XGetVisualInfo

Section: XLIB FUNCTIONS (3)
Updated: libX11 1.6.4
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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

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Index

NAME

SYNTAX

ARGUMENTS

DESCRIPTION

STRUCTURES

SEE ALSO