XVisualInfo (3) - Linux Man Pages

XVisualInfo: obtain visual information and visual structure

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 VisualNoMask 0x0
#define VisualIDMask 0x1
#define VisualScreenMask 0x2
#define VisualDepthMask 0x4
#define VisualClassMask 0x8
#define VisualRedMaskMask 0x10
#define VisualGreenMaskMask 0x20
#define VisualBlueMaskMask 0x40
#define VisualColormapSizeMask 0x80
#define VisualBitsPerRGBMask 0x100
#define VisualAllMask 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