+%
+% feta-params.mf -- global parameters for both feta and parmesan fonts
+%
+% source file of the GNU LilyPond music typesetter
+%
+% (c) 1997--2008 Han-Wen Nienhuys <hanwen@xs4all.nl>
+
+stafflines := 5;
-stafflines = 5;
-% [reuter] URG! This is not always true. One of the effects of
-% keeping this a constant is that, for notation with less stafflines,
-% stafflinethickness gets too small.
+%
+% The design size of a staff should really be the
+% staff_space, but we use staffsize for historical reasons.
+%
-staff_space#:=staffsize#/(stafflines-1);
+staff_space# := staffsize# / (stafflines - 1);
+staff_space_rounded# := staff_space#;
-% URG!
-%font_x_height staff_space# ;
%
-% [D.K.Roush & J.S.Gourlay] say this should be 0.072
-% We know better
-% FIXME: generally, the "blackness" of most chars depends on this.
-% these dimensions should be independent.
-stafflinethickness#:=0.1 staff_space#;
+% Measuring on pocket scores turns out: stafflinethickness is
+% largely independent on staff size, and generally about 0.5 pt.
+%
+% By request of WL, we tune down the blackness a little
+% for increased contrast with beams.
+%
-stemthickness# := stafflinethickness#;
-ledgerlinethickness# := 2 stafflinethickness#;
+%% !! synchronize with paper.scm
+
+save fixed_line_thickness, variable_line_factor;
+fixed_line_thickness + variable_line_factor * 5 pt# = 0.50 pt#;
+fixed_line_thickness + variable_line_factor * 4.125 pt# = 0.47 pt#;
-define_pixels(staff_space, stemthickness);
-define_pixels(stafflinethickness,ledgerlinethickness);
+stafflinethickness# := fixed_line_thickness
+ + variable_line_factor * staff_space#;
+stafflinethickness_rounded# := stafflinethickness#;
%
-% Hand-engraved music often has balls extending above and below
-% the lines. If you like that, modify overdone heads (unit:
-% stafflinethickness)
+% The following tunes the general blackness of the glyphs.
+%
+
+linethickness# := stafflinethickness#; %% 0.5 pt#;
+linethickness_rounded# := linethickness#;
+
+%
+% bigger puff_up_factor, relatively thicker stafflines.
+%
+% 20 pt = puff_up_factor 0
+% 10 pt = puff_up_factor 1
%
-numeric overdone_heads;
-overdone_heads = 0.0;
+puff_up_factor = (linethickness# - 0.1 staff_space#) / (0.1 staff_space#);
+
+
+stemthickness# := 1.3 stafflinethickness#;
+stemthickness_rounded# := stemthickness#;
+ledgerlinethickness# := 2 stafflinethickness#;
+ledgerlinethickness_rounded# := ledgerlinethickness#;
+
+define_pixels (staff_space, stemthickness, stafflinethickness,
+ ledgerlinethickness, linethickness);
+define_whole_pixels (staff_space_rounded);
+define_whole_blacker_pixels (stemthickness_rounded);
+define_whole_vertical_blacker_pixels (stafflinethickness_rounded,
+ ledgerlinethickness_rounded,
+ linethickness_rounded);
+
+if ledgerlinethickness_rounded > 2 stafflinethickness_rounded:
+ ledgerlinethickness_rounded := 2 stafflinethickness_rounded;
+fi;
%
% Because of the engraving/stamping process, no traditional
-% characters have sharp edges and corners
-% The following variable controls the amount of "roundness"
+% characters have sharp edges and corners.
+% The following variable controls the amount of `roundness'.
%
-% this is not a meta variable: it is related to absolute sizes.
+% This is not a meta variable: it is related to absolute sizes.
%
% FIXME: According to [Wanske], only outside corners should be round
% I don't think we do this anywhere -- jcn
-numeric blot_diameter;
-blot_diameter# = .4pt#;
+%
+
+blot_diameter# = .40 pt#;
if (blot_diameter# * hppp) < 1:
- blot_diameter# := 1/hppp;
+ blot_diameter# := 1 / hppp;
fi
if (blot_diameter# * vppp) < 1:
- blot_diameter# := 1/vppp;
+ blot_diameter# := 1 / vppp;
fi
-define_pixels(blot_diameter);
+
+define_pixels (blot_diameter);
+
+
+%
+% symmetry
+% --------
+%
+% Some glyphs have to be positioned exactly between stafflines (clefs,
+% note heads). This needs some care at lower resolutions.
+%
+% Most glyphs use the staffline thickness and the space between two
+% staff lines as the fundamental parameters. The latter is the distance
+% between the middle of one staff line to the middle of the next. To
+% say it differently, the value `staff_space' is the sum of one staff line
+% thickness and the whitespace between two adjacent staff lines.
+%
+% Normally, feta's vertical origin for glyphs is either the middle
+% between two staff lines or the middle of a staff line. For example, the
+% lower edge of the central staff line is at the vertical position
+% `-<staffline thickness> / 2', and the upper edge at
+% `<staffline thickness> / 2'. Here we need a value rounded to an integer
+% (the feta code uses `stafflinethickness_rounded' for that purpose).
+%
+% If we have an odd number of pixels as the staffline thickness, Metafont
+% rounds `-stafflinethickness_rounded / 2' towards zero and
+% `stafflinethickness_rounded / 2' towards infinity. Example: `round -1.5'
+% yields -1, `round 1.5' yields 2. The whitespace between staff lines is
+% handled similarly. If we assume that stafflinethickness_rounded is odd,
+% we have the following cases:
+%
+% o The glyph is centered between three stafflines or five stafflines
+% (clef, `c' meter). We have this:
+%
+% ___________ a
+% ___________ 1
+% ___________ a
+%
+% whitespace
+%
+% ___________ a
+% ...... ___________ 1 .................. x axis
+% ___________ a
+%
+% whitespace
+%
+% ___________ a
+% ___________ 1
+% ___________ a
+%
+% As can be seen, we get symmetry if we split staff lines into two
+% equal parts `a' and a pixel line with thickness 1. Consequently, we
+% use the following algorithm:
+%
+% . Decrease the height `h' by 1 temporarily.
+%
+% . Compute the path for the upper half of the glyph.
+%
+% . Mirror the path at the x axis.
+%
+% . Shift the upper half one pixel up and connect it with the lower path.
+%
+% . Restore height and decrease `d' by 1.
+%
+% o The glyph is centered between two or four staff lines, and the origin is
+% the middle of the whitespace. Assuming that the the whitespace consists
+% of an odd number of pixels, we have this:
+%
+% -----------
+% b
+% 1
+% b
+% ___________
+% b
+% .................. 1 ................. x axis
+% b
+% ___________
+% b
+% 1
+% b
+% ___________
+%
+% For symmetrical glyphs, this leads to a similar algorithm as above.
+% Glyphs which can't be constructed from an upper and lower part need
+% to be handled differently, namely to shift up the vertical center by
+% half a pixel:
+%
+% ___________
+% b
+%
+% 0.5
+% .................. 0.5 ................ x axis
+%
+% b
+% ___________
+%
+
+feta_eps := 0;
+feta_shift := 0;
+feta_space_shift := 0;
+
+% Use this for paths with a slant of 45 degrees to assure that
+% the middle point of a penpos gets covered.
+pair feta_offset;
+feta_offset := (0, 0);
+
+if known miterlimit:
+ pickup nullpen;
+else:
+ feta_eps := eps;
+
+ if odd stafflinethickness_rounded:
+ feta_shift := 1;
+ fi;
+
+ if odd (staff_space_rounded - stafflinethickness_rounded):
+ feta_space_shift := 1;
+ fi;
+
+ feta_offset := (0.5, 0.5);
+
+ pickup pencircle scaled 1;
+fi;
+
+feta_fillpen := savepen;
projects / lilypond.git / blobdiff