Topic       : The GFA-Basic Compendium
Author      : GFA Systemtechnik GmbH
Version     : GFABasic.HYP v2.98 (12/31/2023)
Subject     : Documentation/Programming
Nodes       : 899
Index Size  : 28056
HCP-Version : 3
Compiled on : Atari
@charset    : atarist
@lang       : 
@default    : Document not found
@help       : Help
@options    : +g -i -s +z
@width      : 75
@hostname   : STRNGSRV
@hostname   : CAB     
@hostname   : HIGHWIRE
@hostname   : THING   
View Ref-FileThe compiler options $RC& and $RC% are used to control the interpretation of
the RC_INTERSECT() parameters. By default, these parameters are converted by
the compiler into four-byte parameters.

In many cases, however, the range of two-byte integer variables is quite
sufficient for these parameters. Using option $RC&, you can make the compiler
interpret the RC_INTERSECT() parameters as two-byte parameters.

This option is important only exceptionally and in special cases. The
RC_INTERSECT() function is principally intended for calculating the size of
overlapping rectangles within a redraw.

For a redraw, only two-byte parameters are required since coordinates can only
be two bytes large under GEM. But the speed gain through using the $RC& option
can be neglected here because, on the one hand, other instructions (such as the
screen section renewal) within a redraw take more time than the window overlap
calculation, and on the other, the RC_INTERSECT() function will only be called
a few times in such a case.

However, the $RC& option does save some memory space when using 16 bit
variables. Another application can be found in the context of hidden line
calculations.

Memo: $RC% is the default.