#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.GZDoomEditing;
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 VisualUpper : BaseVisualGeometrySidedef
	{
		#region ================== Constants

		#endregion

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

		#endregion

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

		#endregion

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

		// Constructor
		public VisualUpper(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;
			
			// 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.Data;
			SectorData osd = mode.GetSectorData(Sidedef.Other.Sector);
			if(!osd.Built) osd.BuildLevels(mode);
			
			// Texture given?
			if((Sidedef.HighTexture.Length > 0) && (Sidedef.HighTexture[0] != '-'))
			{
				// Load texture
				base.Texture = General.Map.Data.GetTextureImage(Sidedef.LongHighTexture);
				if(base.Texture == null)
				{
					base.Texture = General.Map.Data.MissingTexture3D;
					setuponloadedtexture = Sidedef.LongHighTexture;
				}
				else
				{
					if(!base.Texture.IsImageLoaded)
						setuponloadedtexture = Sidedef.LongHighTexture;
				}
			}
			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);
			
			// 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 ceilbias = (Sidedef.Other.Sector.CeilHeight == Sidedef.Sector.CeilHeight) ? 1.0f : 0.0f;
			if(!Sidedef.Line.IsFlagSet(General.Map.Config.UpperUnpeggedFlag))
			{
				// When lower unpegged is set, the lower texture is bound to the bottom
				tp.tlt.y = tsz.y - ((float)Sidedef.Sector.CeilHeight - (float)Sidedef.Other.Sector.CeilHeight);
			}
			tp.trb.x = tp.tlt.x + Sidedef.Line.Length;
			tp.trb.y = tp.tlt.y + ((float)Sidedef.Sector.CeilHeight - ((float)Sidedef.Other.Sector.CeilHeight + ceilbias));
			
			// Apply texture offset
			if (General.Map.Config.ScaledTextureOffsets && !base.Texture.WorldPanning)
			{
				tp.tlt += new Vector2D(Sidedef.OffsetX * base.Texture.Scale.x, Sidedef.OffsetY * base.Texture.Scale.y);
				tp.trb += new Vector2D(Sidedef.OffsetX * base.Texture.Scale.x, Sidedef.OffsetY * base.Texture.Scale.y);
			}
			else
			{
				tp.tlt += new Vector2D(Sidedef.OffsetX, Sidedef.OffsetY);
				tp.trb += new Vector2D(Sidedef.OffsetX, Sidedef.OffsetY);
			}
			
			// 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.Sector.CeilHeight);
			tp.vrb = new Vector3D(vr.x, vr.y, (float)Sidedef.Other.Sector.CeilHeight + ceilbias);
			
			// 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);
			
			// Go for all levels to build geometry
			List<WorldVertex> verts = new List<WorldVertex>();
			for(int i = 1; i < sd.Levels.Count; i++)
			{
				SectorLevel l = sd.Levels[i];
				
				PixelColor wallbrightness = PixelColor.FromInt(mode.CalculateBrightness(l.brightnessbelow));
				PixelColor wallcolor = PixelColor.Modulate(l.colorbelow, wallbrightness);
				int c = wallcolor.WithAlpha(255).ToInt();
				
				// 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)));
				
				// Slice off the part below the other plane
				CropPoly(poly, osd.Ceiling.plane, false);
				
				// Now we go for all light planes to splice this polygon
				for(int k = 0; k < sd.Levels.Count; k++)
				{
					SectorLevel ol = sd.Levels[k];
					if((ol != sd.Floor) && (ol != sd.Ceiling) && (ol.type != SectorLevelType.Floor))
					{
						CropPoly(poly, ol.plane, (k >= i));
					}
				}
				
				// Find texture coordinates for each vertex in the polygon
				List<Vector2D> texc = new List<Vector2D>(poly.Count);
				foreach(Vector3D v in poly)
					texc.Add(tp.GetTextureCoordsAt(v));
				
				// Now we create triangles from the polygon.
				// The polygon is convex and clockwise, so this is a piece of cake.
				if(poly.Count >= 3)
				{
					for(int k = 1; k < (poly.Count - 1); k++)
					{
						verts.Add(new WorldVertex(poly[0], c, texc[0]));
						verts.Add(new WorldVertex(poly[k], c, texc[k]));
						verts.Add(new WorldVertex(poly[k + 1], c, texc[k + 1]));
					}
				}
			}
			
			if(verts.Count > 0)
			{
				base.SetVertices(verts);
				return true;
			}
			else
			{
				return false;
			}
		}
		
		#endregion

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

		// Return texture name
		public override string GetTextureName()
		{
			return this.Sidedef.HighTexture;
		}

		// This changes the texture
		protected override void SetTexture(string texturename)
		{
			this.Sidedef.SetTextureHigh(texturename);
			General.Map.Data.UpdateUsedTextures();
			this.Setup();
		}
		
		#endregion
	}
}