implement intesections + misc function options

TODO.md

@@ -1,14 +1,8 @@
 ## TODO:
 1. Function management
 	- Integrals between functions (too hard to implement, maybe will shelve)
-	- Display intersection between functions (would have to rewrite a lot of the function plotting handling)
-	- [Drag and drop support](https://github.com/emilk/egui/discussions/1530) in the UI to re-order functions
-	- Hide/disable functions
 	- Prevent user from making too many function entries
-	- Display function errors as tooltips or a warning box (not preventing the display of the graph)
-	- Clone functions
 2. Smart display of graph
-	- Display of intersections between functions
 3. Allow constants in min/max integral input (like pi or euler's number)
 4. Sliding values for functions (like a user-interactable slider that adjusts a variable in the function, like desmos)
 5. Fix integral display

build.rs

@@ -131,7 +131,12 @@ fn main() {
                 "emoji-icon-font".to_owned(),
                 Arc::new(
                     FontData::from_owned(
-                        font_stripper("emoji-icon-font.ttf", "emoji-icon.ttf", vec!['⚙']).unwrap(),
+                        font_stripper(
+                            "emoji-icon-font.ttf",
+                            "emoji-icon.ttf",
+                            vec!['⚙', '⎘', '👁', '○', '⬆', '⬇', '⚠'],
+                        )
+                        .unwrap(),
                     )
                     .tweak(FontTweak {
                         scale: 0.8,

src/function_entry.rs

@@ -45,6 +45,9 @@ pub struct FunctionEntry {
 
     pub nth_derviative: bool,
 
+    /// If the function is visible on the graph
+    pub visible: bool,
+
     pub back_data: Vec<PlotPoint>,
     pub integral_data: Option<(Vec<Bar>, f64)>,
     pub derivative_data: Vec<PlotPoint>,
@@ -67,6 +70,7 @@ impl Hash for FunctionEntry {
         self.nth_derviative.hash(state);
         self.curr_nth.hash(state);
         self.settings_opened.hash(state);
+        self.visible.hash(state);
     }
 }
 
@@ -75,11 +79,12 @@ impl Serialize for FunctionEntry {
     where
         S: Serializer,
     {
-        let mut s = serializer.serialize_struct("FunctionEntry", 4)?;
+        let mut s = serializer.serialize_struct("FunctionEntry", 5)?;
         s.serialize_field("raw_func_str", &self.raw_func_str)?;
         s.serialize_field("integral", &self.integral)?;
         s.serialize_field("derivative", &self.derivative)?;
         s.serialize_field("curr_nth", &self.curr_nth)?;
+        s.serialize_field("visible", &self.visible)?;
 
         s.end()
     }
@@ -96,6 +101,12 @@ impl<'de> Deserialize<'de> for FunctionEntry {
             integral: bool,
             derivative: bool,
             curr_nth: usize,
+            #[serde(default = "default_visible")]
+            visible: bool,
+        }
+
+        fn default_visible() -> bool {
+            true
         }
 
         let helper = Helper::deserialize(deserializer)?;
@@ -115,6 +126,7 @@ impl<'de> Deserialize<'de> for FunctionEntry {
         new_func_entry.integral = helper.integral;
         new_func_entry.derivative = helper.derivative;
         new_func_entry.curr_nth = helper.curr_nth;
+        new_func_entry.visible = helper.visible;
 
         Ok(new_func_entry)
     }
@@ -129,6 +141,7 @@ impl Default for FunctionEntry {
             integral: false,
             derivative: false,
             nth_derviative: false,
+            visible: true,
             back_data: Vec::new(),
             integral_data: None,
             derivative_data: Vec::new(),
@@ -374,7 +387,7 @@ impl FunctionEntry {
         settings: &AppSettings,
         main_plot_color: Color32,
     ) -> Option<f64> {
-        if self.test_result.is_some() | self.function.is_none() {
+        if self.test_result.is_some() | self.function.is_none() | !self.visible {
             return None;
         }
 

src/function_manager.rs

@@ -86,9 +86,14 @@ impl FunctionManager {
         let initial_hash = self.get_hash();
 
         let can_remove = self.functions.len() > 1;
+        let can_add = self.functions.len() < COLORS.len();
+        let num_functions = self.functions.len();
 
         let available_width = ui.available_width();
         let mut remove_i: Option<usize> = None;
+        let mut clone_i: Option<usize> = None;
+        let mut move_up_i: Option<usize> = None;
+        let mut move_down_i: Option<usize> = None;
         let target_size = vec2(available_width, crate::consts::FONT_SIZE);
         for (i, (te_id, function)) in self.functions.iter_mut().map(|(a, b)| (*a, b)).enumerate() {
             let mut new_string = function.autocomplete.string.clone();
@@ -116,6 +121,19 @@ impl FunctionManager {
             // Only keep valid chars
             new_string.retain(crate::misc::is_valid_char);
 
+            // Display error indicator with tooltip if there's a parsing error
+            if let Some(error) = function.get_test_result() {
+                ui.horizontal(|ui| {
+                    ui.label(egui::RichText::new("⚠").color(egui::Color32::YELLOW))
+                        .on_hover_text(error);
+                    ui.label(
+                        egui::RichText::new(error)
+                            .color(egui::Color32::LIGHT_RED)
+                            .small(),
+                    );
+                });
+            }
+
             // If not fully open, return here as buttons cannot yet be displayed, therefore the user is inable to mark it for deletion
             let animate_bool = ui.ctx().animate_bool(te_id, re.has_focus());
             if animate_bool == 1.0 {
@@ -197,6 +215,47 @@ impl FunctionManager {
                             remove_i = Some(i);
                         }
 
+                        // Toggle visibility
+                        function.visible.bitxor_assign(
+                            ui.add(button_area_button(if function.visible {
+                                "👁"
+                            } else {
+                                "○"
+                            }))
+                            .on_hover_text(match function.visible {
+                                true => "Hide Function",
+                                false => "Show Function",
+                            })
+                            .clicked(),
+                        );
+
+                        // Clone function
+                        if ui
+                            .add_enabled(can_add, button_area_button("⎘"))
+                            .on_hover_text("Clone Function")
+                            .clicked()
+                        {
+                            clone_i = Some(i);
+                        }
+
+                        // Move up (only if not first)
+                        if ui
+                            .add_enabled(i > 0, button_area_button("⬆"))
+                            .on_hover_text("Move Up")
+                            .clicked()
+                        {
+                            move_up_i = Some(i);
+                        }
+
+                        // Move down (only if not last)
+                        if ui
+                            .add_enabled(i < num_functions - 1, button_area_button("⬇"))
+                            .on_hover_text("Move Down")
+                            .clicked()
+                        {
+                            move_down_i = Some(i);
+                        }
+
                         ui.add_enabled_ui(function.is_some(), |ui| {
                             // Toggle integral being enabled or not
                             function.integral.bitxor_assign(
@@ -240,6 +299,26 @@ impl FunctionManager {
             self.functions.remove(remove_i_unwrap);
         }
 
+        // Clone function if the user requests it
+        if let Some(clone_i_unwrap) = clone_i {
+            let cloned = self.functions[clone_i_unwrap].1.clone();
+            self.push_cloned(cloned);
+        }
+
+        // Move function up if the user requests it
+        if let Some(i) = move_up_i
+            && i > 0
+        {
+            self.functions.swap(i, i - 1);
+        }
+
+        // Move function down if the user requests it
+        if let Some(i) = move_down_i
+            && i < self.functions.len() - 1
+        {
+            self.functions.swap(i, i + 1);
+        }
+
         let final_hash = self.get_hash();
 
         initial_hash != final_hash
@@ -253,6 +332,16 @@ impl FunctionManager {
         ));
     }
 
+    /// Push a cloned function entry
+    pub fn push_cloned(&mut self, mut entry: FunctionEntry) {
+        // Reset settings_opened so the cloned function doesn't have settings open
+        entry.settings_opened = false;
+        self.functions.push((
+            create_id(random_u64().expect("unable to generate random id")),
+            entry,
+        ));
+    }
+
     /// Detect if any functions are using integrals
     pub fn any_using_integral(&self) -> bool {
         self.functions.iter().any(|(_, func)| func.integral)

src/math_app.rs

@@ -2,7 +2,7 @@ use crate::{
     consts::{BUILD_INFO, COLORS, DEFAULT_INTEGRAL_NUM, DEFAULT_MAX_X, DEFAULT_MIN_X, build},
     function_entry::Riemann,
     function_manager::FunctionManager,
-    misc::option_vec_printer,
+    misc::{EguiHelper, find_intersections, option_vec_printer},
 };
 use eframe::App;
 use egui::{
@@ -13,7 +13,7 @@ use egui_plot::Plot;
 
 use emath::{Align, Align2};
 use epaint::{CornerRadius, Margin};
-use itertools::Itertools;
+
 use std::{io::Read, ops::BitXorAssign};
 use web_time::Instant;
 
@@ -47,6 +47,9 @@ pub struct AppSettings {
     /// Stores whether or not displaying roots is enabled
     pub do_roots: bool,
 
+    /// Stores whether or not displaying intersections between functions is enabled
+    pub do_intersections: bool,
+
     /// Stores current plot pixel width
     pub plot_width: usize,
 }
@@ -64,6 +67,7 @@ impl Default for AppSettings {
             integral_num: DEFAULT_INTEGRAL_NUM,
             do_extrema: true,
             do_roots: true,
+            do_intersections: true,
             plot_width: 0,
         }
     }
@@ -108,6 +112,9 @@ pub struct MathApp {
 
     /// Stores settings (pretty self-explanatory)
     settings: AppSettings,
+
+    /// Stores intersection points between functions
+    intersections: Vec<egui_plot::PlotPoint>,
 }
 
 #[cfg(target_arch = "wasm32")]
@@ -246,6 +253,7 @@ impl MathApp {
             last_info: (None, None),
             opened: Opened::default(),
             settings: AppSettings::default(),
+            intersections: Vec::new(),
         }
     }
 
@@ -354,6 +362,15 @@ impl MathApp {
                         })
                         .clicked(),
                 );
+
+                self.settings.do_intersections.bitxor_assign(
+                    ui.add(Button::new("Intersections"))
+                        .on_hover_text(match self.settings.do_intersections {
+                            true => "Disable Displaying Intersections",
+                            false => "Display Intersections between functions",
+                        })
+                        .clicked(),
+                );
             });
 
             if self.functions.display_entries(ui) {
@@ -530,7 +547,7 @@ impl App for MathApp {
             self.side_panel(ctx);
         }
 
-        // Central panel which contains the central plot (or an error created when parsing)
+        // Central panel which contains the central plot
         CentralPanel::default()
             .frame(Frame {
                 inner_margin: Margin::ZERO,
@@ -540,29 +557,6 @@ impl App for MathApp {
                 ..Frame::NONE
             })
             .show(ctx, |ui| {
-                // Display an error if it exists
-                let errors_formatted: String = self
-                    .functions
-                    .get_entries()
-                    .iter()
-                    .map(|(_, func)| func.get_test_result())
-                    .enumerate()
-                    .filter(|(_, error)| error.is_some())
-                    .map(|(i, error)| {
-                        // use unwrap_unchecked as None Errors are already filtered out
-                        unsafe {
-                            format!("(Function #{}) {}\n", i, error.as_ref().unwrap_unchecked())
-                        }
-                    })
-                    .join("");
-
-                if !errors_formatted.is_empty() {
-                    ui.centered_and_justified(|ui| {
-                        ui.heading(errors_formatted);
-                    });
-                    return;
-                }
-
                 let available_width: usize = (ui.available_width() as usize) + 1; // Used in later logic
                 let width_changed = available_width != self.settings.plot_width;
                 self.settings.plot_width = available_width;
@@ -607,6 +601,41 @@ impl App for MathApp {
                             })
                             .collect();
 
+                        // Calculate and display intersections between functions
+                        if self.settings.do_intersections {
+                            let entries = self.functions.get_entries();
+                            let visible_entries: Vec<_> = entries
+                                .iter()
+                                .filter(|(_, f)| f.visible && f.is_some())
+                                .collect();
+
+                            // Clear previous intersections
+                            self.intersections.clear();
+
+                            // Find intersections between all pairs of visible functions
+                            for i in 0..visible_entries.len() {
+                                for j in (i + 1)..visible_entries.len() {
+                                    let (_, func1) = visible_entries[i];
+                                    let (_, func2) = visible_entries[j];
+
+                                    let mut intersections =
+                                        find_intersections(&func1.back_data, &func2.back_data);
+                                    self.intersections.append(&mut intersections);
+                                }
+                            }
+
+                            // Display intersection points
+                            if !self.intersections.is_empty() {
+                                plot_ui.points(
+                                    self.intersections
+                                        .clone()
+                                        .to_points()
+                                        .color(Color32::from_rgb(255, 105, 180)) // Hot pink for visibility
+                                        .radius(6.0),
+                                );
+                            }
+                        }
+
                         self.last_info.0 = if area.iter().any(|e| e.is_some()) {
                             Some(format!("Area: {}", option_vec_printer(area.as_slice())))
                         } else {

src/misc.rs

@@ -214,3 +214,47 @@ include!(concat!(env!("OUT_DIR"), "/valid_chars.rs"));
 pub fn is_valid_char(c: char) -> bool {
     c.is_alphanumeric() | VALID_EXTRA_CHARS.contains(&c)
 }
+
+/// Find intersection points between two functions given their plotted data
+/// Returns a vector of PlotPoints where the functions intersect
+pub fn find_intersections(data1: &[PlotPoint], data2: &[PlotPoint]) -> Vec<PlotPoint> {
+    if data1.is_empty() || data2.is_empty() || data1.len() != data2.len() {
+        return Vec::new();
+    }
+
+    // Calculate difference between functions at each x point
+    let differences: Vec<(f64, f64)> = data1
+        .iter()
+        .zip(data2.iter())
+        .filter(|(p1, p2)| p1.y.is_finite() && p2.y.is_finite())
+        .map(|(p1, p2)| (p1.x, p1.y - p2.y))
+        .collect();
+
+    // Find where sign changes (intersection points)
+    differences
+        .iter()
+        .tuple_windows()
+        .filter(|((_, diff1), (_, diff2))| diff1.signum() != diff2.signum())
+        .map(|((x1, diff1), (x2, diff2))| {
+            // Linear interpolation to find approximate x of intersection
+            let t = diff1.abs() / (diff1.abs() + diff2.abs());
+            let x = x1 + t * (x2 - x1);
+
+            // Find corresponding y values and average them for the intersection point
+            // We need to interpolate y values from both functions
+            let y1_at_x1 = data1
+                .iter()
+                .find(|p| (p.x - x1).abs() < f64::EPSILON)
+                .map(|p| p.y)
+                .unwrap_or(0.0);
+            let y1_at_x2 = data1
+                .iter()
+                .find(|p| (p.x - x2).abs() < f64::EPSILON)
+                .map(|p| p.y)
+                .unwrap_or(0.0);
+            let y = y1_at_x1 + t * (y1_at_x2 - y1_at_x1);
+
+            PlotPoint::new(x, y)
+        })
+        .collect()
+}

tests/function.rs

@@ -19,6 +19,7 @@ fn app_settings_constructor(
         integral_num,
         do_extrema: false,
         do_roots: false,
+        do_intersections: false,
         plot_width: pixel_width,
     }
 }