sneak/Shared/ShmupWorld.cs

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

namespace SemiColinGames {
  public sealed class ShmupWorld : IWorld {
    public class ShmupPlayer {
      public TextureRef Texture = Textures.Yellow2;
      // Center of player sprite.
      public Vector2 Position = new Vector2(48, 1080 / 8);
      public Vector2 HalfSize = new Vector2(16, 10);
      public float Speed = 150f;
    }

    public class Shot {
      public TextureRef Texture = Textures.Projectile1;
      public Vector2 Position;
      public Vector2 HalfSize = new Vector2(11, 8);
      public Vector2 Velocity;
      public Shot(Vector2 position, Vector2 velocity) {
        Position = position;
        Velocity = velocity;
      }
    }

    public readonly Point Size;
    public readonly ShmupPlayer Player;
    public readonly ProfilingList<Shot> Shots;

    public ShmupWorld() {
      Size = new Point(1920 / 4, 1080 / 4);
      Player = new ShmupPlayer();
      Shots = new ProfilingList<Shot>(100, "shots");
      Vector2 velocity = new Vector2(100, 0);
      Shots.Add(new Shot(new Vector2(96, 1080 / 8), velocity));
      Shots.Add(new Shot(new Vector2(96 * 2, 1080 / 8), velocity));
      Shots.Add(new Shot(new Vector2(96 * 4, 1080 / 8), velocity));
    }

    ~ShmupWorld() {
      Dispose();
    }

    public void Dispose() {
      GC.SuppressFinalize(this);
    }

    public void Update(float modelTime, History<Input> input) {
      Vector2 motion = Vector2.Multiply(input[0].Motion, modelTime * Player.Speed);
      Player.Position = Vector2.Add(Player.Position, motion);
      Player.Position.X = Math.Max(Player.Position.X, Player.HalfSize.X);
      Player.Position.X = Math.Min(Player.Position.X, Size.X - Player.HalfSize.X);
      Player.Position.Y = Math.Max(Player.Position.Y, Player.HalfSize.Y);
      Player.Position.Y = Math.Min(Player.Position.Y, Size.Y - Player.HalfSize.Y);

      foreach (Shot shot in Shots) {
        shot.Position = Vector2.Add(shot.Position, Vector2.Multiply(shot.Velocity, modelTime));
        shot.Position.X = Math.Max(shot.Position.X, shot.HalfSize.X);
        shot.Position.X = Math.Min(shot.Position.X, Size.X - shot.HalfSize.X);
        shot.Position.X = Math.Max(shot.Position.X, shot.HalfSize.X);
        shot.Position.X = Math.Min(shot.Position.X, Size.X - shot.HalfSize.X);
      }

      // Shots.RemoveAll(shot => shot.Position.X > Size.X);
    }
  }
}