www.pudn.com > IntroductionTo3DGameEngineDesign.rar > BillBoard.cs
using System;
using System.Collections;
using System.Drawing;
using Microsoft.DirectX;
using Microsoft.DirectX.Direct3D;
namespace GameEngine
{
///
/// Summary description for BillBoard.
///
public class BillBoard : Object3D, IDisposable
{
#region Attributes
private CustomVertex.PositionNormalTextured[] m_Corners;
private Texture m_Texture; // image for face
private bool m_bValid = false;
private string m_sTexture;
private static string m_sLastTexture;
private static VertexBuffer m_VB;
private static Matrix m_TheMatrix;
private static ArrayList m_List = new ArrayList();
public static ArrayList Objects { get { return m_List; } }
public bool Valid { get { return m_bValid; } }
#endregion
private static void SetupMatrix( Camera cam )
{
// Set up a rotation matrix to orient the billboard towards the camera.
Vector3 vDir = Vector3.Subtract(cam.LookAtVector, cam.EyeVector);
if( vDir.X > 0.001f )
m_TheMatrix = Matrix.RotationY( (float)(-Math.Atan(vDir.Z/vDir.X)+Math.PI/2) );
else if( vDir.X < -0.001f )
m_TheMatrix = Matrix.RotationY( (float)(-Math.Atan(vDir.Z/vDir.X)-Math.PI/2) );
else
{
if ( cam.Heading < 179.0f || cam.Heading > 181.0f )
m_TheMatrix = Matrix.Identity;
else
m_TheMatrix = Matrix.RotationY( (float)Math.PI );
}
}
public static void Add( float north, float east, float altitude, string sName,
string sTextureName, float fWidth, float fHeight)
{
BillBoard obj;
if ( sTextureName.CompareTo(m_sLastTexture) == 0 )
{
BillBoard lastObject = (BillBoard)m_List[m_List.Count-1];
obj = new BillBoard(sName,lastObject);
}
else
{
obj = new BillBoard(sName, sTextureName, fWidth, fHeight);
}
m_sLastTexture = sTextureName;
float height = CGameEngine.Ground.TerrainHeight(east,north);
if ( altitude < height )
{
altitude = height;
}
obj.m_vPosition.X = east;
obj.m_vPosition.Y = altitude;
obj.m_vPosition.Z = north;
try
{
m_List.Add( obj );
CGameEngine.QuadTree.AddObject((Object3D)obj);
}
catch (DirectXException d3de)
{
Console.AddLine("Unable to add billboard " + sName);
Console.AddLine(d3de.ErrorString);
}
catch ( Exception e )
{
Console.AddLine("Unable to add billboard " + sName);
Console.AddLine(e.Message);
}
}
public BillBoard(string sName, BillBoard other) : base( sName )
{
m_sName = sName;
Copy(other);
}
public BillBoard(string sName, string sTextureName, float fWidth, float fHeight) : base( sName )
{
m_sName = sName;
m_sTexture = sTextureName;
m_fRadius = fWidth / 2.0f;
// create the vertices for the box
m_Corners = new CustomVertex.PositionNormalTextured[4];
m_Corners[0].X = m_fRadius; // upper left
m_Corners[0].Y = fHeight; // upper left
m_Corners[0].Z = 0.0f; // upper left
m_Corners[0].Tu = 1.0f;
m_Corners[0].Tv = 0.0f;
m_Corners[0].Nx = 0.0f;
m_Corners[0].Ny = 0.0f;
m_Corners[0].Nz = -1.0f;
m_Corners[1].X = -m_fRadius; // upper right
m_Corners[1].Y = fHeight; // upper right
m_Corners[1].Z = 0.0f; // upper right
m_Corners[1].Tu = 0.0f;
m_Corners[1].Tv = 0.0f;
m_Corners[1].Nx = 0.0f;
m_Corners[1].Ny = 0.0f;
m_Corners[1].Nz = -1.0f;
m_Corners[2].X = m_fRadius; // lower left
m_Corners[2].Y = 0.0f; // lower left
m_Corners[2].Z = 0.0f; // lower left
m_Corners[2].Tu = 1.0f;
m_Corners[2].Tv = 1.0f;
m_Corners[2].Nx = 0.0f;
m_Corners[2].Ny = 0.0f;
m_Corners[2].Nz = -1.0f;
m_Corners[3].X = -m_fRadius; // lower right
m_Corners[3].Y = 0.0f; // lower right
m_Corners[3].Z = 0.0f; // lower right
m_Corners[3].Tu = 0.0f;
m_Corners[3].Tv = 1.0f;
m_Corners[3].Nx = 0.0f;
m_Corners[3].Ny = 0.0f;
m_Corners[3].Nz = -1.0f;
// load the texture for the face
try
{
m_Texture = GraphicsUtility.CreateTexture(CGameEngine.Device3D, sTextureName);
m_bValid = true;
}
catch
{
Console.AddLine("Unable to create billboard texture for " + sName);
}
}
private void Copy(BillBoard other)
{
m_sTexture = other.m_sTexture;
m_fRadius = other.m_fRadius;
// create the vertices for the box
m_Corners = other.m_Corners;
m_bValid = true;
}
public static void RenderAll( Camera cam )
{
string currentTexture = "";
if ( m_List.Count > 0 )
{
CGameEngine.Device3D.RenderState.CullMode = Microsoft.DirectX.Direct3D.Cull.Clockwise;
// Set diffuse blending for alpha set in vertices.
CGameEngine.Device3D.RenderState.AlphaBlendEnable = true;
CGameEngine.Device3D.RenderState.SourceBlend = Blend.SourceAlpha;
CGameEngine.Device3D.RenderState.DestinationBlend = Blend.InvSourceAlpha;
// Enable alpha testing (skips pixels with less than a certain alpha.)
if( CGameEngine.Device3D.DeviceCaps.AlphaCompareCaps.SupportsGreaterEqual )
{
CGameEngine.Device3D.RenderState.AlphaTestEnable = true;
CGameEngine.Device3D.RenderState.ReferenceAlpha = 0x08;
CGameEngine.Device3D.RenderState.AlphaFunction = Compare.GreaterEqual;
}
SetupMatrix( cam );
CGameEngine.Device3D.VertexFormat = CustomVertex.PositionNormalTextured.Format;
if ( m_VB == null )
{
m_VB = new VertexBuffer(typeof(CustomVertex.PositionNormalTextured),
4, CGameEngine.Device3D, Usage.WriteOnly, CustomVertex.PositionNormalTextured.Format, Pool.Default );
}
CGameEngine.Device3D.SetStreamSource( 0, m_VB, 0 );
foreach ( BillBoard obj in m_List )
{
if ( currentTexture.CompareTo(obj.m_sTexture) != 0 )
{
m_VB.SetData(obj.m_Corners, 0, 0);
// Set the texture
CGameEngine.Device3D.SetTexture(0, obj.m_Texture );
currentTexture = obj.m_sTexture;
}
obj.Render( cam );
}
foreach ( BillBoard obj in m_List )
{
obj.RenderChildren( cam );
}
}
}
public override void Render( Camera cam )
{
if ( Visible && m_bValid && !IsCulled )
{
// Translate the billboard into place
m_TheMatrix.M41 = m_vPosition.X;
m_TheMatrix.M42 = m_vPosition.Y;
m_TheMatrix.M43 = m_vPosition.Z;
CGameEngine.Device3D.Transform.World = m_TheMatrix;
// Render the face
CGameEngine.Device3D.DrawPrimitives( PrimitiveType.TriangleStrip, 0, 2 );
}
}
public void RenderChildren( Camera cam )
{
if ( Visible && m_bValid && !IsCulled )
{
// Translate the billboard into place
CGameEngine.Device3D.Transform.World = m_TheMatrix;
Culled = true;
if ( m_Children.Count > 0 )
{
Object3D obj;
for ( int i=0; i 0 )
{
Object3D obj;
for ( int i=0; i