#region ================== Copyright (c) 2007 Pascal vd Heiden

/*
 * Copyright (c) 2007 Pascal vd Heiden, www.codeimp.com
 * This program is released under GNU General Public License
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 */

#endregion

#region ================== Namespaces

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Reflection;
using CodeImp.DoomBuilder.Windows;
using CodeImp.DoomBuilder.IO;
using CodeImp.DoomBuilder.Map;
using CodeImp.DoomBuilder.Rendering;
using CodeImp.DoomBuilder.Geometry;
using CodeImp.DoomBuilder.Editing;
using CodeImp.DoomBuilder.Actions;
using CodeImp.DoomBuilder.VisualModes;

#endregion

namespace CodeImp.DoomBuilder.BuilderModes.Editing
{
	[EditMode(SwitchAction = "visualmode",		// Action name used to switch to this mode
			  ButtonDesc = "Visual Mode",		// Description on the button in toolbar/menu
			  ButtonImage = "VisualMode.png",	// Image resource name for the button
			  ButtonOrder = 0)]					// Position of the button (lower is more to the left)

	public class BaseVisualMode : VisualMode
	{
		#region ================== Constants

		#endregion

		#region ================== Variables

		// All constructed visual sectors
		private Dictionary<Sector, BaseVisualSector> allsectors;

		// List of visible sectors
		private Dictionary<Sector, BaseVisualSector> visiblesectors;
		
		// Visual view range ^ 2
		private float visualviewrange2;
		
		#endregion

		#region ================== Properties

		#endregion

		#region ================== Constructor / Disposer

		// Constructor
		public BaseVisualMode()
		{
			// Initialize
			allsectors = new Dictionary<Sector, BaseVisualSector>(General.Map.Map.Sectors.Count);
			visiblesectors = new Dictionary<Sector, BaseVisualSector>();
			visualviewrange2 = General.Settings.VisualViewRange * General.Settings.VisualViewRange;
			
			// We have no destructor
			GC.SuppressFinalize(this);
		}

		// Disposer
		public override void Dispose()
		{
			// Not already disposed?
			if(!isdisposed)
			{
				// Clean up
				foreach(KeyValuePair<Sector, BaseVisualSector> s in allsectors) s.Value.Dispose();
				visiblesectors = null;
				allsectors = null;
				
				// Done
				base.Dispose();
			}
		}

		#endregion

		#region ================== Private Tools

		// This finds the nearest sector to the camera
		private Sector FindStartSector(Vector2D campos)
		{
			float side;
			Linedef l;
			
			// Get nearest linedef
			l = General.Map.Map.NearestLinedef(campos);
			if(l != null)
			{
				// Check if we are on front or back side
				side = l.SideOfLine(campos);
				if(side > 0)
				{
					// Is there a sidedef here?
					if(l.Back != null)
						return l.Back.Sector;
					else if(l.Front != null)
						return l.Front.Sector;
					else
						return null;
				}
				else
				{
					// Is there a sidedef here?
					if(l.Front != null)
						return l.Front.Sector;
					else if(l.Back != null)
						return l.Back.Sector;
					else
						return null;
				}
			}
			else
				return null;
		}

		// This recursively finds and adds visible sectors
		private void ProcessVisibleSectors(Sector start, Vector2D campos, Clipper clipper)
		{
			BaseVisualSector vs;
			Clipper newclip;
			Sector os;
			float side;
			
			// Find the basesector and make it if needed
			if(allsectors.ContainsKey(start))
			{
				// Take existing visualsector
				vs = allsectors[start];
			}
			else
			{
				// Make new visualsector
				vs = new BaseVisualSector(start);
				allsectors.Add(start, vs);
			}
			
			// Add sector to visibility list
			visiblesectors.Add(start, vs);
			
			// Go for all sidedefs in the sector
			foreach(Sidedef sd in start.Sidedefs)
			{
				// Camera on the front of this side?
				side = sd.Line.SideOfLine(campos);
				if(((side > 0) && sd.IsFront) ||
				   ((side < 0) && !sd.IsFront))
				{
					// Sidedef blocking the view?
					if((sd.Other == null) ||
					   (sd.Other.Sector.FloorHeight >= (sd.Sector.CeilHeight - 0.0001f)) ||
					   (sd.Other.Sector.CeilHeight <= (sd.Sector.FloorHeight + 0.0001f)) ||
					   (sd.Other.Sector.FloorHeight >= (sd.Other.Sector.CeilHeight - 0.0001f)))
					{
						// This blocks the view
						//clipper.InsertRange(sd.Line.Start.Position, sd.Line.End.Position);
					}
				}
			}
			
			// Go for all sidedefs in the sector
			foreach(Sidedef sd in start.Sidedefs)
			{
				// Doublesided and not referring to same sector?
				if((sd.Other != null) && (sd.Other.Sector != sd.Sector))
				{
					// Get the other sector
					os = sd.Other.Sector;

					// Sector not yet added?
					if(!visiblesectors.ContainsKey(os))
					{
						// Within view range?
						if(sd.Line.DistanceToSq(campos, true) < visualviewrange2)
						{
							// Check if the sector can be seen
							//if(clipper.TestRange(sd.Line.Start.Position, sd.Line.End.Position))
							{
								// Make a copy of the visibility clipper
								newclip = new Clipper(clipper);

								// Process this sector as well
								ProcessVisibleSectors(os, campos, newclip);

								// Done with this clipper
								newclip.Dispose();
							}
						}
					}
				}
			}
		}
		
		#endregion

		#region ================== Methods

		[EndAction("reloadresources", BaseAction = true)]
		public void ReloadResources()
		{
			foreach(KeyValuePair<Sector, BaseVisualSector> s in allsectors) s.Value.Dispose();
			allsectors.Clear();
			visiblesectors.Clear();
		}
		
		// Mode engages
		public override void OnEngage()
		{
			// Update the used textures
			General.Map.Data.UpdateUsedTextures();
			
			base.OnEngage();
		}
		
		// This draws a frame
		public override void OnRedrawDisplay()
		{
			// Start drawing
			if(renderer.Start())
			{
				// Begin with geometry
				renderer.StartGeometry();

				// Render all visible sectors
				foreach(KeyValuePair<Sector, BaseVisualSector> vs in visiblesectors)
					renderer.RenderGeometry(vs.Value);

				// Done rendering geometry
				renderer.FinishGeometry();

				// Present!
				renderer.Finish();
			}
			
			// Call base
			base.OnRedrawDisplay();
		}

		// This processes a frame
		public override void OnProcess()
		{
			Vector2D campos;
			Clipper clipper;
			
			// Process base class first
			base.OnProcess();
			
			// Get the 2D camera position
			campos = new Vector2D(base.CameraPosition.x, base.CameraPosition.y);
			
			// Make visibility clipper
			clipper = new Clipper((Vector2D)base.CameraPosition);
			
			// Make new visibility list
			visiblesectors = new Dictionary<Sector, BaseVisualSector>(General.Map.Map.Sectors.Count);
			
			// Process all visible sectors starting with the nearest
			ProcessVisibleSectors(FindStartSector(campos), campos, clipper);

			// Clean up
			clipper.Dispose();
		}
		
		#endregion
	}
}