added copy paste for the images

src/app.rs

@@ -1,9 +1,11 @@
 use std::sync::mpsc::{self, Receiver, TryRecvError};
 use std::thread;
 
+use arboard::{Clipboard, ImageData};
 use eframe::egui::{
-    self, Color32, ColorImage, Context, DragValue, Frame, RichText, Sense, Slider, TextureHandle,
-    TextureOptions, Ui, Vec2,
+    self, Align2, Color32, ColorImage, Context, CornerRadius, DragValue, Event, Frame, Key,
+    Response, RichText, Sense, Slider, Stroke, StrokeKind, TextureHandle, TextureOptions, Ui,
+    Vec2,
 };
 use rand::Rng;
 
@@ -114,6 +116,56 @@ impl TerrainApp {
         });
     }
 
+    fn copy_preview(&mut self, preview: PreviewFocus) {
+        let Some(generated) = &self.generated else {
+            self.status_message = String::from("No generated image is available to copy.");
+            return;
+        };
+
+        let image = match preview {
+            PreviewFocus::Heightmap => &generated.heightmap_image,
+            PreviewFocus::Bumpmap => &generated.bumpmap_image,
+        };
+
+        match copy_gray_image_to_clipboard(image) {
+            Ok(()) => {
+                self.status_message = match preview {
+                    PreviewFocus::Heightmap => String::from("Heightmap copied to clipboard."),
+                    PreviewFocus::Bumpmap => String::from("Bumpmap copied to clipboard."),
+                };
+            }
+            Err(error) => {
+                self.status_message = format!("Failed to copy image: {error}");
+            }
+        }
+    }
+
+    fn preview_context_menu(&mut self, response: &Response, preview: PreviewFocus) {
+        response.context_menu(|ui| {
+            if ui.button("Copy").clicked() {
+                self.copy_preview(preview);
+                ui.close();
+            }
+        });
+    }
+
+    fn overlay_copy_button(&mut self, ui: &mut Ui, anchor_rect: egui::Rect, preview: PreviewFocus) {
+        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)));
+
+        let response = ui.put(
+            button_rect,
+            egui::Button::new(RichText::new("🗍").size(14.0)),
+        );
+
+        if response.clicked() {
+            self.copy_preview(preview);
+        }
+
+        response.on_hover_text("Copy");
+    }
+
     fn tab_button(ui: &mut Ui, current: &mut LeftTab, tab: LeftTab, label: &str) {
         let selected = *current == tab;
         if ui.selectable_label(selected, label).clicked() {
@@ -231,24 +283,29 @@ impl TerrainApp {
                 });
                 return;
             };
+            let heightmap_texture = textures.heightmap.clone();
+            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 main_height = (available.y - bottom_strip_height - 8.0).max(100.0);
 
             let main_texture = match self.preview_focus {
-                PreviewFocus::Heightmap => &textures.heightmap,
-                PreviewFocus::Bumpmap => &textures.bumpmap,
+                PreviewFocus::Heightmap => &heightmap_texture,
+                PreviewFocus::Bumpmap => &bumpmap_texture,
             };
 
-            render_clickable_image(ui, main_texture, Vec2::new(available.x, main_height), false);
+            let main_response =
+                render_clickable_image(ui, main_texture, Vec2::new(available.x, main_height), true);
+            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 panel_width = (thumb_width + 32.0).min(available.x);
             let secondary_texture = match self.preview_focus {
-                PreviewFocus::Heightmap => &textures.bumpmap,
-                PreviewFocus::Bumpmap => &textures.heightmap,
+                PreviewFocus::Heightmap => &bumpmap_texture,
+                PreviewFocus::Bumpmap => &heightmap_texture,
             };
             let secondary_focus = match self.preview_focus {
                 PreviewFocus::Heightmap => PreviewFocus::Bumpmap,
@@ -266,12 +323,14 @@ impl TerrainApp {
                     ui.vertical_centered(|ui| {
                         ui.label(RichText::new(secondary_label).strong());
                         ui.add_space(6.0);
-                        if render_clickable_image(
+                        let secondary_response = render_clickable_image(
                             ui,
                             secondary_texture,
                             Vec2::new(thumb_width, bottom_strip_height - 32.0),
                             true,
-                        ) {
+                        );
+                        self.preview_context_menu(&secondary_response, secondary_focus);
+                        if secondary_response.clicked() {
                             self.preview_focus = secondary_focus;
                         }
                     });
@@ -283,6 +342,24 @@ impl TerrainApp {
 
 impl eframe::App for TerrainApp {
     fn update(&mut self, ctx: &Context, _frame: &mut eframe::Frame) {
+        let wants_keyboard_input = ctx.wants_keyboard_input();
+        let should_copy = ctx.input(|input| {
+            !wants_keyboard_input
+                && input.events.iter().any(|event| match event {
+                    Event::Copy => true,
+                    Event::Key {
+                        key: Key::C,
+                        pressed: true,
+                        modifiers,
+                        ..
+                    } => modifiers.ctrl || modifiers.command,
+                    _ => false,
+                })
+        });
+
+        if should_copy {
+            self.copy_preview(self.preview_focus);
+        }
         self.poll_generation(ctx);
         self.ui_left_panel(ctx);
         self.ui_right_panel(ctx);
@@ -335,7 +412,7 @@ fn render_clickable_image(
     texture: &TextureHandle,
     max_size: Vec2,
     clickable: bool,
-) -> bool {
+) -> Response {
     let image_size = texture.size_vec2();
     let scale = (max_size.x / image_size.x).min(max_size.y / image_size.y);
     let desired_size = image_size * scale.max(0.01);
@@ -344,7 +421,35 @@ fn render_clickable_image(
         .sense(if clickable {
             Sense::click()
         } else {
-            Sense::hover()
+            Sense::click()
         });
-    ui.add(image).clicked()
+    let response = ui.add(image);
+
+    if response.hovered() {
+        ui.painter().rect_stroke(
+            response.rect.expand(4.0),
+            CornerRadius::same(8),
+            Stroke::new(2.0, Color32::from_rgba_premultiplied(180, 220, 255, 180)),
+            StrokeKind::Outside,
+        );
+    }
+
+    response
+}
+
+fn copy_gray_image_to_clipboard(image: &image::GrayImage) -> Result<(), String> {
+    let mut rgba = Vec::with_capacity((image.width() * image.height() * 4) as usize);
+    for pixel in image.pixels() {
+        let gray = pixel.0[0];
+        rgba.extend_from_slice(&[gray, gray, gray, 255]);
+    }
+
+    let data = ImageData {
+        width: image.width() as usize,
+        height: image.height() as usize,
+        bytes: rgba.into(),
+    };
+
+    let mut clipboard = Clipboard::new().map_err(|error| error.to_string())?;
+    clipboard.set_image(data).map_err(|error| error.to_string())
 }