diff --git a/crates/anim/src/lib.rs b/crates/anim/src/lib.rs index fae7e4dd..bea76eb8 100644 --- a/crates/anim/src/lib.rs +++ b/crates/anim/src/lib.rs @@ -27,7 +27,7 @@ pub use deckcraft_model::Rgba; use serde::{Deserialize, Serialize}; pub use easing::ease; -pub use morph::{MorphFrame, MorphPath, MorphText, morph_frame, morph_pairs, morph_xfrm}; +pub use morph::{MorphFrame, MorphPath, MorphText, morph_crop, morph_frame, morph_pairs, morph_xfrm}; pub use path::{MotionPath, default_path}; pub use show::{LinkJump, ShowAction, ShowState, safe_url, show_order}; pub use timeline::{EffectTiming, Sequence, Timeline, TriggerPlay}; diff --git a/crates/anim/src/morph.rs b/crates/anim/src/morph.rs index b5808c4f..96bd761b 100644 --- a/crates/anim/src/morph.rs +++ b/crates/anim/src/morph.rs @@ -173,9 +173,58 @@ fn reshaped(a: &Shape, b: &Shape) -> bool { a.geom != b.geom && outlined(a) && outlined(b) && Shape { geom: Geom::default(), ..content(a) } == Shape { geom: Geom::default(), ..content(b) } } +/// The content of a shape apart from what Morph interpolates, with a picture's crop left out. +fn uncropped(s: &Shape) -> Shape { + let mut c = content(s); + if let ShapeKind::Picture { fill } = &mut c.kind { + fill.crop = [0.0; 4]; + } + c +} + +fn crop_of(s: &Shape) -> [f64; 4] { + match &s.kind { + ShapeKind::Picture { fill } => fill.crop, + _ => [0.0; 4], + } +} + +/// Whether two pictures differ in their crop only (apart from box and fill), so the crop can morph. +fn recropped(a: &Shape, b: &Shape) -> bool { + matches!(a.kind, ShapeKind::Picture { .. }) && crop_of(a) != crop_of(b) && uncropped(a) == uncropped(b) +} + +/// The crop (left, top, right, bottom) of a picture morphing from box `xa` cropped by `ca` to box +/// `xb` cropped by `cb`, when its box is `x` at progress `t`: the whole image moves and scales +/// linearly between where it lies on either slide, and the crop is what of it `x` shows. Falls back +/// to blending the crops when a crop leaves nothing visible. +pub fn morph_crop(ca: [f64; 4], xa: Xfrm, cb: [f64; 4], xb: Xfrm, x: Xfrm, t: f64) -> [f64; 4] { + // Along one axis: (box start, box size, crop before, crop after) → the crops at `t`. + let axis = |(pa, sa, la, ha): (f64, f64, f64, f64), (pb, sb, lb, hb): (f64, f64, f64, f64), (p, s): (f64, f64)| { + let (va, vb) = (1.0 - la - ha, 1.0 - lb - hb); + if va <= 1e-6 || vb <= 1e-6 { + return (lerp(la, lb, t), lerp(ha, hb, t)); + } + // The whole image: its extent and start on either slide. + let (ea, eb) = (sa / va, sb / vb); + let e = lerp(ea, eb, t); + if !e.is_finite() || e.abs() <= 1e-9 { + return (lerp(la, lb, t), lerp(ha, hb, t)); + } + let o = lerp(pa - la * ea, pb - lb * eb, t); + let lo = (p - o) / e; + (lo, 1.0 - lo - s / e) + }; + let (l, r) = axis((xa.x, xa.w, ca[0], ca[2]), (xb.x, xb.w, cb[0], cb[2]), (x.x, x.w)); + let (tp, bt) = axis((xa.y, xa.h, ca[1], ca[3]), (xb.y, xb.h, cb[1], cb[3]), (x.y, x.h)); + let c = [l, tp, r, bt]; + if c.iter().all(|v| v.is_finite()) { c } else { cb } +} + /// Morph frame from slide `a` to slide `b` at progress `t` (0..1, eased here). Paired shapes /// ([`morph_pairs`]) move along [`morph_xfrm`]; when they differ only in solid fill colour the -/// colour blends, when only in geometry (and fill colour) the outline morphs ([`MorphFrame::paths`]), +/// colour blends, when pictures differ only in crop the crop morphs ([`morph_crop`]), when only +/// in geometry (and fill colour) the outline morphs ([`MorphFrame::paths`]), /// otherwise the new shape fades in under the fading old one on the same moving /// box; with the transition option `words` or `characters` their texts are listed in /// [`MorphFrame::text`] to morph word by word or character by character. Unpaired shapes of `a` fade out, unpaired shapes of `b` fade in, and shapes of `b` for @@ -223,8 +272,18 @@ pub fn morph_frame(pres: &Presentation, a: &Slide, b: &Slide, t: f64, hidden_b: (_, xb) => xb, }; let reshape = reshaped(sa, sb); - if reshape || content(sa) == content(sb) { + let recrop = recropped(sa, sb); + if reshape || recrop || content(sa) == content(sb) { let mut m = Shape { xfrm: x, ..sb.clone() }; + if recrop && let ShapeKind::Picture { fill } = &mut m.kind { + fill.crop = match (xa, xb, x) { + (Some(xa), Some(xb), Some(x)) => morph_crop(crop_of(sa), xa, crop_of(sb), xb, x, s), + _ => { + let (ca, cb) = (crop_of(sa), crop_of(sb)); + [lerp(ca[0], cb[0], s), lerp(ca[1], cb[1], s), lerp(ca[2], cb[2], s), lerp(ca[3], cb[3], s)] + } + }; + } if let (Some(fa), Some(fb)) = (solid_color(ca.as_ref(), sa), solid_color(cb.as_ref(), sb)) && fa != fb { diff --git a/crates/anim/src/tests.rs b/crates/anim/src/tests.rs index 1fd82d78..4d4a7745 100644 --- a/crates/anim/src/tests.rs +++ b/crates/anim/src/tests.rs @@ -529,6 +529,41 @@ fn morph_pairs_by_name_text_and_geometry() { assert!(morph_pairs(&Slide::default(), &b).is_empty()); } +#[test] +fn morph_crop_moves_the_image_linearly() { + let bx = |x, w| Xfrm::new(x, 0.0, w, 100.0); + // Same box, the crop pans from the left half to the right half of a 200-wide image. + let c = morph_crop([0.0, 0.0, 0.5, 0.0], bx(0.0, 100.0), [0.5, 0.0, 0.0, 0.0], bx(0.0, 100.0), bx(0.0, 100.0), 0.5); + assert!(c.iter().zip([0.25, 0.0, 0.25, 0.0]).all(|(a, b)| (a - b).abs() < 1e-9), "{c:?}"); + // The box shrinks over an image that stays put: only the right crop grows. + let c = morph_crop([0.0; 4], bx(0.0, 100.0), [0.0, 0.0, 0.5, 0.0], bx(0.0, 50.0), bx(0.0, 75.0), 0.5); + assert!(c.iter().zip([0.0, 0.0, 0.25, 0.0]).all(|(a, b)| (a - b).abs() < 1e-9), "{c:?}"); + // Nothing visible on one side: the crops blend. + let c = morph_crop([0.5, 0.0, 0.5, 0.0], bx(0.0, 100.0), [0.0; 4], bx(0.0, 100.0), bx(0.0, 100.0), 0.5); + assert!(c.iter().all(|v| v.is_finite()) && (c[0] - 0.25).abs() < 1e-9, "{c:?}"); +} + +#[test] +fn morph_frame_morphs_a_picture_crop() { + // A picture recropped on the next slide stays one picture whose crop morphs (#118). + let p = deckcraft_model::defaults::new_presentation(None); + let pic = |id, crop| Shape { + kind: deckcraft_model::ShapeKind::Picture { fill: deckcraft_model::style::PictureFill { crop, ..Default::default() } }, + ..shape(id, "Picture 1") + }; + let mut a = Slide::default(); + let mut b = Slide::default(); + a.shapes = vec![pic(1, [0.0, 0.0, 0.5, 0.0])]; + b.shapes = vec![pic(2, [0.5, 0.0, 0.0, 0.0])]; + let f = morph_frame(&p, &a, &b, 0.5, &|_| false); + assert_eq!(f.shapes.len(), 1); + assert!(f.opacity.is_empty()); + let deckcraft_model::ShapeKind::Picture { fill } = &f.shapes[0].0.kind else { panic!("not a picture") }; + let want = 0.5 * f.mix; + assert!((fill.crop[0] - want).abs() < 1e-9 && (fill.crop[2] - (0.5 - want)).abs() < 1e-9, "{:?}", fill.crop); + assert_eq!(morph_frame(&p, &a, &b, 1.0, &|_| false).shapes[0].0.kind, b.shapes[0].kind); +} + #[test] fn morph_xfrm_interpolates() { let a = Xfrm { rot: 350.0, ..Xfrm::new(0.0, 0.0, 100.0, 100.0) }; diff --git a/docs/animation-parity.md b/docs/animation-parity.md index 1d50766b..7f3d9878 100644 --- a/docs/animation-parity.md +++ b/docs/animation-parity.md @@ -24,7 +24,7 @@ three groups, with its Effect Options. All 48 round-trip through PPTX | Duration, advance on click / after time, Apply To All | yes | yes | | Transition sounds | yes | **no** (the model has the field; no picker, no playback) | | Preview in the editor | yes | yes | -| Morph: objects move, resize, recolour | yes | yes | +| Morph: objects move, resize, recolour; a picture's crop morphs | yes | yes (#118) | | Morph: Words and Characters | yes | yes (#5) | | Morph: geometry (circle to star) | yes | yes (#27) | | Morph: `!!` name forcing, pictures, 3-D models, ink | yes | names partly; no 3-D or ink | @@ -76,4 +76,5 @@ In, Wipe, Zoom, Float In, Grow/Shrink, Pulse, Spin, motion lines): weighted, ~85 | Date | Change | Summary | |---|---|---| +| 2026-10-11 | minor | Morph animates a changed picture crop (#118) | | 2026-10-10 | major | Created: 48/48 transitions, 64 of ~190 animation effects, pane and option depth, estimates |