XInitImage, XCreateImage, XGetPixel, XPutPixel, XSubImage, XAddPixel,
XDestroyImage - image utilities
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
int XPutPixel(XImage *ximage, int x, int y,
unsigned long pixel);
XImage *XSubImage(XImage *ximage, int x, int
y, unsigned int subimage_width, unsigned int
int XAddPixel(XImage *ximage, long value);
int XDestroyImage(XImage *ximage);
- Specifies the quantum of a scanline (8, 16, or 32). In other words, the
start of one scanline is separated in client memory from the start of the
next scanline by an integer multiple of this many bits.
- Specifies the number of bytes in the client image between the start of one
scanline and the start of the next.
- Specifies the image data.
- Specifies the depth of the image.
- Specifies the connection to the X server.
- Specifies the format for the image. You can pass XYBitmap,
XYPixmap, or ZPixmap.
- Specifies the height of the image, in pixels.
- Specifies the number of pixels to ignore at the beginning of the
- Specifies the new pixel value.
- Specifies the height of the new subimage, in pixels.
- Specifies the width of the new subimage, in pixels.
- Specifies the constant value that is to be added.
- Specifies the Visual structure.
- Specifies the width of the image, in pixels.
- Specifies the image.
- Specify the x and y coordinates.
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
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 specified 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 structure is
successful. It returns zero if it detected some error or inconsistency in the
structure, in which case the image is not changed.
function allocates the memory needed for an
structure for the specified display but does not allocate space
for the image itself. Rather, it initializes the structure byte-order,
bit-order, and bitmap-unit values from the display and returns a pointer to
structure. The red, green, and blue mask values are defined
for Z format images only and are derived from the Visual
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
Note that when the image is created using XCreateImage
, the destroy procedure that the XDestroyImage
function calls frees both the image structure and the data pointed to by the
The basic functions used to get a pixel, set a pixel, create a subimage, and add
a constant value to an image are defined in the image object. The functions in
this section are really macro invocations of the functions in the image object
and are defined in < X11/Xutil.h
function returns the specified pixel from the named image.
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.
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 coordinates.
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.
function adds a constant value to every pixel in an image.
It is useful when you have a base pixel value from allocating color resources
and need to manipulate the image to that form.
function deallocates the memory associated with the
Xlib - C Language X Interface