2022-03-03 09:14:22 -05:00

232 lines
7.9 KiB
Rust

#![allow(clippy::too_many_arguments)] // Clippy, shut
#[allow(unused_imports)]
use crate::misc::debug_log;
use eframe::egui::{
plot::{BarChart, Line, Value, Values},
widgets::plot::Bar,
};
use meval::Expr;
use std::fmt::{self, Debug};
#[derive(PartialEq, Debug, Copy, Clone)]
pub enum RiemannSum {
Left,
Middle,
Right,
}
impl fmt::Display for RiemannSum {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{:?}", self) }
}
pub struct Function {
function: Box<dyn Fn(f64) -> f64>,
func_str: String,
min_x: f64,
max_x: f64,
pixel_width: usize,
back_cache: Option<Vec<Value>>,
front_cache: Option<(Vec<Bar>, f64)>,
pub(crate) integral: bool,
integral_min_x: f64,
integral_max_x: f64,
integral_num: usize,
sum: RiemannSum,
}
fn default_function(x: f64) -> f64 { x.powi(2) }
impl Function {
// Creates Empty Function instance
pub fn empty() -> Self {
Self {
function: Box::new(default_function),
func_str: String::new(),
min_x: -1.0,
max_x: 1.0,
pixel_width: 100,
back_cache: None,
front_cache: None,
integral: false,
integral_min_x: f64::NAN,
integral_max_x: f64::NAN,
integral_num: 0,
sum: crate::egui_app::DEFAULT_RIEMANN,
}
}
// Runs the internal function to get values
fn run_func(&self, x: f64) -> f64 { (self.function)(x) }
pub fn update(
&mut self, func_str: String, integral: bool, integral_min_x: Option<f64>,
integral_max_x: Option<f64>, integral_num: Option<usize>, sum: Option<RiemannSum>,
) {
// If the function string changes, just wipe and restart from scratch
if func_str != self.func_str {
self.func_str = func_str.clone();
self.function = Box::new({
let expr: Expr = func_str.parse().unwrap();
expr.bind("x").unwrap()
});
self.back_cache = None;
self.front_cache = None;
}
self.integral = integral;
// Makes sure proper arguments are passed when integral is enabled
if integral
&& (integral_min_x != Some(self.integral_min_x))
| (integral_max_x != Some(self.integral_max_x))
| (integral_num != Some(self.integral_num))
| (sum != Some(self.sum))
{
self.front_cache = None;
self.integral_min_x = integral_min_x.expect("integral_min_x is None");
self.integral_max_x = integral_max_x.expect("integral_max_x is None");
self.integral_num = integral_num.expect("integral_num is None");
self.sum = sum.expect("sum is None");
}
}
pub fn update_bounds(&mut self, min_x: f64, max_x: f64, pixel_width: usize) {
if pixel_width != self.pixel_width {
self.back_cache = None;
self.min_x = min_x;
self.max_x = max_x;
self.pixel_width = pixel_width;
} else if ((min_x != self.min_x) | (max_x != self.max_x)) && self.back_cache.is_some() {
let resolution: f64 = self.pixel_width as f64 / (max_x.abs() + min_x.abs());
let back_cache = self.back_cache.as_ref().unwrap();
let x_data: Vec<f64> = back_cache.iter().map(|ele| ele.x).collect();
self.back_cache = Some(
(0..=self.pixel_width)
.map(|x| (x as f64 / resolution as f64) + min_x)
.map(|x| {
// If x is outside of previous bounds, just go ahead and just skip searching for the index
if (x < self.min_x) | (self.max_x < x) {
return Value::new(x, self.run_func(x));
}
let i_option = x_data.iter().position(|&r| r == x); // Optimize this later, this could be done much much better, but tbh it doesn't matter that much as the program is already super fast
if let Some(i) = i_option {
back_cache[i]
} else {
Value::new(x, self.run_func(x))
}
})
.collect(),
);
} else {
self.back_cache = None;
self.min_x = min_x;
self.max_x = max_x;
self.pixel_width = pixel_width;
}
}
pub fn run(&mut self) -> (Line, Option<(BarChart, f64)>) {
let back_values: Line = Line::new(Values::from_values({
if self.back_cache.is_none() {
let resolution: f64 =
(self.pixel_width as f64 / (self.max_x - self.min_x).abs()) as f64;
self.back_cache = Some(
(0..=self.pixel_width)
.map(|x| (x as f64 / resolution as f64) + self.min_x)
.map(|x| Value::new(x, self.run_func(x)))
.collect(),
);
}
self.back_cache.as_ref().unwrap().clone()
}));
match self.integral {
true => {
let front_bars: (BarChart, f64) = {
if self.front_cache.is_none() {
let (data, area) = self.integral_rectangles();
self.front_cache =
Some((data.iter().map(|(x, y)| Bar::new(*x, *y)).collect(), area));
}
let cache = self.front_cache.as_ref().unwrap();
(BarChart::new(cache.0.clone()), cache.1)
};
(back_values, Some(front_bars))
}
false => (back_values, None),
}
}
// Creates and does the math for creating all the rectangles under the graph
fn integral_rectangles(&self) -> (Vec<(f64, f64)>, f64) {
if self.integral_min_x.is_nan() {
panic!("integral_min_x is NaN")
} else if self.integral_max_x.is_nan() {
panic!("integral_max_x is NaN")
}
let step = (self.integral_min_x - self.integral_max_x).abs() / (self.integral_num as f64);
let half_step = step / 2.0;
let data2: Vec<(f64, f64)> = (0..self.integral_num)
.map(|e| {
let x: f64 = ((e as f64) * step) + self.integral_min_x;
let x2: f64 = match x.is_sign_positive() {
true => x + step,
false => x - step,
};
let (left_x, right_x) = match x.is_sign_positive() {
true => (x, x2),
false => (x2, x),
};
(
match x.is_sign_positive() {
true => x + half_step,
false => x - half_step,
},
match self.sum {
RiemannSum::Left => self.run_func(left_x),
RiemannSum::Right => self.run_func(right_x),
RiemannSum::Middle => {
(self.run_func(left_x) + self.run_func(right_x)) / 2.0
}
},
)
})
.filter(|(_, y)| !y.is_nan())
.collect();
let area: f64 = data2.iter().map(|(_, y)| y * step).sum(); // sum of all rectangles' areas
(data2, area)
}
// Set func_str to an empty string
pub fn empty_func_str(&mut self) { self.func_str = String::new(); }
// Updates riemann value and invalidates front_cache if needed
pub fn update_riemann(mut self, riemann: RiemannSum) -> Self {
if self.sum != riemann {
self.sum = riemann;
self.front_cache = None;
}
self
}
// Toggles integral
pub fn integral(mut self, integral: bool) -> Self {
self.integral = integral;
self
}
}