XGetVisualInfo(3) | Library Functions Manual | 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 | 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

X Version 11 | XLIB FUNCTIONS