1362 lines
47 KiB
Rust
1362 lines
47 KiB
Rust
use crate::bounding_box::BoundingBox;
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use crate::matrix::Matrix;
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use smallvec::SmallVec;
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use swf::{CharacterId, FillStyle, LineStyle, Shape, ShapeRecord, Twips};
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pub fn calculate_shape_bounds(shape_records: &[swf::ShapeRecord]) -> swf::Rectangle<Twips> {
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let mut bounds = swf::Rectangle {
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x_min: Twips::new(i32::MAX),
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y_min: Twips::new(i32::MAX),
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x_max: Twips::new(i32::MIN),
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y_max: Twips::new(i32::MIN),
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};
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let mut x = Twips::ZERO;
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let mut y = Twips::ZERO;
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for record in shape_records {
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match record {
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swf::ShapeRecord::StyleChange(style_change) => {
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if let Some((move_x, move_y)) = style_change.move_to {
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x = move_x;
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y = move_y;
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bounds.x_min = Twips::min(bounds.x_min, x);
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bounds.x_max = Twips::max(bounds.x_max, x);
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bounds.y_min = Twips::min(bounds.y_min, y);
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bounds.y_max = Twips::max(bounds.y_max, y);
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}
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}
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swf::ShapeRecord::StraightEdge { delta_x, delta_y } => {
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x += *delta_x;
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y += *delta_y;
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bounds.x_min = Twips::min(bounds.x_min, x);
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bounds.x_max = Twips::max(bounds.x_max, x);
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bounds.y_min = Twips::min(bounds.y_min, y);
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bounds.y_max = Twips::max(bounds.y_max, y);
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}
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swf::ShapeRecord::CurvedEdge {
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control_delta_x,
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control_delta_y,
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anchor_delta_x,
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anchor_delta_y,
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} => {
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x += *control_delta_x;
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y += *control_delta_y;
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bounds.x_min = Twips::min(bounds.x_min, x);
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bounds.x_max = Twips::max(bounds.x_max, x);
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bounds.y_min = Twips::min(bounds.y_min, y);
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bounds.y_max = Twips::max(bounds.y_max, y);
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x += *anchor_delta_x;
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y += *anchor_delta_y;
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bounds.x_min = Twips::min(bounds.x_min, x);
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bounds.x_max = Twips::max(bounds.x_max, x);
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bounds.y_min = Twips::min(bounds.y_min, y);
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bounds.y_max = Twips::max(bounds.y_max, y);
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}
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}
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}
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if bounds.x_max < bounds.x_min || bounds.y_max < bounds.y_min {
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bounds = Default::default();
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}
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bounds
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}
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/// `DrawPath` represents a solid fill or a stroke.
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/// Fills are always closed paths, while strokes may be open or closed.
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/// Closed paths will have the first point equal to the last point.
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#[derive(Clone, Debug, Eq, PartialEq)]
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pub enum DrawPath<'a> {
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Stroke {
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style: &'a LineStyle,
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is_closed: bool,
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commands: Vec<DrawCommand>,
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},
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Fill {
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style: &'a FillStyle,
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commands: Vec<DrawCommand>,
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},
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}
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/// `DistilledShape` represents a ready-to-be-consumed collection of paths (both fills and strokes)
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/// that has been converted down from another source (such as SWF's `swf::Shape` format).
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#[derive(Clone, Debug, Eq, PartialEq)]
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pub struct DistilledShape<'a> {
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pub paths: Vec<DrawPath<'a>>,
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pub shape_bounds: BoundingBox,
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pub edge_bounds: BoundingBox,
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pub id: CharacterId,
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}
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impl<'a> From<&'a swf::Shape> for DistilledShape<'a> {
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fn from(shape: &'a Shape) -> Self {
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Self {
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paths: ShapeConverter::from_shape(shape).into_commands(),
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shape_bounds: (&shape.shape_bounds).into(),
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edge_bounds: (&shape.edge_bounds).into(),
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id: shape.id,
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}
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}
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}
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/// `DrawCommands` trace the outline of a path.
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/// Fills follow the even-odd fill rule, with opposite winding for holes.
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#[derive(Clone, Debug, Eq, PartialEq)]
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pub enum DrawCommand {
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MoveTo {
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x: Twips,
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y: Twips,
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},
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LineTo {
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x: Twips,
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y: Twips,
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},
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CurveTo {
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x1: Twips,
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y1: Twips,
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x2: Twips,
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y2: Twips,
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},
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}
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impl DrawCommand {
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pub fn end_point(&self) -> (Twips, Twips) {
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match self {
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DrawCommand::MoveTo { x, y } => (*x, *y),
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DrawCommand::LineTo { x, y } => (*x, *y),
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DrawCommand::CurveTo { x2, y2, .. } => (*x2, *y2),
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}
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}
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}
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#[derive(Clone, Copy, Debug)]
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struct Point {
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x: Twips,
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y: Twips,
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is_bezier_control: bool,
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}
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/// A continuous series of edges in a path.
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/// Fill segments are directed, because the winding determines the fill-rule.
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/// Stroke segments are undirected.
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#[derive(Clone, Debug)]
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struct PathSegment {
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pub points: Vec<Point>,
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}
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impl PathSegment {
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fn new(start: (Twips, Twips)) -> Self {
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Self {
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points: vec![Point {
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x: start.0,
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y: start.1,
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is_bezier_control: false,
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}],
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}
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}
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fn reset(&mut self, start: (Twips, Twips)) {
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self.points.clear();
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self.points.push(Point {
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x: start.0,
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y: start.1,
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is_bezier_control: false,
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});
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}
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/// Flips the direction of the path segment.
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/// Flash fill paths are dual-sided, with fill style 1 indicating the positive side
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/// and fill style 0 indicating the negative. We have to flip fill style 0 paths
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/// in order to link them to fill style 1 paths.
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fn flip(&mut self) {
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self.points.reverse();
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}
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/// Adds an edge to the end of the path segment.
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fn add_point(&mut self, point: Point) {
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self.points.push(point);
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}
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fn is_empty(&self) -> bool {
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self.points.len() <= 1
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}
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fn start(&self) -> Option<(Twips, Twips)> {
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let pt = &self.points.first()?;
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Some((pt.x, pt.y))
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}
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fn end(&self) -> Option<(Twips, Twips)> {
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let pt = &self.points.last()?;
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Some((pt.x, pt.y))
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}
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fn is_closed(&self) -> bool {
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self.start() == self.end()
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}
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fn to_draw_commands(&self) -> impl '_ + Iterator<Item = DrawCommand> {
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assert!(!self.is_empty());
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let mut i = self.points.iter();
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let first = i.next().expect("Points should not be empty");
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std::iter::once(DrawCommand::MoveTo {
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x: first.x,
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y: first.y,
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})
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.chain(std::iter::from_fn(move || match i.next() {
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Some(&Point {
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is_bezier_control: false,
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x,
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y,
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}) => Some(DrawCommand::LineTo { x, y }),
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Some(&Point {
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is_bezier_control: true,
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x,
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y,
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}) => {
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let end = i.next().expect("Bezier without endpoint");
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Some(DrawCommand::CurveTo {
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x1: x,
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y1: y,
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x2: end.x,
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y2: end.y,
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})
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}
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None => None,
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}))
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}
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}
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/// The internal path structure used by ShapeConverter.
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///
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/// Each path is uniquely identified by its fill/stroke style. But Flash gives
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/// the path edges as an "edge soup" -- they can arrive in an arbitrary order.
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/// We have to link the edges together for each path. This structure contains
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/// a list of path segment, and each time a path segment is added, it will try
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/// to merge it with an existing segment.
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#[derive(Clone, Debug)]
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struct PendingPath {
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/// The list of path segments for this fill/stroke.
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/// For fills, this should turn into a list of closed paths when the shape is complete.
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/// Strokes may or may not be closed.
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segments: Vec<PathSegment>,
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}
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impl PendingPath {
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fn new() -> Self {
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Self { segments: vec![] }
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}
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/// Adds a path segment to the path, attempting to link it to existing segments.
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fn add_segment(&mut self, mut new_segment: PathSegment) {
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if !new_segment.is_empty() {
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// Try to link this segment onto existing segments with a matching endpoint.
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// Both the start and the end points of the new segment can be linked.
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let mut start_open = true;
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let mut end_open = true;
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let mut i = 0;
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while (start_open || end_open) && i < self.segments.len() {
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let other = &mut self.segments[i];
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if start_open && other.end() == new_segment.start() {
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other.points.extend_from_slice(&new_segment.points[1..]);
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new_segment = self.segments.swap_remove(i);
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start_open = false;
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} else if end_open && new_segment.end() == other.start() {
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std::mem::swap(&mut other.points, &mut new_segment.points);
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other.points.extend_from_slice(&new_segment.points[1..]);
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new_segment = self.segments.swap_remove(i);
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end_open = false;
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} else {
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i += 1;
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}
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}
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// The segment can't link to any further segments. Add it to list.
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self.segments.push(new_segment);
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}
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}
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fn push_path(&mut self, segment: PathSegment) {
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self.segments.push(segment);
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}
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fn to_draw_commands(&self) -> impl '_ + Iterator<Item = DrawCommand> {
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self.segments.iter().flat_map(PathSegment::to_draw_commands)
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}
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}
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#[derive(Clone, Debug)]
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pub struct ActivePath {
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style_id: u32,
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segment: PathSegment,
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}
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impl ActivePath {
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fn new() -> Self {
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Self {
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style_id: 0,
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segment: PathSegment::new(Default::default()),
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}
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}
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fn add_point(&mut self, point: Point) {
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self.segment.add_point(point)
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}
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fn flush_fill(&mut self, start: (Twips, Twips), pending: &mut [PendingPath], flip: bool) {
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if self.style_id > 0 && !self.segment.is_empty() {
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if flip {
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self.segment.flip();
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}
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pending[self.style_id as usize - 1].add_segment(self.segment.clone());
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}
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self.segment.reset(start);
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}
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fn flush_stroke(&mut self, start: (Twips, Twips), pending: &mut [PendingPath]) {
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if self.style_id > 0 && !self.segment.is_empty() {
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pending[self.style_id as usize - 1].push_path(self.segment.clone());
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}
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self.segment.reset(start);
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}
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}
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pub struct ShapeConverter<'a> {
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// SWF shape commands.
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iter: std::slice::Iter<'a, swf::ShapeRecord>,
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// Pen position.
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x: Twips,
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y: Twips,
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// Fill styles and line styles.
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// These change from StyleChangeRecords, and a flush occurs when these change.
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fill_styles: &'a [swf::FillStyle],
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line_styles: &'a [swf::LineStyle],
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fill_style0: ActivePath,
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fill_style1: ActivePath,
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line_style: ActivePath,
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// Paths. These get flushed for each new layer.
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fills: Vec<PendingPath>,
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strokes: Vec<PendingPath>,
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// Output.
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commands: Vec<DrawPath<'a>>,
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}
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impl<'a> ShapeConverter<'a> {
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const DEFAULT_CAPACITY: usize = 512;
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fn from_shape(shape: &'a swf::Shape) -> Self {
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ShapeConverter {
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iter: shape.shape.iter(),
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x: Twips::ZERO,
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y: Twips::ZERO,
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fill_styles: &shape.styles.fill_styles,
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line_styles: &shape.styles.line_styles,
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fill_style0: ActivePath::new(),
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fill_style1: ActivePath::new(),
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line_style: ActivePath::new(),
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fills: vec![PendingPath::new(); shape.styles.fill_styles.len()],
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strokes: vec![PendingPath::new(); shape.styles.line_styles.len()],
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commands: Vec::with_capacity(Self::DEFAULT_CAPACITY),
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}
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}
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fn into_commands(mut self) -> Vec<DrawPath<'a>> {
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// As u32 is okay because SWF has a max of 65536 fills (TODO: should be u16?)
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let mut num_fill_styles = self.fill_styles.len() as u32;
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let mut num_line_styles = self.line_styles.len() as u32;
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while let Some(record) = self.iter.next() {
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match record {
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ShapeRecord::StyleChange(style_change) => {
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if let Some((x, y)) = style_change.move_to {
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self.x = x;
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self.y = y;
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// We've lifted the pen, so we're starting a new path.
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// Flush the previous path.
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self.flush_paths();
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}
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if let Some(styles) = &style_change.new_styles {
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// A new style list is also used to indicate a new drawing layer.
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self.flush_layer();
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self.fill_styles = &styles.fill_styles[..];
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self.line_styles = &styles.line_styles[..];
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self.fills
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.resize_with(self.fill_styles.len(), PendingPath::new);
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self.strokes
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.resize_with(self.line_styles.len(), PendingPath::new);
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num_fill_styles = self.fill_styles.len() as u32;
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num_line_styles = self.line_styles.len() as u32;
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}
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if let Some(new_style_id) = style_change.fill_style_1 {
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self.fill_style1
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.flush_fill((self.x, self.y), &mut self.fills[..], false);
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// Validate in case we index an invalid fill style.
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// <= because fill ID 0 (no fill) is implicit, so the array is actually 1-based
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self.fill_style1.style_id = if new_style_id <= num_fill_styles {
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new_style_id
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} else {
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0
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};
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}
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if let Some(new_style_id) = style_change.fill_style_0 {
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self.fill_style0
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.flush_fill((self.x, self.y), &mut self.fills[..], true);
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self.fill_style0.style_id = if new_style_id <= num_fill_styles {
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new_style_id
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} else {
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0
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}
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}
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if let Some(new_style_id) = style_change.line_style {
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self.line_style
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.flush_stroke((self.x, self.y), &mut self.strokes[..]);
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self.line_style.style_id = if new_style_id <= num_line_styles {
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new_style_id
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} else {
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0
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}
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}
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}
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ShapeRecord::StraightEdge { delta_x, delta_y } => {
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self.x += *delta_x;
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self.y += *delta_y;
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self.visit_point(Point {
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x: self.x,
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y: self.y,
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is_bezier_control: false,
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});
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}
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ShapeRecord::CurvedEdge {
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control_delta_x,
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control_delta_y,
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anchor_delta_x,
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anchor_delta_y,
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} => {
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let x1 = self.x + *control_delta_x;
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let y1 = self.y + *control_delta_y;
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self.visit_point(Point {
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x: x1,
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y: y1,
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is_bezier_control: true,
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});
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let x2 = x1 + *anchor_delta_x;
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let y2 = y1 + *anchor_delta_y;
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self.visit_point(Point {
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x: x2,
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y: y2,
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is_bezier_control: false,
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});
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self.x = x2;
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self.y = y2;
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}
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}
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}
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// Flush any open paths.
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self.flush_layer();
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self.commands
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}
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/// Adds a point to the current path for the active fills/strokes.
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fn visit_point(&mut self, point: Point) {
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if self.fill_style1.style_id > 0 {
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self.fill_style1.add_point(point);
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}
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if self.fill_style0.style_id > 0 {
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self.fill_style0.add_point(point);
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}
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if self.line_style.style_id > 0 {
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self.line_style.add_point(point);
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}
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}
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/// When the pen jumps to a new position, we reset the active path.
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fn flush_paths(&mut self) {
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// Move the current paths to the active list.
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self.fill_style1
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.flush_fill((self.x, self.y), &mut self.fills, false);
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self.fill_style0
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.flush_fill((self.x, self.y), &mut self.fills, true);
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self.line_style
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.flush_stroke((self.x, self.y), &mut self.strokes);
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}
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/// When a new layer starts, all paths are flushed and turned into drawing commands.
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fn flush_layer(&mut self) {
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self.flush_paths();
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// Draw fills, and then strokes.
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// Paths are drawn in order of style id, not based on the order of the draw commands.
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for (i, path) in self.fills.iter_mut().enumerate() {
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// These invariants are checked above (any invalid/empty fill ID should not have been added).
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debug_assert!(i < self.fill_styles.len());
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if path.segments.is_empty() {
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continue;
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}
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let style = unsafe { self.fill_styles.get_unchecked(i) };
|
|
self.commands.push(DrawPath::Fill {
|
|
style,
|
|
commands: path.to_draw_commands().collect(),
|
|
});
|
|
path.segments.clear();
|
|
}
|
|
|
|
// Strokes are drawn last because they always appear on top of fills in the same layer.
|
|
// Because path segments can either be open or closed, we convert each stroke segment into
|
|
// a separate draw command.
|
|
for (i, path) in self.strokes.iter_mut().enumerate() {
|
|
debug_assert!(i < self.line_styles.len());
|
|
let style = unsafe { self.line_styles.get_unchecked(i) };
|
|
for segment in &path.segments {
|
|
if segment.is_empty() {
|
|
continue;
|
|
}
|
|
self.commands.push(DrawPath::Stroke {
|
|
style,
|
|
is_closed: segment.is_closed(),
|
|
commands: segment.to_draw_commands().collect(),
|
|
});
|
|
}
|
|
path.segments.clear();
|
|
}
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod tests {
|
|
use super::*;
|
|
|
|
const FILL_STYLES: [FillStyle; 1] = [FillStyle::Color(swf::Color {
|
|
r: 255,
|
|
g: 0,
|
|
b: 0,
|
|
a: 255,
|
|
})];
|
|
|
|
const LINE_STYLES: [LineStyle; 0] = [];
|
|
|
|
/// Convenience method to quickly make a shape,
|
|
fn build_shape(records: Vec<ShapeRecord>) -> swf::Shape {
|
|
let bounds = calculate_shape_bounds(&records);
|
|
swf::Shape {
|
|
version: 2,
|
|
id: 1,
|
|
shape_bounds: bounds.clone(),
|
|
edge_bounds: bounds,
|
|
flags: swf::ShapeFlag::HAS_SCALING_STROKES,
|
|
styles: swf::ShapeStyles {
|
|
fill_styles: FILL_STYLES.to_vec(),
|
|
line_styles: LINE_STYLES.to_vec(),
|
|
},
|
|
shape: records,
|
|
}
|
|
}
|
|
|
|
/// A simple solid square.
|
|
#[test]
|
|
fn basic_shape() {
|
|
let shape = build_shape(vec![
|
|
ShapeRecord::StyleChange(Box::new(swf::StyleChangeData {
|
|
move_to: Some((Twips::from_pixels(100.0), Twips::from_pixels(100.0))),
|
|
fill_style_0: None,
|
|
fill_style_1: Some(1),
|
|
line_style: None,
|
|
new_styles: None,
|
|
})),
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(100.0),
|
|
delta_y: Twips::from_pixels(0.0),
|
|
},
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(0.0),
|
|
delta_y: Twips::from_pixels(100.0),
|
|
},
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(-100.0),
|
|
delta_y: Twips::from_pixels(0.0),
|
|
},
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(0.0),
|
|
delta_y: Twips::from_pixels(-100.0),
|
|
},
|
|
]);
|
|
let commands = ShapeConverter::from_shape(&shape).into_commands();
|
|
let expected = vec![DrawPath::Fill {
|
|
style: &FILL_STYLES[0],
|
|
commands: vec![
|
|
DrawCommand::MoveTo {
|
|
x: Twips::from_pixels(100.0),
|
|
y: Twips::from_pixels(100.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(200.0),
|
|
y: Twips::from_pixels(100.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(200.0),
|
|
y: Twips::from_pixels(200.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(100.0),
|
|
y: Twips::from_pixels(200.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(100.0),
|
|
y: Twips::from_pixels(100.0),
|
|
},
|
|
],
|
|
}];
|
|
assert_eq!(commands, expected);
|
|
}
|
|
|
|
/// A solid square with one edge flipped (fillstyle0 instead of fillstyle1).
|
|
#[test]
|
|
fn flipped_edges() {
|
|
let shape = build_shape(vec![
|
|
ShapeRecord::StyleChange(Box::new(swf::StyleChangeData {
|
|
move_to: Some((Twips::from_pixels(100.0), Twips::from_pixels(100.0))),
|
|
fill_style_0: None,
|
|
fill_style_1: Some(1),
|
|
line_style: None,
|
|
new_styles: None,
|
|
})),
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(100.0),
|
|
delta_y: Twips::from_pixels(0.0),
|
|
},
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(0.0),
|
|
delta_y: Twips::from_pixels(100.0),
|
|
},
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(-100.0),
|
|
delta_y: Twips::from_pixels(0.0),
|
|
},
|
|
ShapeRecord::StyleChange(Box::new(swf::StyleChangeData {
|
|
move_to: Some((Twips::from_pixels(100.0), Twips::from_pixels(100.0))),
|
|
fill_style_0: Some(1),
|
|
fill_style_1: Some(0),
|
|
line_style: None,
|
|
new_styles: None,
|
|
})),
|
|
ShapeRecord::StraightEdge {
|
|
delta_x: Twips::from_pixels(0.0),
|
|
delta_y: Twips::from_pixels(100.0),
|
|
},
|
|
]);
|
|
let commands = ShapeConverter::from_shape(&shape).into_commands();
|
|
let expected = vec![DrawPath::Fill {
|
|
style: &FILL_STYLES[0],
|
|
commands: vec![
|
|
DrawCommand::MoveTo {
|
|
x: Twips::from_pixels(100.0),
|
|
y: Twips::from_pixels(100.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(200.0),
|
|
y: Twips::from_pixels(100.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(200.0),
|
|
y: Twips::from_pixels(200.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(100.0),
|
|
y: Twips::from_pixels(200.0),
|
|
},
|
|
DrawCommand::LineTo {
|
|
x: Twips::from_pixels(100.0),
|
|
y: Twips::from_pixels(100.0),
|
|
},
|
|
],
|
|
}];
|
|
assert_eq!(commands, expected);
|
|
}
|
|
}
|
|
|
|
/* SHAPEFLAG HITTEST (point-in-contour)
|
|
*
|
|
* To determine whether a point is inside a shape, we shoot a ray on the +x axis and calculate a winding number based
|
|
* on the edges that intersect with the ray.
|
|
*
|
|
* For each edge:
|
|
* if the edge cross the ray downward (+y), we add 1 to the winding number.
|
|
* if the edge cross the ray upward (-y), we add -1 to the winding number.
|
|
*
|
|
* We must also handle intersection with edge endpoints consistently to avoid double counting:
|
|
* the initial point of an edge is considered for upwards rays.
|
|
* the final point of an edge is considered for downward rays.
|
|
*
|
|
* For SWF shapes, edges with fillstyle1 use clockwise winding, and edges with fillstyle0 use CCW winding (flip them).
|
|
* We ignore any edges with fills on both sides (interior edges).
|
|
*
|
|
* If the final winding number is odd, then the point is inside the shape (for default even-odd winding).
|
|
*
|
|
* For strokes, we calculate the distance to the line segment or curve and compare it to the stroke width.
|
|
* Note that Flash renders with a minimum stroke width of 1px (20 twips) that we must account for.
|
|
* TODO: We currently don't consider non-round endcaps or joins, or stroke scaling flags.
|
|
*/
|
|
|
|
/// Test whether the given point in object space is contained within the contour of the given shape.
|
|
/// local_matrix is used to calculate the proper stroke widths.
|
|
pub fn shape_hit_test(
|
|
shape: &swf::Shape,
|
|
(point_x, point_y): (Twips, Twips),
|
|
local_matrix: &Matrix,
|
|
) -> bool {
|
|
// Transform point to local space.
|
|
let mut x = Twips::ZERO;
|
|
let mut y = Twips::ZERO;
|
|
let mut winding = 0;
|
|
|
|
let mut has_fill_style0: bool = false;
|
|
let mut has_fill_style1: bool = false;
|
|
|
|
let min_width = stroke_minimum_width(local_matrix);
|
|
let mut stroke_width = None;
|
|
let mut line_styles = &shape.styles.line_styles;
|
|
|
|
for record in &shape.shape {
|
|
match record {
|
|
swf::ShapeRecord::StyleChange(style_change) => {
|
|
// New styles indicates a new layer;
|
|
// Check if the point is within the current layer, then reset winding.
|
|
if let Some(new_styles) = &style_change.new_styles {
|
|
if winding & 0b1 != 0 {
|
|
return true;
|
|
}
|
|
line_styles = &new_styles.line_styles;
|
|
winding = 0;
|
|
}
|
|
|
|
if let Some((move_x, move_y)) = style_change.move_to {
|
|
x = move_x;
|
|
y = move_y;
|
|
}
|
|
|
|
if let Some(i) = style_change.fill_style_0 {
|
|
has_fill_style0 = i > 0;
|
|
}
|
|
if let Some(i) = style_change.fill_style_1 {
|
|
has_fill_style1 = i > 0;
|
|
}
|
|
if let Some(i) = style_change.line_style {
|
|
stroke_width = if i > 0 {
|
|
// Flash renders strokes with a 1px minimum width.
|
|
if let Some(line_style) = line_styles.get(i as usize - 1) {
|
|
let width = line_style.width().get() as f64;
|
|
let scaled_width = 0.5 * width.max(min_width);
|
|
Some((scaled_width, scaled_width * scaled_width))
|
|
} else {
|
|
None
|
|
}
|
|
} else {
|
|
None
|
|
};
|
|
}
|
|
}
|
|
swf::ShapeRecord::StraightEdge { delta_x, delta_y } => {
|
|
let x1 = x + *delta_x;
|
|
let y1 = y + *delta_y;
|
|
// If this edge has a fill style on only one-side, check for a crossing.
|
|
if has_fill_style1 {
|
|
if !has_fill_style0 {
|
|
winding += winding_number_line((point_x, point_y), (x, y), (x1, y1));
|
|
}
|
|
} else if has_fill_style0 {
|
|
winding += winding_number_line((point_x, point_y), (x1, y1), (x, y));
|
|
}
|
|
|
|
if let Some(width) = stroke_width {
|
|
if hit_test_stroke((point_x, point_y), (x, y), (x1, y1), width) {
|
|
return true;
|
|
}
|
|
}
|
|
x = x1;
|
|
y = y1;
|
|
}
|
|
swf::ShapeRecord::CurvedEdge {
|
|
control_delta_x,
|
|
control_delta_y,
|
|
anchor_delta_x,
|
|
anchor_delta_y,
|
|
} => {
|
|
let x1 = x + *control_delta_x;
|
|
let y1 = y + *control_delta_y;
|
|
|
|
let x2 = x1 + *anchor_delta_x;
|
|
let y2 = y1 + *anchor_delta_y;
|
|
|
|
// If this edge has a fill style on only one-side, check for a crossing.
|
|
if has_fill_style1 {
|
|
if !has_fill_style0 {
|
|
winding +=
|
|
winding_number_curve((point_x, point_y), (x, y), (x1, y1), (x2, y2));
|
|
}
|
|
} else if has_fill_style0 {
|
|
winding += winding_number_curve((point_x, point_y), (x2, y2), (x1, y1), (x, y));
|
|
}
|
|
|
|
if let Some(width) = stroke_width {
|
|
if hit_test_stroke_curve((point_x, point_y), (x, y), (x1, y1), (x2, y2), width)
|
|
{
|
|
return true;
|
|
}
|
|
}
|
|
|
|
x = x2;
|
|
y = y2;
|
|
}
|
|
}
|
|
}
|
|
winding & 0b1 != 0
|
|
}
|
|
|
|
/// Test whether the given point is contained within the paths specified by the draw commands.
|
|
pub fn draw_command_fill_hit_test(commands: &[DrawCommand], test_point: (Twips, Twips)) -> bool {
|
|
let mut cursor = (Twips::ZERO, Twips::ZERO);
|
|
let mut fill_start = (Twips::ZERO, Twips::ZERO);
|
|
let mut winding = 0;
|
|
|
|
// Draw command only contains a single fill, so don't have to worry about fill styles.
|
|
for command in commands {
|
|
match *command {
|
|
DrawCommand::MoveTo { x: x1, y: y1 } => {
|
|
cursor = (x1, y1);
|
|
fill_start = (x1, y1);
|
|
}
|
|
DrawCommand::LineTo { x: x1, y: y1 } => {
|
|
winding += winding_number_line(test_point, cursor, (x1, y1));
|
|
cursor = (x1, y1);
|
|
}
|
|
DrawCommand::CurveTo { x1, y1, x2, y2 } => {
|
|
winding += winding_number_curve(test_point, cursor, (x1, y1), (x2, y2));
|
|
cursor = (x2, y2);
|
|
}
|
|
}
|
|
}
|
|
if cursor != fill_start {
|
|
// Close fill.
|
|
winding += winding_number_line(test_point, cursor, fill_start);
|
|
}
|
|
|
|
winding & 0b1 != 0
|
|
}
|
|
|
|
/// Test whether the given point is contained within the strokes specified by the draw commands.
|
|
/// local_matrix is used to calculate the minimum stroke width.
|
|
pub fn draw_command_stroke_hit_test(
|
|
commands: &[DrawCommand],
|
|
stroke_width: Twips,
|
|
(point_x, point_y): (Twips, Twips),
|
|
local_matrix: &Matrix,
|
|
) -> bool {
|
|
let stroke_min_width = stroke_minimum_width(local_matrix);
|
|
let stroke_width = 0.5 * f64::max(stroke_width.get().into(), stroke_min_width);
|
|
let stroke_widths = (stroke_width, stroke_width * stroke_width);
|
|
let mut x = Twips::default();
|
|
let mut y = Twips::default();
|
|
for command in commands {
|
|
match *command {
|
|
DrawCommand::MoveTo { x: x1, y: y1 } => {
|
|
x = x1;
|
|
y = y1;
|
|
}
|
|
DrawCommand::LineTo { x: x1, y: y1 } => {
|
|
if hit_test_stroke((point_x, point_y), (x, y), (x1, y1), stroke_widths) {
|
|
return true;
|
|
}
|
|
x = x1;
|
|
y = y1;
|
|
}
|
|
DrawCommand::CurveTo { x1, y1, x2, y2 } => {
|
|
if hit_test_stroke_curve(
|
|
(point_x, point_y),
|
|
(x, y),
|
|
(x1, y1),
|
|
(x2, y2),
|
|
stroke_widths,
|
|
) {
|
|
return true;
|
|
}
|
|
x = x2;
|
|
y = y2;
|
|
}
|
|
}
|
|
}
|
|
|
|
false
|
|
}
|
|
|
|
/// Given a matrix, calculates the scale for stroke widths.
|
|
/// TODO: Verify the actual behavior; I think it's more like the average between scaleX and scaleY.
|
|
/// Does not yet support vertical/horizontal stroke scaling flags.
|
|
/// This might be better to add as a method to Matrix.
|
|
fn stroke_minimum_width(matrix: &Matrix) -> f64 {
|
|
let sx = (matrix.a * matrix.a + matrix.b * matrix.b).sqrt();
|
|
let sy = (matrix.c * matrix.c + matrix.d * matrix.d).sqrt();
|
|
let scale: f64 = sx.max(sy).into();
|
|
20.0 * scale
|
|
}
|
|
|
|
/// Returns whether the given point is inside the stroked line segment.
|
|
/// `width_sq` should be the squared width of the stroke.
|
|
fn hit_test_stroke(
|
|
(point_x, point_y): (Twips, Twips),
|
|
(x0, y0): (Twips, Twips),
|
|
(x1, y1): (Twips, Twips),
|
|
(stroke_width, stroke_width_sq): (f64, f64),
|
|
) -> bool {
|
|
let px = point_x.get() as f64;
|
|
let py = point_y.get() as f64;
|
|
let x0 = x0.get() as f64;
|
|
let y0 = y0.get() as f64;
|
|
let x1 = x1.get() as f64;
|
|
let y1 = y1.get() as f64;
|
|
|
|
// Early exit: out of bounds
|
|
let x_min = x0.min(x1);
|
|
let x_max = x0.max(x1);
|
|
if px < x_min - stroke_width || px > x_max + stroke_width {
|
|
return false;
|
|
}
|
|
let y_min = y0.min(y1);
|
|
let y_max = y0.max(y1);
|
|
if py < y_min - stroke_width || py > y_max + stroke_width {
|
|
return false;
|
|
}
|
|
|
|
// AB is the segment from (x0, y0) to (x1, y1) and P is (point_x, point_y).
|
|
// P
|
|
// .
|
|
// .
|
|
// A----->B
|
|
// If AP dot AB is <= 0.0, then PA is pointing away from AB, so A is the closest point.
|
|
let abx = x1 - x0;
|
|
let aby = y1 - y0;
|
|
let apx = px - x0;
|
|
let apy = py - y0;
|
|
let dot_a = abx * apx + aby * apy;
|
|
let dist = if dot_a <= 0.0 {
|
|
apx * apx + apy * apy
|
|
} else {
|
|
// If BP dot AB is >= 0.0, then BP is pointing away from BA, so B is the closest point.
|
|
let bpx = px - x1;
|
|
let bpy = py - y1;
|
|
let dot_b = abx * bpx + aby * bpy;
|
|
if dot_b >= 0.0 {
|
|
bpx * bpx + bpy * bpy
|
|
} else {
|
|
// Otherwise, the closest point will be within the interval of the segment.
|
|
// Project the point onto the segment.
|
|
let len = abx * abx + aby * aby;
|
|
let ex = apx - dot_a * abx / len;
|
|
let ey = apy - dot_a * aby / len;
|
|
ex * ex + ey * ey
|
|
}
|
|
};
|
|
|
|
dist <= stroke_width_sq
|
|
}
|
|
|
|
/// Returns whether the given point is inside the stroked bezier curve.
|
|
/// `width_sq` should be the squared width of the stroke.
|
|
fn hit_test_stroke_curve(
|
|
(point_x, point_y): (Twips, Twips),
|
|
(x0, y0): (Twips, Twips),
|
|
(x1, y1): (Twips, Twips),
|
|
(x2, y2): (Twips, Twips),
|
|
(stroke_width, stroke_width_sq): (f64, f64),
|
|
) -> bool {
|
|
let px = point_x.get() as f64;
|
|
let py = point_y.get() as f64;
|
|
let x0 = x0.get() as f64;
|
|
let y0 = y0.get() as f64;
|
|
let x1 = x1.get() as f64;
|
|
let y1 = y1.get() as f64;
|
|
let x2 = x2.get() as f64;
|
|
let y2 = y2.get() as f64;
|
|
|
|
// Early exit: out of bounds
|
|
// TODO: Since this involves an expensive cubic, probably wortwhile to calculate the tight bounds for the curve:
|
|
// https://www.iquilezles.org/www/articles/bezierbbox/bezierbbox.htm
|
|
let x_min = x0.min(x1).min(x2);
|
|
let x_max = x0.max(x1).max(x2);
|
|
if px < x_min - stroke_width || px > x_max + stroke_width {
|
|
return false;
|
|
}
|
|
|
|
let y_min = y0.min(y1).min(y2);
|
|
let y_max = y0.max(y1).max(y2);
|
|
if py < y_min - stroke_width || py > y_max + stroke_width {
|
|
return false;
|
|
}
|
|
|
|
// The closest point on the curve will be normal to the curve.
|
|
// The tangent of a quadratic bezier:
|
|
// C'(t) = -2 * (1-t) * P0 + 2 * (1-t) * P1 + 2*t*P2
|
|
// Dot product to determine when we are perpendicular to the tangent.
|
|
// (point - C(t)) . C'(t) = 0
|
|
// The result is a cubic polynomial that we can solve for.
|
|
// After solving this polynomial, we choose the t with [0, 1.0] that gives us the minimum distance
|
|
// (also considering the endcaps).
|
|
// via http://blog.gludion.com/2009/08/distance-to-quadratic-bezier-curve.html
|
|
|
|
let ax = x1 - x0;
|
|
let ay = y1 - y0;
|
|
let bx = x2 - x1 - ax;
|
|
let by = y2 - y1 - ay;
|
|
let mx = x0 - px;
|
|
let my = y0 - py;
|
|
|
|
let a = bx * bx + by * by;
|
|
let b = 3.0 * (ax * bx + ay * by);
|
|
let c = 2.0 * (ax * ax + ay * ay) + (mx * bx + my * by);
|
|
let d = mx * ax + my * ay;
|
|
|
|
let distance_to_curve = |t| -> f64 {
|
|
// Sample bezier at the given t and return distance to the point.
|
|
let comp_t = 1.0 - t;
|
|
let cx = comp_t * comp_t * x0 + 2.0 * comp_t * t * x1 + t * t * x2;
|
|
let cy = comp_t * comp_t * y0 + 2.0 * comp_t * t * y1 + t * t * y2;
|
|
let dx = cx - px;
|
|
let dy = cy - py;
|
|
dx * dx + dy * dy
|
|
};
|
|
|
|
// Test end-caps
|
|
let mut dist = distance_to_curve(0.0);
|
|
dist = dist.min(distance_to_curve(1.0));
|
|
|
|
// Test roots.
|
|
for t in solve_cubic(a, b, c, d) {
|
|
if t >= 0.0 && t <= 1.0 {
|
|
dist = dist.min(distance_to_curve(t));
|
|
}
|
|
}
|
|
|
|
dist <= stroke_width_sq
|
|
}
|
|
|
|
/// Calculates the winding number for a line segment relative to the given point.
|
|
fn winding_number_line(
|
|
(point_x, point_y): (Twips, Twips),
|
|
(x0, y0): (Twips, Twips),
|
|
(x1, y1): (Twips, Twips),
|
|
) -> i32 {
|
|
let point_x = point_x.get() as f64;
|
|
let point_y = point_y.get() as f64;
|
|
let x0 = x0.get() as f64;
|
|
let y0 = y0.get() as f64;
|
|
let x1 = x1.get() as f64;
|
|
let y1 = y1.get() as f64;
|
|
|
|
// Adjust winding number if we are on the left side of the segment.
|
|
// An upward segment (-y) increments the winding number (including the initial endpoint).
|
|
// A downward segment (+y) decrements the winding number (including the final endpoint)
|
|
// Perp-dot indicates which side of the segment the point is on.
|
|
if y0 < point_y {
|
|
if y1 >= point_y {
|
|
let val = (x1 - x0) * (point_y - y0) - (y1 - y0) * (point_x - x0);
|
|
if val > 0.0 {
|
|
return 1;
|
|
}
|
|
}
|
|
} else if y1 < point_y {
|
|
let val = (x1 - x0) * (point_y - y0) - (y1 - y0) * (point_x - x0);
|
|
|
|
if val < 0.0 {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
0
|
|
}
|
|
|
|
/// Calculates the winding number for a bezier curve around the given point.
|
|
fn winding_number_curve(
|
|
(point_x, point_y): (Twips, Twips),
|
|
(ax0, ay0): (Twips, Twips),
|
|
(ax1, ay1): (Twips, Twips),
|
|
(ax2, ay2): (Twips, Twips),
|
|
) -> i32 {
|
|
// Intersect a ray on the +x axis with the quadratic bezier.
|
|
//
|
|
// Translate so the test point and ray is at the origin.
|
|
// The ray-curve intersection is solving the quadratic:
|
|
// y_0*(1-t)^2 + y_1*2*t*(1-t) + y_2*t^2 = 0
|
|
|
|
// However, there are two issues:
|
|
// 1) Solving the quadratic needs to be numerically robust, particularly near the endpoints 0.0 and 1.0, and as the curve is tangent to the ray.
|
|
// We use the "Citardauq" method for improved numerical stability.
|
|
// 2) The convention for including/excluding endpoints needs to act similarly to lines, with the initial point included if the curve is "upward",
|
|
// and the final point included if the curve is pointing "downward". This is complicated by the fact that the curve could be tangent to the ray
|
|
// at the endpoint (this is still considered "upward" or "downward" depending on the slope at earlier t).
|
|
// We solve this by splitting the curve into y-monotonic subcurves. This is helpful because
|
|
// a) each subcurve will have 1 intersection with the ray
|
|
// b) if the subcurve surrounds the ray, we know it has an intersection without having to check if t is in [0, 1]
|
|
// c) we know the winding of the segment upward/downward based on which root it contains
|
|
|
|
let x0 = ax0.get() - point_x.get();
|
|
let y0 = ay0.get() - point_y.get();
|
|
let x1 = ax1.get() - point_x.get();
|
|
let y1 = ay1.get() - point_y.get();
|
|
let x2 = ax2.get() - point_x.get();
|
|
let y2 = ay2.get() - point_y.get();
|
|
|
|
// Early exit: all control points out of bounds.
|
|
if (y0 < 0 && y1 < 0 && y2 < 0)
|
|
|| (y0 > 0 && y1 > 0 && y2 > 0)
|
|
|| (x0 <= 0 && x1 <= 0 && x2 <= 0)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
let x0 = x0 as f64;
|
|
let y0 = y0 as f64;
|
|
let x1 = x1 as f64;
|
|
let y1 = y1 as f64;
|
|
let x2 = x2 as f64;
|
|
let y2 = y2 as f64;
|
|
|
|
let a = y0 - 2.0 * y1 + y2;
|
|
let b = 2.0 * (y1 - y0);
|
|
let c = y0;
|
|
|
|
let (t0, t1) = solve_quadratic(a, b, c);
|
|
let is_t0_valid = t0.is_finite();
|
|
let is_t1_valid = t1.is_finite();
|
|
if !is_t0_valid && !is_t1_valid {
|
|
return 0;
|
|
}
|
|
|
|
// Split the curve into two y-monotonic segments.
|
|
let mut winding = 0;
|
|
let ax = x0 - 2.0 * x1 + x2;
|
|
let bx = 2.0 * (x1 - x0);
|
|
let t_extrema = -0.5 * b / a;
|
|
let is_monotonic = t_extrema <= 0.0 || t_extrema >= 1.0;
|
|
if a >= 0.0 {
|
|
// Downward opening parabola.
|
|
let y_min = if is_monotonic {
|
|
y0.min(y2)
|
|
} else {
|
|
a * t_extrema * t_extrema + b * t_extrema + c
|
|
};
|
|
|
|
// First subcurve is moving upward, include initial point.
|
|
if is_t0_valid && y0 >= 0.0 && y_min < 0.0 {
|
|
// If curve point is to the right of the ray origin (x > 0), the ray will hit it.
|
|
// We don't have to check 0 <= t <= 1 check because we've already guaranteed that the subcurve
|
|
// straddles the ray.
|
|
let x = x0 + bx * t0 + ax * t0 * t0;
|
|
if x > 0.0 {
|
|
winding += 1;
|
|
}
|
|
}
|
|
|
|
// Second subcurve is moving downard, include final point.
|
|
if is_t1_valid && y_min < 0.0 && y2 >= 0.0 {
|
|
let x = x0 + bx * t1 + ax * t1 * t1;
|
|
if x > 0.0 {
|
|
winding -= 1;
|
|
}
|
|
}
|
|
} else {
|
|
// Upward opening parabola.
|
|
let y_max = if is_monotonic {
|
|
y0.max(y2)
|
|
} else {
|
|
a * t_extrema * t_extrema + b * t_extrema + c
|
|
};
|
|
|
|
// First subcurve is moving downward, include extrema point.
|
|
if is_t1_valid && y0 < 0.0 && y_max >= 0.0 {
|
|
let x = x0 + bx * t1 + ax * t1 * t1;
|
|
if x > 0.0 {
|
|
winding -= 1;
|
|
}
|
|
}
|
|
|
|
// Second subcurve is moving upward, include extrema point.
|
|
if is_t0_valid && y_max >= 0.0 && y2 < 0.0 {
|
|
let x = x0 + bx * t0 + ax * t0 * t0;
|
|
if x > 0.0 {
|
|
winding += 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
winding
|
|
}
|
|
|
|
const COEFFICIENT_EPSILON: f64 = 0.0000001;
|
|
|
|
/// Returns the roots of the quadratic ax^2 + bx + c = 0.
|
|
/// The roots may not be unique. NAN is returned for invalid roots. The first root will be where
|
|
/// the curve is sloping upward, the second root will be where the curve is slopping downward.
|
|
/// Uses the "Citardauq" formula for numerical stability.
|
|
/// See https://math.stackexchange.com/questions/866331
|
|
fn solve_quadratic(a: f64, b: f64, c: f64) -> (f64, f64) {
|
|
if a.abs() <= COEFFICIENT_EPSILON {
|
|
// Nearly linear, solve as linear equation.
|
|
if b >= 0.0 {
|
|
return (f64::NAN, -c / b);
|
|
} else {
|
|
return (-c / b, f64::NAN);
|
|
}
|
|
}
|
|
let mut disc = b * b - 4.0 * a * c;
|
|
if disc < 0.0 {
|
|
return (f64::NAN, f64::NAN);
|
|
}
|
|
disc = disc.sqrt();
|
|
// Order the roots so that the first root is where the curve slopes upward,
|
|
// and the second root is where the root slopes downward.
|
|
if b >= 0.0 {
|
|
let root0 = (-b - disc) / (2.0 * a);
|
|
let root1 = c / (a * root0);
|
|
(root0, root1)
|
|
} else {
|
|
let root0 = (-b + disc) / (2.0 * a);
|
|
let root1 = c / (a * root0);
|
|
(root1, root0)
|
|
}
|
|
}
|
|
|
|
/// Returns the roots of a cubic polynomial, ax^3 + bx^2 + cx + d = 0
|
|
/// from http://www.cplusplus.com/forum/beginner/234717/
|
|
/// The roots are not necessarily unique.
|
|
/// TODO: This probably isn't numerically robust
|
|
#[allow(clippy::many_single_char_names)]
|
|
fn solve_cubic(a: f64, b: f64, c: f64, d: f64) -> SmallVec<[f64; 3]> {
|
|
let mut roots = SmallVec::new();
|
|
|
|
if a.abs() <= COEFFICIENT_EPSILON {
|
|
// Fall back to quadratic formula.
|
|
let (t0, t1) = solve_quadratic(b, c, d);
|
|
roots.extend_from_slice(&[t0, t1]);
|
|
return roots;
|
|
}
|
|
|
|
// Reduce to a "depressed cubic", x^3 + px + q = 0
|
|
// https://en.wikipedia.org/wiki/Cubic_equation#Cardano's_formula
|
|
let p = (b * b - 3.0 * a * c) / (9.0 * a * a);
|
|
let q = (9.0 * a * b * c - 27.0 * a * a * d - 2.0 * b * b * b) / (54.0 * a * a * a);
|
|
let offset = b / (3.0 * a);
|
|
let disc = p * p * p - q * q;
|
|
|
|
// The discriminant determines the number of real roots.
|
|
if disc > 0.0 {
|
|
let theta = f64::acos(q / (p * f64::sqrt(p)));
|
|
let r = 2.0 * f64::sqrt(p);
|
|
let t0 = r * f64::cos(theta / 3.0) - offset;
|
|
let t1 = r * f64::cos((theta + 2.0 * std::f64::consts::PI) / 3.0) - offset;
|
|
let t2 = r * f64::cos((theta + 4.0 * std::f64::consts::PI) / 3.0) - offset;
|
|
roots.extend([t0, t1, t2]);
|
|
} else {
|
|
let gamma1 = f64::cbrt(q + f64::sqrt(-disc));
|
|
let gamma2 = f64::cbrt(q - f64::sqrt(-disc));
|
|
|
|
let t0 = gamma1 + gamma2 - offset;
|
|
let t1 = -0.5 * (gamma1 + gamma2) - offset;
|
|
roots.push(t0);
|
|
if disc == 0.0 {
|
|
roots.push(t1);
|
|
}
|
|
}
|
|
|
|
roots
|
|
}
|
|
|
|
/// Converts an SWF glyph into an SWF shape, for ease of use by rendering backends.
|
|
pub fn swf_glyph_to_shape(glyph: &swf::Glyph) -> swf::Shape {
|
|
// Per SWF19 p.164, the FontBoundsTable can contain empty bounds for every glyph (reserved).
|
|
// SWF19 says this is true through SWFv7, but it seems like it might be generally true?
|
|
// In any case, we have to be sure to calculate the shape bounds ourselves to make a proper
|
|
// SVG.
|
|
let bounds = glyph
|
|
.bounds
|
|
.clone()
|
|
.filter(|b| b.x_min != b.x_max || b.y_min != b.y_max)
|
|
.unwrap_or_else(|| calculate_shape_bounds(&glyph.shape_records));
|
|
swf::Shape {
|
|
version: 2,
|
|
id: 0,
|
|
shape_bounds: bounds.clone(),
|
|
edge_bounds: bounds,
|
|
flags: swf::ShapeFlag::HAS_SCALING_STROKES,
|
|
styles: swf::ShapeStyles {
|
|
fill_styles: vec![swf::FillStyle::Color(swf::Color {
|
|
r: 255,
|
|
g: 255,
|
|
b: 255,
|
|
a: 255,
|
|
})],
|
|
line_styles: vec![],
|
|
},
|
|
shape: glyph.shape_records.clone(),
|
|
}
|
|
}
|
|
|
|
/// Scale mode used by strokes in a shape.
|
|
///
|
|
/// Determines how the line thickness is affected by the shape's transform.
|
|
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
|
|
pub enum LineScaleMode {
|
|
None = 0,
|
|
Horizontal,
|
|
Vertical,
|
|
Both,
|
|
}
|
|
|
|
/// Helper type for calculating line widths for a transformed shape.
|
|
pub struct LineScales<'a> {
|
|
matrix: &'a Matrix,
|
|
scales: Option<[f32; 4]>,
|
|
}
|
|
|
|
impl<'a> LineScales<'a> {
|
|
/// Create a new line scaler for the given matrix.
|
|
#[inline]
|
|
pub fn new(matrix: &'a Matrix) -> Self {
|
|
Self {
|
|
matrix,
|
|
scales: None,
|
|
}
|
|
}
|
|
|
|
/// Returns the final width of a line after transformation.
|
|
#[inline]
|
|
pub fn transform_width(&mut self, width: f32, scale_mode: LineScaleMode) -> f32 {
|
|
// Lazily calculate the scale to avoid doing so for shapes that have no strokes.
|
|
let scales = self.scales.get_or_insert_with(|| {
|
|
let line_scale_x = f32::abs(self.matrix.a + self.matrix.c);
|
|
let line_scale_y = f32::abs(self.matrix.b + self.matrix.d);
|
|
let line_scale =
|
|
((line_scale_x * line_scale_x + line_scale_y * line_scale_y) / 2.0).sqrt();
|
|
[1.0, line_scale_x, line_scale_y, line_scale]
|
|
});
|
|
let scaled_width = width * scales[scale_mode as usize];
|
|
// Flash draws all strokes with a minimum width of 1 pixel.
|
|
// This usually occurs in "hairline" strokes (exported with width of 1 twip).
|
|
scaled_width.max(1.0)
|
|
}
|
|
}
|