4D Doc Center : SCREEN DEPTH

4D v13.4

SCREEN DEPTH


SCREEN DEPTH ( depth ; color {; screen} )

Parameter	Type	Description
depth	Longint	Depth of the screen (number of colors = 2 ^ depth)
color	Longint	1 = Color screen, 0 = Black and white or Gray scale
screen	Longint	Screen number, or main screen if omitted

Description

The SCREEN DEPTH command returns in depth and color information about the monitor.

The depth of the screen is returned in depth. The depth of the screen is the exponent of the power of 2 expressing the number of colors displayed on your monitor. For example, if your monitor is set for 256 colors (2^8), the depth of your screen is 8.

The following predefined constants are provided by 4D:

Constant	Type	Value
Black and white	Longint	0
Four colors	Longint	2
Millions of colors 24 bit	Longint	24
Millions of colors 32 bit	Longint	32
Sixteen colors	Longint	4
Thousands of colors	Longint	16
Two fifty six colors	Longint	8

If the monitor is set to display in color, 1 is returned in color. If the monitor is set to display in gray scale, 0 is returned in color. Note that this value is significant on the Macintosh platform.

The following predefined constants are provided by 4D:

Constant	Type	Value
Is color	Longint	1
Is gray scale	Longint	0

The optional parameter screen specifies the monitor for which you want to get information. If you omit the screen parameter, the command returns the depth of the main screen.

Example

Your application displays many color graphics. Somewhere in your database, you could write:

 SCREEN DEPTH($vlDepth;$vlColor)

 If($vlDepth<8)

    ALERT("The forms will look better if the monitor"+" was set to display 256 colors or more.")

 End if