mirror of
https://github.com/storytold/lightcraft.git
synced 2026-11-10 10:29:55 -06:00
Marco Arnulfo
07d7d5d498
Resize::apply rounds the size, then the render fit the frame into that box again: on a frame a hair under 3:2 the refit gave 1333 x 1.4999999 = 1999.49 and lost a pixel of the long edge. Frame::fit now keeps a box that already has the frame's aspect up to rounding, and output_size rounds the native size to whole pixels first so float noise can't decide a half-pixel tie.
415 lines
17 KiB
Rust
415 lines
17 KiB
Rust
//! Output framing: user orientation, lens corrections and perspective ([`Warp`]), crop + straighten,
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//! flips — and the mapping between output pixels and normalized coordinates (used by masks, spots and
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//! on-canvas tools).
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//!
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//! Normalized coordinates (masks, spots, crop) refer to the *transformed* image: the oriented source after
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//! lens correction and perspective, at the source's size. Everything is sampled in one resample.
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use lightcraft_develop::{DevelopSettings, EmbeddedLens};
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use lightcraft_geom::{Affine, CropGeometry, Homography, Orientation, Point, Rect};
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use lightcraft_raster::resample::{Filter, resize};
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use lightcraft_raster::{Rgb32f, par_rows};
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use crate::optics::{Warp, reorient_lens};
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/// Linear value of areas outside the source after a warp (a light neutral, like an empty canvas).
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pub const BLANK: [f32; 3] = [0.55, 0.55, 0.55];
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/// The geometric frame of a render.
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#[derive(Clone, Debug)]
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pub struct Frame {
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/// Source (EXIF-oriented) dimensions in pixels.
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pub src_w: usize,
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pub src_h: usize,
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/// User orientation (Rotate Left/Right, Flip) on top of the source.
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pub orient: Orientation,
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/// Oriented dimensions.
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pub ow: f64,
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pub oh: f64,
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pub crop: CropGeometry,
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pub flip_h: bool,
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pub flip_v: bool,
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/// Lens corrections / perspective (None = identity).
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pub warp: Option<Warp>,
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/// Set when this frame draws only a window of a larger output (see [`Frame::window`]).
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pub view: Option<ViewWindow>,
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}
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/// Where a windowed [`Frame`]'s pixels sit in the full output: its offset and the full output's
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/// size, for effects defined by the whole frame (post-crop vignette).
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#[derive(Clone, Copy, Debug, PartialEq)]
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pub struct ViewWindow {
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pub x: f64,
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pub y: f64,
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pub full_w: f64,
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pub full_h: f64,
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}
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impl Frame {
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pub fn new(src_w: usize, src_h: usize, s: &DevelopSettings, apply_crop: bool) -> Frame {
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Frame::with_lens(src_w, src_h, s, apply_crop, None)
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}
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/// Like [`Frame::new`], with the source's embedded lens corrections (relative to the EXIF-oriented source).
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pub fn with_lens(src_w: usize, src_h: usize, s: &DevelopSettings, apply_crop: bool, lens: Option<&EmbeddedLens>) -> Frame {
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let orient = s.orientation;
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let (ow, oh) = if orient.swaps_axes() { (src_h as f64, src_w as f64) } else { (src_w as f64, src_h as f64) };
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let crop = if apply_crop { s.crop.geometry } else { CropGeometry::default() };
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let lens = lens.map(|l| reorient_lens(l, orient, src_w as f64, src_h as f64));
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let mut warp = Warp::from_settings(ow, oh, s, lens.as_ref());
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let persp = perspective(s, ow, oh);
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if persp != Homography::IDENTITY
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&& let Some(inv) = persp.inverse()
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{
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warp.persp = persp;
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warp.persp_inv = inv;
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}
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let mut f = Frame {
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src_w,
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src_h,
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orient,
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ow,
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oh,
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crop,
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// a flip is not part of the crop: the crop tool's uncropped view shows it too
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flip_h: s.crop.flip_h,
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flip_v: s.crop.flip_v,
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warp: (!warp.is_identity()).then_some(warp),
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view: None,
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};
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if apply_crop && s.geometry.constrain_crop {
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f.constrain_to_image();
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}
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f
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}
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/// "Constrain Crop": shrink the crop about its centre until it contains no area outside the warped source.
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fn constrain_to_image(&mut self) {
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let Some(wp) = self.warp.as_ref().filter(|w| w.moves_pixels()) else { return };
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let a = self.crop.output_to_source(self.ow, self.oh, 1.0, 1.0);
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let (w, h) = (self.ow, self.oh);
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let fits = |t: f64| {
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(0..=48).all(|i| {
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let u = i as f64 / 48.0;
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[(u, 0.0), (u, 1.0), (0.0, u), (1.0, u)].iter().all(|&(x, y)| {
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let p = Point::new(0.5 + t * (x - 0.5), 0.5 + t * (y - 0.5));
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let s = wp.to_source(a.apply(p), 1);
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s.x >= -1e-6 * w && s.y >= -1e-6 * h && s.x <= w * (1.0 + 1e-6) && s.y <= h * (1.0 + 1e-6)
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})
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})
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};
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if fits(1.0) {
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return;
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}
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let (mut lo, mut hi) = (0.0, 1.0);
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for _ in 0..30 {
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let m = (lo + hi) / 2.0;
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if fits(m) { lo = m } else { hi = m }
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}
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let t = lo.max(0.02);
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let r = self.crop.rect;
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self.crop.rect = Rect::from_center(r.center(), r.width() * t, r.height() * t);
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}
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/// Long edge, in pixels, of the whole output this frame draws (its own size unless it is a
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/// window of a larger one): what size-relative effects (noise reduction, edge refinement)
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/// must scale with, so a window matches the same pixels of the whole render.
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pub fn output_long(&self, w: usize, h: usize) -> usize {
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self.view.map_or(w.max(h), |v| v.full_w.max(v.full_h) as usize)
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}
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/// This frame narrowed to `win` of its `full_w × full_h` output: the same mapping, but the
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/// output is only that window (the crop rectangle shrinks to it; flips are as drawn).
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pub fn window(&self, full_w: usize, full_h: usize, win: crate::PixelWindow) -> Frame {
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let (fw, fh) = (full_w.max(1) as f64, full_h.max(1) as f64);
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let (x0, x1) = (win.x as f64 / fw, (win.x + win.w) as f64 / fw);
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let (y0, y1) = (win.y as f64 / fh, (win.y + win.h) as f64 / fh);
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// flips happen on the output before it maps onto the crop: undo them for the range
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let (x0, x1) = if self.flip_h { (1.0 - x1, 1.0 - x0) } else { (x0, x1) };
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let (y0, y1) = if self.flip_v { (1.0 - y1, 1.0 - y0) } else { (y0, y1) };
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let r = self.crop.rect;
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let (rw, rh) = (r.width(), r.height());
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let mut f = self.clone();
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f.crop.rect = Rect { x0: r.x0 + x0 * rw, y0: r.y0 + y0 * rh, x1: r.x0 + x1 * rw, y1: r.y0 + y1 * rh };
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f.view = Some(ViewWindow { x: win.x as f64, y: win.y as f64, full_w: fw, full_h: fh });
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f
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}
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/// Add automatically estimated lateral CA (`[α_R, α_B]`, see [`crate::optics::estimate_lateral_ca`]).
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pub fn add_lateral_ca(&mut self, ca: [f64; 2]) {
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if ca == [0.0; 2] {
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return;
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}
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let w = self.warp.get_or_insert_with(|| Warp::identity(self.ow, self.oh));
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w.ca[0] += ca[0];
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w.ca[2] += ca[1];
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}
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/// Map a point of the transformed image (normalized) to the lens-corrected, pre-perspective image (normalized).
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pub fn transformed_to_corrected(&self, p: Point) -> Point {
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match &self.warp {
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Some(w) => {
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let q = w.to_corrected(Point::new(p.x * self.ow, p.y * self.oh));
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Point::new(q.x / self.ow, q.y / self.oh)
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}
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None => p,
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}
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}
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/// Inverse of [`Frame::transformed_to_corrected`].
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pub fn corrected_to_transformed(&self, p: Point) -> Point {
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match &self.warp {
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Some(w) => {
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let q = w.from_corrected(Point::new(p.x * self.ow, p.y * self.oh));
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Point::new(q.x / self.ow, q.y / self.oh)
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}
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None => p,
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}
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}
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/// Aspect ratio (w/h) of the output.
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pub fn aspect(&self) -> f64 {
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let r = self.crop.rect_px(self.ow, self.oh);
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r.width() / r.height()
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}
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/// Size of the (cropped) output at the source's own resolution, in pixels.
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pub fn native_size(&self) -> (f64, f64) {
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let r = self.crop.rect_px(self.ow, self.oh);
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(r.width(), r.height())
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}
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pub fn fit(&self, max_w: usize, max_h: usize) -> (usize, usize) {
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let a = self.aspect();
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let (mw, mh) = (max_w.max(1) as f64, max_h.max(1) as f64);
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// a box that is already this aspect up to rounding (an export size) is the size: fitting
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// into it again rounds twice and can lose a pixel of the edge that was asked for
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if (mw - 0.5) / a <= mh + 0.5 && (mw + 0.5) / a >= mh - 0.5 {
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return (max_w.max(1), max_h.max(1));
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}
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let (w, h) = if mw / mh > a { (mh * a, mh) } else { (mw, mw / a) };
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((w.round() as usize).max(1), (h.round() as usize).max(1))
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}
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/// Output pixels per unit of the oriented image's long edge.
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pub fn px_per_long(&self, out_w: usize) -> f64 {
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let r = self.crop.rect_px(self.ow, self.oh);
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out_w as f64 / r.width() * self.ow.max(self.oh)
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}
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/// Affine from output pixel coordinates to oriented-image pixel coordinates.
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pub fn out_to_oriented(&self, out_w: usize, out_h: usize) -> Affine {
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let (w, h) = (out_w as f64, out_h as f64);
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let mut flip = Affine::IDENTITY;
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if self.flip_h {
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flip = Affine([-1.0, 0.0, 0.0, 1.0, w, 0.0]) * flip;
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}
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if self.flip_v {
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flip = Affine([1.0, 0.0, 0.0, -1.0, 0.0, h]) * flip;
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}
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self.crop.output_to_source(self.ow, self.oh, w, h) * flip
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}
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/// Map an output pixel to normalized oriented-image coordinates (0..1).
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pub fn out_to_norm(&self, out_w: usize, out_h: usize) -> Affine {
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Affine::scale(1.0 / self.ow, 1.0 / self.oh) * self.out_to_oriented(out_w, out_h)
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}
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/// Normalized oriented coords → output pixel (inverse of `out_to_norm`).
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pub fn norm_to_out(&self, out_w: usize, out_h: usize) -> Affine {
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self.out_to_norm(out_w, out_h).inverse().unwrap_or(Affine::IDENTITY)
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}
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/// Convert normalized oriented coordinates to "long-edge units" (isotropic), used by mask shapes.
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pub fn norm_to_long(&self, p: Point) -> Point {
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let l = self.ow.max(self.oh);
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Point::new(p.x * self.ow / l, p.y * self.oh / l)
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}
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/// How [`Frame::sample`] resamples a (EXIF-oriented) source of `src_w × src_h` into `w × h`.
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pub fn sample_plan(&self, src_w: usize, src_h: usize, w: usize, h: usize) -> SamplePlan {
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let (ow, oh) = if self.orient.swaps_axes() { (src_h, src_w) } else { (src_w, src_h) };
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let crop_px = self.crop.rect_px(self.ow, self.oh);
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let k = crop_px.width() / w as f64;
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let prefilter = (k > 1.25).then(|| (((ow as f64 / k).round() as usize).max(1), ((oh as f64 / k).round() as usize).max(1)));
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let (bw, bh) = prefilter.unwrap_or((ow, oh));
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let (sx, sy) = (bw as f64 / ow as f64, bh as f64 / oh as f64);
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let mode = if self.warp.is_some() {
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SampleMode::Warp(self.out_to_oriented(w, h))
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} else if self.crop.is_identity() && !self.flip_h && !self.flip_v && bw == w && bh == h {
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SampleMode::Copy
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} else {
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SampleMode::Affine(Affine::scale(sx, sy) * self.out_to_oriented(w, h))
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};
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SamplePlan { ow, oh, prefilter, sx, sy, mode }
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}
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/// Sample the source into a `w × h` output buffer: orientation, crop, rotation, flips — one
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/// bilinear resample from a pre-filtered (area-downscaled) copy, so minification never aliases.
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pub fn sample(&self, src: &Rgb32f, w: usize, h: usize) -> Rgb32f {
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let oriented = if self.orient == Orientation::Normal { None } else { Some(src.oriented(self.orient)) };
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let o = oriented.as_ref().unwrap_or(src);
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let plan = self.sample_plan(src.width, src.height, w, h);
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let base = match plan.prefilter {
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Some((nw, nh)) => std::borrow::Cow::Owned(resize(o, nw, nh, Filter::Mitchell)),
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None => std::borrow::Cow::Borrowed(o),
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};
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let affine = |xf: Affine| {
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let mut out = Rgb32f::new(w, h);
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par_rows(&mut out.data, w, |y, row| {
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for (x, px) in row.iter_mut().enumerate() {
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let p = xf.apply(Point::new(x as f64 + 0.5, y as f64 + 0.5));
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*px = base.sample_bilinear(p.x as f32, p.y as f32);
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}
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});
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out
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};
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match (plan.mode, self.warp.as_ref()) {
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(SampleMode::Copy, _) => base.into_owned(),
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(SampleMode::Warp(o2t), Some(warp)) => sample_warped(&base, plan.sx, plan.sy, warp, o2t, w, h),
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// `sample_plan` plans a warp only when there is one; without it the same mapping is affine
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(SampleMode::Warp(o2t), None) => affine(Affine::scale(plan.sx, plan.sy) * o2t),
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(SampleMode::Affine(xf), _) => affine(xf),
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}
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}
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/// The crop rectangle as a quad in normalized oriented coordinates (for overlays).
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pub fn crop_quad_norm(&self) -> [Point; 4] {
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let r = self.crop.rect_px(self.ow, self.oh);
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let back = Affine::rotate_about(-self.crop.angle.to_radians(), Point::new(self.ow / 2.0, self.oh / 2.0));
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r.corners().map(|p| {
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let q = back.apply(p);
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Point::new(q.x / self.ow, q.y / self.oh)
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})
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}
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}
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/// How a render resamples its source (see [`Frame::sample_plan`]).
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#[derive(Clone, Debug)]
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pub struct SamplePlan {
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/// Oriented source size.
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pub ow: usize,
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pub oh: usize,
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/// Size of the Mitchell prefilter (area downscale before the bilinear resample), if any.
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pub prefilter: Option<(usize, usize)>,
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/// Oriented-source px → prefiltered px.
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pub sx: f64,
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pub sy: f64,
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pub mode: SampleMode,
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}
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#[derive(Clone, Debug)]
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pub enum SampleMode {
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/// The (prefiltered) oriented source is the output.
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Copy,
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/// Bilinear through this affine (output px → prefiltered px).
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Affine(Affine),
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/// Through the warp; the affine maps output px → transformed px.
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Warp(Affine),
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}
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/// The perspective homography of the settings (Upright, then the manual Transform sliders), lens-corrected →
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/// transformed, in centred coordinates.
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pub fn perspective(s: &DevelopSettings, ow: f64, oh: f64) -> Homography {
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if !s.section_enabled("geometry") {
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return Homography::IDENTITY;
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}
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crate::transform::manual(&s.geometry).mul(&crate::upright::homography(&s.geometry, ow, oh))
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}
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/// One resample through the warp: `o2t` maps output px → transformed px, the warp maps those to source px
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/// (scaled by `sx, sy` into `base`).
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fn sample_warped(base: &Rgb32f, sx: f64, sy: f64, wp: &Warp, o2t: Affine, w: usize, h: usize) -> Rgb32f {
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let per_channel = wp.per_channel();
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let gain = wp.has_gain();
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let mut out = Rgb32f::new(w, h);
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par_rows(&mut out.data, w, |y, row| {
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for (x, px) in row.iter_mut().enumerate() {
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let Some((c, g)) = wp.frame(&o2t, x, y) else {
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*px = BLANK;
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continue;
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};
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let mut v = base.sample_bilinear((g.x * sx) as f32, (g.y * sy) as f32);
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if per_channel {
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for ch in [0usize, 2] {
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let q = wp.corrected_to_source(c, ch);
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v[ch] = base.sample_bilinear((q.x * sx) as f32, (q.y * sy) as f32)[ch];
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}
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}
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if gain {
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let k = wp.gain(g);
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v = v.map(|c| c * k);
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}
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*px = v;
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}
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});
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out
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}
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/// Whole-image rectangle in normalized coordinates.
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pub const FULL: Rect = Rect::UNIT;
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#[cfg(test)]
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mod tests {
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use super::*;
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#[test]
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fn default_frame_is_identity() {
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let s = DevelopSettings::default();
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let f = Frame::new(300, 200, &s, true);
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assert_eq!(f.fit(3000, 3000), (3000, 2000));
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let m = f.out_to_norm(300, 200);
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let p = m.apply(Point::new(150.0, 100.0));
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assert!((p.x - 0.5).abs() < 1e-9 && (p.y - 0.5).abs() < 1e-9);
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assert!((f.px_per_long(300) - 300.0).abs() < 1e-9);
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}
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#[test]
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fn rotation_swaps_aspect() {
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let s = DevelopSettings { orientation: Orientation::Rotate90, ..Default::default() };
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let f = Frame::new(300, 200, &s, true);
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assert_eq!(f.fit(1000, 1000), (667, 1000));
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}
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#[test]
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fn crop_changes_aspect_and_mapping() {
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let mut s = DevelopSettings::default();
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s.crop.geometry.rect = Rect::new(0.5, 0.0, 1.0, 1.0);
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let f = Frame::new(400, 200, &s, true);
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assert_eq!(f.fit(1000, 1000), (1000, 1000));
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let p = f.out_to_norm(100, 100).apply(Point::new(0.0, 0.0));
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assert!((p.x - 0.5).abs() < 1e-9 && p.y.abs() < 1e-9);
|
||
let back = f.norm_to_out(100, 100).apply(Point::new(0.75, 0.5));
|
||
assert!((back.x - 50.0).abs() < 1e-6 && (back.y - 50.0).abs() < 1e-6);
|
||
}
|
||
|
||
#[test]
|
||
fn flip_mirrors() {
|
||
let mut s = DevelopSettings::default();
|
||
s.crop.flip_h = true;
|
||
let src = Rgb32f::from_fn(4, 1, |x, _| [x as f32, 0.0, 0.0]);
|
||
let f = Frame::new(4, 1, &s, true);
|
||
let out = f.sample(&src, 4, 1);
|
||
assert!((out.get(0, 0)[0] - 3.0).abs() < 1e-5);
|
||
assert!((out.get(3, 0)[0] - 0.0).abs() < 1e-5);
|
||
}
|
||
|
||
/// The crop tool's uncropped frame keeps the flips: Flip H / Flip V show while cropping, and
|
||
/// screen points map back through the mirror (the crop box is drawn and dragged right).
|
||
#[test]
|
||
fn uncropped_frame_keeps_the_flips() {
|
||
let mut s = DevelopSettings::default();
|
||
s.crop.flip_h = true;
|
||
s.crop.flip_v = true;
|
||
s.crop.geometry.rect = Rect::new(0.1, 0.2, 0.6, 0.9);
|
||
let src = Rgb32f::from_fn(4, 2, |x, y| [x as f32, y as f32, 0.0]);
|
||
let f = Frame::new(4, 2, &s, false);
|
||
let out = f.sample(&src, 4, 2);
|
||
assert!((out.get(0, 0)[0] - 3.0).abs() < 1e-5 && (out.get(0, 0)[1] - 1.0).abs() < 1e-5, "{:?}", out.get(0, 0));
|
||
assert!((out.get(3, 1)[0] - 0.0).abs() < 1e-5 && (out.get(3, 1)[1] - 0.0).abs() < 1e-5, "{:?}", out.get(3, 1));
|
||
// the whole image, mirrored: output top-left is the image's bottom-right
|
||
let p = f.out_to_norm(400, 200).apply(Point::new(0.0, 0.0));
|
||
assert!((p.x - 1.0).abs() < 1e-9 && (p.y - 1.0).abs() < 1e-9, "{p:?}");
|
||
}
|
||
}
|