---
name: "ImageByteOrder"
section: "3x"
platform: "linux"
package: "libx11-dev"
version: "4.3.0.dfsg.1-14sarge7"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/ImageByteOrder/3x"
---

# ImageByteOrder(3x)

image format functions and macros

## NAME

ImageByteOrder, BitmapBitOrder, BitmapPad, BitmapUnit, DisplayHeight, DisplayHeightMM, DisplayWidth, DisplayWidthMM, XListPixmapFormats, XPixmapFormatValues - image format functions and macros

## SYNTAX

XPixmapFormatValues \*XListPixmapFormats(Display \**display*, int \**count\_return*);

int ImageByteOrder(Display \**display*);

int BitmapBitOrder(Display \**display*);

int BitmapPad(Display \**display*);

int BitmapUnit(Display \**display*);

int DisplayHeight(Display \**display*, int *screen\_number*);

int DisplayHeightMM(Display \**display*, int *screen\_number*);

int DisplayWidth(Display \**display*, int *screen\_number*);

int DisplayWidthMM(Display \**display*, int *screen\_number*);

## ARGUMENTS

- *display*

  Specifies the connection to the X server.

- *count\_return*

  Returns the number of pixmap formats that are supported by the display.

- *screen\_number*

  Specifies the appropriate screen number on the host server.

## DESCRIPTION

The *XListPixmapFormats* function returns an array of *XPixmapFormatValues* structures that describe the types of Z format images supported by the specified display. If insufficient memory is available, *XListPixmapFormats* returns NULL. To free the allocated storage for the *XPixmapFormatValues* structures, use *XFree*.

The *ImageByteOrder* macro specifies the required byte order for images for each scanline unit in XY format (bitmap) or for each pixel value in Z format.

The *BitmapBitOrder* macro returns  *LSBFirst* or *MSBFirst* to indicate whether the leftmost bit in the bitmap as displayed on the screen is the least or most significant bit in the unit.

The *BitmapPad* macro returns the number of bits that each scanline must be padded.

The *BitmapUnit* macro returns the size of a bitmap's scanline unit in bits.

The *DisplayHeight* macro returns the height of the specified screen in pixels.

The *DisplayHeightMM* macro returns the height of the specified screen in millimeters.

The *DisplayWidth* macro returns the width of the screen in pixels.

The *DisplayWidthMM* macro returns the width of the specified screen in millimeters.

## STRUCTURES

The *XPixmapFormatValues* structure provides an interface to the pixmap format information that is returned at the time of a connection setup. It contains:

```
typedef struct {
	int depth;
	int bits_per_pixel;
	int scanline_pad;
} XPixmapFormatValues;

```

## SEE ALSO

AllPlanes(3X11), BlackPixelOfScreen(3X11), IsCursorKey(3X11), XFree(3X11)\
 *Xlib - C Language X Interface*