2026-07-14 07:43:52 +02:00

575 lines
19 KiB
Rust

use super::Matrix;
use crate::render::{RenderState, SurfaceId};
use crate::shapes::{BoolType, Path, Segment, Shape, StructureEntry, ToPath, Type};
use crate::state::ShapesPoolRef;
use crate::uuid::Uuid;
use bezier_rs::{Bezier, BezierHandles, ProjectionOptions, TValue};
use glam::DVec2;
use skia_safe as skia;
use std::cmp::Ordering;
use std::collections::HashMap;
const INTERSECT_THRESHOLD_SAME: f32 = 0.1;
const INTERSECT_THRESHOLD_DIFFERENT: f32 = 0.5;
const INTERSECT_ERROR: f64 = 0.1;
const INTERSECT_MIN_SEPARATION: f64 = 0.05;
const PROJECT_OPTS: ProjectionOptions = ProjectionOptions {
lut_size: 20,
convergence_epsilon: 0.01,
convergence_limit: 10,
iteration_limit: 20,
};
fn to_point(v: DVec2) -> skia::Point {
skia::Point::new(v.x as f32, v.y as f32)
}
pub fn path_to_beziers(path: &Path) -> Vec<Bezier> {
let mut start: Option<(f64, f64)> = None;
let mut prev: Option<(f64, f64)> = None;
path.segments()
.iter()
.filter_map(|s| match s {
Segment::MoveTo((x, y)) => {
let x = f64::from(*x);
let y = f64::from(*y);
prev = Some((x, y));
start = Some((x, y));
None
}
Segment::LineTo((x2, y2)) => {
let (x1, y1) = prev?;
let x2 = f64::from(*x2);
let y2 = f64::from(*y2);
let s = Bezier::from_linear_coordinates(x1, y1, x2, y2);
prev = Some((x2, y2));
Some(s)
}
Segment::CurveTo(((c1x, c1y), (c2x, c2y), (x2, y2))) => {
let (x1, y1) = prev?;
let x2 = f64::from(*x2);
let y2 = f64::from(*y2);
let c1x = f64::from(*c1x);
let c1y = f64::from(*c1y);
let c2x = f64::from(*c2x);
let c2y = f64::from(*c2y);
let s = Bezier::from_cubic_coordinates(x1, y1, c1x, c1y, c2x, c2y, x2, y2);
prev = Some((x2, y2));
Some(s)
}
Segment::Close => {
let (x1, y1) = prev?;
let (x2, y2) = start?;
prev = Some((x2, y2));
// Skip degenerate zero-length close segment: path already returned
// to the start point via an explicit LineTo/CurveTo, so adding a
// zero-length linear bezier here would confuse intersection detection.
if (x1 - x2).abs() < 1e-6 && (y1 - y2).abs() < 1e-6 {
return None;
}
let s = Bezier::from_linear_coordinates(x1, y1, x2, y2);
Some(s)
}
})
.collect()
}
pub fn split_intersections(segment: Bezier, intersections: &[f64]) -> Vec<Bezier> {
if intersections.is_empty() {
return vec![segment];
}
let mut result = Vec::new();
// Clamp to the valid parametric range: `intersections()`/`project()` can
// return values a hair outside [0,1] due to float error, which would make
// `split` panic on its `(0.0..=1.).contains(&t)` assertion below.
let mut intersections: Vec<f64> = intersections.iter().map(|t| t.clamp(0.0, 1.0)).collect();
intersections.sort_by(|a, b| a.partial_cmp(b).unwrap_or(Ordering::Equal));
let mut prev = 0.0;
let mut cur_segment = segment;
for t_i in &intersections {
// Skip duplicated split points (the same crossing can be reported by
// two adjacent opposing segments that share an endpoint): re-splitting
// at (almost) the same t would emit a zero-length sliver segment whose
// midpoint containment test is unstable in union/difference/intersection.
if *t_i - prev < 1e-6 {
continue;
}
let denom = 1.0 - prev;
// Degenerate split (prev already at the segment end); nothing left to cut.
if denom <= f64::EPSILON {
continue;
}
// Re-normalize the global t into the remaining segment, clamped so float
// noise / out-of-order duplicates can never push it outside [0,1].
let rti = ((t_i - prev) / denom).clamp(0.0, 1.0);
let [s, rest] = cur_segment.split(TValue::Parametric(rti));
prev = *t_i;
cur_segment = rest;
result.push(s);
}
result.push(cur_segment);
result
}
pub fn split_segments(path_a: &Path, path_b: &Path) -> (Vec<Bezier>, Vec<Bezier>) {
let path_a = path_to_beziers(path_a);
let path_b = path_to_beziers(path_b);
let mut intersects_a = Vec::<Vec<f64>>::with_capacity(path_a.len());
intersects_a.resize_with(path_a.len(), Default::default);
let mut intersects_b = Vec::<Vec<f64>>::with_capacity(path_b.len());
intersects_b.resize_with(path_b.len(), Default::default);
// Broad-phase: precompute a conservative (control-hull) AABB per segment,
// padded by the intersection tolerance. Two segments can only intersect if
// their boxes overlap, so we skip the expensive `intersections()` call for
// the (typically vast) majority of non-overlapping pairs. This turns the
// O(A*B) inner loop from A*B curve-subdivision solves into A*B cheap box
// tests plus only the handful of solves that can actually produce a hit.
let bbox = |b: &Bezier| {
let [min, max] = b.bounding_box_of_anchors_and_handles();
[
DVec2::new(min.x - INTERSECT_ERROR, min.y - INTERSECT_ERROR),
DVec2::new(max.x + INTERSECT_ERROR, max.y + INTERSECT_ERROR),
]
};
let boxes_a: Vec<[DVec2; 2]> = path_a.iter().map(bbox).collect();
let boxes_b: Vec<[DVec2; 2]> = path_b.iter().map(bbox).collect();
for i in 0..path_a.len() {
let [amin, amax] = boxes_a[i];
for j in 0..path_b.len() {
let [bmin, bmax] = boxes_b[j];
// AABB overlap test; skip pairs that cannot intersect.
if amin.x > bmax.x || bmin.x > amax.x || amin.y > bmax.y || bmin.y > amax.y {
continue;
}
let segment_a = path_a[i];
let segment_b = path_b[j];
let mut intersections_a = segment_a.intersections(
&segment_b,
Some(INTERSECT_ERROR),
Some(INTERSECT_MIN_SEPARATION),
);
// Clamp at the source: float error can report a t just outside
// [0,1], and every `TValue::Parametric` consumer downstream
// (`evaluate`, `project`, `split`) asserts `(0.0..=1.).contains(&t)`.
for t in intersections_a.iter_mut() {
*t = t.clamp(0.0, 1.0);
}
intersects_b[j].extend(intersections_a.iter().map(|t_a| {
segment_b
.project(
segment_a.evaluate(TValue::Parametric(*t_a)),
Some(PROJECT_OPTS),
)
.clamp(0.0, 1.0)
}));
intersects_a[i].extend(intersections_a);
}
}
let mut result_a = Vec::new();
for i in 0..path_a.len() {
let cur_segment = path_a[i];
result_a.extend(split_intersections(cur_segment, &intersects_a[i]));
}
let mut result_b = Vec::new();
for i in 0..path_b.len() {
let cur_segment = path_b[i];
result_b.extend(split_intersections(cur_segment, &intersects_b[i]));
}
(result_a, result_b)
}
fn union(
path_a: &Path,
segments_a: Vec<Bezier>,
path_b: &Path,
segments_b: Vec<Bezier>,
) -> Vec<(BezierSource, Bezier)> {
let mut result = Vec::new();
result.extend(
segments_a
.iter()
.filter(|s| !path_b.contains(to_point(s.evaluate(TValue::Parametric(0.5)))))
.copied()
.map(|b| (BezierSource::A, b)),
);
result.extend(
segments_b
.iter()
.filter(|s| !path_a.contains(to_point(s.evaluate(TValue::Parametric(0.5)))))
.copied()
.map(|b| (BezierSource::B, b)),
);
result
}
fn intersection(
path_a: &Path,
segments_a: Vec<Bezier>,
path_b: &Path,
segments_b: Vec<Bezier>,
) -> Vec<(BezierSource, Bezier)> {
let mut result = Vec::new();
result.extend(
segments_a
.iter()
.filter(|s| path_b.contains(to_point(s.evaluate(TValue::Parametric(0.5)))))
.copied()
.map(|b| (BezierSource::A, b)),
);
result.extend(
segments_b
.iter()
.filter(|s| path_a.contains(to_point(s.evaluate(TValue::Parametric(0.5)))))
.copied()
.map(|b| (BezierSource::B, b)),
);
result
}
fn difference(
path_a: &Path,
segments_a: Vec<Bezier>,
path_b: &Path,
segments_b: Vec<Bezier>,
) -> Vec<(BezierSource, Bezier)> {
let mut result = Vec::new();
result.extend(
segments_a
.iter()
.filter(|s| !path_b.contains(to_point(s.evaluate(TValue::Parametric(0.5)))))
.copied()
.map(|b| (BezierSource::A, b)),
);
result.extend(
segments_b
.iter()
.filter(|s| path_a.contains(to_point(s.evaluate(TValue::Parametric(0.5)))))
.copied()
.map(|s| s.reverse())
.map(|b| (BezierSource::B, b)),
);
result
}
fn exclusion(segments_a: Vec<Bezier>, segments_b: Vec<Bezier>) -> Vec<(BezierSource, Bezier)> {
let mut result = Vec::new();
result.extend(segments_a.iter().copied().map(|b| (BezierSource::A, b)));
result.extend(
segments_b
.iter()
.copied()
.map(|s| s.reverse())
.map(|b| (BezierSource::B, b)),
);
result
}
#[derive(Debug, Clone, PartialEq, Copy)]
enum BezierSource {
A,
B,
}
type BezierPool = Vec<Option<(BezierSource, Bezier)>>;
fn init_pool(beziers: &[(BezierSource, Bezier)]) -> BezierPool {
beziers.iter().copied().map(Some).collect()
}
// Pop the first remaining entry from the pool (arbitrary start for a new subpath).
fn pop_first_from_pool(pool: &mut BezierPool) -> Option<(BezierSource, Bezier)> {
pool.iter_mut().find_map(|e| e.take())
}
// Find and remove the segment whose start point is closest to `end` within the
// appropriate threshold. Same-source segments use a tight threshold
// (INTERSECT_THRESHOLD_SAMEd) so we prefer staying on the same original path;
// cross-source segments use a wider threshold (INTERSECT_THRESHOLD_DIFFERENT)
// to allow switching paths at intersection points.
fn find_next_in_pool(
pool: &mut BezierPool,
end: DVec2,
source: BezierSource,
) -> Option<(BezierSource, Bezier)> {
let mut best_idx: Option<usize> = None;
let mut best_dist_sq = f64::MAX;
for (i, entry) in pool.iter().enumerate() {
let Some((src, bezier)) = entry else {
continue;
};
let threshold = if *src == source {
INTERSECT_THRESHOLD_SAME as f64
} else {
INTERSECT_THRESHOLD_DIFFERENT as f64
};
let dx = bezier.start.x - end.x;
let dy = bezier.start.y - end.y;
let dist_sq = dx * dx + dy * dy;
if dist_sq <= threshold * threshold && dist_sq < best_dist_sq {
best_dist_sq = dist_sq;
best_idx = Some(i);
}
}
best_idx.and_then(|i| pool[i].take())
}
fn push_bezier(result: &mut Vec<Segment>, bezier: &Bezier) {
match bezier.handles {
BezierHandles::Linear => {
result.push(Segment::LineTo((bezier.end.x as f32, bezier.end.y as f32)));
}
BezierHandles::Quadratic { handle } => {
let s = bezier.start;
let e = bezier.end;
let cp1x = s.x + (2.0 / 3.0) * (handle.x - s.x);
let cp1y = s.y + (2.0 / 3.0) * (handle.y - s.y);
let cp2x = e.x + (2.0 / 3.0) * (handle.x - e.x);
let cp2y = e.y + (2.0 / 3.0) * (handle.y - e.y);
result.push(Segment::CurveTo((
(cp1x as f32, cp1y as f32),
(cp2x as f32, cp2y as f32),
(e.x as f32, e.y as f32),
)));
}
BezierHandles::Cubic {
handle_start,
handle_end,
} => {
result.push(Segment::CurveTo((
(handle_start.x as f32, handle_start.y as f32),
(handle_end.x as f32, handle_end.y as f32),
(bezier.end.x as f32, bezier.end.y as f32),
)));
}
}
}
fn beziers_to_segments(beziers: &[(BezierSource, Bezier)]) -> Vec<Segment> {
let mut result = Vec::new();
let mut pool = init_pool(beziers);
while let Some((mut cur_src, first_bezier)) = pop_first_from_pool(&mut pool) {
let start = (first_bezier.start.x as f32, first_bezier.start.y as f32);
result.push(Segment::MoveTo(start));
push_bezier(&mut result, &first_bezier);
let mut last_end = (first_bezier.end.x as f32, first_bezier.end.y as f32);
let mut cur_end = first_bezier.end;
loop {
let Some((next_src, next_bezier)) = find_next_in_pool(&mut pool, cur_end, cur_src)
else {
break;
};
push_bezier(&mut result, &next_bezier);
last_end = (next_bezier.end.x as f32, next_bezier.end.y as f32);
cur_end = next_bezier.end;
cur_src = next_src;
}
// Close the subpath if the last point is close to the start.
if (last_end.0 - start.0).abs() < INTERSECT_THRESHOLD_SAME
&& (last_end.1 - start.1).abs() < INTERSECT_THRESHOLD_SAME
{
// Remove the redundant LineTo that goes back to start, if present.
if let Some(Segment::LineTo(p)) = result.last() {
if (p.0 - start.0).abs() < INTERSECT_THRESHOLD_SAME
&& (p.1 - start.1).abs() < INTERSECT_THRESHOLD_SAME
{
result.pop();
}
}
result.push(Segment::Close);
}
}
result
}
pub fn bool_from_shapes(bool_type: BoolType, children_ids: &[Uuid], shapes: ShapesPoolRef) -> Path {
if children_ids.is_empty() {
return Path::default();
}
let Some(child) = shapes.get(&children_ids[children_ids.len() - 1]) else {
return Path::default();
};
let mut current_path = child.to_path(shapes);
for idx in (0..children_ids.len() - 1).rev() {
let Some(other) = shapes.get(&children_ids[idx]) else {
continue;
};
let other_path = other.to_path(shapes);
let (segs_a, segs_b) = split_segments(&current_path, &other_path);
let is_even_odd = current_path.is_even_odd() || other_path.is_even_odd();
let beziers = match bool_type {
BoolType::Union => union(&current_path, segs_a, &other_path, segs_b),
BoolType::Difference => difference(&current_path, segs_a, &other_path, segs_b),
BoolType::Intersection => intersection(&current_path, segs_a, &other_path, segs_b),
BoolType::Exclusion => exclusion(segs_a, segs_b),
};
current_path = Path::new(beziers_to_segments(&beziers)).with_even_odd(is_even_odd);
}
current_path
}
pub fn update_bool_to_path(shape: &mut Shape, shapes: ShapesPoolRef) {
let children_ids = shape.children_ids(true);
let Type::Bool(bool_data) = &mut shape.shape_type else {
return;
};
bool_data.path = bool_from_shapes(bool_data.bool_type, &children_ids, shapes);
}
// Debug utility for boolean shapes
#[allow(dead_code)]
pub fn debug_render_bool_paths(
render_state: &mut RenderState,
shape: &Shape,
shapes: ShapesPoolRef,
_modifiers: &HashMap<Uuid, Matrix>,
_structure: &HashMap<Uuid, Vec<StructureEntry>>,
) {
let canvas = render_state.surfaces.canvas(SurfaceId::Strokes);
let mut shape = shape.clone();
let children_ids = shape.children_ids(true);
let Type::Bool(bool_data) = &mut shape.shape_type else {
return;
};
if children_ids.is_empty() {
return;
}
let Some(child) = shapes.get(&children_ids[children_ids.len() - 1]) else {
return;
};
let mut current_path = child.to_path(shapes);
for idx in (0..children_ids.len() - 1).rev() {
let Some(other) = shapes.get(&children_ids[idx]) else {
continue;
};
let other_path = other.to_path(shapes);
let (segs_a, segs_b) = split_segments(&current_path, &other_path);
let is_even_odd = current_path.is_even_odd() || other_path.is_even_odd();
let beziers = match bool_data.bool_type {
BoolType::Union => union(&current_path, segs_a, &other_path, segs_b),
BoolType::Difference => difference(&current_path, segs_a, &other_path, segs_b),
BoolType::Intersection => intersection(&current_path, segs_a, &other_path, segs_b),
BoolType::Exclusion => exclusion(segs_a, segs_b),
};
current_path = Path::new(beziers_to_segments(&beziers)).with_even_odd(is_even_odd);
if idx == 0 {
for b in &beziers {
let mut paint = skia::Paint::default();
paint.set_color(skia::Color::RED);
paint.set_alpha_f(1.0);
paint.set_style(skia::PaintStyle::Stroke);
let path = {
let mut pb = skia::PathBuilder::new();
pb.move_to((b.1.start.x as f32, b.1.start.y as f32));
match b.1.handles {
BezierHandles::Linear => {
pb.line_to((b.1.end.x as f32, b.1.end.y as f32));
}
BezierHandles::Quadratic { handle } => {
pb.quad_to(
(handle.x as f32, handle.y as f32),
(b.1.end.x as f32, b.1.end.y as f32),
);
}
BezierHandles::Cubic {
handle_start,
handle_end,
} => {
pb.cubic_to(
(handle_start.x as f32, handle_start.y as f32),
(handle_end.x as f32, handle_end.y as f32),
(b.1.end.x as f32, b.1.end.y as f32),
);
}
}
pb.detach()
};
canvas.draw_path(&path, &paint);
let mut v1 = b.1.normal(TValue::Parametric(1.0));
v1 *= 0.5;
let v2 = v1.perp();
let p1 = b.1.end + v1 + v2;
let p2 = b.1.end - v1 + v2;
canvas.draw_line(
(b.1.end.x as f32, b.1.end.y as f32),
(p1.x as f32, p1.y as f32),
&paint,
);
canvas.draw_line(
(b.1.end.x as f32, b.1.end.y as f32),
(p2.x as f32, p2.y as f32),
&paint,
);
let v3 = b.1.normal(TValue::Parametric(0.0));
let p3 = b.1.start + v3;
let p4 = b.1.start - v3;
canvas.draw_line(
(b.1.start.x as f32, b.1.start.y as f32),
(p3.x as f32, p3.y as f32),
&paint,
);
canvas.draw_line(
(b.1.start.x as f32, b.1.start.y as f32),
(p4.x as f32, p4.y as f32),
&paint,
);
}
}
}
}