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/* 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. */
/* This file contains the Plotter-specific _retrieve_font method, which is
called by the _set_font() function, which in turn is invoked by the API
functions alabel() and flabelwidth(). It is called when the font_name,
font_size, and textangle fields of the current drawing state have been
filled in. It retrieves the specified font, and fills in the font_type,
typeface_index, font_index, font_is_iso8858, true_font_size, and
font_ascent, and font_descent fields of the drawing state. */
/* This version is for FigPlotters. It also fills in the fig_point_size
field of the drawing state. */
/* This Fig-specific version is needed because xfig supports arbitrary
(non-integer) font sizes for PS fonts only on paper. The current
releases (3.1 and 3.2) of xfig round them to integers. So we quantize
the user-specified font size in such a way that the font size that xfig
will see, and use, will be precisely an integer. */
#include "sys-defines.h"
#include "extern.h"
bool
_pl_f_retrieve_font (S___(Plotter *_plotter))
{
double theta;
double dx, dy, device_dx, device_dy, device_vector_len;
double pointsize, fig_pointsize, size, quantized_size;
int int_fig_pointsize;
double quantization_factor;
/* sanity check */
if (_plotter->drawstate->font_type != PL_F_POSTSCRIPT)
return false;
if (!_plotter->drawstate->transform.uniform
|| !_plotter->drawstate->transform.nonreflection)
/* anamorphically transformed PS font not supported, will use Hershey */
return false;
/* text rotation in radians */
theta = _plotter->drawstate->text_rotation * M_PI / 180.0;
/* unit vector along which we'll move when printing label */
dx = cos (theta);
dy = sin (theta);
/* convert to device frame, and compute length in fig units */
device_dx = XDV(dx, dy);
device_dy = YDV(dx, dy);
device_vector_len = sqrt(device_dx * device_dx + device_dy * device_dy);
/* compute xfig pointsize we should use when printing a string in a PS
font, so as to match this vector length. */
size = _plotter->drawstate->font_size; /* in user units */
pointsize = FIG_UNITS_TO_POINTS(size * device_vector_len);
/* FIG_FONT_SCALING = 80/72 is a silly undocumented factor that shouldn't
exist, but does. In xfig, a `point' is not 1/72 inch, but 1/80 inch! */
fig_pointsize = FIG_FONT_SCALING * pointsize;
/* integer xfig pointsize (which really refers to ascent, not overall size)*/
int_fig_pointsize = IROUND(fig_pointsize);
/* Integer font size that xfig will see, in the .fig file. If this is
zero, we won't actually emit a text object to the .fig file, since
xfig can't handle text strings with zero font size. See f_text.c. */
_plotter->drawstate->fig_font_point_size = int_fig_pointsize;
/* what size in user units should have been, to make fig_font_point_size
an integer */
if (device_vector_len == 0.0)
quantized_size = 0.0; /* degenerate case */
else
quantized_size =
(POINTS_TO_FIG_UNITS((double)int_fig_pointsize / FIG_FONT_SCALING))
/ (device_vector_len);
_plotter->drawstate->true_font_size = quantized_size;
/* quantize other fields */
if (size == 0.0)
quantization_factor = 0.0; /* degenerate case */
else
quantization_factor = quantized_size / size;
_plotter->drawstate->font_ascent *= quantization_factor;
_plotter->drawstate->font_descent *= quantization_factor;
_plotter->drawstate->font_cap_height *= quantization_factor;
return true;
}
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