egui/crates/epaint/src/shapes/shape.rs

563 lines
18 KiB
Rust

//! The different shapes that can be painted.
use std::sync::Arc;
use emath::{pos2, Align2, Pos2, Rangef, Rect, TSTransform, Vec2};
use crate::{
stroke::PathStroke,
text::{FontId, Fonts, Galley},
Color32, Mesh, Rounding, Stroke, TextureId,
};
use super::{
CircleShape, CubicBezierShape, EllipseShape, PaintCallback, PathShape, QuadraticBezierShape,
RectShape, TextShape,
};
/// A paint primitive such as a circle or a piece of text.
/// Coordinates are all screen space points (not physical pixels).
///
/// You should generally recreate your [`Shape`]s each frame,
/// but storing them should also be fine with one exception:
/// [`Shape::Text`] depends on the current `pixels_per_point` (dpi scale)
/// and so must be recreated every time `pixels_per_point` changes.
#[must_use = "Add a Shape to a Painter"]
#[derive(Clone, Debug, PartialEq)]
pub enum Shape {
/// Paint nothing. This can be useful as a placeholder.
Noop,
/// Recursively nest more shapes - sometimes a convenience to be able to do.
/// For performance reasons it is better to avoid it.
Vec(Vec<Shape>),
/// Circle with optional outline and fill.
Circle(CircleShape),
/// Ellipse with optional outline and fill.
Ellipse(EllipseShape),
/// A line between two points.
LineSegment { points: [Pos2; 2], stroke: Stroke },
/// A series of lines between points.
/// The path can have a stroke and/or fill (if closed).
Path(PathShape),
/// Rectangle with optional outline and fill.
Rect(RectShape),
/// Text.
///
/// This needs to be recreated if `pixels_per_point` (dpi scale) changes.
Text(TextShape),
/// A general triangle mesh.
///
/// Can be used to display images.
///
/// Wrapped in an [`Arc`] to minimize the size of [`Shape`].
Mesh(Arc<Mesh>),
/// A quadratic [Bézier Curve](https://en.wikipedia.org/wiki/B%C3%A9zier_curve).
QuadraticBezier(QuadraticBezierShape),
/// A cubic [Bézier Curve](https://en.wikipedia.org/wiki/B%C3%A9zier_curve).
CubicBezier(CubicBezierShape),
/// Backend-specific painting.
Callback(PaintCallback),
}
#[test]
fn shape_size() {
assert_eq!(
std::mem::size_of::<Shape>(), 64,
"Shape changed size! If it shrank - good! Update this test. If it grew - bad! Try to find a way to avoid it."
);
assert!(
std::mem::size_of::<Shape>() <= 64,
"Shape is getting way too big!"
);
}
#[test]
fn shape_impl_send_sync() {
fn assert_send_sync<T: Send + Sync>() {}
assert_send_sync::<Shape>();
}
impl From<Vec<Self>> for Shape {
#[inline(always)]
fn from(shapes: Vec<Self>) -> Self {
Self::Vec(shapes)
}
}
impl From<Mesh> for Shape {
#[inline(always)]
fn from(mesh: Mesh) -> Self {
Self::Mesh(mesh.into())
}
}
impl From<Arc<Mesh>> for Shape {
#[inline(always)]
fn from(mesh: Arc<Mesh>) -> Self {
Self::Mesh(mesh)
}
}
/// ## Constructors
impl Shape {
/// A line between two points.
/// More efficient than calling [`Self::line`].
#[inline]
pub fn line_segment(points: [Pos2; 2], stroke: impl Into<Stroke>) -> Self {
Self::LineSegment {
points,
stroke: stroke.into(),
}
}
/// A horizontal line.
pub fn hline(x: impl Into<Rangef>, y: f32, stroke: impl Into<Stroke>) -> Self {
let x = x.into();
Self::LineSegment {
points: [pos2(x.min, y), pos2(x.max, y)],
stroke: stroke.into(),
}
}
/// A vertical line.
pub fn vline(x: f32, y: impl Into<Rangef>, stroke: impl Into<Stroke>) -> Self {
let y = y.into();
Self::LineSegment {
points: [pos2(x, y.min), pos2(x, y.max)],
stroke: stroke.into(),
}
}
/// A line through many points.
///
/// Use [`Self::line_segment`] instead if your line only connects two points.
#[inline]
pub fn line(points: Vec<Pos2>, stroke: impl Into<PathStroke>) -> Self {
Self::Path(PathShape::line(points, stroke))
}
/// A line that closes back to the start point again.
#[inline]
pub fn closed_line(points: Vec<Pos2>, stroke: impl Into<PathStroke>) -> Self {
Self::Path(PathShape::closed_line(points, stroke))
}
/// Turn a line into equally spaced dots.
pub fn dotted_line(
path: &[Pos2],
color: impl Into<Color32>,
spacing: f32,
radius: f32,
) -> Vec<Self> {
let mut shapes = Vec::new();
points_from_line(path, spacing, radius, color.into(), &mut shapes);
shapes
}
/// Turn a line into dashes.
pub fn dashed_line(
path: &[Pos2],
stroke: impl Into<Stroke>,
dash_length: f32,
gap_length: f32,
) -> Vec<Self> {
let mut shapes = Vec::new();
dashes_from_line(
path,
stroke.into(),
&[dash_length],
&[gap_length],
&mut shapes,
0.,
);
shapes
}
/// Turn a line into dashes with different dash/gap lengths and a start offset.
pub fn dashed_line_with_offset(
path: &[Pos2],
stroke: impl Into<Stroke>,
dash_lengths: &[f32],
gap_lengths: &[f32],
dash_offset: f32,
) -> Vec<Self> {
let mut shapes = Vec::new();
dashes_from_line(
path,
stroke.into(),
dash_lengths,
gap_lengths,
&mut shapes,
dash_offset,
);
shapes
}
/// Turn a line into dashes. If you need to create many dashed lines use this instead of
/// [`Self::dashed_line`].
pub fn dashed_line_many(
points: &[Pos2],
stroke: impl Into<Stroke>,
dash_length: f32,
gap_length: f32,
shapes: &mut Vec<Self>,
) {
dashes_from_line(
points,
stroke.into(),
&[dash_length],
&[gap_length],
shapes,
0.,
);
}
/// Turn a line into dashes with different dash/gap lengths and a start offset. If you need to
/// create many dashed lines use this instead of [`Self::dashed_line_with_offset`].
pub fn dashed_line_many_with_offset(
points: &[Pos2],
stroke: impl Into<Stroke>,
dash_lengths: &[f32],
gap_lengths: &[f32],
dash_offset: f32,
shapes: &mut Vec<Self>,
) {
dashes_from_line(
points,
stroke.into(),
dash_lengths,
gap_lengths,
shapes,
dash_offset,
);
}
/// A convex polygon with a fill and optional stroke.
///
/// The most performant winding order is clockwise.
#[inline]
pub fn convex_polygon(
points: Vec<Pos2>,
fill: impl Into<Color32>,
stroke: impl Into<PathStroke>,
) -> Self {
Self::Path(PathShape::convex_polygon(points, fill, stroke))
}
#[inline]
pub fn circle_filled(center: Pos2, radius: f32, fill_color: impl Into<Color32>) -> Self {
Self::Circle(CircleShape::filled(center, radius, fill_color))
}
#[inline]
pub fn circle_stroke(center: Pos2, radius: f32, stroke: impl Into<Stroke>) -> Self {
Self::Circle(CircleShape::stroke(center, radius, stroke))
}
#[inline]
pub fn ellipse_filled(center: Pos2, radius: Vec2, fill_color: impl Into<Color32>) -> Self {
Self::Ellipse(EllipseShape::filled(center, radius, fill_color))
}
#[inline]
pub fn ellipse_stroke(center: Pos2, radius: Vec2, stroke: impl Into<Stroke>) -> Self {
Self::Ellipse(EllipseShape::stroke(center, radius, stroke))
}
#[inline]
pub fn rect_filled(
rect: Rect,
rounding: impl Into<Rounding>,
fill_color: impl Into<Color32>,
) -> Self {
Self::Rect(RectShape::filled(rect, rounding, fill_color))
}
/// The stroke extends _outside_ the [`Rect`].
#[inline]
pub fn rect_stroke(
rect: Rect,
rounding: impl Into<Rounding>,
stroke: impl Into<Stroke>,
) -> Self {
Self::Rect(RectShape::stroke(rect, rounding, stroke))
}
#[allow(clippy::needless_pass_by_value)]
pub fn text(
fonts: &Fonts,
pos: Pos2,
anchor: Align2,
text: impl ToString,
font_id: FontId,
color: Color32,
) -> Self {
let galley = fonts.layout_no_wrap(text.to_string(), font_id, color);
let rect = anchor.anchor_size(pos, galley.size());
Self::galley(rect.min, galley, color)
}
/// Any uncolored parts of the [`Galley`] (using [`Color32::PLACEHOLDER`]) will be replaced with the given color.
///
/// Any non-placeholder color in the galley takes precedence over this fallback color.
#[inline]
pub fn galley(pos: Pos2, galley: Arc<Galley>, fallback_color: Color32) -> Self {
TextShape::new(pos, galley, fallback_color).into()
}
/// All text color in the [`Galley`] will be replaced with the given color.
#[inline]
pub fn galley_with_override_text_color(
pos: Pos2,
galley: Arc<Galley>,
text_color: Color32,
) -> Self {
TextShape::new(pos, galley, text_color)
.with_override_text_color(text_color)
.into()
}
#[inline]
#[deprecated = "Use `Shape::galley` or `Shape::galley_with_override_text_color` instead"]
pub fn galley_with_color(pos: Pos2, galley: Arc<Galley>, text_color: Color32) -> Self {
Self::galley_with_override_text_color(pos, galley, text_color)
}
#[inline]
pub fn mesh(mesh: impl Into<Arc<Mesh>>) -> Self {
let mesh = mesh.into();
debug_assert!(mesh.is_valid());
Self::Mesh(mesh)
}
/// An image at the given position.
///
/// `uv` should normally be `Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0))`
/// unless you want to crop or flip the image.
///
/// `tint` is a color multiplier. Use [`Color32::WHITE`] if you don't want to tint the image.
pub fn image(texture_id: TextureId, rect: Rect, uv: Rect, tint: Color32) -> Self {
let mut mesh = Mesh::with_texture(texture_id);
mesh.add_rect_with_uv(rect, uv, tint);
Self::mesh(mesh)
}
/// The visual bounding rectangle (includes stroke widths)
pub fn visual_bounding_rect(&self) -> Rect {
match self {
Self::Noop => Rect::NOTHING,
Self::Vec(shapes) => {
let mut rect = Rect::NOTHING;
for shape in shapes {
rect = rect.union(shape.visual_bounding_rect());
}
rect
}
Self::Circle(circle_shape) => circle_shape.visual_bounding_rect(),
Self::Ellipse(ellipse_shape) => ellipse_shape.visual_bounding_rect(),
Self::LineSegment { points, stroke } => {
if stroke.is_empty() {
Rect::NOTHING
} else {
Rect::from_two_pos(points[0], points[1]).expand(stroke.width / 2.0)
}
}
Self::Path(path_shape) => path_shape.visual_bounding_rect(),
Self::Rect(rect_shape) => rect_shape.visual_bounding_rect(),
Self::Text(text_shape) => text_shape.visual_bounding_rect(),
Self::Mesh(mesh) => mesh.calc_bounds(),
Self::QuadraticBezier(bezier) => bezier.visual_bounding_rect(),
Self::CubicBezier(bezier) => bezier.visual_bounding_rect(),
Self::Callback(custom) => custom.rect,
}
}
}
/// ## Inspection and transforms
impl Shape {
#[inline(always)]
pub fn texture_id(&self) -> crate::TextureId {
if let Self::Mesh(mesh) = self {
mesh.texture_id
} else if let Self::Rect(rect_shape) = self {
rect_shape.fill_texture_id()
} else {
crate::TextureId::default()
}
}
/// Scale the shape by `factor`, in-place.
///
/// A wrapper around [`Self::transform`].
#[inline(always)]
pub fn scale(&mut self, factor: f32) {
self.transform(TSTransform::from_scaling(factor));
}
/// Move the shape by `delta`, in-place.
///
/// A wrapper around [`Self::transform`].
#[inline(always)]
pub fn translate(&mut self, delta: Vec2) {
self.transform(TSTransform::from_translation(delta));
}
/// Move the shape by this many points, in-place.
///
/// If using a [`PaintCallback`], note that only the rect is scaled as opposed
/// to other shapes where the stroke is also scaled.
pub fn transform(&mut self, transform: TSTransform) {
match self {
Self::Noop => {}
Self::Vec(shapes) => {
for shape in shapes {
shape.transform(transform);
}
}
Self::Circle(circle_shape) => {
circle_shape.center = transform * circle_shape.center;
circle_shape.radius *= transform.scaling;
circle_shape.stroke.width *= transform.scaling;
}
Self::Ellipse(ellipse_shape) => {
ellipse_shape.center = transform * ellipse_shape.center;
ellipse_shape.radius *= transform.scaling;
ellipse_shape.stroke.width *= transform.scaling;
}
Self::LineSegment { points, stroke } => {
for p in points {
*p = transform * *p;
}
stroke.width *= transform.scaling;
}
Self::Path(path_shape) => {
for p in &mut path_shape.points {
*p = transform * *p;
}
path_shape.stroke.width *= transform.scaling;
}
Self::Rect(rect_shape) => {
rect_shape.rect = transform * rect_shape.rect;
rect_shape.stroke.width *= transform.scaling;
rect_shape.rounding *= transform.scaling;
}
Self::Text(text_shape) => {
text_shape.pos = transform * text_shape.pos;
// Scale text:
let galley = Arc::make_mut(&mut text_shape.galley);
for row in &mut galley.rows {
row.visuals.mesh_bounds = transform.scaling * row.visuals.mesh_bounds;
for v in &mut row.visuals.mesh.vertices {
v.pos = Pos2::new(transform.scaling * v.pos.x, transform.scaling * v.pos.y);
}
}
galley.mesh_bounds = transform.scaling * galley.mesh_bounds;
galley.rect = transform.scaling * galley.rect;
}
Self::Mesh(mesh) => {
Arc::make_mut(mesh).transform(transform);
}
Self::QuadraticBezier(bezier_shape) => {
bezier_shape.points[0] = transform * bezier_shape.points[0];
bezier_shape.points[1] = transform * bezier_shape.points[1];
bezier_shape.points[2] = transform * bezier_shape.points[2];
bezier_shape.stroke.width *= transform.scaling;
}
Self::CubicBezier(cubic_curve) => {
for p in &mut cubic_curve.points {
*p = transform * *p;
}
cubic_curve.stroke.width *= transform.scaling;
}
Self::Callback(shape) => {
shape.rect = transform * shape.rect;
}
}
}
}
// ----------------------------------------------------------------------------
/// Creates equally spaced filled circles from a line.
fn points_from_line(
path: &[Pos2],
spacing: f32,
radius: f32,
color: Color32,
shapes: &mut Vec<Shape>,
) {
let mut position_on_segment = 0.0;
path.windows(2).for_each(|window| {
let (start, end) = (window[0], window[1]);
let vector = end - start;
let segment_length = vector.length();
while position_on_segment < segment_length {
let new_point = start + vector * (position_on_segment / segment_length);
shapes.push(Shape::circle_filled(new_point, radius, color));
position_on_segment += spacing;
}
position_on_segment -= segment_length;
});
}
/// Creates dashes from a line.
fn dashes_from_line(
path: &[Pos2],
stroke: Stroke,
dash_lengths: &[f32],
gap_lengths: &[f32],
shapes: &mut Vec<Shape>,
dash_offset: f32,
) {
assert_eq!(dash_lengths.len(), gap_lengths.len());
let mut position_on_segment = dash_offset;
let mut drawing_dash = false;
let mut step = 0;
let steps = dash_lengths.len();
path.windows(2).for_each(|window| {
let (start, end) = (window[0], window[1]);
let vector = end - start;
let segment_length = vector.length();
let mut start_point = start;
while position_on_segment < segment_length {
let new_point = start + vector * (position_on_segment / segment_length);
if drawing_dash {
// This is the end point.
shapes.push(Shape::line_segment([start_point, new_point], stroke));
position_on_segment += gap_lengths[step];
// Increment step counter
step += 1;
if step >= steps {
step = 0;
}
} else {
// Start a new dash.
start_point = new_point;
position_on_segment += dash_lengths[step];
}
drawing_dash = !drawing_dash;
}
// If the segment ends and the dash is not finished, add the segment's end point.
if drawing_dash {
shapes.push(Shape::line_segment([start_point, end], stroke));
}
position_on_segment -= segment_length;
});
}