XCreateImage(3X) XLIB FUNCTIONS XCreateImage(3X)NAMEXCreateImage - image utilities
SYNTAX
XImage *XCreateImage(display, visual, depth, format, offset, data,
width, height, bitmap_pad,
bytes_per_line)
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;
ARGUMENTS
display Specifies the connection to the X server.
visual Specifies the Visual structure.
depth Specifies the depth of the image.
format Specifies the format for the image. You can pass XYBitmap,
XYPixmap, or ZPixmap.
.IP offset 1i Specifies the number of pixels to ignore at
the beginning of the scanline.
data Specifies the image data.
width Specifies the width of the image, in pixels.
height Specifies the height of the image, in pixels.
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.
DESCRIPTION
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-
order, 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
object. The functions in this section are really macro invocations of
the functions in the image object and are defined in <X11/Xutil.h>.
SEE ALSOXInitImage(3X), XGetPixel(3X), XPutPixel(3X), XSubImage(3X), XAd‐
dPixel(3X), XDestroyImage(3X)X Version 11 Release 6 XCreateImage(3X)
