diff --git a/src/app.rs b/src/app.rs
index c7bcac1..a955bbd 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -22,6 +22,7 @@ enum PreviewFocus {
     Bumpmap,
 }
 
+#[derive(Clone)]
 struct TexturePair {
     heightmap: TextureHandle,
     bumpmap: TextureHandle,
@@ -141,16 +142,18 @@ impl TerrainApp {
         }
     }
 
-    fn preview_context_menu(&mut self, response: &Response, preview: PreviewFocus) {
+    fn preview_context_menu(response: &Response) -> bool {
+        let mut should_copy = false;
         response.context_menu(|ui| {
             if ui.button("Copy").clicked() {
-                self.copy_preview(preview);
+                should_copy = true;
                 ui.close();
             }
         });
+        should_copy
     }
 
-    fn overlay_copy_button(&mut self, ui: &mut Ui, anchor_rect: egui::Rect, preview: PreviewFocus) {
+    fn overlay_copy_button(ui: &mut Ui, anchor_rect: egui::Rect, preview: PreviewFocus) -> bool {
         let button_size = Vec2::new(28.0, 28.0);
         let button_rect = Align2::RIGHT_TOP
             .align_size_within_rect(button_size, anchor_rect.shrink2(Vec2::new(8.0, 8.0)));
@@ -165,7 +168,8 @@ impl TerrainApp {
         } else {
             Color32::from_rgba_premultiplied(40, 40, 40, 180)
         };
-        ui.painter().rect_filled(button_rect, CornerRadius::same(6), fill);
+        ui.painter()
+            .rect_filled(button_rect, CornerRadius::same(6), fill);
         ui.painter().rect_stroke(
             button_rect,
             CornerRadius::same(6),
@@ -180,11 +184,10 @@ impl TerrainApp {
             Color32::WHITE,
         );
 
-        if response.clicked() {
-            self.copy_preview(preview);
-        }
-
+        let clicked = response.clicked();
         response.on_hover_text("Copy");
+        let _ = preview;
+        clicked
     }
 
     fn tab_button(ui: &mut Ui, current: &mut LeftTab, tab: LeftTab, label: &str) {
@@ -297,8 +300,13 @@ impl TerrainApp {
     }
 
     fn ui_right_panel(&mut self, ctx: &Context) {
+        let mut pending_copy = None;
+        let mut pending_focus = None;
+        let mut pending_hover = None;
+        let preview_focus = self.preview_focus;
+        let textures = self.textures.clone();
         egui::CentralPanel::default().show(ctx, |ui| {
-            let Some(textures) = &self.textures else {
+            let Some(textures) = &textures else {
                 ui.centered_and_justified(|ui| {
                     ui.label("No generated images yet.");
                 });
@@ -308,10 +316,10 @@ impl TerrainApp {
             let bumpmap_texture = textures.bumpmap.clone();
 
             let available = ui.available_size();
-            let bottom_strip_height = (available.y * 0.24).max(120.0).min(220.0);
+            let bottom_strip_height = (available.y * 0.24).clamp(120.0, 220.0);
             let main_height = (available.y - bottom_strip_height - 8.0).max(100.0);
 
-            let main_texture = match self.preview_focus {
+            let main_texture = match preview_focus {
                 PreviewFocus::Heightmap => &heightmap_texture,
                 PreviewFocus::Bumpmap => &bumpmap_texture,
             };
@@ -319,19 +327,22 @@ impl TerrainApp {
             let main_response =
                 render_clickable_image(ui, main_texture, Vec2::new(available.x, main_height), true);
             if main_response.hovered() {
-                self.hovered_preview = Some(self.preview_focus);
+                pending_hover = Some(preview_focus);
+            }
+            if Self::preview_context_menu(&main_response)
+                || Self::overlay_copy_button(ui, main_response.rect, preview_focus)
+            {
+                pending_copy = Some(preview_focus);
             }
-            self.preview_context_menu(&main_response, self.preview_focus);
-            self.overlay_copy_button(ui, main_response.rect, self.preview_focus);
             ui.add_space(8.0);
 
-            let thumb_width = (available.x * 0.28).max(120.0).min(240.0);
+            let thumb_width = (available.x * 0.28).clamp(120.0, 240.0);
             let panel_width = (thumb_width + 32.0).min(available.x);
-            let secondary_texture = match self.preview_focus {
+            let secondary_texture = match preview_focus {
                 PreviewFocus::Heightmap => &bumpmap_texture,
                 PreviewFocus::Bumpmap => &heightmap_texture,
             };
-            let secondary_focus = match self.preview_focus {
+            let secondary_focus = match preview_focus {
                 PreviewFocus::Heightmap => PreviewFocus::Bumpmap,
                 PreviewFocus::Bumpmap => PreviewFocus::Heightmap,
             };
@@ -354,16 +365,26 @@ impl TerrainApp {
                             true,
                         );
                         if secondary_response.hovered() {
-                            self.hovered_preview = Some(secondary_focus);
+                            pending_hover = Some(secondary_focus);
+                        }
+                        if Self::preview_context_menu(&secondary_response) {
+                            pending_copy = Some(secondary_focus);
                         }
-                        self.preview_context_menu(&secondary_response, secondary_focus);
                         if secondary_response.clicked() {
-                            self.preview_focus = secondary_focus;
+                            pending_focus = Some(secondary_focus);
                         }
                     });
                 });
             });
         });
+
+        if let Some(preview) = pending_copy {
+            self.copy_preview(preview);
+        }
+        if let Some(preview) = pending_focus {
+            self.preview_focus = preview;
+        }
+        self.hovered_preview = pending_hover;
     }
 }
 
@@ -451,7 +472,7 @@ fn render_clickable_image(
         .sense(if clickable {
             Sense::click()
         } else {
-            Sense::click()
+            Sense::hover()
         });
     let response = ui.add(image);
 
diff --git a/src/generator.rs b/src/generator.rs
index ebde71a..c93866f 100644
--- a/src/generator.rs
+++ b/src/generator.rs
@@ -128,7 +128,7 @@ fn hash22(p: Vec2, random_seed: u64) -> Vec2 {
     let scrambled_y = splitmix64(random_seed ^ 0xBF58_476D_1CE4_E5B9);
     let seed_x = u64_to_unit_f64(scrambled_x) * 1024.0;
     let seed_y = u64_to_unit_f64(scrambled_y) * 1024.0;
-    let kx = 0.318_309_9_f64;
+    let kx = std::f64::consts::FRAC_1_PI;
     let ky = 0.367_879_4_f64;
 
     let px = ((p.x as f64) + seed_x) * kx + ky;