1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
|
/* This file is part of the GNU plotutils package. Copyright (C) 1995,
1996, 1997, 1998, 1999, 2000, 2005, 2008, Free Software Foundation, Inc.
The GNU plotutils package is free software. You may redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software foundation; either version 2, or (at your
option) any later version.
The GNU plotutils package is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License along
with the GNU plotutils package; see the file COPYING. If not, write to
the Free Software Foundation, Inc., 51 Franklin St., Fifth Floor,
Boston, MA 02110-1301, USA. */
#include "sys-defines.h"
#include "extern.h"
#include "xmi.h"
bool
_pl_i_begin_page (S___(Plotter *_plotter))
{
/* 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 = (void *)NULL;
_plotter->i_canvas = (void *)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. */
_pl_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
_pl_i_new_image (S___(Plotter *_plotter))
{
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 */
_pl_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 */
_pl_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 = (void *)miNewPaintedSet ();
_plotter->i_canvas = (void *)miNewCanvas ((unsigned int)_plotter->i_xn, (unsigned int)_plotter->i_yn, pixel);
}
|