undo is really almost done :D

src/undo.rs

@@ -1,7 +1,7 @@
+use bevy::math::Vec3Swizzles;
 use bevy::prelude::*;
 
-use crate::ui::SelectedItem;
-use crate::{CreateShape, ShapeData, ImageData};
+use crate::{ShapeData, ImageData};
 
 #[derive(Debug, Clone)]
 pub enum UndoItem {
@@ -73,23 +73,24 @@ impl UndoStack {
 pub fn undo_redo_sys(
     mut coms: Commands,
     mut stack: ResMut<UndoStack>,
-    mut inspector: ResMut<SelectedItem>,
     keyboard: Res<Input<KeyCode>>,
     mut shapes: Query<&mut ShapeData>,
     mut transforms: Query<&mut Transform>,
+    global_transforms: Query<&GlobalTransform>,
     mut images: Query<(&mut ImageData, &Handle<Image>)>,
+    mut paths: Query<&mut bevy_prototype_lyon::prelude::Path>,
 ) {
     if keyboard.just_pressed(KeyCode::Z) && keyboard.pressed(KeyCode::LControl) {
         let item = if keyboard.pressed(KeyCode::LShift) { stack.unpop() } else { stack.pop() };
         if let Some(item) = item {
             match item {
                 UndoItem::Base => bevy::log::error!("POP/UNPOP: Got UndoItem::Base as a result!"),
-                UndoItem::CreateShape { entity } => {
+                UndoItem::CreateShape { entity: _ } => {
                     bevy::log::error!("NOT IMPLEMENTED : CreateShape");
                 },
                 UndoItem::DeleteShape {
-                    sd,
-                    transform,
+                    sd: _,
+                    transform: _,
                 } => {
                     bevy::log::error!("NOT IMPLEMENTED : DeleteShape");
                 },
@@ -102,7 +103,33 @@ pub fn undo_redo_sys(
                     *to = t;
                 },
                 UndoItem::MoveDot { shape_data, dot, from, to } => {
-                    bevy::log::error!("NOT IMPLEMENTED : MoveDot");
+                    let gt = global_transforms.get(*dot).unwrap();
+
+                    let sd = shapes.get(*shape_data).unwrap();
+                    let rot = gt.to_scale_rotation_translation().1;
+                    let ang = rot.to_euler(EulerRot::XYZ).2;
+                    let delta = Mat2::from_angle(-ang) * (*from - gt.translation().xy());
+                    if let Ok(mut t) = transforms.get_mut(*dot) {
+                        t.translation += delta.extend(0.0);
+                    }
+                    // We need to recalculate the center, and update the points to be the new relevant point from the center
+                    let center_offset = crate::modify::calc_shape_center_offset(&transforms, &*sd);
+                    // Update each edge's offset, and then move the main shape's translation
+                    for edge in sd.edges.iter() {
+                        if let Ok(mut t) = transforms.get_mut(*edge) {
+                            t.translation -= center_offset.extend(0.0);
+                        }
+                    }
+                    if let Ok(mut t) = transforms.get_mut(sd.main_shape) {
+                        t.translation += (Mat2::from_angle(ang) * center_offset).extend(0.0);
+                    }
+
+                    // Now we need to update the shape itself
+                    crate::modify::update_main_shape(&mut paths, &transforms, &*sd);
+
+                    let t = *from;
+                    *from = *to;
+                    *to = t;
                 },
                 UndoItem::Rotate { entity, from, to } => {
                     if let Ok(mut t) = transforms.get_mut(*entity) {