Rainbow Generator

Category:

Screen/Graphics

Type:

Snippets

Difficulty:

Beginning

Author:

Anonymous

Version Compatibility: Visual Basic 6, Visual Basic 5

More information:

This is an extremly simple Rainbow Generator. See how a rainbow is generated with the varaitions in the values of primary colors - Red, Green and Blue. No APIs used.

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
' (None)

Code:

Private Sub Form_Load()
Me.AutoRedraw = True
Me.ScaleMode = vbTwips
Me.Caption = "Rainbow Generator by " & _
                   "K. O. Thaha Hussain"
'MsgBox "Resize the window to resize the Rainbow", , _
'             "Thaha Hussain's Rainbow Generator"
End Sub

Private Sub Form_Resize()
Call Rainbow
End Sub

Private Sub Rainbow()
On Error Resume Next

Dim Position As Integer, Red As Integer, Green As _
                         Integer, Blue As Integer

Dim ScaleFactor As Double, Length As Integer

ScaleFactor = Me.ScaleWidth / (255 * 6)
Length = Int(ScaleFactor * 255)

Position = 0
Red = 255
Blue = 1

'Purposfully avoided nested loops
 '------------- 1
 For Green = 1 To Length
   Me.Line (Position, 0)-(Position, Me.ScaleHeight), _
                  RGB(Red, Green \ ScaleFactor, Blue)
   Position = Position + 1
 Next Green

'--------------- 2

For Red = Length To 1 Step -1
   Me.Line (Position, 0)-(Position, Me.ScaleHeight), _
                    RGB(Red \ ScaleFactor, Green, Blue)
   Position = Position + 1
 Next Red
'---------------- 3
For Blue = 0 To Length
   Me.Line (Position, 0)-(Position, Me.ScaleHeight), _
                   RGB(Red, Green, Blue \ ScaleFactor)
   Position = Position + 1
 Next Blue
 
 '----------------- 4
For Green = Length To 1 Step -1
   Me.Line (Position, 0)-(Position, Me.ScaleHeight), _
                    RGB(Red, Green \ ScaleFactor, Blue)
   Position = Position + 1
 Next Green
 
 '------------------ 5
 For Red = 1 To Length
   Me.Line (Position, 0)-(Position, Me.ScaleHeight), _
                   RGB(Red \ ScaleFactor, Green, Blue)
   Position = Position + 1
 Next Red

'------------------- 6
For Blue = Length To 1 Step -1
   Me.Line (Position, 0)-(Position, Me.ScaleHeight), _
                    RGB(Red, Green, Blue \ ScaleFactor)
   Position = Position + 1
 Next Blue

End Sub