From 4c8452c84124f692f55d547744b2ad65ff8e293f Mon Sep 17 00:00:00 2001
From: Urho Laukkarinen <urho.laukkarinen@gmail.com>
Date: Sun, 6 Oct 2024 13:53:29 +0300
Subject: [PATCH] Implemented scaling with global orientation (#7)

---
 crates/transform-gizmo/src/config.rs | 14 +-------------
 crates/transform-gizmo/src/gizmo.rs  | 24 +++++++++++++++++++-----
 2 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/crates/transform-gizmo/src/config.rs b/crates/transform-gizmo/src/config.rs
index 6823795..16f1578 100644
--- a/crates/transform-gizmo/src/config.rs
+++ b/crates/transform-gizmo/src/config.rs
@@ -93,19 +93,7 @@ impl GizmoConfig {
 
     /// Transform orientation of the gizmo
     pub(crate) fn orientation(&self) -> GizmoOrientation {
-        if self.is_scaling() {
-            // Scaling currently only works in local orientation,
-            // so the configured orientation is ignored.
-            GizmoOrientation::Local
-        } else {
-            self.orientation
-        }
-    }
-
-    /// Whether the config includes any scaling modes
-    fn is_scaling(&self) -> bool {
-        (self.mode_override.is_none() && !self.modes.is_disjoint(GizmoMode::all_scale()))
-            || self.mode_override.filter(GizmoMode::is_scale).is_some()
+        self.orientation
     }
 
     /// Whether the modes have changed, compared to given other config
diff --git a/crates/transform-gizmo/src/gizmo.rs b/crates/transform-gizmo/src/gizmo.rs
index 92f2f2b..c794d5c 100644
--- a/crates/transform-gizmo/src/gizmo.rs
+++ b/crates/transform-gizmo/src/gizmo.rs
@@ -9,7 +9,7 @@ use crate::config::{
 use crate::math::{screen_to_world, Transform};
 use crate::GizmoOrientation;
 use epaint::Mesh;
-use glam::{DQuat, DVec3};
+use glam::{DMat4, DQuat, DVec3};
 
 use crate::subgizmo::rotation::RotationParams;
 use crate::subgizmo::scale::ScaleParams;
@@ -223,7 +223,7 @@ impl Gizmo {
                     self.update_translation(delta, transform, start_transform)
                 }
                 GizmoResult::Scale { total } => {
-                    Self::update_scale(transform, start_transform, total)
+                    self.update_scale(transform, start_transform, total)
                 }
                 GizmoResult::Arcball { delta, total: _ } => {
                     self.update_rotation_quat(transform, delta.into())
@@ -287,14 +287,28 @@ impl Gizmo {
     }
 
     fn update_scale(
+        &self,
         transform: &Transform,
         start_transform: &Transform,
         scale: mint::Vector3<f64>,
     ) -> Transform {
+        let new_scale = match self.config.orientation() {
+            GizmoOrientation::Global => {
+                let scaled_transform_mat = DMat4::from_scale(scale.into())
+                    * DMat4::from_scale_rotation_translation(
+                        DVec3::from(start_transform.scale),
+                        DQuat::from(start_transform.rotation),
+                        DVec3::from(start_transform.translation),
+                    );
+                let (scale, _, _) = scaled_transform_mat.to_scale_rotation_translation();
+                scale
+            }
+            GizmoOrientation::Local => DVec3::from(start_transform.scale) * DVec3::from(scale),
+        };
+
         Transform {
-            scale: (DVec3::from(start_transform.scale) * DVec3::from(scale)).into(),
-            rotation: transform.rotation,
-            translation: transform.translation,
+            scale: new_scale.into(),
+            ..*transform
         }
     }