The Begin Image order, together with the Image Data and End Image orders
approximate to the GSIMG and GSIMGS calls.
An image consists of a rectangular array of display points.
It is represented by a sequence of orders. The first is a Begin Image
order and the last is an End Image order (see below). Between these
delimiters, several Image Data orders may occur, giving the array of
display points in the image.
The initial coordinate pair (x0,y0) can be omitted. The current position
is then used to place the image data, and the order code becomes X'91'.
The current position is not changed by a series of Image orders.
The size of the display point array and its representation are given by
the Begin Image order. The fields IMAGEWIDTH and IMAGEDEPTH are optional
and may be either both specified, or both omitted. When specified, the
image is scaled to fill the area identified by the fields, using the rules
defined in the GSIMGS call. When omitted, each display point is
represented by one bit in the display point array.
|
|
|
Fld
len |
Content
|
Meaning
|
1
|
X'D1' or X'91'
|
Begin Image (at given position) order code or
Begin Image (at current position) order code |
| 1 |
LEN |
Length of following data |
*
|
x0
|
The x position at which the image is to be
placed (omitted for order X'91') |
*
|
y0
|
The y position at which the image is to be
placed (omitted for order X'91') |
2
|
FORMAT
|
The format of the image data. This field must
have the value 0. |
| 2 |
WIDTH |
The width of the image in display points |
| 2 |
DEPTH |
The depth of the image in display points |
*
|
IMAGEWIDTH
|
The desired width of the image in coordinate
units |
*
|
IMAGEDEPTH
|
The desired depth of the image in coordinate
units |
|
GDDM V3R2 Base Application Programming Reference
Copyright IBM Corporation 1990, 2012