vb.net Code:
'
' Defines the Point3D class that represents points in 3D space.
' http://codentronix.com
'
Option Explicit On
Public Class Point3D
Protected m_x As Double, m_y As Double, m_z As Double
Public Sub New(ByVal x As Double, ByVal y As Double, ByVal z As Double)
Me.X = x
Me.Y = y
Me.Z = z
End Sub
Public Property X() As Double
Get
Return m_x
End Get
Set(ByVal value As Double)
m_x = value
End Set
End Property
Public Property Y() As Double
Get
Return m_y
End Get
Set(ByVal value As Double)
m_y = value
End Set
End Property
Public Property Z() As Double
Get
Return m_z
End Get
Set(ByVal value As Double)
m_z = value
End Set
End Property
Public Function RotateX(ByVal angle As Integer) As Point3D
Dim rad As Double, cosa As Double, sina As Double, yn As Double, zn As Double
rad = angle * Math.PI / 180
cosa = Math.Cos(rad)
sina = Math.Sin(rad)
yn = Me.Y * cosa - Me.Z * sina
zn = Me.Y * sina + Me.Z * cosa
Return New Point3D(Me.X, yn, zn)
End Function
Public Function RotateY(ByVal angle As Integer) As Point3D
Dim rad As Double, cosa As Double, sina As Double, Xn As Double, Zn As Double
rad = angle * Math.PI / 180
cosa = Math.Cos(rad)
sina = Math.Sin(rad)
Zn = Me.Z * cosa - Me.X * sina
Xn = Me.Z * sina + Me.X * cosa
Return New Point3D(Xn, Me.Y, Zn)
End Function
Public Function RotateZ(ByVal angle As Integer) As Point3D
Dim rad As Double, cosa As Double, sina As Double, Xn As Double, Yn As Double
rad = angle * Math.PI / 180
cosa = Math.Cos(rad)
sina = Math.Sin(rad)
Xn = Me.X * cosa - Me.Y * sina
Yn = Me.X * sina + Me.Y * cosa
Return New Point3D(Xn, Yn, Me.Z)
End Function
Public Function Project(ByVal viewWidth, ByVal viewHeight, ByVal fov, ByVal viewDistance)
Dim factor As Double, Xn As Double, Yn As Double
factor = fov / (viewDistance + Me.Z)
Xn = Me.X * factor + viewWidth / 2
Yn = Me.Y * factor + viewHeight / 2
Return New Point3D(Xn, Yn, Me.Z)
End Function
End Class
vb.net Code:
'
' Simulation of a Rotating Cube using GDI+
' http://codentronix.com
'
Imports System.Drawing.Graphics
Imports System.Drawing.Color
Imports System.Drawing.Brush
Imports System.Drawing.Point
Public Class Main
Protected m_timer As Timer
Protected m_vertices(8) As Point3D
Protected m_faces(6, 4) As Integer
Protected m_colors(6) As Color
Protected m_brushes(6) As Brush
Protected m_angle As Integer
Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' Enable double-buffering to eliminate flickering.
Me.SetStyle(ControlStyles.AllPaintingInWmPaint, True)
Me.SetStyle(ControlStyles.OptimizedDoubleBuffer, True)
InitCube()
' Create the timer.
m_timer = New Timer()
' Set the timer interval to 25 milliseconds. This will give us 1000/25 ~ 40 frames per second.
m_timer.Interval = 25
' Set the callback for the timer.
AddHandler m_timer.Tick, AddressOf AnimationLoop
' Start the timer.
m_timer.Start()
End Sub
Private Sub InitCube()
' Create the cube vertices.
m_vertices = New Point3D() {
New Point3D(-1, 1, -1),
New Point3D(1, 1, -1),
New Point3D(1, -1, -1),
New Point3D(-1, -1, -1),
New Point3D(-1, 1, 1),
New Point3D(1, 1, 1),
New Point3D(1, -1, 1),
New Point3D(-1, -1, 1)}
' Create an array representing the 6 faces of a cube. Each face is composed by indices to the vertex array
' above.
m_faces = New Integer(,) {{0, 1, 2, 3}, {1, 5, 6, 2}, {5, 4, 7, 6}, {4, 0, 3, 7}, {0, 4, 5, 1}, {3, 2, 6, 7}}
' Define the colors of each face.
m_colors = New Color() {Color.BlueViolet, Color.Cyan, Color.Green, Color.Yellow, Color.Violet, Color.LightSkyBlue}
' Create the brushes to draw each face. Brushes are used to draw filled polygons.
For i = 0 To 5
m_brushes(i) = New SolidBrush(m_colors(i))
Next
End Sub
Private Sub AnimationLoop()
' Forces the Paint event to be called.
Me.Invalidate()
' Update the variable after each frame.
m_angle += 1
End Sub
Private Sub Main_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
Dim t(8) As Point3D
Dim f(4) As Integer
Dim v As Point3D
Dim avgZ(6) As Double
Dim order(6) As Integer
Dim tmp As Double
Dim iMax As Integer
' Clear the window
e.Graphics.Clear(Color.LightBlue)
' Transform all the points and store them on the "t" array.
For i = 0 To 7
Dim b As Brush = New SolidBrush(Color.White)
v = m_vertices(i)
t(i) = v.RotateX(m_angle).RotateY(m_angle).RotateZ(Me.m_angle)
t(i) = t(i).Project(Me.ClientSize.Width, Me.ClientSize.Height, 256, 4)
Next
' Compute the average Z value of each face.
For i = 0 To 5
avgZ(i) = (t(m_faces(i, 0)).Z + t(m_faces(i, 1)).Z + t(m_faces(i, 2)).Z + t(m_faces(i, 3)).Z) / 4.0
order(i) = i
Next
' Next we sort the faces in descending order based on the Z value.
' The objective is to draw distant faces first. This is called
' the PAINTERS ALGORITHM. So, the visible faces will hide the invisible ones.
' The sorting algorithm used is the SELECTION SORT.
For i = 0 To 4
iMax = i
For j = i + 1 To 5
If avgZ(j) > avgZ(iMax) Then
iMax = j
End If
Next
If iMax <> i Then
tmp = avgZ(i)
avgZ(i) = avgZ(iMax)
avgZ(iMax) = tmp
tmp = order(i)
order(i) = order(iMax)
order(iMax) = tmp
End If
Next
' Draw the faces using the PAINTERS ALGORITHM (distant faces first, closer faces last).
For i = 0 To 5
Dim points() As Point
Dim index As Integer = order(i)
points = New Point() {
New Point(CInt(t(m_faces(index, 0)).X), CInt(t(m_faces(index, 0)).Y)),
New Point(CInt(t(m_faces(index, 1)).X), CInt(t(m_faces(index, 1)).Y)),
New Point(CInt(t(m_faces(index, 2)).X), CInt(t(m_faces(index, 2)).Y)),
New Point(CInt(t(m_faces(index, 3)).X), CInt(t(m_faces(index, 3)).Y))
}
e.Graphics.FillPolygon(m_brushes(index), points)
Next
End Sub
End Class
