JB's Blog

Ok, a few weeks ago, i implemented multiplayer views on my race game, and, i have to admit, it was pretty easy. (Thanks to XNA, defining a viewport is only a few lines of code)

so, here is the code i use to set each player it’s part in the screen (for one to four players, you just have to call this function before you draw your player X stuff).

		private void SetupViewport()
		{
			// 1 player
			if (m_raceScreen.InitDatas.TotalPlayerCount == 0) 
				return; // don't touch viewport, we're obviously the only player :)
			
			Viewport v = new Viewport();
			v.X = 0;
			v.Y = 0;
			v.Width = XeGame.Device.PresentationParameters.BackBufferWidth;
			v.Height = XeGame.Device.PresentationParameters.BackBufferHeight;

			#region 2 players
			if (m_raceScreen.InitDatas.TotalPlayerCount == 1) // 2 player
			{
				if (v.Height > v.Width) // cut height in 2
				{
					v.Height = v.Height / 2;

					if (this.m_playerIndex == PlayerIndex.One)
					{
						v.Y = 0;
					}

					if (this.m_playerIndex == PlayerIndex.Two)
					{
						v.Y = v.Height;
					}
				}
				else
				{
					v.Width = v.Width / 2;

					if (this.m_playerIndex == PlayerIndex.One)
					{
						v.X = 0;
					}
					
					if (this.m_playerIndex == PlayerIndex.Two)
					{
						v.X = v.Width;
					}
				}
			}
			#endregion

			#region 3 players
			if (m_raceScreen.InitDatas.TotalPlayerCount == 2) // 3 player
			{
				if (v.Height > v.Width)
				{
					v.Height = v.Height / 3;

					if (this.m_playerIndex == PlayerIndex.One)
						v.Y = 0;

					if (this.m_playerIndex == PlayerIndex.Two)
						v.Y = v.Height;

					if (this.m_playerIndex == PlayerIndex.Three)
						v.Y = v.Height * 2;
				}
				else // standard case (4/3, 16/9, 16/10)
				{
					v.Width = v.Width / 2;

					if (this.m_playerIndex == PlayerIndex.One)
					{
						v.Y = 0;
						v.X = 0;
					}
					
					if (this.m_playerIndex == PlayerIndex.Two)
					{
						v.Height = v.Height / 2;
						v.X = v.Width;
					}

					if (this.m_playerIndex == PlayerIndex.Three)
					{
						v.Height = v.Height / 2;
						v.X = v.Width;
						v.Y = v.Height;
					}
				}
			}
			#endregion

			#region 4 players
			if (m_raceScreen.InitDatas.TotalPlayerCount == 3) // 4 player
			{
				if (v.Height > v.Width)
				{
					v.Height = v.Height / 4;

					if (this.m_playerIndex == PlayerIndex.One)
						v.Y = 0;

					if (this.m_playerIndex == PlayerIndex.Two)
						v.Y = v.Height;

					if (this.m_playerIndex == PlayerIndex.Three)
						v.Y = v.Height * 2;

					if (this.m_playerIndex == PlayerIndex.Four)
						v.Y = v.Height * 3;
				}
				else // standard case
				{
					v.Width = v.Width / 2;
					v.Height = v.Height / 2;

					if (this.m_playerIndex == PlayerIndex.One)
					{
						v.Y = 0;
						v.X = 0;
					}

					if (this.m_playerIndex == PlayerIndex.Two)
					{
						v.Y = 0;
						v.X = v.Width;
					}

					if (this.m_playerIndex == PlayerIndex.Three)
					{
						v.X = 0;
						v.Y = v.Height;
					}

					if (this.m_playerIndex == PlayerIndex.Four)
					{
						v.X = v.Width;
						v.Y = v.Height;
					}
				}
			}
			#endregion

			XeGame.Device.Viewport = v;
		}

Actually, a lot of work have been made when i see the screenshots i took 3 months ago. (Sun is now a big heap of particles, models have been smoothed a lot, physics are almost in place, post scree processing engine have been integrated, and the SceneRenderManager is almost ready, and will makes render a lot simpler)

See by yourself :