {
let src = test_image(30, 20, 11);
let persp = Mat3::square_to_quad([vec2(5.0, 4.0), vec2(40.0, 2.0), vec2(44.0, 30.0), vec2(2.0, 35.0)]) * Mat3::scale(vec2(1.0 / 30.0, 1.0 / 20.0));
let mats = [Mat3::translate(vec2(3.0, 4.0)), Mat3::translate(vec2(5.5, 4.25)) * Mat3::rotate_deg(12.0), persp];
let k = 1.0 / mats.len() as f32;
let mut fast = Image::new(48, 40);
let mut slow = Image::new(48, 40);
for m in &mats {
accumulate_warp(&mut fast, &src, m, Sampling::Bilinear, k);
let mut img = Image::new(48, 40);
composite_warp_reference(&mut img, &src, m, &WarpOpts::default());
for (a, b) in slow.data.iter_mut().zip(&img.data) {
for c in 0..4 {
a[c] += b[c] * k;
}
}
}
for (p, q) in fast.data.iter().zip(&slow.data) {
for c in 0..4 {
assert!((p[c] - q[c]).abs() < 1e-4, "{p:?} vs {q:?}");
}
}
}
#[test]
fn downscale_preserves_average() {
let src = Image::filled(64, 64, [0.25, 0.5, 0.75, 1.0]);
let out = resample(&src, 8, 8);
let p = out.get(4, 4);
assert!((p[1] - 0.5).abs() < 1e-4 && (p[3] - 1.0).abs() < 1e-4, "{p:?}");
}
}