Manual Reference Pages  - XGetVisualInfo (3)


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




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);


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.


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.


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;


Xlib - C Language X Interface

X Version 11 XGetVisualInfo (3) libX11 1.5.0
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