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1.11 Open graphic display. <Main>
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[Name]
crt_opengr
[Syntax]
#include <crt.h>
int crt_opengr( void ) ;
[Arguments]
------
[Return]
Returns "0" or "1" if successful. If any error (Graphic board is not
equipped, or the graphic function option is not set.), returns "-1".
The difference between return code "0" and "1" is as follows.
0 The authorization to use graphic display has not been
given to another application after the last calling
of crt_closegr() function. So, initialization of
graphic screen is not required because the state of
graphic display on the last calling of crt_closegr()
is being kept.
1 The authorization to use graphic display has been
given to another application after the last calling of
crt_closegr() function. So, initialization of graphic
screen is required because the state of graphic
display on the last calling of crt_closegr() is not
being kept.
[Description]
Acquire authorization to use graphic display and become ready for the
graphic display.
After successful completion of this function, the authorization of
graphic display is given to the C Executor application program and
the application program become capable of drawing on the graphic
screen.
After the execution of this function, screen switching is disabled
until crt_closegr() function is executed.
Calling crt_setswt(CRT_SWT_GREN) prior to crt_opengr() enables screen
switching while graphics display is open.