X Version 11 (Release 6.1)

XGetVisualInfo(X3xlib)

XGetVisualInfo -- obtain visual information and visual structure

Synopsis

   XVisualInfo *XGetVisualInfo(display, vinfo_mask, vinfo_template,
                               nitems_return)
         Display *display;
         long vinfo_mask;
         XVisualInfo *vinfo_template;
         int *nitems_return;
   
   Status XMatchVisualInfo(display, screen, depth, class, vinfo_return)
         Display *display;
         int screen;
         int depth;
         int class;
         XVisualInfo *vinfo_return;
   

   VisualID XVisualIDFromVisual(visual)
         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;

References

XFree(X3xlib)
Xlib - C Language X Interface

#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