3 files changed, 84 insertions(+), 14 deletions(-)

M src/appdata.rs
M src/grapher.rs
M src/main.rs

@@ 3,5 3,7 @@ use druid::{Data, Lens};
 #[derive(Clone, Data, Default, Lens)]
 pub struct AppData {
     pub k0: f64,
+    pub bias0: f64,
     pub k1: f64,
+    pub bias1: f64,
 }

@@ 1,6 1,6 @@
 //! Custom widget for drawing stuff
 
-use druid::kurbo::{BezPath, Line, Point};
+use druid::kurbo::{Affine, BezPath, Line, Point, Vec2};
 use druid::piet::Color;
 use druid::widget::prelude::*;
 use druid::Data;


@@ 49,6 49,36 @@ fn compute_basis(bias: f64) -> Vec<f64> {
     result
 }
 
+fn compute_thetas(data: &AppData) -> Vec<f64> {
+    let mut basis0 = compute_basis(data.bias0);
+    let basis1 = compute_basis(data.bias1);
+    for (x, y) in basis0.iter_mut().zip(basis1.iter().rev()) {
+        *x = *x * data.k0 - *y * data.k1
+    }
+    basis0
+}
+
+fn integrate_curve(thetas: &[f64]) -> Vec<Point> {
+    let n = thetas.len();
+    let mut p = Point::ORIGIN;
+    let scale = 1.0 / (n - 1) as f64;
+    let mut result = (0..n)
+        .map(|i| {
+            let this_p = p;
+            if i < thetas.len() - 1 {
+                let th = 0.5 * (thetas[i] + thetas[i + 1]);
+                p += scale * Vec2::from_angle(th);
+            }
+            this_p
+        })
+        .collect::<Vec<_>>();
+    let a = Affine::new([p.x, p.y, -p.y, p.x, 0.0, 0.0]).inverse();
+    for p in &mut result {
+        *p = a * *p;
+    }
+    result
+}
+
 fn plot(ctx: &mut PaintCtx, seq: &[f64], origin: Point, width: f64, scale: f64) {
     let mut path = BezPath::new();
     for i in 0..seq.len() {


@@ 63,6 93,19 @@ fn plot(ctx: &mut PaintCtx, seq: &[f64], origin: Point, width: f64, scale: f64) 
     ctx.stroke(path, &Color::WHITE, 1.0);
 }
 
+fn plot_xy(ctx: &mut PaintCtx, seq: &[Point], origin: Point, scale: f64) {
+    let mut path = BezPath::new();
+    for i in 0..seq.len() {
+        let p = origin + scale * seq[i].to_vec2();
+        if i == 0 {
+            path.move_to(p);
+        } else {
+            path.line_to(p);
+        }
+    }
+    ctx.stroke(path, &Color::WHITE, 1.0);
+}
+
 impl Widget<AppData> for Grapher {
     fn event(&mut self, _ctx: &mut EventCtx, _event: &Event, _data: &mut AppData, env: &Env) {}
 


@@ 86,7 129,7 @@ impl Widget<AppData> for Grapher {
         _ctx: &mut LayoutCtx,
         bc: &BoxConstraints,
         _data: &AppData,
-        env: &Env,
+        _env: &Env,
     ) -> Size {
         bc.max()
     }


@@ 94,7 137,10 @@ impl Widget<AppData> for Grapher {
     fn paint(&mut self, ctx: &mut PaintCtx, data: &AppData, _env: &Env) {
         let line = Line::new((0.0, 0.0), (100.0, 100.0));
         ctx.stroke(line, &Color::WHITE, 1.0);
-        let basis = compute_basis(data.k1);
-        plot(ctx, &basis, Point::new(50.0, 400.0), 600.0, 100.0);
+        //let basis = compute_basis(data.bias0);
+        let thetas = compute_thetas(data);
+        plot(ctx, &thetas, Point::new(50.0, 400.0), 600.0, 100.0);
+        let pts = integrate_curve(&thetas);
+        plot_xy(ctx, &pts, Point::new(100.0, 300.0), 400.0);
     }
 }

@@ 1,7 1,5 @@
 use druid::widget::{Flex, Label, Slider};
-use druid::{
-    AppLauncher, Data, Lens, LocalizedString, PlatformError, Widget, WidgetExt, WindowDesc,
-};
+use druid::{AppLauncher, Env, PlatformError, Widget, WidgetExt, WindowDesc};
 
 mod appdata;
 mod grapher;


@@ 18,21 16,45 @@ fn main() -> Result<(), PlatformError> {
 
 fn ui_builder() -> impl Widget<AppData> {
     // The label text will be computed dynamically based on the current locale and count
-    let text = LocalizedString::new("hello-counter").with_arg("count", |data: &AppData, _env| {
-        format!("{:.1}", data.k1).into()
-    });
-    let label = Label::new(text).padding(5.0).center();
-    let slider0 = Slider::new().lens(AppData::k0).padding(5.0);
-    let slider1 = Slider::new()
+    let label0 = Label::new(|data: &AppData, _env: &Env| format!("k0: {:.2}", data.k0))
+        .padding(5.0)
+        .center();
+    let slider0 = Slider::new()
+        .with_range(-2.0, 2.0)
+        .lens(AppData::k0)
+        .padding(5.0);
+    let labelb0 = Label::new(|data: &AppData, _env: &Env| format!("bias0: {:.2}", data.bias0))
+        .padding(5.0)
+        .center();
+    let sliderb0 = Slider::new()
         .with_range(-1.0, 2.0)
+        .lens(AppData::bias0)
+        .padding(5.0);
+    let label1 = Label::new(|data: &AppData, _env: &Env| format!("k1: {:.2}", data.k1))
+        .padding(5.0)
+        .center();
+    let slider1 = Slider::new()
+        .with_range(-2.0, 2.0)
         .lens(AppData::k1)
         .padding(5.0);
+    let labelb1 = Label::new(|data: &AppData, _env: &Env| format!("bias1: {:.2}", data.bias1))
+        .padding(5.0)
+        .center();
+    let sliderb1 = Slider::new()
+        .with_range(-1.0, 2.0)
+        .lens(AppData::bias1)
+        .padding(5.0);
     let grapher = grapher::Grapher;
 
     Flex::column()
-        .with_child(label)
+        .with_child(label0)
         .with_child(slider0)
+        .with_child(labelb0)
+        .with_child(sliderb0)
+        .with_child(label1)
         .with_child(slider1)
+        .with_child(labelb1)
+        .with_child(sliderb1)
         .with_flex_child(grapher, 1.0)
         .must_fill_main_axis(true)
 }