#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 SlimDX;
using CodeImp.DoomBuilder.Geometry;
using SlimDX.Direct3D9;
using CodeImp.DoomBuilder.Data;
using CodeImp.DoomBuilder.VisualModes;
using CodeImp.DoomBuilder.Map;

//mxd
using CodeImp.DoomBuilder.GZBuilder.MD3;
using CodeImp.DoomBuilder.GZBuilder.Data;
using CodeImp.DoomBuilder.GZBuilder.Geometry;
using CodeImp.DoomBuilder.GZBuilder.Rendering;

#endregion

namespace CodeImp.DoomBuilder.Rendering
{
	internal sealed class Renderer3D : Renderer, IRenderer3D
	{
		#region ================== Constants

		private const int RENDER_PASSES = 4;
		private const float PROJ_NEAR_PLANE = 1f;
		private const float CROSSHAIR_SCALE = 0.06f;
		private const float FOG_RANGE = 0.9f;
		
		#endregion

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

		// Matrices
		private Matrix projection;
		private Matrix view3d;
		private Matrix billboard;
		private Matrix worldviewproj;
		private Matrix view2d;
		private Matrix world;
		private Vector3D cameraposition;
		private int shaderpass;
		
		// Options
		private bool fullbrightness;
		
		// Window size
		private Size windowsize;
		
		// Frustum
		private ProjectedFrustum2D frustum;
		
		// Thing cage
        private bool renderthingcages;
        //mxd
        private ThingBoundingBox bbox;
		private VisualVertexHandle vertexHandle;
		private SizelessVisualThingCage sizelessThingHandle;
        private List<VisualThing> thingsWithLight;
        private int[] lightOffsets;
        private Dictionary<Texture, List<VisualGeometry>> litGeometry;
        private Dictionary<ModeldefEntry, List<VisualThing>> thingsWithModel;
		
		// Crosshair
		private FlatVertex[] crosshairverts;
		private bool crosshairbusy;

		// Highlighting
		private IVisualPickable highlighted;
		private float highlightglow;
		private float highlightglowinv;
		private ColorImage highlightimage;
		private ColorImage selectionimage;
		private bool showselection;
		private bool showhighlight;
		
		// Geometry to be rendered.
		// Each Dictionary in the array is a render pass.
		// Each BinaryHeap in the Dictionary contains all geometry that needs
		// to be rendered with the associated ImageData.
		// The BinaryHeap sorts the geometry by sector to minimize stream switchs.
		private Dictionary<ImageData, BinaryHeap<VisualGeometry>>[] geometry;

		// Things to be rendered.
		// Each Dictionary in the array is a render pass.
		// Each VisualThing is inserted in the Dictionary by their texture image.
		private Dictionary<ImageData, List<VisualThing>>[] things;

		// Things to be rendered, sorted by distance from camera
		private BinaryHeap<VisualThing> thingsbydistance;

		//mxd. Visual vertices
		private VisualVertex[] visualvertices;
        
		#endregion

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

		public ProjectedFrustum2D Frustum2D { get { return frustum; } }
		public bool DrawThingCages { get { return renderthingcages; } set { renderthingcages = value; } }
		public bool FullBrightness { get { return fullbrightness; } set { fullbrightness = value; } }
		public bool ShowSelection { get { return showselection; } set { showselection = value; } }
		public bool ShowHighlight { get { return showhighlight; } set { showhighlight = value; } }
		
		#endregion

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

		// Constructor
		internal Renderer3D(D3DDevice graphics) : base(graphics)
		{
			// Initialize
			CreateProjection();
			CreateMatrices2D();
			SetupHelperObjects();
			SetupTextures();
			renderthingcages = true;
			showselection = true;
			showhighlight = true;
			
			// Dummy frustum
			frustum = new ProjectedFrustum2D(new Vector2D(), 0.0f, 0.0f, PROJ_NEAR_PLANE,
				General.Settings.ViewDistance, Angle2D.DegToRad((float)General.Settings.VisualFOV));

			// We have no destructor
			GC.SuppressFinalize(this);
		}

		// Disposer
		internal override void Dispose()
		{
			// Not already disposed?
			if(!isdisposed)
			{
				// Clean up
                //mxd
                if(bbox != null) bbox.Dispose();
				if(vertexHandle != null) vertexHandle.Dispose();
				if(sizelessThingHandle != null)	sizelessThingHandle.Dispose();

				if(selectionimage != null) selectionimage.Dispose();
				if(highlightimage != null) highlightimage.Dispose();
                
                //mxd
                bbox = null;
				vertexHandle = null;
				sizelessThingHandle = null;

				selectionimage = null;
				highlightimage = null;
				
				// Done
				base.Dispose();
			}
		}

		#endregion

		#region ================== Management

		// This is called before a device is reset
		// (when resized or display adapter was changed)
		public override void UnloadResource()
		{
			crosshairverts = null;
            //mxd
            if(bbox != null) bbox.Dispose();
			if(vertexHandle != null) vertexHandle.Dispose();
			if(sizelessThingHandle != null)	sizelessThingHandle.Dispose();

			if(selectionimage != null) selectionimage.Dispose();
			if(highlightimage != null) highlightimage.Dispose();
			
            //mxd
			vertexHandle = null;
            bbox = null;
			sizelessThingHandle = null;

			selectionimage = null;
			highlightimage = null;
		}
		
		// This is called resets when the device is reset
		// (when resized or display adapter was changed)
		public override void ReloadResource()
		{
			CreateMatrices2D();
			SetupHelperObjects();
			SetupTextures();
		}

		// This makes screen vertices for display
		private void CreateCrosshairVerts(Size texturesize)
		{
			// Determine coordinates
			float width = (float)windowsize.Width;
			float height = (float)windowsize.Height;
			float size = (float)height * CROSSHAIR_SCALE;
			RectangleF rect = new RectangleF((width - size) / 2, (height - size) / 2, size, size);
			
			// Make vertices
			crosshairverts = new FlatVertex[4];
			crosshairverts[0].x = rect.Left;
			crosshairverts[0].y = rect.Top;
			crosshairverts[0].c = -1;
			crosshairverts[0].u = 1f / texturesize.Width;
			crosshairverts[0].v = 1f / texturesize.Height;
			crosshairverts[1].x = rect.Right;
			crosshairverts[1].y = rect.Top;
			crosshairverts[1].c = -1;
			crosshairverts[1].u = 1f - 1f / texturesize.Width;
			crosshairverts[1].v = 1f / texturesize.Height;
			crosshairverts[2].x = rect.Left;
			crosshairverts[2].y = rect.Bottom;
			crosshairverts[2].c = -1;
			crosshairverts[2].u = 1f / texturesize.Width;
			crosshairverts[2].v = 1f - 1f / texturesize.Height;
			crosshairverts[3].x = rect.Right;
			crosshairverts[3].y = rect.Bottom;
			crosshairverts[3].c = -1;
			crosshairverts[3].u = 1f - 1f / texturesize.Width;
			crosshairverts[3].v = 1f - 1f / texturesize.Height;
		}
		
		#endregion

		#region ================== Resources

		// This loads the textures for highlight and selection if we need them
		private void SetupTextures()
		{
			if(!graphics.Shaders.Enabled)
			{
				highlightimage = new ColorImage(General.Colors.Highlight, 32, 32);
				highlightimage.LoadImage();
				highlightimage.CreateTexture();
				
				selectionimage = new ColorImage(General.Colors.Selection, 32, 32);
				selectionimage.LoadImage();
				selectionimage.CreateTexture();
			}
		}

        //mxd
        private void SetupHelperObjects() {
			bbox = new ThingBoundingBox(graphics.Device);
			vertexHandle = new VisualVertexHandle(graphics.Device);
			sizelessThingHandle = new SizelessVisualThingCage(graphics.Device);
        }

		#endregion
		
		#region ================== Presentation

		// This creates the projection
		internal void CreateProjection()
		{
			// Calculate aspect
			float aspect = (float)General.Map.Graphics.RenderTarget.ClientSize.Width /
						   (float)General.Map.Graphics.RenderTarget.ClientSize.Height;
			
			// The DirectX PerspectiveFovRH matrix method calculates the scaling in X and Y as follows:
			// yscale = 1 / tan(fovY / 2)
			// xscale = yscale / aspect
			// The fov specified in the method is the FOV over Y, but we want the user to specify the FOV
			// over X, so calculate what it would be over Y first;
			float fov = Angle2D.DegToRad((float)General.Settings.VisualFOV);
			float reversefov = 1.0f / (float)Math.Tan(fov / 2.0f);
			float reversefovy = reversefov * aspect;
			float fovy = (float)Math.Atan(1.0f / reversefovy) * 2.0f;
			
			// Make the projection matrix
			projection = Matrix.PerspectiveFovRH(fovy, aspect, PROJ_NEAR_PLANE, General.Settings.ViewDistance);

			// Apply matrices
			ApplyMatrices3D();
		}
		
		// This creates matrices for a camera view
		public void PositionAndLookAt(Vector3D pos, Vector3D lookat)
		{
			Vector3D delta;
			float anglexy, anglez;
			
			// Calculate delta vector
			cameraposition = pos;
			delta = lookat - pos;
			anglexy = delta.GetAngleXY();
			anglez = delta.GetAngleZ();

			// Create frustum
			frustum = new ProjectedFrustum2D(pos, anglexy, anglez, PROJ_NEAR_PLANE,
				General.Settings.ViewDistance, Angle2D.DegToRad((float)General.Settings.VisualFOV));
			
			// Make the view matrix
			view3d = Matrix.LookAtRH(D3DDevice.V3(pos), D3DDevice.V3(lookat), new Vector3(0f, 0f, 1f));
			
			// Make the billboard matrix
			billboard = Matrix.RotationZ(anglexy + Angle2D.PI);
		}
		
		// This creates 2D view matrix
		private void CreateMatrices2D()
		{
			windowsize = graphics.RenderTarget.ClientSize;
			Matrix scaling = Matrix.Scaling((1f / (float)windowsize.Width) * 2f, (1f / (float)windowsize.Height) * -2f, 1f);
			Matrix translate = Matrix.Translation(-(float)windowsize.Width * 0.5f, -(float)windowsize.Height * 0.5f, 0f);
			view2d = Matrix.Multiply(translate, scaling);
		}
		
		// This applies the matrices
		private void ApplyMatrices3D()
		{
			worldviewproj = world * view3d * projection;
			graphics.Shaders.World3D.WorldViewProj = worldviewproj;
			graphics.Device.SetTransform(TransformState.World, world);
			graphics.Device.SetTransform(TransformState.Projection, projection);
			graphics.Device.SetTransform(TransformState.View, view3d);
		}

		// This sets the appropriate view matrix
		public void ApplyMatrices2D()
		{
			graphics.Device.SetTransform(TransformState.World, world);
			graphics.Device.SetTransform(TransformState.Projection, Matrix.Identity);
			graphics.Device.SetTransform(TransformState.View, view2d);
		}
		
		#endregion

		#region ================== Start / Finish

		// This starts rendering
		public bool Start()
		{
			// Start drawing
			if(graphics.StartRendering(true, General.Colors.Background.ToColorValue(), graphics.BackBuffer, graphics.DepthBuffer))
			{
                // Beginning renderstates
				graphics.Device.SetRenderState(RenderState.CullMode, Cull.None);
				graphics.Device.SetRenderState(RenderState.ZEnable, false);
				graphics.Device.SetRenderState(RenderState.AlphaBlendEnable, false);
				graphics.Device.SetRenderState(RenderState.AlphaTestEnable, false);
				graphics.Device.SetRenderState(RenderState.SourceBlend, Blend.SourceAlpha);
				graphics.Device.SetRenderState(RenderState.DestinationBlend, Blend.InverseSourceAlpha);
				graphics.Device.SetRenderState(RenderState.FogEnable, false);
				graphics.Device.SetRenderState(RenderState.FogDensity, 1.0f);
				graphics.Device.SetRenderState(RenderState.FogColor, General.Colors.Background.ToInt());
				graphics.Device.SetRenderState(RenderState.FogStart, General.Settings.ViewDistance * FOG_RANGE);
				graphics.Device.SetRenderState(RenderState.FogEnd, General.Settings.ViewDistance);
				graphics.Device.SetRenderState(RenderState.FogTableMode, FogMode.Linear);
				graphics.Device.SetRenderState(RenderState.RangeFogEnable, false);
				graphics.Device.SetRenderState(RenderState.TextureFactor, -1);
				graphics.Shaders.World3D.SetModulateColor(-1);
				graphics.Shaders.World3D.SetHighlightColor(0);

				// Texture addressing
				graphics.Device.SetSamplerState(0, SamplerState.AddressU, TextureAddress.Wrap);
				graphics.Device.SetSamplerState(0, SamplerState.AddressV, TextureAddress.Wrap);
				graphics.Device.SetSamplerState(0, SamplerState.AddressW, TextureAddress.Wrap);

				// Matrices
				world = Matrix.Identity;
				ApplyMatrices3D();

				// Highlight
				if(General.Settings.AnimateVisualSelection)
				{
					float time = General.Clock.CurrentTime;
					highlightglow = (float)Math.Sin(time / 100.0f) * 0.1f + 0.4f;
                    //mxd. WHY?!
					//highlightglowinv = -(float)Math.Sin(time / 100.0f) * 0.1f + 0.4f;
                    highlightglowinv = -highlightglow + 0.8f;
				}
				else
				{
					highlightglow = 0.4f;
					highlightglowinv = 0.3f;
				}
				
				// Determine shader pass to use
				if(fullbrightness) shaderpass = 1; else shaderpass = 0;

				// Create crosshair vertices
				if(crosshairverts == null)
					CreateCrosshairVerts(new Size(General.Map.Data.Crosshair3D.Width, General.Map.Data.Crosshair3D.Height));
				
				// Ready
				return true;
			}
			else
			{
				// Can't render now
				return false;
			}
		}
		
		// This begins rendering world geometry
		public void StartGeometry()
		{
			// Make collection
			geometry = new Dictionary<ImageData, BinaryHeap<VisualGeometry>>[RENDER_PASSES];
			things = new Dictionary<ImageData, List<VisualThing>>[RENDER_PASSES];
			thingsbydistance = new BinaryHeap<VisualThing>();
            //mxd 
            thingsWithModel = new Dictionary<ModeldefEntry, List<VisualThing>>();
            litGeometry = new Dictionary<Texture, List<VisualGeometry>>();

			for(int i = 0; i < RENDER_PASSES; i++)
			{
				geometry[i] = new Dictionary<ImageData, BinaryHeap<VisualGeometry>>();
				things[i] = new Dictionary<ImageData, List<VisualThing>>();
			}

            //mxd
            if (General.Settings.GZDrawLights) {
                thingsWithLight = new List<VisualThing>();
            }
		}

		// This ends rendering world geometry
		public void FinishGeometry()
		{
			//mxd. sort lights
            if (General.Settings.GZDrawLights && !fullbrightness && thingsWithLight.Count > 0)
                updateLights();
            
            // Initial renderstates
			graphics.Device.SetRenderState(RenderState.CullMode, Cull.Counterclockwise);
			graphics.Device.SetRenderState(RenderState.ZEnable, true);
			graphics.Device.SetRenderState(RenderState.ZWriteEnable, true);
			graphics.Device.SetRenderState(RenderState.AlphaBlendEnable, false);
			graphics.Device.SetRenderState(RenderState.AlphaTestEnable, false);
			graphics.Device.SetRenderState(RenderState.TextureFactor, -1);
			graphics.Shaders.World3D.Begin();

			// SOLID PASS
			world = Matrix.Identity;
			ApplyMatrices3D();
			RenderSinglePass((int)RenderPass.Solid);

            //mxd. Render models, without culling. The way it's done in GZDoom... Fixes Rendering of things like grass and models with negative Scale
			graphics.Device.SetRenderState(RenderState.AlphaTestEnable, true);
            graphics.Device.SetRenderState(RenderState.CullMode, Cull.None);
            RenderModels();
			graphics.Device.SetRenderState(RenderState.CullMode, Cull.Counterclockwise);

			// MASK PASS
            world = Matrix.Identity;
            ApplyMatrices3D();
            RenderSinglePass((int)RenderPass.Mask);

            // ALPHA PASS
            world = Matrix.Identity;
            ApplyMatrices3D();
            graphics.Device.SetRenderState(RenderState.AlphaBlendEnable, true);
            graphics.Device.SetRenderState(RenderState.AlphaTestEnable, false);
            graphics.Device.SetRenderState(RenderState.ZWriteEnable, false);
            graphics.Device.SetRenderState(RenderState.SourceBlend, Blend.SourceAlpha);
            graphics.Device.SetRenderState(RenderState.DestinationBlend, Blend.InverseSourceAlpha);
            RenderSinglePass((int)RenderPass.Alpha);

            // THINGS
			if(renderthingcages) RenderThingCages();

			//mxd. Visual vertices
			RenderVertices();

            //mxd. LINKS
            if (General.Settings.GZShowEventLines) {
                //mxd. gather links
                List<Line3D> lines = GZBuilder.Data.LinksCollector.GetThingLinks(thingsbydistance);
				if(lines.Count > 0) {
					List<Line3D> normalLines = new List<Line3D>();
					List<Line3D> activatorLines = new List<Line3D>();
					
					foreach(Line3D l in lines){
						if(l.LineType == Line3DType.DEFAULT)
							normalLines.Add(l);
						else
							activatorLines.Add(l);
					}

					if(normalLines.Count > 0)
						renderArrows(normalLines, General.Colors.InfoLine.ToColorValue());
					if(activatorLines.Count > 0)
						renderArrows(activatorLines, General.Colors.Selection3D.ToColorValue());
				}
            }

			// ADDITIVE PASS
			world = Matrix.Identity;
			ApplyMatrices3D();
			graphics.Device.SetRenderState(RenderState.DestinationBlend, Blend.One);
			RenderSinglePass((int)RenderPass.Additive);

            //mxd. LIGHT PASS
            if (General.Settings.GZDrawLights && !fullbrightness && thingsWithLight.Count > 0 && litGeometry.Count > 0) {
                RenderLights(litGeometry, thingsWithLight);
            }
			
			// Remove references
			graphics.Shaders.World3D.Texture1 = null;
			
			// Done
			graphics.Shaders.World3D.End();
			geometry = null;
			visualvertices = null;//mxd
		}

        //mxd
        private void updateLights() {
            thingsWithLight.Sort(sortThingsByCameraDistance);
            if (thingsWithLight.Count > General.Settings.GZMaxDynamicLights) {
                List<VisualThing> tl = new List<VisualThing>();
                for (int i = 0; i < General.Settings.GZMaxDynamicLights; i++)
                    tl.Add(thingsWithLight[i]);
                thingsWithLight = tl;
            }

            thingsWithLight.Sort(sortThingsByLightRenderStyle);
            lightOffsets = new int[3];
            foreach (VisualThing t in thingsWithLight) {
                //add light to apropriate array.
                if (t.LightRenderStyle == (int)GZDoomLightRenderStyle.NORMAL || t.LightRenderStyle == (int)GZDoomLightRenderStyle.VAVOOM)
                    lightOffsets[0]++;
                else if (t.LightRenderStyle == (int)GZDoomLightRenderStyle.ADDITIVE)
                    lightOffsets[1]++;
                else
                    lightOffsets[2]++;
            }
        }

        //mxd
        private int sortThingsByCameraDistance(VisualThing t1, VisualThing t2) {
            if (t1.CameraDistance3D == t2.CameraDistance3D) return 0;
            if (t1.CameraDistance3D > t2.CameraDistance3D) return 1;
            return -1;
        }
        //mxd
        private int sortThingsByLightRenderStyle(VisualThing t1, VisualThing t2) {
            if (t1.LightRenderStyle == t2.LightRenderStyle) return 0;
            if (t1.LightRenderStyle > t2.LightRenderStyle) return 1;
            return -1;
        }

        //mxd.
        //I never particularly liked old ThingCages, so I wrote this instead.
        //It should render faster and it has fancy arrow! :)
        private void RenderThingCages() {
            graphics.Device.SetRenderState(RenderState.AlphaBlendEnable, true);
            graphics.Device.SetRenderState(RenderState.AlphaTestEnable, false);
            graphics.Device.SetRenderState(RenderState.ZWriteEnable, false);
            graphics.Device.SetRenderState(RenderState.SourceBlend, Blend.SourceAlpha);
            graphics.Device.SetRenderState(RenderState.DestinationBlend, Blend.SourceAlpha);

            graphics.Shaders.World3D.BeginPass(16);

            foreach (VisualThing t in thingsbydistance) {
                // Setup matrix
                world = Matrix.Multiply(t.CageScales, t.Position);
                ApplyMatrices3D();

                // Setup color
                Color4 thingColor = new Color4();
                if (t.Selected && showselection) {
                    thingColor = General.Colors.Selection3D.ToColorValue();
                } else {
                    thingColor = t.Thing.Color.ToColorValue();
                    if (t != highlighted) thingColor.Alpha = 0.6f;
                }
                graphics.Shaders.World3D.VertexColor = thingColor;

                //Render cage
                graphics.Shaders.World3D.ApplySettings();

				if(t.Sizeless) {
					graphics.Device.SetStreamSource(0, sizelessThingHandle.Shape, 0, WorldVertex.Stride);
					graphics.Device.DrawPrimitives(PrimitiveType.LineList, 0, 3);
				} else {
					graphics.Device.SetStreamSource(0, bbox.Cage, 0, WorldVertex.Stride);
					graphics.Device.DrawPrimitives(PrimitiveType.LineList, 0, 12);
				}

                //and arrow
                float sx = t.CageScales.M11;
                Matrix arrowScaler = Matrix.Scaling(sx, sx, sx); //scale arrow evenly based on thing width\depth
				if(t.Sizeless) {
					world = Matrix.Multiply(arrowScaler, t.Position);
				} else {
					world = Matrix.Multiply(arrowScaler, t.Position * Matrix.Translation(0.0f, 0.0f, t.CageScales.M33 / 2));
				}
                Matrix rot = Matrix.RotationZ(t.Thing.Angle - Angle2D.PI / 2);
                world = Matrix.Multiply(rot, world);
                ApplyMatrices3D();

                graphics.Shaders.World3D.ApplySettings();
                graphics.Device.SetStreamSource(0, bbox.Arrow, 0, WorldVertex.Stride);
                graphics.Device.DrawPrimitives(PrimitiveType.LineList, 0, 5);
            }

            // Done
            graphics.Shaders.World3D.EndPass();
            graphics.Shaders.World3D.SetModulateColor(-1);
            graphics.Device.SetRenderState(RenderState.TextureFactor, -1);
        }

		//mxd
		private void RenderVertices() {
			if(visualvertices == null) return;

			graphics.Shaders.World3D.BeginPass(16);

			foreach(VisualVertex v in visualvertices) {
				world = v.Position;
				ApplyMatrices3D();

				// Setup color
				Color4 color = new Color4();
				if(v.Selected && showselection) {
					color = General.Colors.Selection3D.ToColorValue();
				} else {
					color = General.Colors.InfoLine.ToColorValue();
					if(v != highlighted) color.Alpha = 0.6f;
				}
				graphics.Shaders.World3D.VertexColor = color;

				//Commence drawing!!11
				graphics.Shaders.World3D.ApplySettings();
				graphics.Device.SetStreamSource(0, v.CeilingVertex ? vertexHandle.Upper : vertexHandle.Lower, 0, WorldVertex.Stride);
				graphics.Device.DrawPrimitives(PrimitiveType.LineList, 0, 16);
			}

			// Done
			graphics.Shaders.World3D.EndPass();
		}

        //mxd
        private void renderArrows(List<Line3D> lines, Color4 color) {
            //create vertices
            WorldVertex[] verts = new WorldVertex[lines.Count * 6];
			float scaler = 20f;
			
            for (int i = 0; i < lines.Count; i++) {
                WorldVertex endPoint = new WorldVertex(lines[i].v2);
				float nz = lines[i].GetDelta().GetNormal().z * scaler;
                float angle = lines[i].GetAngle();
                verts[i * 6] = new WorldVertex(lines[i].v1);
                verts[i * 6 + 1] = endPoint;
                verts[i * 6 + 2] = endPoint;
				verts[i * 6 + 3] = new WorldVertex(new Vector3D(lines[i].v2.x - scaler * (float)Math.Sin(angle - 0.46f), lines[i].v2.y + scaler * (float)Math.Cos(angle - 0.46f), lines[i].v2.z - nz));
                verts[i * 6 + 4] = endPoint;
				verts[i * 6 + 5] = new WorldVertex(new Vector3D(lines[i].v2.x - scaler * (float)Math.Sin(angle + 0.46f), lines[i].v2.y + scaler * (float)Math.Cos(angle + 0.46f), lines[i].v2.z - nz));
            }

            VertexBuffer vb = new VertexBuffer(General.Map.Graphics.Device, WorldVertex.Stride * verts.Length, Usage.WriteOnly | Usage.Dynamic, VertexFormat.None, Pool.Default);
            DataStream s = vb.Lock(0, WorldVertex.Stride * verts.Length, LockFlags.Discard);
            s.WriteRange<WorldVertex>(verts);
            vb.Unlock();
            s.Dispose();
            
            //begin rendering
            graphics.Device.SetRenderState(RenderState.AlphaBlendEnable, true);
            graphics.Device.SetRenderState(RenderState.AlphaTestEnable, false);
            graphics.Device.SetRenderState(RenderState.ZWriteEnable, false);
            graphics.Device.SetRenderState(RenderState.SourceBlend, Blend.SourceAlpha);
            graphics.Device.SetRenderState(RenderState.DestinationBlend, Blend.SourceAlpha);

            graphics.Shaders.World3D.BeginPass(16);

            world = Matrix.Identity;
            ApplyMatrices3D();

            // Setup color
			graphics.Shaders.World3D.VertexColor = color;

            //render
            graphics.Shaders.World3D.ApplySettings();
            graphics.Device.SetStreamSource(0, vb, 0, WorldVertex.Stride);
            graphics.Device.DrawPrimitives(PrimitiveType.LineList, 0, lines.Count * 3);

            // Done
            graphics.Shaders.World3D.EndPass();
            graphics.Shaders.World3D.SetModulateColor(-1);
            graphics.Device.SetRenderState(RenderState.TextureFactor, -1);
			vb.Dispose();
        }

		// This performs a single render pass
		private void RenderSinglePass(int pass)
		{
            Color4 fogColor;
            int currentshaderpass = shaderpass;
			int highshaderpass = shaderpass + 2;
			
			// Get geometry for this pass
			Dictionary<ImageData, BinaryHeap<VisualGeometry>> geopass = geometry[pass];

			// Begin rendering with this shader
			graphics.Shaders.World3D.BeginPass(shaderpass);

			// Render the geometry collected
			foreach(KeyValuePair<ImageData, BinaryHeap<VisualGeometry>> group in geopass)
			{
				ImageData curtexture;

				// What texture to use?
				if(group.Key is UnknownImage)
					curtexture = General.Map.Data.UnknownTexture3D;
				else if((group.Key != null) && group.Key.IsImageLoaded && !group.Key.IsDisposed)
					curtexture = group.Key;
				else
					curtexture = General.Map.Data.Hourglass3D;

				// Create Direct3D texture if still needed
				if((curtexture.Texture == null) || curtexture.Texture.Disposed)
					curtexture.CreateTexture();

				// Apply texture
				if(!graphics.Shaders.Enabled) graphics.Device.SetTexture(0, curtexture.Texture);
				graphics.Shaders.World3D.Texture1 = curtexture.Texture;
				
				// Go for all geometry that uses this texture
				VisualSector sector = null;
                
				foreach(VisualGeometry g in group.Value)
				{
					// Changing sector?
					if(!object.ReferenceEquals(g.Sector, sector))
					{
						// Update the sector if needed
						if(g.Sector.NeedsUpdateGeo) g.Sector.Update();

						// Only do this sector when a vertexbuffer is created
                        //mxd. no Map means that sector was deleted recently, I suppose
                        if (g.Sector.GeometryBuffer != null && g.Sector.Sector.Map != null) 
						{
							// Change current sector
							sector = g.Sector;

							// Set stream source
							graphics.Device.SetStreamSource(0, sector.GeometryBuffer, 0, WorldVertex.Stride);
						}
						else
						{
							sector = null;
						}
					}

                    if (sector != null) 
					{
						// Determine the shader pass we want to use for this object
						int wantedshaderpass = (((g == highlighted) && showhighlight) || (g.Selected && showselection)) ? highshaderpass : shaderpass;

                        //mxd
                        if (General.Settings.GZDrawFog && !fullbrightness && sector.Sector.Brightness < 248)
                            wantedshaderpass += 8;

                        //mxd. Seems that lines rendered with RenderPass.Alpha or RenderPass.Additive aren't affected by dynamic lights in GZDoom
                        if (g.RenderPass != RenderPass.Alpha && g.RenderPass != RenderPass.Additive && General.Settings.GZDrawLights && !fullbrightness && thingsWithLight.Count > 0) {
                            if (curtexture.Texture != null) {
                                if (!litGeometry.ContainsKey(curtexture.Texture))
                                    litGeometry[curtexture.Texture] = new List<VisualGeometry>();
                                litGeometry[curtexture.Texture].Add(g);
                            }
                        }

						// Switch shader pass?
						if(currentshaderpass != wantedshaderpass)
						{
							graphics.Shaders.World3D.EndPass();
							graphics.Shaders.World3D.BeginPass(wantedshaderpass);
							currentshaderpass = wantedshaderpass;
						}
						
						// Set the colors to use
						if(!graphics.Shaders.Enabled)
						{
							graphics.Device.SetTexture(2, (g.Selected && showselection) ? selectionimage.Texture : null);
							graphics.Device.SetTexture(3, ((g == highlighted) && showhighlight) ? highlightimage.Texture : null);
						}
						else
						{
                            //mxd. set variables for fog rendering
                            if (wantedshaderpass > 7) {
                                graphics.Shaders.World3D.World = world;

                                bool sectorHasFogColor = getFogColor(sector.Sector, out fogColor);
                                graphics.Shaders.World3D.LightColor = fogColor;
                                graphics.Shaders.World3D.CameraPosition = new Vector4(cameraposition.x, cameraposition.y, cameraposition.z, getFogEnd(sector.Sector, sectorHasFogColor));
                            }
                            
                            graphics.Shaders.World3D.SetHighlightColor(CalculateHighlightColor((g == highlighted) && showhighlight, (g.Selected && showselection)).ToArgb());
							graphics.Shaders.World3D.ApplySettings();
						}
						
						// Render!
						graphics.Device.DrawPrimitives(PrimitiveType.TriangleList, g.VertexOffset, g.Triangles);
					}
				}
			}

			// Get things for this pass
			Dictionary<ImageData, List<VisualThing>> thingspass = things[pass];
			if(thingspass.Count > 0)
			{
				// Texture addressing
				graphics.Device.SetSamplerState(0, SamplerState.AddressU, TextureAddress.Clamp);
				graphics.Device.SetSamplerState(0, SamplerState.AddressV, TextureAddress.Clamp);
				graphics.Device.SetSamplerState(0, SamplerState.AddressW, TextureAddress.Clamp);

				// Render things collected
				foreach(KeyValuePair<ImageData, List<VisualThing>> group in thingspass)
				{
                    ImageData curtexture;

					if(!(group.Key is UnknownImage))
					{
						// What texture to use?
						if((group.Key != null) && group.Key.IsImageLoaded && !group.Key.IsDisposed)
							curtexture = group.Key;
						else
							curtexture = General.Map.Data.Hourglass3D;

						// Create Direct3D texture if still needed
						if((curtexture.Texture == null) || curtexture.Texture.Disposed)
							curtexture.CreateTexture();

						// Apply texture
						if(!graphics.Shaders.Enabled) graphics.Device.SetTexture(0, curtexture.Texture);
						graphics.Shaders.World3D.Texture1 = curtexture.Texture;

						// Render all things with this texture
						foreach(VisualThing t in group.Value)
						{
                            //mxd
                            if (General.Settings.GZDrawModels && (!General.Settings.GZDrawSelectedModelsOnly || t.Selected) && t.Thing.IsModel)
                                continue;

                            // Update buffer if needed
                            t.Update();

                            // Only do this sector when a vertexbuffer is created
                            if (t.GeometryBuffer != null) {
                                // Determine the shader pass we want to use for this object
                                int wantedshaderpass = (((t == highlighted) && showhighlight) || (t.Selected && showselection)) ? highshaderpass : shaderpass;

                                //mxd. if fog is enagled, switch to shader, which calculates it
                                if (General.Settings.GZDrawFog && !fullbrightness && t.Thing.Sector != null && t.Thing.Sector.Brightness < 248)
                                    wantedshaderpass += 8;

                                //mxd. if current thing is light - set it's color to light color
                                if (Array.IndexOf(GZBuilder.GZGeneral.GZ_LIGHTS, t.Thing.Type) != -1 && !fullbrightness) {
                                    wantedshaderpass += 4; //render using one of passes, which uses World3D.VertexColor
                                    graphics.Shaders.World3D.VertexColor = t.LightColor;
                                    //mxd. check if Thing is affected by dynamic lights and set color accordingly
                                } else if (General.Settings.GZDrawLights && !fullbrightness && thingsWithLight.Count > 0) {
                                    Color4 litColor = getLitColorForThing(t);
                                    if (litColor.ToArgb() != 0) {
                                        wantedshaderpass += 4; //render using one of passes, which uses World3D.VertexColor
                                        graphics.Shaders.World3D.VertexColor = new Color4(t.VertexColor) + litColor;
                                    }
                                }

                                // Switch shader pass?
                                if (currentshaderpass != wantedshaderpass) {
                                    graphics.Shaders.World3D.EndPass();
                                    graphics.Shaders.World3D.BeginPass(wantedshaderpass);
                                    currentshaderpass = wantedshaderpass;
                                }

                                // Set the colors to use
                                if (!graphics.Shaders.Enabled) {
                                    graphics.Device.SetTexture(2, (t.Selected && showselection) ? selectionimage.Texture : null);
                                    graphics.Device.SetTexture(3, ((t == highlighted) && showhighlight) ? highlightimage.Texture : null);
                                } else {
                                    graphics.Shaders.World3D.SetHighlightColor(CalculateHighlightColor((t == highlighted) && showhighlight, (t.Selected && showselection)).ToArgb());
                                }

                                // Create the matrix for positioning / rotation
                                world = t.Orientation;
                                if (t.Billboard) world = Matrix.Multiply(world, billboard);
                                world = Matrix.Multiply(world, t.Position);
                                ApplyMatrices3D();

                                //mxd. set variables for fog rendering
                                if (wantedshaderpass > 7) {
                                    graphics.Shaders.World3D.World = world;

                                    bool sectorHasFogColor = getFogColor(t.Thing.Sector, out fogColor);
                                    graphics.Shaders.World3D.LightColor = fogColor;
                                    graphics.Shaders.World3D.CameraPosition = new Vector4(cameraposition.x, cameraposition.y, cameraposition.z, getFogEnd(t.Thing.Sector, sectorHasFogColor));
                                }

                                graphics.Shaders.World3D.ApplySettings();

                                // Apply buffer
                                graphics.Device.SetStreamSource(0, t.GeometryBuffer, 0, WorldVertex.Stride);

                                // Render!
                                graphics.Device.DrawPrimitives(PrimitiveType.TriangleList, 0, t.Triangles);
                            }
						}
					}
				}

                // Texture addressing
                graphics.Device.SetSamplerState(0, SamplerState.AddressU, TextureAddress.Wrap);
                graphics.Device.SetSamplerState(0, SamplerState.AddressV, TextureAddress.Wrap);
                graphics.Device.SetSamplerState(0, SamplerState.AddressW, TextureAddress.Wrap);
			}

			// Done rendering with this shader
			graphics.Shaders.World3D.EndPass();
		}

        //mxd. Dynamic lights pass!
        private void RenderLights(Dictionary<Texture, List<VisualGeometry>> geometry_to_lit, List<VisualThing> lights) {
			graphics.Shaders.World3D.World = Matrix.Identity;
            graphics.Shaders.World3D.BeginPass(17);

            int i, count;
            Vector4 lpr;

            graphics.Device.SetRenderState(RenderState.SourceBlend, Blend.One);
            graphics.Device.SetRenderState(RenderState.DestinationBlend, Blend.BlendFactor);

            foreach (KeyValuePair<Texture, List<VisualGeometry>> group in geometry_to_lit) {
                graphics.Shaders.World3D.Texture1 = group.Key;

                foreach (VisualGeometry g in group.Value) {
                    i = 0;
                    count = 0;

                    graphics.Device.SetStreamSource(0, g.Sector.GeometryBuffer, 0, WorldVertex.Stride);

                    //normal lights
                    count = lightOffsets[0];
                    if (lightOffsets[0] > 0) {
                        graphics.Device.SetRenderState(RenderState.BlendOperation, BlendOperation.Add);

                        for (i = 0; i < count; i++) {
                            if (checkBBoxIntersection(g.BoundingBox, lights[i].BoundingBox)) {
								lpr = new Vector4(lights[i].Center, lights[i].LightRadius);
                                if (lpr.W == 0)
                                    continue;
                                graphics.Shaders.World3D.LightColor = lights[i].LightColor;
                                graphics.Shaders.World3D.LightPositionAndRadius = lpr;
                                graphics.Shaders.World3D.ApplySettings();
                                graphics.Device.DrawPrimitives(PrimitiveType.TriangleList, g.VertexOffset, g.Triangles);
                            }
                        }
                    }

                    //additive lights.
                    if (lightOffsets[1] > 0) {
                        count += lightOffsets[1];
                        graphics.Device.SetRenderState(RenderState.BlendOperation, BlendOperation.Add);

                        for (i = lightOffsets[0]; i < count; i++) {
                            if (checkBBoxIntersection(g.BoundingBox, lights[i].BoundingBox)) {
                                lpr = new Vector4(lights[i].Center, lights[i].LightRadius);
                                if (lpr.W == 0)
                                    continue;
                                graphics.Shaders.World3D.LightColor = lights[i].LightColor;
                                graphics.Shaders.World3D.LightPositionAndRadius = lpr;
                                graphics.Shaders.World3D.ApplySettings();
                                graphics.Device.DrawPrimitives(PrimitiveType.TriangleList, g.VertexOffset, g.Triangles);
                           }
                        }
                    }

                    //negative lights
                    if (lightOffsets[2] > 0) {
                        count += lightOffsets[2];
                        graphics.Device.SetRenderState(RenderState.BlendOperation, BlendOperation.ReverseSubtract);

                        for (i = lightOffsets[0] + lightOffsets[1]; i < count; i++) {
                            if (checkBBoxIntersection(g.BoundingBox, lights[i].BoundingBox)) {
                                lpr = new Vector4(lights[i].Center, lights[i].LightRadius);
                                if (lpr.W == 0)
                                    continue;
                                Color4 lc = lights[i].LightColor;
                                graphics.Shaders.World3D.LightColor = new Color4(lc.Alpha, (lc.Green + lc.Blue) / 2, (lc.Red + lc.Blue) / 2, (lc.Green + lc.Red) / 2);
                                graphics.Shaders.World3D.LightPositionAndRadius = lpr;
                                graphics.Shaders.World3D.ApplySettings();
                                graphics.Device.DrawPrimitives(PrimitiveType.TriangleList, g.VertexOffset, g.Triangles);
                            }
                        }
                    }
                }
            }

            graphics.Shaders.World3D.EndPass();
            graphics.Device.SetRenderState(RenderState.BlendOperation, BlendOperation.Add);
        }

        //mxd. render models
        private void RenderModels() {
            Color4 fogColor;
            int shaderpass = fullbrightness ? 1 : 4;
            int currentshaderpass = shaderpass;
            int highshaderpass = shaderpass + 2;

            // Begin rendering with this shader
            graphics.Shaders.World3D.BeginPass(currentshaderpass);

            foreach (KeyValuePair<ModeldefEntry, List<VisualThing>> group in thingsWithModel) {
                foreach (VisualThing t in group.Value) {
                    t.Update();
                    
                    Color4 vertexColor = new Color4(t.VertexColor);
                    vertexColor.Alpha = 1.0f;
                    //check if model is affected by dynamic lights and set color accordingly
                    if (General.Settings.GZDrawLights && !fullbrightness && thingsWithLight.Count > 0) {
                        Color4 litColor = getLitColorForThing(t);
                        graphics.Shaders.World3D.VertexColor = vertexColor + litColor;
                    } else {
                        graphics.Shaders.World3D.VertexColor = vertexColor;
                    }

                    // Determine the shader pass we want to use for this object
                    int wantedshaderpass = ((((t == highlighted) && showhighlight) || (t.Selected && showselection)) ? highshaderpass : shaderpass);

                    //mxd. if fog is enagled, switch to shader, which calculates it
                    if (General.Settings.GZDrawFog && !fullbrightness && t.Thing.Sector != null && t.Thing.Sector.Brightness < 248)
                        wantedshaderpass += 8;

                    // Switch shader pass?
                    if (currentshaderpass != wantedshaderpass) {
                        graphics.Shaders.World3D.EndPass();
                        graphics.Shaders.World3D.BeginPass(wantedshaderpass);
                        currentshaderpass = wantedshaderpass;
                    }

                    // Set the colors to use
                    if (!graphics.Shaders.Enabled) {
                        graphics.Device.SetTexture(2, (t.Selected && showselection) ? selectionimage.Texture : null);
                        graphics.Device.SetTexture(3, ((t == highlighted) && showhighlight) ? highlightimage.Texture : null);
                    } else {
                        graphics.Shaders.World3D.SetHighlightColor(CalculateHighlightColor((t == highlighted) && showhighlight, (t.Selected && showselection)).ToArgb());
                    }

                    // Create the matrix for positioning / rotation
                    world = Matrix.Multiply(t.Orientation, Matrix.RotationZ(t.Thing.Angle));
                    world = Matrix.Multiply(world, t.Position);
                    ApplyMatrices3D();

                    //mxd. set variables for fog rendering
                    if (wantedshaderpass > 7) {
                        graphics.Shaders.World3D.World = world;

                        bool sectorHasFogColor = getFogColor(t.Thing.Sector, out fogColor);
                        graphics.Shaders.World3D.LightColor = fogColor;
                        graphics.Shaders.World3D.CameraPosition = new Vector4(cameraposition.x, cameraposition.y, cameraposition.z, getFogEnd(t.Thing.Sector, sectorHasFogColor));
                    }

					for(int i = 0; i < group.Key.Model.Meshes.Count; i++) {
                        if (!graphics.Shaders.Enabled) graphics.Device.SetTexture(0, group.Key.Model.Textures[i]);
                        graphics.Shaders.World3D.Texture1 = group.Key.Model.Textures[i];
                        graphics.Shaders.World3D.ApplySettings();

                        // Render!
                        group.Key.Model.Meshes[i].DrawSubset(0);
                    }
                }
            }
            graphics.Shaders.World3D.EndPass();
        }

        //mxd. This gets color from dynamic lights based on distance to thing. 
        //thing position must be in absolute cordinates 
        //(thing.Position.Z value is relative to floor of the sector the thing is in)
        private Color4 getLitColorForThing(VisualThing t) {
            Color4 litColor = new Color4();
            float radius, radiusSquared, distSquared, scaler;
            int sign;

            for (int i = 0; i < thingsWithLight.Count; i++ ) {
                //don't light self
                if (General.Map.Data.GldefsEntries.ContainsKey(t.Thing.Type) && General.Map.Data.GldefsEntries[t.Thing.Type].DontLightSelf && t.Thing.Index == thingsWithLight[i].Thing.Index) {
                    continue;
                }

                distSquared = Vector3.DistanceSquared(thingsWithLight[i].Center, t.PositionV3);
                radius = thingsWithLight[i].LightRadius;
                radiusSquared = radius * radius;
                if (distSquared < radiusSquared) {
                    sign = thingsWithLight[i].LightRenderStyle == (int)GZDoomLightRenderStyle.NEGATIVE ? -1 : 1;
                    scaler = 1 - distSquared / radiusSquared * thingsWithLight[i].LightColor.Alpha;
                    litColor.Red += thingsWithLight[i].LightColor.Red * scaler * sign;
                    litColor.Green += thingsWithLight[i].LightColor.Green * scaler * sign;
                    litColor.Blue += thingsWithLight[i].LightColor.Blue * scaler * sign;
                }
            }
            return litColor;
        }

        //mxd. This returns distance, at which fog color completely replaces texture color for given sector
        private float getFogEnd(Sector s, bool sectorHasFogColor) {
            float brightness = (float)Math.Max(30, s.Brightness);
            if (sectorHasFogColor) {
                return brightness * 11.0f;
            }
            return (float)Math.Pow(2.0f, brightness / 11.0f);
        }

        //mxd. returns true if sector has fog color
        private bool getFogColor(Sector sector, out Color4 color) {
            if (General.Map.UDMF && sector.Fields.ContainsKey("fadecolor")) {
                color = new Color4((int)sector.Fields["fadecolor"].Value);
                return true;
            } else if (General.Map.Data.MapInfo.HasOutsideFogColor && sector.CeilTexture == General.Map.Config.SkyFlatName) {
                color = General.Map.Data.MapInfo.OutsideFogColor;
                return true;
            } else if (General.Map.Data.MapInfo.HasFadeColor) {
                color = General.Map.Data.MapInfo.FadeColor;
                return true;
            }
            color = new Color4(); //black
            return false;
        }

		// This calculates the highlight/selection color
		public Color4 CalculateHighlightColor(bool ishighlighted, bool isselected)
		{
			Color4 highlightcolor = isselected ? General.Colors.Selection.ToColorValue() : General.Colors.Highlight.ToColorValue();
			highlightcolor.Alpha = ishighlighted ? highlightglowinv : highlightglow;
			return highlightcolor;
		}
		
		// This finishes rendering
		public void Finish()
		{
			General.Plugins.OnPresentDisplayBegin();

			// Done
			graphics.FinishRendering();
			graphics.Present();
			highlighted = null;
		}
		
		#endregion
		
		#region ================== Rendering
		
		// This sets the highlighted object for the rendering
		public void SetHighlightedObject(IVisualPickable obj)
		{
			highlighted = obj;
		}
		
		// This collects a visual sector's geometry for rendering
		public void AddSectorGeometry(VisualGeometry g)
		{
			// Must have a texture and vertices
			if((g.Texture != null) && (g.Triangles > 0))
			{
                // Texture group not yet collected?
				if(!geometry[g.RenderPassInt].ContainsKey(g.Texture))
				{
					// Create texture group
					geometry[g.RenderPassInt].Add(g.Texture, new BinaryHeap<VisualGeometry>());
				}
				
				// Add geometry to texture group
				geometry[g.RenderPassInt][g.Texture].Add(g);
			}
		}

		// This collects a visual sector's geometry for rendering
		public void AddThingGeometry(VisualThing t)
		{
            //mxd. gater lights
            if (General.Settings.GZDrawLights && !fullbrightness && t.LightType != -1) {
                t.UpdateLightRadius();

                if (t.LightRadius > 0) {
                    t.CalculateCameraDistance3D(D3DDevice.V3(cameraposition));
                    //t.CameraDistance3D is actually squared distance, hence (t.LightRadius * t.LightRadius)
                    if (t.CameraDistance3D < (t.LightRadius * t.LightRadius) || isThingOnScreen(t.BoundingBox)) { //always render light if camera is within it's radius 
                        if (Array.IndexOf(GZBuilder.GZGeneral.GZ_ANIMATED_LIGHT_TYPES, t.LightType) != -1)
                            t.UpdateBoundingBox();
                        thingsWithLight.Add(t);
                    }
                }
            }

            if (!isThingOnScreen(t.BoundingBox)) {
                return;
            }

            //mxd. gather models
            if (General.Settings.GZDrawModels && (!General.Settings.GZDrawSelectedModelsOnly || t.Selected) && t.Thing.IsModel) {
                ModeldefEntry mde = General.Map.Data.ModeldefEntries[t.Thing.Type];
                if (!thingsWithModel.ContainsKey(mde)) 
                    thingsWithModel.Add(mde, new List<VisualThing>());
                thingsWithModel[mde].Add(t);
            }
            
            // Make sure the distance to camera is calculated
            t.CalculateCameraDistance(cameraposition);
            thingsbydistance.Add(t);

            // Must have a texture!
            if(t.Texture != null) 
			{
				// Texture group not yet collected?
				if(!things[t.RenderPassInt].ContainsKey(t.Texture))
				{
					// Create texture group
					things[t.RenderPassInt].Add(t.Texture, new List<VisualThing>());
				}

				// Add geometry to texture group
				things[t.RenderPassInt][t.Texture].Add(t);
			}
		}

		//mxd
		public void AddVisualVertices(VisualVertex[] verts) {
			visualvertices = verts;
		}

        //mxd
        private bool isThingOnScreen(Vector3[] bbox) {
            Vector3D camNormal = Vector3D.FromAngleXYZ(General.Map.VisualCamera.AngleXY, General.Map.VisualCamera.AngleZ);
            Vector3D thingNormal = D3DDevice.V3D(bbox[0]) - cameraposition; //bbox[0] is always thing center

            if (Vector3D.DotProduct(camNormal, thingNormal) < 0) return false; //behind camera plane

            int len = bbox.Length;
            Vector3 screenPos;
            int behindCount = 0;
            int leftCount = 0;
            int rightCount = 0;
            int topCount = 0;
            int bottomCount = 0;

            for (int i = 0; i < len; i++) {
                //check visibility
                screenPos = Vector3.Project(bbox[i], 0, 0, 1, 1, PROJ_NEAR_PLANE, General.Settings.ViewDistance, worldviewproj);

                if (screenPos.X > 0 && screenPos.X < 1 && screenPos.Y > 0 && screenPos.Y < 1)
                    return true;

                if (screenPos.Z < 0)
                    behindCount++;

                if (screenPos.X < 0)
                    leftCount++;
                else if (screenPos.X > 1)
                    rightCount++;
                if (screenPos.Y < 0)
                    topCount++;
                else if (screenPos.Y > 1)
                    bottomCount++;
            }

            bool notOnScreen = (behindCount == len || leftCount == len || rightCount == len || topCount == len || bottomCount == len);
            return !notOnScreen;
        }

        //mxd
        private static bool checkBBoxIntersection(Vector3[] bbox1, Vector3[] bbox2) {
            Vector3 dist = bbox1[0] - bbox2[0];

            Vector3 halfSize1 = bbox1[0] - bbox1[1];
            Vector3 halfSize2 = bbox2[0] - bbox2[1];

            if (halfSize1.X + halfSize2.X >= Math.Abs(dist.X) && halfSize1.Y + halfSize2.Y >= Math.Abs(dist.Y) && halfSize1.Z + halfSize2.Z >= Math.Abs(dist.Z))
                return true;
            return false;
        }

		// This renders the crosshair
		public void RenderCrosshair()
		{
			// Set renderstates
            graphics.Device.SetRenderState(RenderState.CullMode, Cull.None);
            graphics.Device.SetRenderState(RenderState.ZEnable, false);
            graphics.Device.SetRenderState(RenderState.AlphaBlendEnable, true);
            graphics.Device.SetRenderState(RenderState.AlphaTestEnable, false);
            graphics.Device.SetRenderState(RenderState.SourceBlend, Blend.SourceAlpha);
            graphics.Device.SetRenderState(RenderState.DestinationBlend, Blend.InverseSourceAlpha);
            graphics.Device.SetRenderState(RenderState.TextureFactor, -1);
            graphics.Device.SetTransform(TransformState.World, Matrix.Identity);
            graphics.Device.SetTransform(TransformState.Projection, Matrix.Identity);
            ApplyMatrices2D();
			
            // Texture
            if(crosshairbusy)
            {
                if(General.Map.Data.CrosshairBusy3D.Texture == null) General.Map.Data.CrosshairBusy3D.CreateTexture();
                graphics.Device.SetTexture(0, General.Map.Data.CrosshairBusy3D.Texture);
                graphics.Shaders.Display2D.Texture1 = General.Map.Data.CrosshairBusy3D.Texture;
            }
            else
            {
                if(General.Map.Data.Crosshair3D.Texture == null) General.Map.Data.Crosshair3D.CreateTexture();
                graphics.Device.SetTexture(0, General.Map.Data.Crosshair3D.Texture);
                graphics.Shaders.Display2D.Texture1 = General.Map.Data.Crosshair3D.Texture;
            }
			
            // Draw
            graphics.Shaders.Display2D.Begin();
            graphics.Shaders.Display2D.SetSettings(1.0f, 1.0f, 0.0f, 1.0f, true);
            graphics.Shaders.Display2D.BeginPass(1);
            graphics.Device.DrawUserPrimitives<FlatVertex>(PrimitiveType.TriangleStrip, 0, 2, crosshairverts);
            graphics.Shaders.Display2D.EndPass();
            graphics.Shaders.Display2D.End();
        }

		// This switches fog on and off
		public void SetFogMode(bool usefog)
		{
			graphics.Device.SetRenderState(RenderState.FogEnable, usefog);
		}

		// This siwtches crosshair busy icon on and off
		public void SetCrosshairBusy(bool busy)
		{
			crosshairbusy = busy;
		}

        //mxd. dbg
        //private int lastTick, lastFrameRate, frameRate;

        /*private int calculateFrameRate() {
            if (System.Environment.TickCount - lastTick >= 1000) {
                lastFrameRate = frameRate;
                frameRate = 0;
                lastTick = System.Environment.TickCount;
            }
            frameRate++;
            return lastFrameRate;
        }*/
		
		#endregion
	}
}