XGetVisualInfo(3X11) — MIT X11R4

Name

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

Syntax

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

classSpecifies the class of the screen.

depthSpecifies the depth of the screen.

displaySpecifies the connection to the X server.

nitems_return
Returns the number of matching visual structures.

screenSpecifies the screen.

visualSpecifies the visual type.

vinfo_maskSpecifies the visual mask value.

vinfo_returnReturns 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 match 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;
unsigned int depth;
int class;
unsigned long red_mask;
unsigned long green_mask;
unsigned long blue_mask;
int colormap_size;
int bits_per_rgb;
} XVisualInfo;

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