add gravity to blob particals and add example to see the gravity in action

blob_guy/examples/blob/main.rs

@@ -0,0 +1,92 @@
+use blob_guy::CHUNK_AMOUNT;
+use blob_guy::blob_guy::{Blob, Pos};
+use blob_guy::chunk::Chunk;
+use eframe::egui;
+use rupl::types::{Graph, GraphType, Name, Show, Vec2};
+use std::array::from_fn;
+fn main() {
+    eframe::run_native(
+        "blob",
+        eframe::NativeOptions {
+            ..Default::default()
+        },
+        Box::new(|_| Ok(Box::new(App::new()))),
+    )
+    .unwrap();
+}
+impl eframe::App for App {
+    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
+        self.main(ctx);
+    }
+}
+
+struct App {
+    plot: Graph,
+    data: Data,
+}
+
+struct Data {
+    blob: Blob,
+    world: [Chunk; CHUNK_AMOUNT * CHUNK_AMOUNT],
+}
+
+impl Data {
+    fn new() -> Self {
+        Self {
+            blob: Blob::new(0.0, 0.0),
+            world: from_fn(|_| Chunk::default()),
+        }
+    }
+    fn update(&mut self, plot: &mut Graph) {
+        let s = &plot.names[0].vars[0];
+        let s = &s[3..s.len() - 1];
+        let (a, b) = s.split_once(',').unwrap();
+        let GraphType::Point(p) = &mut plot.data[0] else {
+            unreachable!()
+        };
+        p.x = a.parse().unwrap();
+        p.y = b.parse().unwrap();
+        self.blob.pos = Pos::new(p.x as f32, p.y as f32);
+        self.blob.update(&mut self.world).unwrap();
+        plot.data.drain(1..);
+        for ((_x, _y), p) in self.blob.pixels.iter() {
+            //let p1 = Vec2::new(*_x as f64, *_y as f64);
+            let p2 = Vec2::new(p.pos.x as f64, p.pos.y as f64);
+            //plot.data.push(GraphType::Point(p1));
+            plot.data.push(GraphType::Point(p2));
+        }
+    }
+}
+impl App {
+    fn new() -> Self {
+        let mut plot = Graph::new(
+            vec![GraphType::Point(Vec2::splat(0.0))],
+            vec![Name {
+                vars: vec!["a={0,0}".to_string()],
+                name: "a".to_string(),
+                show: Show::Real,
+            }],
+            false,
+            -16.0,
+            16.0,
+        );
+        plot.point_size = 8.0;
+        App {
+            plot,
+            data: Data::new(),
+        }
+    }
+    fn main(&mut self, ctx: &egui::Context) {
+        egui::CentralPanel::default()
+            .frame(egui::Frame::default().fill(egui::Color32::from_rgb(255, 255, 255)))
+            .show(ctx, |ui| {
+                self.plot.keybinds(ui);
+                let rect = ctx.available_rect();
+                self.plot
+                    .set_screen(rect.width() as f64, rect.height() as f64, true, true);
+                self.data.update(&mut self.plot);
+                self.plot.update(ctx, ui);
+                ctx.request_repaint();
+            });
+    }
+}