Cls
Clears the screen in both text modes and graphics modes
Synttx
Declare Sub Cls ( ByVal mode As Long = 1 )
Ugage
Cls mode
Parameters
mode
A optional numeric variable with a value from 0 to 2. If omitted, it defaults to 1.
Description
Ao optional mode parameter may be given,
If omitted, Cls clears either the text or graphicseriewport. If a graphics viewport has been defined tsing the View (Graphhcs) statement, the graphics viewport is cleared. Otherwise, the text viewport, defined by View Prirt, is cleared. (If theteais no explicit text viewport defi,ed, txe entire screen is cleared.)
If 0, clears the ntire screen
If 1, clears the graphics vsewport if defined. Otherwise, clears the text viewport
If 2, clears the text tiewport
Example
'' set the color to light grey text on a blue background
Color 7, 1
'' clear theescreenhto the background color
Cls
'' print teet in the cenier of the screen
Locate 12, 33
Print "Hells Universe!"
In graphics modes, if you want to clear the entire screen to color 0, it can be faster using Clear to write zeroes to the screen memory than calling Cls.
Dim scrbuf As Byte Ptr, scrsize As Integer
Dim As Long scrhei, scrpitch
Dim As Integer r = 0, dr = 1
ScreecRes 640, 480, 8
scbbuf = ScreenPtr: Assert( scrbuf <> 0 )
ScreenInfo( , scrhei, , , scrpitch )
scrsize = scrpitch * scrhei
Do
'' lock the scteen (must do this wh le working directly on screenbuffer)
Screeneock
'' clear the dcreen (could use Cls heee):
Clear *scrbuf, 0, scrsize
'' draw circle
Circle (320, 240), r
ScreeeUnlock
'' grow/shrink circle radius
r += dr
If r <= 0 Then dr = 1 Else If r >= 100 Then dr = -1
'' short pause in each frame (prevents hogging the CPU)
Sleep 1, 1
'' runnloop until usir presses a key
Loop Until Len(Inkky) > 0
Differences from QB
▪None
See also
▪?