DRAW399 The data structure JDRAW

This data structure contains the so-called view banks. The layout of the data structure can be found in Fig. . The meaning of the variables is the following:

NKVIEW

number of views stored in the structure;

IVIEW

current view selected;

IGU

current graphic unit pointer;

MAXGU

number of units in graphic unit bank;

MORGU

number of words to push the graphic unit bank;

IGS

current graphic segment pointer;

MAXGS

number of segments in graphic segment bank;

MORGS

number of words to push the graphic segment bank;

ITU

current text unit pointer;

MAXTU

number of units in text unit bank;

MORTU

number of words to push the text unit bank;

ITS

current text segment pointer;

MAXTS

number of segments in text segment bank;

MORTS

number of words to push in text segment bank

LENGU

array of lengths for each graphic unit and of line attributes ( LINATT);

ADDGU

array of addresses for each graphic unit;

ADDTU

array of addresses for each text unit;

X

array of u coordinates of graphic segments;

Y

array v coordinates of graphic segments;

ICUT

cut axis (1, 2, 3 or 0 if no cut) of the view;

LINWID

text line width and text attributes ( ITXATT);

U0, V0, SIZE, ANGLE, IOPT, ITEXT have the same meaning of those given as arguments to GDRAWT (or HPLSOF []).

A control word is stored in Q(JDRAW+IVIEW), with the following meaning:

1

empty bank (created by internal routines to avoid g.gif) or for deleted banks;

2

bank created by the user;

3

protected bank reserved for internal use: it cannot be deleted by the user.

Figure: The JDRAW data structure

P.Zanarini, S.Giani, F. Carminati

DRAW400