XGetVisualInfo(3)
NAME
XGetVisualInfo, XMatchVisualInfo, XVisualIDFromVisual, XVisualInfo obtain visual information and visual structure
SYNTAX
- XVisualInfo *XGetVisualInfo(Display *display, long vinfo_mask, XVisual
- Info *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