diff --git a/crates/compose/src/lib.rs b/crates/compose/src/lib.rs index 9a11229c4..9c423cec0 100644 --- a/crates/compose/src/lib.rs +++ b/crates/compose/src/lib.rs @@ -6157,15 +6157,26 @@ fn vertical_justify( // The last baseline stays above the bottom of the text, and the rows above it fit. let most = (space / inc + 1e-9).floor().min((room / unit + 1e-9).floor()).max(0.0); // Bottom and Justify take the lowest grid line, Center the one nearest the middle. - let mut steps = if center { (space / 2.0 / inc).round().min(most) } else { most }; - // A shaped frame can narrow and widen again, so a lower step may not fit either: take - // the nearest step that fits, and leave the lines in place when none of the next - // `MAX_GRID_TRIES` does. + let target = if center { (space / 2.0 / inc).round().min(most) } else { most }; + // A shaped frame can narrow and widen again, so the target step may not fit: take + // the fitting step nearest it, up to `most` (the lower one on a tie, and no step + // when that is as near), and leave the lines in place when none within + // `MAX_GRID_TRIES` steps of it fits. const MAX_GRID_TRIES: usize = 512; - let mut tries = 0; - while steps > 0.0 && !fits(&shifts(steps * unit)) { - tries += 1; - steps = if tries < MAX_GRID_TRIES { steps - 1.0 } else { 0.0 }; + let mut steps = 0.0; + for d in 0..MAX_GRID_TRIES { + let (below, above) = (target - d as f64, target + d as f64); + if below <= 0.0 { + break; + } + if fits(&shifts(below * unit)) { + steps = below; + break; + } + if d > 0 && above <= most && fits(&shifts(above * unit)) { + steps = above; + break; + } } // With no step taken the lines stay put, even when Center's doubled step overflows. shifts(if steps > 0.0 { steps * unit } else { 0.0 }) diff --git a/crates/compose/src/tests.rs b/crates/compose/src/tests.rs index ab8f56837..59777d657 100644 --- a/crates/compose/src/tests.rs +++ b/crates/compose/src/tests.rs @@ -2878,37 +2878,49 @@ fn vertical_justification_with_an_extreme_grid_increment_stays_finite() { } } -/// In a shaped frame that narrows and widens again, Bottom with Align to Baseline Grid takes the -/// lowest grid step at which the line's slot fits the outline, even when the grid steps next to -/// the lowest room all fall in the narrow part. +/// In a shaped frame that narrows and widens again, Align to Baseline Grid takes the grid step +/// nearest the place Bottom or Center would choose at which the line's slot fits the outline: +/// Bottom goes up past steps in the narrow part, and Center goes down a step when the step nearest +/// the middle is in the narrow part and the next one fits. #[test] fn vertical_justification_on_the_grid_skips_steps_that_leave_a_shaped_frame() { use designcraft_doc::GridAlign; - use designcraft_doc::VerticalJustification::Bottom; + use designcraft_doc::VerticalJustification::{self, Bottom, Center, Top}; use designcraft_geom::{Anchor, PathData, Point, SubPath}; // Full width down to 100 pt, a waist at 150 pt, full width again from 200 to 230 pt, then a // point at 300 pt. let pts = [(0.0, 0.0), (300.0, 0.0), (300.0, 100.0), (200.0, 150.0), (300.0, 200.0), (300.0, 230.0), (150.0, 300.0)]; let pts: Vec<(f64, f64)> = pts.iter().copied().chain([(0.0, 230.0), (0.0, 200.0), (100.0, 150.0), (0.0, 100.0)]).collect(); - let para = ParaAttrs { grid_align: Some(GridAlign::AllLines), ..Default::default() }; - let (mut d, sid, fid) = doc_with("Typography", Rect::new(0.0, 0.0, 300.0, 300.0), para); - let it = d.item_mut(fid).unwrap(); - it.path = PathData::single(SubPath { anchors: pts.iter().map(|&(x, y)| Anchor::corner(Point::new(x, y))).collect(), closed: true }); - let o = &mut it.text_frame_mut().unwrap().options; - o.inset = [0.0; 4]; - o.baseline_grid = Some(designcraft_doc::FrameBaselineGrid::new(0.0, 40.0)); - let grid = frame_specs(&d, sid)[0].grid.unwrap(); - let top = all_lines(&compose_story(&d, sid, &ComposeOptions::default()))[0].baseline; + let compose_with = |mode: VerticalJustification, inc: f64| { + let para = ParaAttrs { grid_align: Some(GridAlign::AllLines), ..Default::default() }; + let (mut d, sid, fid) = doc_with("Typography", Rect::new(0.0, 0.0, 300.0, 300.0), para); + let it = d.item_mut(fid).unwrap(); + it.path = PathData::single(SubPath { anchors: pts.iter().map(|&(x, y)| Anchor::corner(Point::new(x, y))).collect(), closed: true }); + let o = &mut it.text_frame_mut().unwrap().options; + o.inset = [0.0; 4]; + o.baseline_grid = Some(designcraft_doc::FrameBaselineGrid::new(0.0, inc)); + o.vertical_justification = mode; + let grid = frame_specs(&d, sid)[0].grid.unwrap(); + let cs = compose_story(&d, sid, &ComposeOptions::default()); + let l = all_lines(&cs)[0]; + (grid, l.baseline, l.baseline - l.ascent) + }; + let lower = |b: f64, band_top: f64| band_top >= 200.0 - 1e-6 && b <= 230.0 + 1e-6; + + // A 40 pt grid: the lowest room ends between 160 and 200 pt, and the steps above it down to + // 120 pt put the line in the waist. + let (grid, top, _) = compose_with(Top, 40.0); assert!(on_grid(top, grid), "Top: baseline {top} on the grid {grid:?}"); - d.item_mut(fid).unwrap().text_frame_mut().unwrap().options.vertical_justification = Bottom; - let cs = compose_story(&d, sid, &ComposeOptions::default()); - let l = all_lines(&cs)[0]; - let (b, band_top) = (l.baseline, l.baseline - l.ascent); + let (_, b, band_top) = compose_with(Bottom, 40.0); assert!(on_grid(b, grid), "Bottom: baseline {b} on the grid {grid:?}"); - let upper = b <= 100.0 + 1e-6; - let lower = band_top >= 200.0 - 1e-6 && b <= 230.0 + 1e-6; - assert!(upper || lower, "Bottom: the line's band {band_top}..{b} reaches into the narrow part"); + assert!(b <= 100.0 + 1e-6 || lower(b, band_top), "Bottom: the line's band {band_top}..{b} reaches into the narrow part"); assert!(b > top, "Bottom moves the line down a grid step that fits: {b}, Top at {top}"); + + // A 45 pt grid: the step nearest the middle puts the baseline at 180 pt, in the waist; the + // step below it fits in the lower full-width part. + let (grid, b, band_top) = compose_with(Center, 45.0); + assert!(on_grid(b, grid), "Center: baseline {b} on the grid {grid:?}"); + assert!(lower(b, band_top), "Center: the line's band {band_top}..{b} is not in the lower full-width part"); } /// A corner radius leaves a Cap Height first line where it sits in a rectangular frame, with Top