The presentation space is a data structure that contains an element
for each row and column position in the session window (but not including
the last row of the session window, which is used for the Operator
Information Area). The size of the presentation space depends on the
size of the session window. For example, if the session window has
80 rows and 25 columns, then the size of the presentation space is
80 * 24 = 1920.
The position of the elements in the presentation space corresponds
serially to the row and column positions in the session window, reading
from left to right, top to bottom. For example, if the session window
has 80 rows and 25 columns, then:
Figure 1. Correspondence of row and column location
in the session window to the position in the presentation space
Row of Column of Corresponds to
Session Session element at this
Window: Window: position in PS:
1 1 1
1 2 2
1 3 3
...
1 80 80
2 1 81
2 2 82
2 3 83
...
24 79 1919
24 80 1920
Z and I Emulator for Web uses the presentation space to store the characters
that are to be displayed in the session window. Each element in the
presentation space is used to store one character (and information
about that character, such as intensity). For example, if the string Message appears
at row 1 and column 1 of the session window, then:
Figure 2. Layout when 'Message' appears
in row 1, column 1
Row of Column of Corresponds Character
Session Session to element stored in
Window: Window: at this pos- this element:
ition in PS:
1 1 1 M
1 2 2 e
1 3 3 s
1 4 4 s
1 5 5 a
1 6 6 g
1 7 7 e