XGetVisualInfo(3)

NAME
XGetVisualInfo, XMatchVisualInfo, XVisualIDFromVisual, XVisualInfo - obtain visual information and visual structure

SYNTAX

XVisualInfo *XGetVisualInfo(Display *display, long vinfo_mask, XVisualInfo *vinfo_template, int *nitems_return);

Status XMatchVisualInfo(Display *display, int screen, int depth, int class, XVisualInfo *vinfo_return);

VisualID XVisualIDFromVisual(Visual *visual);

ARGUMENTS

class
    Specifies the class of the screen.

depth
    Specifies the depth of the screen.

display
    Specifies the connection to the X server.

nitems_return
    Returns the number of matching visual structures.

screen
    Specifies the screen.

visual
    Specifies the visual type.

vinfo_mask
    Specifies the visual mask value.

vinfo_return
    Returns the matched visual information.

vinfo_template
    Specifies the visual attributes that are to be used in matching the visual structures.

DESCRIPTION
The XGetVisualInfo function returns a list of visual structures that have attributes equal to the attributes specified by vinfo_template. If no visual structures match the template using the specified vinfo_mask, XGetVisualInfo returns a NULL. To free the data returned by this function, use XFree.

The XMatchVisualInfo function returns the visual information for a visual that matches the specified depth and class for a screen. Because multiple visuals that match the specified depth and class can exist, the exact visual chosen is undefined. If a visual is found, XMatchVisualInfo returns nonzero and the information on the visual to vinfo_return. Otherwise, when a visual is not found, XMatchVisualInfo returns zero.

The XVisualIDFromVisual function returns the visual ID for the specified visual type.

STRUCTURES
The XVisualInfo structure contains:

/* Visual information mask bits */
#define |  | 0x0
#define |  | 0x1
#define |  | 0x2
#define |  | 0x4
#define |  | 0x8
#define |  | 0x10
#define |  | 0x20
#define |  | 0x40
#define |  | 0x80
#define |  | 0x100
#define |  | 0x1FF
    /* Values */
    typedef struct {
            Visual *visual;
            VisualID visualid;
            int screen;
            int depth;
            int class;
            unsigned long red_mask;
            unsigned long green_mask;
            unsigned long blue_mask;
            int colormap_size;
            int bits_per_rgb;
    } XVisualInfo;

SEE ALSO
XFree(3)
Xlib - C Language X Interface