#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 System.Drawing;
using System.ComponentModel;
using CodeImp.DoomBuilder.Map;
using CodeImp.DoomBuilder.Geometry;
using System.Drawing.Imaging;
using CodeImp.DoomBuilder.Data;
using CodeImp.DoomBuilder.Editing;
using CodeImp.DoomBuilder.IO;
using CodeImp.DoomBuilder.Rendering;
using CodeImp.DoomBuilder.VisualModes;

#endregion

namespace CodeImp.DoomBuilder.GZDoomEditing
{
	internal sealed class VisualLower : BaseVisualGeometrySidedef
	{
		#region ================== Constants

		#endregion

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

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

		#endregion

		#region ================== Constructor / Setup

		// Constructor
		public VisualLower(BaseVisualMode mode, VisualSector vs, Sidedef s) : base(mode, vs, s)
		{
			// We have no destructor
			GC.SuppressFinalize(this);
		}
		
		// This builds the geometry. Returns false when no geometry created.
		public override bool Setup()
		{
			Vector2D vl, vr;
			
			int lightvalue = Sidedef.Fields.GetValue("light", 0);
			bool lightabsolute = Sidedef.Fields.GetValue("lightabsolute", false);
			
			Vector2D tscale = new Vector2D(Sidedef.Fields.GetValue("scalex_bottom", 1.0f),
										   Sidedef.Fields.GetValue("scaley_bottom", 1.0f));
			Vector2D toffset = new Vector2D(Sidedef.Fields.GetValue("offsetx_bottom", 0.0f),
											Sidedef.Fields.GetValue("offsety_bottom", 0.0f));
			
			// Left and right vertices for this sidedef
			if(Sidedef.IsFront)
			{
				vl = new Vector2D(Sidedef.Line.Start.Position.x, Sidedef.Line.Start.Position.y);
				vr = new Vector2D(Sidedef.Line.End.Position.x, Sidedef.Line.End.Position.y);
			}
			else
			{
				vl = new Vector2D(Sidedef.Line.End.Position.x, Sidedef.Line.End.Position.y);
				vr = new Vector2D(Sidedef.Line.Start.Position.x, Sidedef.Line.Start.Position.y);
			}
			
			// Load sector data
			SectorData sd = Sector.GetSectorData();
			SectorData osd = mode.GetSectorData(Sidedef.Other.Sector);
			if(!osd.Updated) osd.Update();
			
			// Texture given?
			if((Sidedef.LowTexture.Length > 0) && (Sidedef.LowTexture[0] != '-'))
			{
				// Load texture
				base.Texture = General.Map.Data.GetTextureImage(Sidedef.LongLowTexture);
				if(base.Texture == null)
				{
					base.Texture = General.Map.Data.MissingTexture3D;
					setuponloadedtexture = Sidedef.LongLowTexture;
				}
				else
				{
					if(!base.Texture.IsImageLoaded)
						setuponloadedtexture = Sidedef.LongLowTexture;
				}
			}
			else
			{
				// Use missing texture
				base.Texture = General.Map.Data.MissingTexture3D;
				setuponloadedtexture = 0;
			}
			
			// Get texture scaled size
			Vector2D tsz = new Vector2D(base.Texture.ScaledWidth, base.Texture.ScaledHeight);
			tsz = tsz / tscale;
			
			// Get texture offsets
			Vector2D tof = new Vector2D(Sidedef.OffsetX, Sidedef.OffsetY);
			tof = tof + toffset;
			if(General.Map.Config.ScaledTextureOffsets && !base.Texture.WorldPanning)
				tof = tof * base.Texture.Scale;
			
			// Determine texture coordinates plane as they would be in normal circumstances.
			// We can then use this plane to find any texture coordinate we need.
			// The logic here is the same as in the original VisualMiddleSingle (except that
			// the values are stored in a TexturePlane)
			// NOTE: I use a small bias for the floor height, because if the difference in
			// height is 0 then the TexturePlane doesn't work!
			TexturePlane tp = new TexturePlane();
			float floorbias = (Sidedef.Other.Sector.FloorHeight == Sidedef.Sector.FloorHeight) ? 1.0f : 0.0f;
			if(Sidedef.Line.IsFlagSet(General.Map.Config.LowerUnpeggedFlag))
			{
				// When lower unpegged is set, the lower texture is bound to the bottom
				tp.tlt.y = (float)Sidedef.Sector.CeilHeight - (float)Sidedef.Other.Sector.FloorHeight;
			}
			tp.trb.x = tp.tlt.x + Sidedef.Line.Length;
			tp.trb.y = tp.tlt.y + ((float)Sidedef.Other.Sector.FloorHeight - ((float)Sidedef.Sector.FloorHeight + floorbias));
			
			// Apply texture offset
			tp.tlt += tof;
			tp.trb += tof;
			
			// Transform pixel coordinates to texture coordinates
			tp.tlt /= tsz;
			tp.trb /= tsz;
			
			// Left top and right bottom of the geometry that
			tp.vlt = new Vector3D(vl.x, vl.y, (float)Sidedef.Other.Sector.FloorHeight);
			tp.vrb = new Vector3D(vr.x, vr.y, (float)Sidedef.Sector.FloorHeight + floorbias);
			
			// Make the right-top coordinates
			tp.trt = new Vector2D(tp.trb.x, tp.tlt.y);
			tp.vrt = new Vector3D(tp.vrb.x, tp.vrb.y, tp.vlt.z);
			
			// Create initial polygon, which is just a quad between floor and ceiling
			WallPolygon poly = new WallPolygon();
			poly.Add(new Vector3D(vl.x, vl.y, sd.Floor.plane.GetZ(vl)));
			poly.Add(new Vector3D(vl.x, vl.y, sd.Ceiling.plane.GetZ(vl)));
			poly.Add(new Vector3D(vr.x, vr.y, sd.Ceiling.plane.GetZ(vr)));
			poly.Add(new Vector3D(vr.x, vr.y, sd.Floor.plane.GetZ(vr)));
			
			// Determine initial color
			int lightlevel = lightabsolute ? lightvalue : sd.Ceiling.brightnessbelow + lightvalue;
			PixelColor wallbrightness = PixelColor.FromInt(mode.CalculateBrightness(lightlevel));
			PixelColor wallcolor = PixelColor.Modulate(sd.Ceiling.colorbelow, wallbrightness);
			poly.color = wallcolor.WithAlpha(255).ToInt();
			
			// Cut off the part above the other floor
			CropPoly(ref poly, osd.Floor.plane, false);
			CropPoly(ref poly, osd.Ceiling.plane, true);
			
			if(poly.Count > 2)
			{
				// Keep top and bottom planes for intersection testing
				top = osd.Floor.plane;
				bottom = sd.Floor.plane;
				
				// Process the polygon and create vertices
				List<WorldVertex> verts = CreatePolygonVertices(poly, tp, sd, lightvalue, lightabsolute);
				if(verts.Count > 0)
				{
					base.SetVertices(verts);
					return true;
				}
			}
			
			return false;
		}
		
		#endregion

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

		// Return texture name
		public override string GetTextureName()
		{
			return this.Sidedef.LowTexture;
		}
		
		// This changes the texture
		protected override void SetTexture(string texturename)
		{
			this.Sidedef.SetTextureLow(texturename);
			General.Map.Data.UpdateUsedTextures();
			this.Setup();
		}
		
		#endregion
	}
}