starter for your game levels using odin+raylib code

game_level_switcher.odin

package main

import rl "vendor:raylib"

State :: enum {
    LevelPicker,
    LevelView,
}

main :: proc() {
    screen_width :: 800
    screen_height :: 600
    
    rl.InitWindow(i32(screen_width), i32(screen_height), "Level Switcher with Back")
    rl.SetTargetFPS(60)
    
    box_width :: 100
    box_height :: 60
    spacing_x :: 20
    spacing_y :: 20
    cols :: 5
    rows :: 3
    start_x :: (screen_width - (cols * box_width + (cols - 1) * spacing_x)) / 2
    start_y :: (screen_height - (rows * box_height + (rows - 1) * spacing_y)) / 2
    
    state := State.LevelPicker
    selected_level := -1
    
    for !rl.WindowShouldClose() {
        rl.BeginDrawing()
        rl.ClearBackground(rl.RAYWHITE)
        
        mouse_pos := rl.GetMousePosition()
        
        if state == State.LevelPicker {
            for row in 0..<rows {
                for col in 0..<cols {
                    i := row * cols + col
                    x := f32(start_x + col * (box_width + spacing_x))
                    y := f32(start_y + row * (box_height + spacing_y))
                    rect := rl.Rectangle{x, y, f32(box_width), f32(box_height)}
                    
                    rl.DrawRectangleRec(rect, rl.LIGHTGRAY)
                    rl.DrawRectangleLinesEx(rect, 2, rl.DARKGRAY)
                    
                    label := rl.TextFormat("%d", i32(i + 1))
                    text_width := rl.MeasureText(label, 20)
                    rl.DrawText(label,
                        i32(x + f32(box_width - int(text_width))/2),
                        i32(y + f32(box_height - 20)/2),
                        20,
                        rl.DARKBLUE)
                    
                    if rl.CheckCollisionPointRec(mouse_pos, rect) && rl.IsMouseButtonPressed(rl.MouseButton.LEFT) {
                        selected_level = i + 1
                        state = State.LevelView
                    }
                }
            }
        } else if state == State.LevelView {
            message := rl.TextFormat("Level %d", i32(selected_level))
            text_width := rl.MeasureText(message, 40)
            rl.DrawText(message, i32((screen_width - int(text_width))/2), i32(screen_height/2 - 50), 40, rl.DARKGREEN)
            
            // Back button
            back_width :: 120
            back_height :: 40
            back_x := f32((screen_width - back_width)/2)
            back_y := f32(screen_height - 100)
            back_rect := rl.Rectangle{back_x, back_y, f32(back_width), f32(back_height)}
            
            rl.DrawRectangleRec(back_rect, rl.SKYBLUE)
            rl.DrawRectangleLinesEx(back_rect, 2, rl.BLUE)
            rl.DrawText("Back", i32(back_x + 30), i32(back_y + 10), 20, rl.DARKBLUE)
            
            if rl.CheckCollisionPointRec(mouse_pos, back_rect) && rl.IsMouseButtonPressed(rl.MouseButton.LEFT) {
                state = State.LevelPicker
                selected_level = -1
            }
        }
        
        rl.EndDrawing()
    }
    
    rl.CloseWindow()
}