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Table of Contents
XPutImage, XGetImage,
XGetSubImage - transfer images
- int XPutImage(Display *display, Drawable
d, GC gc,
- XImage *image, int src_x, int src_y, int dest_x, int dest_y,
unsigned int width, unsigned int height);
- XImage *XGetImage(Display *display,
Drawable d, int
- x, int y, unsigned int width, unsigned int height, unsigned
long plane_mask, int format);
- XImage *XGetSubImage(Display *display, Drawable
d, int
- x, int y, unsigned int width, unsigned int height, unsigned long
plane_mask, int format, XImage *dest_image, int dest_x, dest_y);
- d
- Specifies
the drawable.
- dest_image
- Specifies the destination image. and are the coordinates
of the subimage or which are relative to the origin of the destination
rectangle, specify its upper-left corner, and determine where the subimage
is placed in the destination image
- dest_x
- dest_y
- Specify the x and y coordinates, which are relative to the origin
of the drawable.
- display
- Specifies the connection to the X server.
- format
- Specifies
the format for the image. You can pass XYPixmap or ZPixmap.
- gc
- Specifies
the GC.
- image
- Specifies the image you want combined with the rectangle.
- plane_mask
- Specifies
the plane mask.
- src_x
- Specifies the offset in X from the left edge of the
image defined by the XImage structure.
- src_y
- Specifies the offset in Y
from the top edge of the image defined by the XImage structure.
- width
- height
- Specify the width and height of the subimage, which define the dimensions
of the rectangle. and define the upper-left corner of the rectangle
- x
- y
- Specify the x and y coordinates, which are relative to the origin of
the drawable.
The XPutImage function combines an image with
a rectangle of the specified drawable. The section of the image defined
by the src_x, src_y, width, and height arguments is drawn on the specified
part of the drawable. If XYBitmap format is used, the depth of the image
must be one, or a BadMatch error results. The foreground pixel in the
GC defines the source for the one bits in the image, and the background
pixel defines the source for the zero bits. For XYPixmap and ZPixmap,
the depth of the image must match the depth of the drawable, or a BadMatch
error results.
If the characteristics of the image (for example, byte_order
and bitmap_unit) differ from what the server requires, XPutImage automatically
makes the appropriate conversions.
This function uses these GC components:
function, plane-mask, subwindow-mode, clip-x-origin, clip-y-origin, and clip-mask.
It also uses these GC mode-dependent components: foreground and background.
XPutImage can generate BadDrawable, BadGC, BadMatch, and BadValue
errors.
The XGetImage function returns a pointer to an XImage structure.
This structure provides you with the contents of the specified rectangle
of the drawable in the format you specify. If the format argument is XYPixmap,
the image contains only the bit planes you passed to the plane_mask argument.
If the plane_mask argument only requests a subset of the planes of the
display, the depth of the returned image will be the number of planes requested.
If the format argument is ZPixmap, XGetImage returns as zero the bits
in all planes not specified in the plane_mask argument. The function performs
no range checking on the values in plane_mask and ignores extraneous bits.
XGetImage returns the depth of the image to the depth member of the XImage
structure. The depth of the image is as specified when the drawable was
created, except when getting a subset of the planes in XYPixmap format,
when the depth is given by the number of bits set to 1 in plane_mask.
If
the drawable is a pixmap, the given rectangle must be wholly contained
within the pixmap, or a BadMatch error results. If the drawable is a
window, the window must be viewable, and it must be the case that if
there were no inferiors or overlapping windows, the specified rectangle
of the window would be fully visible on the screen and wholly contained
within the outside edges of the window, or a BadMatch error results. Note
that the borders of the window can be included and read with this request.
If the window has backing-store, the backing-store contents are returned
for regions of the window that are obscured by noninferior windows. If
the window does not have backing-store, the returned contents of such obscured
regions are undefined. The returned contents of visible regions of inferiors
of a different depth than the specified window's depth are also undefined.
The pointer cursor image is not included in the returned contents. If a
problem occurs, XGetImage returns NULL.
XGetImage can generate BadDrawable,
BadMatch, and BadValue errors.
The XGetSubImage function updates
dest_image with the specified subimage in the same manner as XGetImage.
If the format argument is XYPixmap, the image contains only the bit
planes you passed to the plane_mask argument. If the format argument is
ZPixmap, XGetSubImage returns as zero the bits in all planes not
specified in the plane_mask argument. The function performs no range checking
on the values in plane_mask and ignores extraneous bits. As a convenience,
XGetSubImage returns a pointer to the same XImage structure specified
by dest_image.
The depth of the destination XImage structure must be the
same as that of the drawable. If the specified subimage does not fit at
the specified location on the destination image, the right and bottom edges
are clipped. If the drawable is a pixmap, the given rectangle must be wholly
contained within the pixmap, or a BadMatch error results. If the drawable
is a window, the window must be viewable, and it must be the case that
if there were no inferiors or overlapping windows, the specified rectangle
of the window would be fully visible on the screen and wholly contained
within the outside edges of the window, or a BadMatch error results. If
the window has backing-store, then the backing-store contents are returned
for regions of the window that are obscured by noninferior windows. If
the window does not have backing-store, the returned contents of such obscured
regions are undefined. The returned contents of visible regions of inferiors
of a different depth than the specified window's depth are also undefined.
If a problem occurs, XGetSubImage returns NULL.
XGetSubImage can generate
BadDrawable, BadGC, BadMatch, and BadValue errors.
- BadDrawable
- A value for a Drawable argument does not name a defined Window or Pixmap.
- BadGC
- A value for a GContext argument does not name a defined GContext.
- BadMatch
- An InputOnly window is used as a Drawable.
- BadMatch
- Some
argument or pair of arguments has the correct type and range but fails
to match in some other way required by the request.
- BadValue
- Some numeric
value falls outside the range of values accepted by the request. Unless
a specific range is specified for an argument, the full range defined by
the argument's type is accepted. Any argument defined as a set of alternatives
can generate this error.
Xlib - C Language X Interface
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