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/* This file contains the Plotter-specific _retrieve_font method, which is
called when the font_name, font_size, and textangle fields of the
current drawing state have been filled in, and _set_font() is being
invoked. 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,
definitively. */
/* 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 fig
will see, and use, will be precisely an integer. */
#include "sys-defines.h"
#include "extern.h"
bool
#ifdef _HAVE_PROTOS
_f_retrieve_font (S___(Plotter *_plotter))
#else
_f_retrieve_font (S___(_plotter))
S___(Plotter *_plotter;)
#endif
{
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 != 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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