egui/egui/src/widgets/plot/transform.rs
Sven Niederberger 838f3e4ff2
Add plot legends (#349)
* add plot legends

* don't show crosshairs when hovering over legend

* add a toggle for the legend

* changes based on review

* improve legend behavior when curves share names
2021-05-07 10:32:17 +02:00

244 lines
7 KiB
Rust

use std::ops::RangeInclusive;
use super::items::Value;
use crate::*;
/// 2D bounding box of f64 precision.
/// The range of data values we show.
#[derive(Clone, Copy, PartialEq, Debug)]
#[cfg_attr(feature = "persistence", derive(serde::Deserialize, serde::Serialize))]
pub(crate) struct Bounds {
pub min: [f64; 2],
pub max: [f64; 2],
}
impl Bounds {
pub const NOTHING: Self = Self {
min: [f64::INFINITY; 2],
max: [-f64::INFINITY; 2],
};
pub fn new_symmetrical(half_extent: f64) -> Self {
Self {
min: [-half_extent; 2],
max: [half_extent; 2],
}
}
pub fn is_finite(&self) -> bool {
self.min[0].is_finite()
&& self.min[1].is_finite()
&& self.max[0].is_finite()
&& self.max[1].is_finite()
}
pub fn is_valid(&self) -> bool {
self.is_finite() && self.width() > 0.0 && self.height() > 0.0
}
pub fn width(&self) -> f64 {
self.max[0] - self.min[0]
}
pub fn height(&self) -> f64 {
self.max[1] - self.min[1]
}
pub fn extend_with(&mut self, value: &Value) {
self.extend_with_x(value.x);
self.extend_with_y(value.y);
}
/// Expand to include the given x coordinate
pub fn extend_with_x(&mut self, x: f64) {
self.min[0] = self.min[0].min(x);
self.max[0] = self.max[0].max(x);
}
/// Expand to include the given y coordinate
pub fn extend_with_y(&mut self, y: f64) {
self.min[1] = self.min[1].min(y);
self.max[1] = self.max[1].max(y);
}
pub fn expand_x(&mut self, pad: f64) {
self.min[0] -= pad;
self.max[0] += pad;
}
pub fn expand_y(&mut self, pad: f64) {
self.min[1] -= pad;
self.max[1] += pad;
}
pub fn merge(&mut self, other: &Bounds) {
self.min[0] = self.min[0].min(other.min[0]);
self.min[1] = self.min[1].min(other.min[1]);
self.max[0] = self.max[0].max(other.max[0]);
self.max[1] = self.max[1].max(other.max[1]);
}
pub fn translate_x(&mut self, delta: f64) {
self.min[0] += delta;
self.max[0] += delta;
}
pub fn translate_y(&mut self, delta: f64) {
self.min[1] += delta;
self.max[1] += delta;
}
pub fn translate(&mut self, delta: Vec2) {
self.translate_x(delta.x as f64);
self.translate_y(delta.y as f64);
}
pub fn add_relative_margin(&mut self, margin_fraction: Vec2) {
let width = self.width().max(0.0);
let height = self.height().max(0.0);
self.expand_x(margin_fraction.x as f64 * width);
self.expand_y(margin_fraction.y as f64 * height);
}
pub fn range_x(&self) -> RangeInclusive<f64> {
self.min[0]..=self.max[0]
}
pub fn make_x_symmetrical(&mut self) {
let x_abs = self.min[0].abs().max(self.max[0].abs());
self.min[0] = -x_abs;
self.max[0] = x_abs;
}
pub fn make_y_symmetrical(&mut self) {
let y_abs = self.min[1].abs().max(self.max[1].abs());
self.min[1] = -y_abs;
self.max[1] = y_abs;
}
}
/// Contains the screen rectangle and the plot bounds and provides methods to transform them.
#[derive(Clone)]
pub(crate) struct ScreenTransform {
/// The screen rectangle.
frame: Rect,
/// The plot bounds.
bounds: Bounds,
/// Whether to always center the x-range of the bounds.
x_centered: bool,
/// Whether to always center the y-range of the bounds.
y_centered: bool,
}
impl ScreenTransform {
pub fn new(frame: Rect, bounds: Bounds, x_centered: bool, y_centered: bool) -> Self {
Self {
frame,
bounds,
x_centered,
y_centered,
}
}
pub fn frame(&self) -> &Rect {
&self.frame
}
pub fn bounds(&self) -> &Bounds {
&self.bounds
}
pub fn translate_bounds(&mut self, mut delta_pos: Vec2) {
if self.x_centered {
delta_pos.x = 0.;
}
if self.y_centered {
delta_pos.y = 0.;
}
delta_pos.x *= self.dvalue_dpos()[0] as f32;
delta_pos.y *= self.dvalue_dpos()[1] as f32;
self.bounds.translate(delta_pos);
}
/// Zoom by a relative factor with the given screen position as center.
pub fn zoom(&mut self, zoom_factor: f32, center: Pos2) {
let zoom_factor = zoom_factor as f64;
let center = self.value_from_position(center);
let mut new_bounds = self.bounds;
new_bounds.min[0] = center.x + (new_bounds.min[0] - center.x) / zoom_factor;
new_bounds.max[0] = center.x + (new_bounds.max[0] - center.x) / zoom_factor;
new_bounds.min[1] = center.y + (new_bounds.min[1] - center.y) / zoom_factor;
new_bounds.max[1] = center.y + (new_bounds.max[1] - center.y) / zoom_factor;
if new_bounds.is_valid() {
self.bounds = new_bounds;
}
}
pub fn position_from_value(&self, value: &Value) -> Pos2 {
let x = remap(
value.x,
self.bounds.min[0]..=self.bounds.max[0],
(self.frame.left() as f64)..=(self.frame.right() as f64),
);
let y = remap(
value.y,
self.bounds.min[1]..=self.bounds.max[1],
(self.frame.bottom() as f64)..=(self.frame.top() as f64), // negated y axis!
);
pos2(x as f32, y as f32)
}
pub fn value_from_position(&self, pos: Pos2) -> Value {
let x = remap(
pos.x as f64,
(self.frame.left() as f64)..=(self.frame.right() as f64),
self.bounds.min[0]..=self.bounds.max[0],
);
let y = remap(
pos.y as f64,
(self.frame.bottom() as f64)..=(self.frame.top() as f64), // negated y axis!
self.bounds.min[1]..=self.bounds.max[1],
);
Value::new(x, y)
}
/// delta position / delta value
pub fn dpos_dvalue_x(&self) -> f64 {
self.frame.width() as f64 / self.bounds.width()
}
/// delta position / delta value
pub fn dpos_dvalue_y(&self) -> f64 {
-self.frame.height() as f64 / self.bounds.height() // negated y axis!
}
/// delta position / delta value
pub fn dpos_dvalue(&self) -> [f64; 2] {
[self.dpos_dvalue_x(), self.dpos_dvalue_y()]
}
/// delta value / delta position
pub fn dvalue_dpos(&self) -> [f64; 2] {
[1.0 / self.dpos_dvalue_x(), 1.0 / self.dpos_dvalue_y()]
}
pub fn get_aspect(&self) -> f64 {
let rw = self.frame.width() as f64;
let rh = self.frame.height() as f64;
(self.bounds.width() / rw) / (self.bounds.height() / rh)
}
pub fn set_aspect(&mut self, aspect: f64) {
let epsilon = 1e-5;
let current_aspect = self.get_aspect();
if current_aspect < aspect - epsilon {
self.bounds
.expand_x((aspect / current_aspect - 1.0) * self.bounds.width() * 0.5);
} else if current_aspect > aspect + epsilon {
self.bounds
.expand_y((current_aspect / aspect - 1.0) * self.bounds.height() * 0.5);
}
}
}