Tetris/ViewsModels/GameViewModel.cs

using System;
using System.ComponentModel;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Threading;
using Tetris.Models;
using Color = System.Drawing.Color;

namespace Tetris.ViewsModels;

public class GameViewModel : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler? PropertyChanged;
    
    public static readonly Game Game = new("...", new Grid(new Color[20, 40]));
    
    private const int RendererHertz = 5;
    private const int GameRendererHertz = (1 / RendererHertz) * 1000;
    private const int Multiplier = 10;
    private readonly int _width = (Game.Grid.MaxGrid.X + 1) * Multiplier;
    private readonly int _height = (Game.Grid.MaxGrid.Y + 1) * Multiplier;
    private readonly WriteableBitmap _writeableBitmap;

    public GameViewModel()
    {
        _writeableBitmap = BitmapFactory.New(_width, _height);
        
        var dispatcherRenderTimer = new DispatcherTimer
        {
            Interval = new TimeSpan(0, 0, 0, 0, GameRendererHertz)
        };
        
        dispatcherRenderTimer.Tick += Render;
        dispatcherRenderTimer.Start();
        
        var dispatcherUpdateTimer = new DispatcherTimer
        {
            Interval = new TimeSpan(0, 0, 0, 0, 100)
        };
        
        dispatcherUpdateTimer.Tick += Update;
        dispatcherUpdateTimer.Start();
    }
    
    public ImageSource Source => _writeableBitmap;

    private void Render(object? sender, EventArgs eventArgs)
    {
        _writeableBitmap.Lock();
        _writeableBitmap.Clear(Colors.Black);

        var colorGrid = Game.Grid.CGrid;
        for (var x = 0; x < Game.Grid.MaxGrid.X + 1; x++)
        {
            for (var y = 0; y < Game.Grid.MaxGrid.Y + 1; y++)
            {
                if (colorGrid[x, y] == Color.Empty) continue;
                
                var startX = x * Multiplier;
                var startY = y * Multiplier;
                _writeableBitmap.FillRectangle(startX, startY, startX + Multiplier, startY + Multiplier, colorGrid[x, y].ToArgb());
            }
        }

        var tetrominoeWidth = Game.CurrentTetrominoe?.Shape.GetLength(0);
        var tetrominoeHeight = Game.CurrentTetrominoe?.Shape.GetLength(1);

        for (int x = 0; x < tetrominoeWidth; x++)
        {
            for (int y = 0; y < tetrominoeHeight; y++)
            {
                var currentPiece = Game.CurrentTetrominoe!;
                if (currentPiece.Shape[x, y] == false) continue;
                var color = currentPiece.Color;

                var startX = (currentPiece.Coordinates.X + x) * Multiplier;
                var startY = (currentPiece.Coordinates.Y + y) * Multiplier;
                _writeableBitmap.FillRectangle(startX, startY, startX + Multiplier, startY + Multiplier, color.ToArgb());
            }
        }
        
        _writeableBitmap.Unlock();
    }
    
    private void Update(object? sender, EventArgs eventArgs)
    {
        Game.CurrentTetrominoe?.GoDown();

        if (Game.HitBottom())
        {
            Game.PrintTetrominoe();
        }
    }
}