From 2dfdea361e06ecb9bb2929a42829d8f213e91c8f Mon Sep 17 00:00:00 2001
From: Bradlee Speice <bradlee@speice.io>
Date: Sun, 23 Feb 2025 21:56:31 -0500
Subject: [PATCH] Aspect ratio scaling for transform editor

Feels like there _must_ be a simpler way to do this math
---
 crates/flare/examples/transform_editor.rs |  4 +---
 crates/flare/src/transform_editor.rs      | 16 +++++++++++++++-
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/crates/flare/examples/transform_editor.rs b/crates/flare/examples/transform_editor.rs
index 65f8da9..65cd0a2 100644
--- a/crates/flare/examples/transform_editor.rs
+++ b/crates/flare/examples/transform_editor.rs
@@ -33,9 +33,7 @@ impl eframe::App for TransformEditorApp {
         });
 
         egui::CentralPanel::default().show(ctx, |ui| {
-            egui::Frame::canvas(ui.style()).show(ui, |ui| {
-                self.transform_editor.ui(ui)
-            })
+            self.transform_editor.ui(ui)
         });
     }
 }
diff --git a/crates/flare/src/transform_editor.rs b/crates/flare/src/transform_editor.rs
index bad915c..2a9c59d 100644
--- a/crates/flare/src/transform_editor.rs
+++ b/crates/flare/src/transform_editor.rs
@@ -43,7 +43,21 @@ impl TransformEditor {
     pub fn ui(&mut self, ui: &mut egui::Ui) -> egui::Response {
         let (response, painter) = ui.allocate_painter(ui.available_size(), Sense::hover());
 
-        let transform_area = Rect::from_min_max(egui::pos2(-2.0, -2.0), egui::pos2(2.0, 2.0));
+        let interact_rect = response.interact_rect;
+
+        // Aspect-ratio scaling; minimum dimension will be [-2.0, 2.0]
+        let interact_max_dim = interact_rect.width().max(interact_rect.height());
+        let interact_min_dim = interact_rect.width().min(interact_rect.height());
+        let interact_max_is_width = interact_max_dim == interact_rect.width();
+        let ifs_scale = interact_max_dim / interact_min_dim * 4.0;
+
+        let ifs_min = if interact_max_is_width {
+            egui::pos2(-ifs_scale / 2.0, -2.0)
+        } else {
+            egui::pos2(-2.0, -ifs_scale / 2.0)
+        };
+
+        let transform_area = Rect::from_min_max(ifs_min, ifs_min * -1.0);
         let to_screen = emath::RectTransform::from_to(transform_area, response.interact_rect);
 
         self.transforms.iter().map(|coef| {