using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using System;
using System.Collections.Generic;
using System.Text;

namespace WormsGame
{
    internal class MapGenerator
    {
        public int Width { get; set; }
        public int Height { get; set; }
        public Texture2D LevelTexture { get; set; }

        private Random rnd = new Random();
        private Color[] colorData;

        public MapGenerator(int width, int height)
        {
            Width = width;
            Height = height;
        }

        public void Generate(GraphicsDevice device)
        {
            colorData = new Color[Width * Height];
            List<double> HeightMap = new List<double> { 0, 0 };
            LevelTexture = new Texture2D(device, Width, Height);

            double Max = 1.0;
            double Roughness = ((double)100 / 100.0);

            for (int j = 0; j < 10; j++)
            {
                int count = HeightMap.Count;
                for (int i = 0; i < count - 1; i++)
                {
                    double tmp = (HeightMap[i * 2] + HeightMap[i * 2 + 1]) / 2.0;
                    double offset = (rnd.NextDouble() * 2.0 - 1.0) * Max;
                    HeightMap.Insert(i * 2 + 1, tmp + offset);
                }
                Max = Max * Math.Pow(2, -Roughness);
            }

            for(int x = 0; x < Width; x++)
            {
                double index = (x / (double)Width) * (HeightMap.Count - 1);
                int start = (int)Math.Floor(index);

                double r2 = index - Math.Floor(index);
                double r1 = 1.0 - r2;
                double height = HeightMap[start] * r1 + HeightMap[start + 1] * r2;

                var yStart = (int)(300 + 250.0 * height);
                for (int y = yStart; y < Height; y++)
                    colorData[y * Width + x] = Color.Chocolate;
            }

            LevelTexture.SetData(colorData);
        }
    }
}

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;

namespace WormsGame
{
    public class Game1 : Game
    {
        private GraphicsDeviceManager _graphics;
        private SpriteBatch _spriteBatch;
        private MapGenerator mapGenerator;

        public Game1()
        {
            _graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
            IsMouseVisible = true;

            _graphics.PreferredBackBufferWidth = 1280;
            _graphics.PreferredBackBufferHeight = 720;
        }

        protected override void Initialize()
        {
            mapGenerator = new MapGenerator(1280, 720);

            base.Initialize();
        }

        protected override void LoadContent()
        {
            _spriteBatch = new SpriteBatch(GraphicsDevice);

            mapGenerator.Generate(GraphicsDevice);
        }

        protected override void Update(GameTime gameTime)
        {
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
                Exit();

            var kbState = Keyboard.GetState();
            if (kbState.IsKeyDown(Keys.R))
                mapGenerator.Generate(GraphicsDevice);

            base.Update(gameTime);
        }

        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);

            _spriteBatch.Begin();
            _spriteBatch.Draw(mapGenerator.LevelTexture, Vector2.Zero, Color.White);
            _spriteBatch.End();

            base.Draw(gameTime);
        }
    }
}