These functions insert or modify a PHIGS attribute specific to a sub-object of a structure produced by PHIGURE. E.g. to modify the line colr ind attribute of sub-object n° i in the structure STRID, it is necessary to call the following function :
TSPLCI (STRID, -i, line_colr_ind)
This function carries out the following operations :
it opens the structure identifier STRID,
it looks for any PSPLCI element there may be between the two PLB (-i) elements,
if there is one PSPLCI element then
it with the new PSPLCI (line_colr) element
otherwise
it inserts the PSPLCI (line_colr) element after the first PLB (-i) element
then closes the structure
There is a similar function for all the main primitive attributes. Except for the first letter, they have the same name as the PHIGS function which created the element, but they also include the first two parameters STRID and n° of the label.
These functions provide useful programing shortcuts for modifying existing structures. These are all described in the chapter on "graphics attributes of structures". These functions must be called after the structure has been built.
If the structure is rebuilt following modification by one of these attribute functions, the modification is lost. E.g. :
TCUBE (STRID, x1,y1,z1, x2,y2,z2); /* create structure */
TSICI (STRID, -1, 3); /* insert an int_colr_ind attribute in the structure */
TCUBE (STRID, x1,y1,z1, x2,y2,z2); /* rebuilds the structure : the int_colr_ind attribute is lost */
Refer to the description of the function which created the structure in this manual to find out the logical breakdown into sub-objects.
If a structure only has one sub-object (true in most cases), no description is given : this means that the structure has a pair of (0) labels then a pair of (-1) labels, followed by the primitives in the structure (there is no other label with a value < -1).
In other cases, the full breakdown of sub-objects in the structure is given.