by K. O. Thaha Hussain (5 Submissions)
Category: Graphics
Compatability: Visual Basic 3.0
Difficulty: Intermediate
Date Added: Wed 3rd February 2021
Rating: 
(6 Votes)
It is an extremly simple Rainbow Generator - the code which was always asked by the viewers. See how a rainbow is generated with the varaitions in the values of primary colors - Red, Green and Blue. No API's used. Interesting and Full of Fun! Easy even for beginners!
VBcoders'(C)2001 K. O. Thaha Hussain. India
' Analyst Programmer
' All Rights Reserved
' URL : www.bcity.com/thahahussain
' Company : www.induswareonline.com
Option Explicit
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
