www.pudn.com > raytrace.rar > Plane.cls, change:2000-12-16,size:5895b

VERSION 1.0 CLASS 
BEGIN 
  MultiUse = -1  'True 
  Persistable = 0  'NotPersistable 
  DataBindingBehavior = 0  'vbNone 
  DataSourceBehavior  = 0  'vbNone 
  MTSTransactionMode  = 0  'NotAnMTSObject 
END 
Attribute VB_Name = "Plane" 
Attribute VB_GlobalNameSpace = False 
Attribute VB_Creatable = True 
Attribute VB_PredeclaredId = False 
Attribute VB_Exposed = False 
Option Explicit 
 
' Infinite plane 
 
Implements RayTraceable 
 
' Position 
Private Point1 As Point3D ' A point on the plane 
Private Point2 As Point3D ' point2-point1 = surface normal 
' This way to calculate the normal makes sure the normal 
' is not distorted after applying a transformation matrix 
' to the plane 
 
' Lighting values: 
' Ambient: 
Private AmbKr As Single 
Private AmbKg As Single 
Private AmbKb As Single 
' Diffuse 
Private DiffKr As Single 
Private DiffKg As Single 
Private DiffKb As Single 
' Specular 
Private Spec_K As Single 
Private Spec_N As Single 
' Reflected factor 
Private ReflKr As Single 
Private ReflKg As Single 
Private ReflKb As Single 
 
' Culling values 
' True if we had a hit on this scanline 
Private HadHit As Boolean 
' True if we had a hit on previous scanline 
Private HadHitPrev As Boolean 
' True if we are culled forever 
Private ForeverCulled As Boolean 
' True if we are done on this scanline 
Private ScanlineDone As Boolean 
 
' Find the unit surface normal 
Public Sub GetUNormal(ByRef Nx As Single, ByRef Ny As Single, ByRef Nz As Single) 
    Dim Nlen As Single 
    Nx = Point2.Trans(1) - Point1.Trans(1) 
    Ny = Point2.Trans(2) - Point1.Trans(2) 
    Nz = Point2.Trans(3) - Point1.Trans(3) 
    Nlen = Sqr(Nx * Nx + Ny * Ny + Nz * Nz) 
    Nx = Nx / Nlen 
    Ny = Ny / Nlen 
    Nz = Nz / Nlen 
End Sub 
 
Public Sub RayTraceable_Apply(M() As Single) 
    m3Apply Point1.Coord, M, Point1.Trans 
    m3Apply Point2.Coord, M, Point2.Trans 
End Sub 
 
Public Sub RayTraceable_ApplyFull(M() As Single) 
    m3ApplyFull Point1.Coord, M, Point1.Trans 
    m3ApplyFull Point2.Coord, M, Point2.Trans 
End Sub 
 
Public Sub RayTraceable_CullScanline(ByVal px As Single, ByVal py As Single, ByVal pz As Single, ByVal Nx As Single, ByVal Ny As Single, ByVal Nz As Single) 
    ' Do not cull planes 
    ScanlineDone = False 
End Sub 
 
Public Sub RayTraceable_FindHitColor(Objects As Collection, ByVal eyeX As Single, ByVal eyeY As Single, ByVal eyeZ As Single, ByVal px As Single, ByVal py As Single, ByVal pz As Single, R As Integer, G As Integer, B As Integer) 
    Dim Nx As Single 
    Dim Ny As Single 
    Dim Nz As Single 
    Dim Vx As Single 
    Dim Vy As Single 
    Dim Vz As Single 
    Dim NdotV As Single 
     
    ' Get the unit normal 
    GetUNormal Nx, Ny, Nz 
     
    ' Make sure the normal points towards the eye 
    Vx = Eye_X - px 
    Vy = Eye_Y - py 
    Vz = Eye_Z - pz 
    NdotV = Nx * Vx + Ny * Vy + Nz * Vz 
    If NdotV  0 Then 
        Nx = -Nx 
        Ny = -Ny 
        Nz = -Nz 
    End If 
     
    ' Calculate the hit color 
    CalculateHitColor Objects, Me, _ 
        eyeX, eyeY, eyeZ, _ 
        px, py, pz, _ 
        Nx, Ny, Nz, _ 
        DiffKr, DiffKg, DiffKb, _ 
        AmbKr, AmbKg, AmbKb, _ 
        Spec_K, Spec_N, _ 
        ReflKr, ReflKg, ReflKb, _ 
        R, G, B 
End Sub 
 
Public Function RayTraceable_FindT(DirectC As Boolean, px As Single, py As Single, pz As Single, Vx As Single, Vy As Single, Vz As Single) As Single 
    Dim A As Single 
    Dim B As Single 
    Dim C As Single 
    Dim D As Single 
    Dim Nx As Single 
    Dim Ny As Single 
    Dim Nz As Single 
    Dim Denom As Single 
    Dim t As Single 
     
    ' Find the unit normal 
    GetUNormal Nx, Ny, Nz 
     
    ' Calculate the plane's parameters 
    A = Nx 
    B = Ny 
    C = Nz 
    D = -(Nx * Point1.Trans(1) + _ 
        Ny * Point1.Trans(2) + _ 
        Nz * Point1.Trans(3)) 
             
    ' If the denominator in the equation for t equals 0, 
    ' the ray is parralel to the plane so there's no 
    ' intersection 
    Denom = A * Vx + B * Vy + C * Vz 
    If Denom = 0 Then 
        RayTraceable_FindT = -1 
        Exit Function 
    End If 
     
    ' Solve for t 
    t = -(A * px + B * py + C * pz + D) / Denom 
     
    ' If there's no positive t value, there's no intersection 
    ' in this direction 
    If t  0.01 Then 
        RayTraceable_FindT = -1 
        Exit Function 
    End If 
     
    ' We had a hit 
    If DirectC Then HadHit = True 
    RayTraceable_FindT = t 
End Function 
 
Public Sub SetValues(ByVal p1x As Single, ByVal p1y As Single, ByVal p1z As Single, _ 
    ByVal p2x As Single, ByVal p2y As Single, ByVal p2z As Single, _ 
    ByVal AmbientKr As Single, ByVal AmbientKg As Single, ByVal AmbientKb As Single, _ 
    ByVal DiffuseKr As Single, ByVal DiffuseKg As Single, ByVal DiffuseKb As Single, _ 
    ByVal SpecularK As Single, ByVal SpecularN As Single) 
     
    ' Set point1 
    Point1.Coord(1) = p1x 
    Point1.Coord(2) = p1y 
    Point1.Coord(3) = p1z 
     
    ' Set point2 
    Point2.Coord(1) = p2x 
    Point2.Coord(2) = p2y 
    Point2.Coord(3) = p2z 
     
    ' Set ambient lighting 
    AmbKr = AmbientKr 
    AmbKg = AmbientKg 
    AmbKb = AmbientKb 
     
    ' Set diffuse lighting 
    DiffKr = DiffuseKr 
    DiffKg = DiffuseKg 
    DiffKb = DiffuseKb 
     
    ' Set specular lighting 
    Spec_K = SpecularK 
    Spec_N = SpecularN 
End Sub 
 
Private Sub RayTraceable_GetRminRmax(new_min As Single, new_max As Single, ByVal X As Single, ByVal Y As Single, ByVal Z As Single) 
Dim Dx As Single 
Dim Dy As Single 
Dim Dz As Single 
Dim Dist As Single 
 
    Dx = X - Point1.Trans(1) 
    Dy = Y - Point1.Trans(2) 
    Dz = Z - Point1.Trans(3) 
    Dist = Sqr(Dx * Dx + Dy * Dy + Dz * Dz) 
    new_max = Dist 
    new_min = Dist 
End Sub 
 
Public Sub RayTraceable_ResetCulling() 
    ForeverCulled = False 
    HadHitPrev = False 
End Sub