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/* This file contains the erase method, which is a standard part of
libplot. It erases all objects on the graphics device display.
This generic version is designed mostly for Plotters that do not do
real-time plotting, and have no internal state. It simply resets the
output buffer for the current `page', discarding all objects written
to it. */
#include "sys-defines.h"
#include "extern.h"
int
#ifdef _HAVE_PROTOS
_API_erase (S___(Plotter *_plotter))
#else
_API_erase (S___(_plotter))
S___(Plotter *_plotter;)
#endif
{
bool retval1;
int retval2 = 0;
if (!_plotter->data->open)
{
_plotter->error (R___(_plotter)
"erase: invalid operation");
return -1;
}
_API_endpath (S___(_plotter)); /* flush path if any */
switch ((int)_plotter->data->output_model)
{
case (int)PL_OUTPUT_NONE:
/* Plotter doesn't do output, so do nothing */
break;
case (int)PL_OUTPUT_ONE_PAGE:
case (int)PL_OUTPUT_ONE_PAGE_AT_A_TIME:
case (int)PL_OUTPUT_PAGES_ALL_AT_ONCE:
/* the builtin plOutbuf mechanism is being used for storing pages, so
remove all stored graphics code from the buffer corresponding to
the current page; reset page bounding box, etc. */
if (_plotter->data->page) /* paranoid */
_reset_outbuf (_plotter->data->page);
break;
case (int)PL_OUTPUT_VIA_CUSTOM_ROUTINES:
case (int)PL_OUTPUT_VIA_CUSTOM_ROUTINES_IN_REAL_TIME:
case (int)PL_OUTPUT_VIA_CUSTOM_ROUTINES_TO_NON_STREAM:
/* Plotter does its own output, and doesn't use libplot's
plOutbuf-based output system. So do nothing. */
break;
default: /* shouldn't happen */
break;
}
/* Invoke Plotter-specific method to do device-dependent aspects of page
erasure. For example, reset the elements of the Plotter that keep
track of the output device's graphics state to their default
values. */
retval1 = _plotter->erase_page (S___(_plotter));
/* if Plotter is using custom output routines, and is, or could be,
drawing graphics in real time, flush out the erasure */
if (_plotter->data->output_model ==
PL_OUTPUT_VIA_CUSTOM_ROUTINES_IN_REAL_TIME
|| _plotter->data->output_model ==
PL_OUTPUT_VIA_CUSTOM_ROUTINES_TO_NON_STREAM)
retval2 = _API_flushpl (S___(_plotter));
/* on to next frame */
_plotter->data->frame_number++;
return (retval1 == true && retval2 == 0 ? 0 : -1);
}
/* Plotter-specific things that take place when erase() is invoked. In a
generic Plotter, this does nothing. */
bool
#ifdef _HAVE_PROTOS
_g_erase_page (S___(Plotter *_plotter))
#else
_g_erase_page (S___(_plotter))
S___(Plotter *_plotter;)
#endif
{
return true;
}
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