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XCreateImage(3)			XLIB FUNCTIONS		       XCreateImage(3)

NAME
       XInitImage, XCreateImage, XGetPixel, XPutPixel, XSubImage, XAddPixel,
       XDestroyImage - image utilities

SYNTAX
       Status XInitImage(XImage	*image);

       XImage *XCreateImage(Display *display, Visual *visual, unsigned int
	      depth, int format, int offset, char *data, unsigned int width,
	      unsigned int height, int bitmap_pad, int bytes_per_line);

       unsigned	long XGetPixel(XImage *ximage, int x, int y);

       int XPutPixel(XImage *ximage, int x, int	y, unsigned long pixel);

       XImage *XSubImage(XImage	*ximage, int x,	int y, unsigned	int subim-
	      age_width, unsigned int subimage_height);

       int XAddPixel(XImage *ximage, long value);

       int XDestroyImage(XImage	*ximage);

ARGUMENTS
       bitmap_pad
		 Specifies the quantum of a scanline (8, 16, or	32).  In other
		 words,	the start of one scanline is separated in client mem-
		 ory from the start of the next	scanline by an integer multi-
		 ple of	this many bits.

       bytes_per_line
		 Specifies the number of bytes in the client image between the
		 start of one scanline and the start of	the next.

       data	 Specifies the image data.

       depth	 Specifies the depth of	the image.

       display	 Specifies the connection to the X server.

       format	 Specifies the format for the image.  You can pass XYBitmap,
		 XYPixmap, or ZPixmap.

       height	 Specifies the height of the image, in pixels.

       offset	 Specifies the number of pixels	to ignore at the beginning of
		 the scanline.

       pixel	 Specifies the new pixel value.

       subimage_height
		 Specifies the height of the new subimage, in pixels.

       subimage_width
		 Specifies the width of	the new	subimage, in pixels.

       value	 Specifies the constant	value that is to be added.

       visual	 Specifies the Visual structure.

       width	 Specifies the width of	the image, in pixels.

       ximage	 Specifies the image.

       x
       y	 Specify the x and y coordinates.

DESCRIPTION
       The XInitImage function initializes the internal	image manipulation
       routines	of an image structure, based on	the values of the various
       structure members.  All fields other than the manipulation routines
       must already be initialized.  If	the bytes_per_line member is zero,
       XInitImage will assume the image	data is	contiguous in memory and set
       the bytes_per_line member to an appropriate value based on the other
       members;	otherwise, the value of	bytes_per_line is not changed.	All of
       the manipulation	routines are initialized to functions that other Xlib
       image manipulation functions need to operate on the type	of image spec-
       ified by	the rest of the	structure.

       This function must be called for	any image constructed by the client
       before passing it to any	other Xlib function.  Image structures created
       or returned by Xlib do not need to be initialized in this fashion.

       This function returns a nonzero status if initialization	of the struc-
       ture is successful.  It returns zero if it detected some	error or in-
       consistency in the structure, in	which case the image is	not changed.

       The XCreateImage	function allocates the memory needed for an XImage
       structure for the specified display but does not	allocate space for the
       image itself.  Rather, it initializes the structure byte-order, bit-or-
       der, and	bitmap-unit values from	the display and	returns	a pointer to
       the XImage structure.  The red, green, and blue mask values are defined
       for Z format images only	and are	derived	from the Visual	structure
       passed in.  Other values	also are passed	in.  The offset	permits	the
       rapid displaying	of the image without requiring each scanline to	be
       shifted into position.  If you pass a zero value	in bytes_per_line,
       Xlib assumes that the scanlines are contiguous in memory	and calculates
       the value of bytes_per_line itself.

       Note that when the image	is created using XCreateImage, XGetImage, or
       XSubImage, the destroy procedure	that the XDestroyImage function	calls
       frees both the image structure and the data pointed to by the image
       structure.

       The basic functions used	to get a pixel,	set a pixel, create a subim-
       age, and	add a constant value to	an image are defined in	the image ob-
       ject.  The functions in this section are	really macro invocations of
       the functions in	the image object and are defined in <X11/Xutil.h>.

       The XGetPixel function returns the specified pixel from the named im-
       age.  The pixel value is	returned in normalized format (that is,	the
       least significant byte of the long is the least significant byte	of the
       pixel).	The image must contain the x and y coordinates.

       The XPutPixel function overwrites the pixel in the named	image with the
       specified pixel value.  The input pixel value must be in	normalized
       format (that is,	the least significant byte of the long is the least
       significant byte	of the pixel).	The image must contain the x and y co-
       ordinates.

       The XSubImage function creates a	new image that is a subsection of an
       existing	one.  It allocates the memory necessary	for the	new XImage
       structure and returns a pointer to the new image.  The data is copied
       from the	source image, and the image must contain the rectangle defined
       by x, y,	subimage_width,	and subimage_height.

       The XAddPixel function adds a constant value to every pixel in an im-
       age.  It	is useful when you have	a base pixel value from	allocating
       color resources and need	to manipulate the image	to that	form.

       The XDestroyImage function deallocates the memory associated with the
       XImage structure.

SEE ALSO
       XPutImage(3)
       Xlib - C	Language X Interface

X Version 11			 libX11	1.6.5		       XCreateImage(3)

NAME | SYNTAX | ARGUMENTS | DESCRIPTION | SEE ALSO

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