initial commit with basic functionality

src/main.rs

@@ -0,0 +1,107 @@
+use eframe::egui;
+use egui::{Color32, Stroke};
+
+fn main() -> eframe::Result<()> {
+    let options = eframe::NativeOptions::default();
+
+    eframe::run_native(
+        "Desktop Dungeon Generator",
+        options,
+        Box::new(|_cc| Ok(Box::new(DungeonApp::default()))),
+    )
+}
+
+struct DungeonApp {
+    cols: usize,
+    rows: usize,
+}
+
+impl Default for DungeonApp {
+    fn default() -> Self {
+        Self { cols: 12, rows: 8 }
+    }
+}
+
+impl eframe::App for DungeonApp {
+    fn update(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
+        egui::SidePanel::left("options_panel")
+            .resizable(true)
+            .min_width(180.0)
+            .default_width(260.0)
+            .show_separator_line(true)
+            .show(ctx, |ui| {
+                ui.heading("Grid Options");
+                ui.add_space(8.0);
+
+                ui.label("Columns");
+                ui.horizontal(|ui| {
+                    ui.add(egui::Slider::new(&mut self.cols, 2..=100).show_value(false));
+                    ui.add(
+                        egui::DragValue::new(&mut self.cols)
+                            .speed(1.0)
+                            .range(2..=500),
+                    );
+                });
+
+                ui.add_space(8.0);
+                ui.label("Rows");
+                ui.horizontal(|ui| {
+                    ui.add(egui::Slider::new(&mut self.rows, 2..=100).show_value(false));
+                    ui.add(
+                        egui::DragValue::new(&mut self.rows)
+                            .speed(1.0)
+                            .range(2..=500),
+                    );
+                });
+            });
+
+        egui::CentralPanel::default().show(ctx, |ui| {
+            let available = ui.available_size_before_wrap();
+            let (response, painter) = ui.allocate_painter(available, egui::Sense::hover());
+            let canvas = response.rect.shrink(12.0);
+            draw_grid(&painter, canvas, self.cols, self.rows);
+        });
+    }
+}
+
+fn draw_grid(painter: &egui::Painter, area: egui::Rect, cols: usize, rows: usize) {
+    let cols = cols.max(1);
+    let rows = rows.max(1);
+
+    let cell_size = (area.width() / cols as f32).min(area.height() / rows as f32);
+    let grid_width = cell_size * cols as f32;
+    let grid_height = cell_size * rows as f32;
+
+    let grid_rect = egui::Rect::from_min_size(
+        egui::pos2(
+            area.center().x - (grid_width * 0.5),
+            area.center().y - (grid_height * 0.5),
+        ),
+        egui::vec2(grid_width, grid_height),
+    );
+
+    let stroke = Stroke::new(1.0, Color32::from_gray(160));
+    painter.rect_stroke(grid_rect, 0.0, stroke, egui::StrokeKind::Middle);
+
+    for col in 1..cols {
+        let x = grid_rect.left() + (col as f32 * cell_size);
+        painter.line_segment(
+            [
+                egui::pos2(x, grid_rect.top()),
+                egui::pos2(x, grid_rect.bottom()),
+            ],
+            stroke,
+        );
+    }
+
+    for row in 1..rows {
+        let y = grid_rect.top() + (row as f32 * cell_size);
+        painter.line_segment(
+            [
+                egui::pos2(grid_rect.left(), y),
+                egui::pos2(grid_rect.right(), y),
+            ],
+            stroke,
+        );
+    }
+}