SCREEN DEPTH
SCREEN DEPTH ( depth ; color {; screen} )
| Parameter | Type | Description | |
|---|---|---|---|
| depth | Integer | ← | Depth of the screen (number of colors = 2 ^ depth) |
| color | Integer | ← | 1 = Color screen, 0 = Black and white or Gray scale |
| screen | Integer | → | Screen number, or main screen if omitted |
This command is not thread-safe, it cannot be used in preemptive code.
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