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#include "sys-defines.h"
#include "extern.h"
#include "xmi.h"
bool
#ifdef _HAVE_PROTOS
_i_begin_page (S___(Plotter *_plotter))
#else
_i_begin_page (S___(_plotter))
S___(Plotter *_plotter;)
#endif
{
/* With each call to openpl(), we reset the dynamic GIF-specific data
members of the GIFPlotter. The data members, and the values that are
set, are the same as are used in initializing the GIFPlotter (see
i_defplot.c). */
_plotter->i_painted_set = (voidptr_t)NULL;
_plotter->i_canvas = (voidptr_t)NULL;
_plotter->i_num_color_indices = 0;
_plotter->i_bit_depth = 0;
_plotter->i_frame_nonempty = false;
_plotter->i_pixels_scanned = 0;
_plotter->i_pass = 0;
_plotter->i_hot.x = 0;
_plotter->i_hot.y = 0;
_plotter->i_header_written = false;
/* Create new image, consisting of bitmap and colormap; initialized to
background color. First entries in color table will be (1)
transparent color [if there is one, and we're animating] and (2)
background color. May be the same. */
_i_new_image (S___(_plotter));
/* frame starts empty */
_plotter->i_frame_nonempty = false;
/* GIF file header not yet written */
_plotter->i_header_written = false;
return true;
}
/* Internal function: Create new image, consisting of bitmap and colormap;
initialized to background color. First entries in color table will be
(1) transparent color [if there is one, and we're animating] and (2)
background color. Maybe the same. */
void
#ifdef _HAVE_PROTOS
_i_new_image (S___(Plotter *_plotter))
#else
_i_new_image (S___(_plotter))
S___(Plotter *_plotter;)
#endif
{
int i;
miPixel pixel;
/* colormap starts empty (unused entries initted to `black'; we may later
need to output some of the unused entries because GIF colormap lengths
are always powers of 2) */
_plotter->i_num_color_indices = 0;
for (i = 0; i < 256; i++)
{
_plotter->i_colormap[i].red = 0;
_plotter->i_colormap[i].green = 0;
_plotter->i_colormap[i].blue = 0;
}
/* flag any color indices stored in current drawing state as bogus */
_plotter->drawstate->i_pen_color_status = false;
_plotter->drawstate->i_fill_color_status = false;
_plotter->drawstate->i_bg_color_status = false;
/* Transparency feature of GIF89a files requires that the index of the
transparent color be the same for all images in the file. So if we're
animating, i.e. writing a multi-image file, we allocate the
transparent color as the first color index (#0) in all images. */
if (_plotter->i_transparent && _plotter->i_animation)
/* allocate color cell in colormap; see i_color.c */
_i_new_color_index (R___(_plotter)
_plotter->i_transparent_color.red,
_plotter->i_transparent_color.green,
_plotter->i_transparent_color.blue);
/* allocate bg color as next color index in colormap (it could well be
the same as the transparent index); also construct a miPixel for it */
_i_set_bg_color (S___(_plotter));
pixel.type = MI_PIXEL_INDEX_TYPE;
pixel.u.index = _plotter->drawstate->i_bg_color_index;
/* create libxmi miPaintedSet and miCanvas structs */
_plotter->i_painted_set = (voidptr_t)miNewPaintedSet ();
_plotter->i_canvas = (voidptr_t)miNewCanvas ((unsigned int)_plotter->i_xn, (unsigned int)_plotter->i_yn, pixel);
}
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