Issue 3449: Shift accordion register symbols down by half a line width

This makes the documented proposals for combining the accordion
register symbols together with the accordion dot symbol match in
positioning.  It would have been feasible instead to shift the
(centered) accordion dot, but some register symbols work with
different line widths.

The net result will now exhibit a slight descender (namely half a
linewidth) of the accordion register symbols when used in a running
line.

diff --git a/mf/feta-accordion.mf b/mf/feta-accordion.mf
index 354e0f3e91df756b2de4f16823af564a6f50cdf0..68271bf995cd4db66d55d6729adb7e21303e4e0b 100644 (file)
--- a/mf/feta-accordion.mf
+++ b/mf/feta-accordion.mf
@@ -40,12 +40,13 @@ fet_beginchar ("accordion register discant", "discant")
 
        set_char_box (r# + accreg_linethickness# / 2,
                      r# + accreg_linethickness# / 2,
-                     0, 2 r# + 0.7 accreg_linethickness#);
+                     0.7 accreg_linethickness# / 2,
+                     2 r# + 0.7 accreg_linethickness# / 2);
 
        lh = vround (2/3 r);
        lt = vround (0.7 accreg_linethickness);
-
-       h := 3 lh + lt;
+       d := vround (0.7 accreg_linethickness / 2);
+       h := 3 lh + lt - d;
        b := w := (3 lh + hround accreg_linethickness) / 2;
 
        penpos1 (hround accreg_linethickness, 0);
@@ -53,10 +54,10 @@ fet_beginchar ("accordion register discant", "discant")
        penpos3 (hround accreg_linethickness, 180);
        penpos4 (lt, 270);
 
-       z1r = (w, h / 2);
+       z1r = (w, 0.5 [-d, h]);
        z2r = (0, h);
-       z3r = (-b, h / 2);
-       z4r = (0, 0);
+       z3r = (-b, 0.5 [-d, h]);
+       z4r = (0, -d);
 
        penlabels (1, 2, 3, 4);
 
@@ -88,9 +89,9 @@ fet_beginchar ("accordion register discant", "discant")
 
        pickup penrazor scaled lt rotated 90;
 
-       top z5 = pat intersectionpoint ((0, lh + lt) -- (w, lh + lt));
+       top z5 = pat intersectionpoint ((0, lh + lt - d) -- (w, lh + lt - d));
        z6 = z5 xscaled -1;
-       bot z7 = pat intersectionpoint ((0, 2 lh) -- (w, 2 lh));
+       bot z7 = pat intersectionpoint ((0, 2 lh - d) -- (w, 2 lh - d));
        z8 = z7 xscaled -1;
 
        labels (5, 6, 7, 8);
@@ -123,12 +124,13 @@ fet_beginchar ("accordion register freebass", "freebass")
 
        set_char_box (r# + accreg_linethickness# / 2,
                      r# + accreg_linethickness# / 2,
-                     0, 2 r# + 0.7 accreg_linethickness#);
+                     0.7 accreg_linethickness# / 2,
+                     2 r# + 0.7 accreg_linethickness# / 2);
 
        lh = vround r;
        lt = vround (0.7 accreg_linethickness);
-
-       h := 2 lh + lt;
+       d := vround (0.7 accreg_linethickness / 2);
+       h := 2 lh + lt - d;
        b := w := (2 lh + hround accreg_linethickness) / 2;
 
        penpos1 (hround accreg_linethickness, 0);
@@ -136,10 +138,10 @@ fet_beginchar ("accordion register freebass", "freebass")
        penpos3 (accreg_linethickness, 180);
        penpos4 (lt, 270);
 
-       z1r = (w, h / 2);
+       z1r = (w, 0.5 [-d, h]);
        z2r = (0, h);
-       z3r = (-b, h / 2);
-       z4r = (0, 0);
+       z3r = (-b, 0.5 [-d, h]);
+       z4r = (0, -d);
 
        penlabels (1, 2, 3, 4);
 
@@ -181,12 +183,13 @@ fet_beginchar ("accordion register stdbass", "stdbass")
 
        set_char_box (r# + accreg_linethickness# / 2,
                      r# + accreg_linethickness# / 2,
-                     0, 2 r# + 0.7 accreg_linethickness#);
+                     0.7 accreg_linethickness# / 2,
+                     2 r# + 0.7 accreg_linethickness# / 2);
 
        lh = vround (1/2 r);
        lt = vround (0.7 accreg_linethickness);
-
-       h := 4 lh + lt;
+       d := vround (0.7 accreg_linethickness / 2);
+       h := 4 lh + lt - d;
        b := w := (4 lh + hround accreg_linethickness) / 2;
 
        penpos1 (hround accreg_linethickness, 0);
@@ -194,10 +197,10 @@ fet_beginchar ("accordion register stdbass", "stdbass")
        penpos3 (hround accreg_linethickness, 180);
        penpos4 (lt, 270);
 
-       z1r = (w, h / 2);
+       z1r = (w, 0.5 [-d, h]);
        z2r = (0, h);
-       z3r = (-b, h / 2);
-       z4r = (0, 0);
+       z3r = (-b, 0.5 [-d, h]);
+       z4r = (0, -d);
 
        penlabels (1, 2, 3, 4);
 
@@ -229,9 +232,9 @@ fet_beginchar ("accordion register stdbass", "stdbass")
 
        pickup penrazor scaled lt rotated 90;
 
-       top z5 = pat intersectionpoint ((0, lh + lt) -- (w, lh + lt));
+       top z5 = pat intersectionpoint ((0, lh + lt - d) -- (w, lh + lt - d));
        z6 = z5 xscaled -1;
-       bot z7 = pat intersectionpoint ((0, 3 lh) -- (w, 3 lh));
+       bot z7 = pat intersectionpoint ((0, 3 lh - d) -- (w, 3 lh - d));
        z8 = z7 xscaled -1;
 
        labels (5, 6, 7, 8);
@@ -253,24 +256,26 @@ fet_beginchar ("accordion register bayanbass", "bayanbass")
 
        set_char_box (accreg_lh# + accreg_linethickness# / 2,
                      accreg_lh# + accreg_linethickness# / 2,
-                     0, 3 accreg_lh# + accreg_linethickness#);
+                     accreg_linethickness# / 2,
+                     3 accreg_lh# + accreg_linethickness# / 2);
 
-       h := 3 lh + lt;
+       d := vround (accreg_linethickness# / 2);
+       h := 3 lh + lt - d;
 
-       draw_rounded_block ((-w, 0), (-w + lt, h), lt);
-       draw_rounded_block ((w - lt, 0), (w, h), lt);
+       draw_rounded_block ((-w, -d), (-w + lt, h), lt);
+       draw_rounded_block ((w - lt, -d), (w, h), lt);
 
        pickup penrazor scaled lt rotated 90;
 
-       bot z1 = (-w + lt / 2, 0);
-       bot z2 = (-w + lt / 2, lh);
-       bot z3 = (-w + lt / 2, 2 lh);
-       bot z4 = (-w + lt / 2, 3 lh);
+       bot z1 = (-w + lt / 2, -d);
+       bot z2 = (-w + lt / 2, lh - d);
+       bot z3 = (-w + lt / 2, 2 lh - d);
+       bot z4 = (-w + lt / 2, 3 lh - d);
 
-       bot z5 = (w - lt / 2, 0);
-       bot z6 = (w - lt / 2, lh);
-       bot z7 = (w - lt / 2, 2 lh);
-       bot z8 = (w - lt / 2, 3 lh);
+       bot z5 = (w - lt / 2, -d);
+       bot z6 = (w - lt / 2, lh - d);
+       bot z7 = (w - lt / 2, 2 lh - d);
+       bot z8 = (w - lt / 2, 3 lh - d);
 
        draw z1
             -- z5;