% define accents for vietnamese letters

vn_accent_gap# := max(.15x_height#, .5stem#);
vn_letter_height# := if case_ = small: x_height# else: cap_height# fi;
vn_max_ac_top# := 0;

vn_tt_corr# := if low_asterisk: crisp# else: 0 fi;
define_pixels(vn_tt_corr);

if serifs:
    vn_acute_stem#   := .8stem#;
    vn_acute_hair#   := min(hair#, .4vn_acute_stem#);
else:
    vn_acute_stem#   := .7[vair#, stem#];
    vn_acute_hair#   := .9vair#;
fi

vn_acute_side_thickness# := .6vn_acute_stem#;
vn_acute_corner# := .5vn_acute_hair#;
vn_tt_corner_corr# := .25vn_tt_corr#;
vn_corner_corr# := vn_acute_corner# + vn_tt_corner_corr#;
vn_acute_width#  := 4u#;
ds# := vn_acute_corner# + vn_acute_side_thickness#;
vn_acute_height# := max(.4x_height#, (vn_acute_width# - ds#)*tand(30) + ds#);
vn_slant_width_corr# := slant*(vn_acute_height# - ds#);
vn_slant_weight_corr := if slant > 0:
                         if crisp > 0: .2 else: .3 fi slant
                     else: 0 fi;
define_blacker_pixels(vn_acute_stem, vn_acute_hair, vn_acute_side_thickness);

define_accent_dimens(
    acute_,
    vn_acute_width# - vn_slant_width_corr#,
    vn_acute_height#
);

begin_accent(acute_);
    if serifs:
        pickup crisp.nib;
        x1 = w - vn_acute_side_thickness;
        y1 = h - vn_acute_side_thickness;
        x2 = hp(vn_corner_corr#);
        y2 = vp(vn_corner_corr#);
        vn_acute_theta := angle(charwd - vn_corner_corr# - vn_acute_side_thickness#,
                             charht - vn_corner_corr# - vn_acute_side_thickness#);
        pos1(vn_acute_stem*(1 + vn_slant_weight_corr), vn_acute_theta + 90);
        pos2(vn_acute_hair*(1 + vn_slant_weight_corr), vn_acute_theta + 90);
        filldraw circ_stroke z1e -- z2e;  % diagonal
        vn_set_ac_join(acute_, .4w, .4w#, h# - vn_acute_side_thickness#);
    else:
        pickup fine.nib;
        % the following magic lines are to calculate the slope angle according
        % to vn_acute_stem and vn_acute_hair by solving the equation
        %   tand(theta)*(w - .5(vn_acute_stem + vn_acute_hair)/sind(theta)) = h;
        A := charwd/charht;
        B := .5(vn_acute_stem# + vn_acute_hair#)/charht;
        vn_acute_theta := angle(A*sqrt(A*A + 1 - B*B) - B, A*A + 1);
        pos1(vn_acute_stem/sind(vn_acute_theta), 0);
        pos2(vn_acute_hair/sind(vn_acute_theta), 0);
        rt x1r = w;
        lft x2l = 0;
        top y1 = h;
        bot y2 = 0;
        filldraw stroke z1e -- z2e;
        vn_set_ac_join(acute_, .3w, .3w#, h#);
    fi  % diagonal
    penlabels(1, 2);
end_accent;

define_accent_dimens(
    grave_,
    vn_acute_width# + vn_slant_width_corr#,
    vn_acute_height#
);

begin_accent(grave_);
    if serifs:
        pickup crisp.nib;
        x1 = vn_acute_side_thickness;
        y1 = h - vn_acute_side_thickness;
        x2 = w - hp(vn_corner_corr#);
        y2 = vp(vn_corner_corr#);
        vn_grave_theta := 180 - angle(z1 - z2);
        pos1(vn_acute_stem*(1 - vn_slant_weight_corr), 90 - vn_grave_theta);
        pos2(vn_acute_hair*(1 - vn_slant_weight_corr), 90 - vn_grave_theta);
        filldraw circ_stroke z1e -- z2e;
        vn_set_ac_join(grave_, .7w, .7w#, vn_corner_corr#);
    else:
        pickup fine.nib;
        pos1(vn_acute_stem/sind(vn_acute_theta), 0);
        pos2(vn_acute_hair/sind(vn_acute_theta), 0);
        lft x1l = 0;
        rt x2r = w;
        top y1 = h;
        bot y2 = 0;
        filldraw stroke z1e -- z2e;
        vn_set_ac_join(grave_, .7w, .7w#, 0);
    fi  % diagonal
    penlabels(1, 2);
end_accent;

define_accent_dimens(
    dotless_question_,
    4.5u#,
    if serifs: .6min(asc_height#, 1.5x_height#)
    else: .6min(asc_height#, 1.3x_height#) fi
);

hook_scale_stem := .65;

begin_accent(dotless_question_); % based on roman question mark
    numeric bot_width;
    bot_width = hook_scale_stem * 
        if hefty: max(hround .8dot_size, fine.breadth) else: hair fi;
    pickup fine.nib;
    pos2(hook_scale_stem*vair, 90);
    pos3(hook_scale_stem*curve, 0);
    pos4(hook_scale_stem*vair, -90);
    pos5(hook_scale_stem*bot_width, 0);
    pos6(hook_scale_stem*bot_width, 0);
    x2 = x4 = x5 = x6 = .5w - .125u;
    rt x3r = hround(w - .5u);
    bot_hook# := .15[dot_size#, x_height#]
        if serifs: + .2x_height# - .5dot_size# - .75vn_tt_corr#
        else: + .1x_height# - .5dot_size# fi;
    define_pixels(bot_hook);
    bot y6 = 1 + bot_hook;
    top y2r = h + oo;
%     y3 = .75[y6, y2];
    y3 = .7[y6, y2];
    if serifs:
%         y4 = .5[y6, y2];
        y4 = .45[y6, y2];
    else:
        y4 = .45[y6, y2];
    fi
    y5 = .1[y6, y2];
    {{interim superness := more_super;
        filldraw stroke pulled_super_arc.e(2, 3)(superpull)
        & subpath (0, 1) of super_arc.e(3, 4) .. z5e --- z6e\\}}; % arc and stem
    if serifs:
        pos1(hook_scale_stem*hair, 180);
        pos0(hook_scale_stem*flare, 180);
        lft x1r = hround .5u;
        y1 = y3;
        bulb(2, 1, 0); % bulb
    else:
        pos1(Vround 5/7[hook_scale_stem*vair, hook_scale_stem*flare], 110);
        lft x1r = hround .5u;
        top y1r = vround .8[y6, top y2r];
        filldraw stroke term.e(2, 1, left, 1, 4);
    fi % terminal
    penlabels(0, 1, 2, 3, 4, 5, 6);
% now we need to calculate the accent dimens:
%     lft x1r = hround .5u;
%     rt x3r = hround(w - .5u);
    vn_hook_width# := w# - u#;
%     bot y6 = 1 + bot_hook;
%     top y2r = h + oo;
%     oo:=vround(.5o#*hppp*o_correction)+eps;
    vn_hook_height# := h# + .5o#*o_correction - bot_hook#;
    vn_hook_shift_y := bot_hook;
    vn_hook_shift_x := .5u + vn_hook_shift_y*slant;
%     x2 = x4 = x5 = x6 = .5w - .125u;
    vn_hook_join_x := .5w - .125u - .5u;
    vn_hook_join_x# := .5w# - .25u# - .5u#;
end_accent;

define_accent_dimens(
    hook_,
    vn_hook_width#,
    vn_hook_height#
);

def bboxcolor = blue enddef;
begin_accent(hook_);
    currentpicture := vn_pic(dotless_question_) 
        shifted -(vn_hook_shift_x, vn_hook_shift_y);
    vn_set_ac_join(hook_, vn_hook_join_x, vn_hook_join_x#, .75h#);
end_accent;
def bboxcolor = red enddef;

vn_circumflex_width# := 1.5vn_acute_width#;
if serifs:
vn_left_theta := .8vn_acute_theta;
vn_right_theta := .8vn_grave_theta;
vn_circumflex_height# := vn_corner_corr# + .5vn_acute_stem# +
    (.5vn_circumflex_width# - vn_corner_corr#)*tand(vn_left_theta);
else:
vn_circumflex_height# := vn_acute_height#;
fi
define_accent_dimens(
    circumflex_,
    vn_circumflex_width#,
    vn_circumflex_height#
);

begin_accent(circumflex_);
    if serifs:
        pickup crisp.nib;
        x1 = w - x3 = hp(vn_corner_corr#);
        if vn_tt_corr = 0:
            y1 = y3 + .3vp(vn_slant_width_corr#)
        else:
            y1 = y3
        fi
            = vp(vn_corner_corr#);
        pos1(vn_acute_hair*(1 + vn_slant_weight_corr), vn_left_theta + 90);
        pos3(vn_acute_hair*(1 - vn_slant_weight_corr), 90 - vn_right_theta);
        pos2(.9vn_acute_stem, 90);
        x2 = .5w - .3hp(vn_slant_width_corr#);
        z1 - z2 = whatever * dir vn_left_theta;
        filldraw stroke z1e -- z2e -- z3e; % diagonals
        penlabels(0, 1, 2, 3, 4);
        vn_set_ac_join(circumflex_, .5w, .5w#, 0);
    else:
        pickup fine.nib;
        % similiarly to acute
        A := .5(charwd + vn_acute_stem#)/charht;
        B := .5(vn_acute_stem# + vn_acute_hair#)/charht;
        theta := angle(A*sqrt(A*A + 1 - B*B) - B, A*A + 1);
        pos1(vn_acute_hair/sind(theta), 0);
        pos2(min(stem/sind(theta), .6h), 0);
        pos3(vn_acute_hair/sind(theta), 0);
        lft x1l = w - rt x3r = 0;
        bot y1 = bot y3 = 0;
        x2 = 1/2w;
        top y2 = h;
        z0 = whatever[z1r, z2r] = whatever[z2l, z3l];
        y4l = y4r = y2;
        x4l = good.x 1/5[x2l, x2];
        x4r = w - x4l;
        filldraw z4l -- z1l -- z1r -- z0 -- z3l -- z3r -- z4r -- cycle;
        penlabels(0, 1, 2, 3, 4);
        vn_set_ac_join(circumflex_, .5w, .5w#, 0);
    fi  % diagonals
end_accent;

vn_breve_width# := .9vn_circumflex_width#;
vn_breve_height# := min(if not serifs: .8 fi vn_circumflex_height#, .5vn_breve_width#);

define_accent_dimens(
    breve_,
    vn_breve_width#,
    vn_breve_height#
);

begin_accent(breve_);
    if serifs:
        pickup crisp.nib;
        vn_breve_stem := .8vn_acute_stem;
        vn_breve_vair := vn_acute_hair;
    else:
        pickup fine.nib;
        vn_breve_stem := .9vair;
        vn_breve_vair := .9vair;
    fi
    pos1(vn_breve_vair, -180);
    pos3(vn_breve_vair, 0);
    top y1 = top y3 = h;
    lft x1r = w - rt x3r = 0;
    pos2(vn_breve_stem, -90);
    x2 = .5w;
    bot y2r = 0;
    filldraw stroke z1e{down} ... z2e{right} ... {up}z3e;
    penlabels(1, 2, 3);
    vn_set_ac_join(breve_, .5w, .5w#, 0);
end_accent;

vn_tilde_h# := min(asc_height# - x_height#, 3/7x_height# + .5dot_size#);
if serifs:
    vn_tilde_width# := vn_breve_width#;
    vn_tilde_height# := .4vn_tilde_h# + .5vn_tt_corr# + .2stem#
        if beak_jut < 0: + .4vn_tilde_h# fi;
else:
    vn_tilde_width# := vn_circumflex_width#;
    vn_tilde_height# := .7vn_breve_height# + .2stem#;
fi
vn_tilde_h := vp(vn_tilde_h#);

define_accent_dimens(
    tilde_,
    vn_tilde_width#,
    vn_tilde_height#
);

vn_gap(tilde_) := .1x_height#;

begin_accent(tilde_);
    if serifs:
        vn_tilde_stem := min(vn_acute_stem, .2w);
        vn_tilde_vair := max(vair, .5vn_tilde_stem);
        theta := angle(1/4(4u - vn_tilde_vair), 1/4vn_tilde_h);
        pickup crisp.nib;
        numeric vn_mid_width;
%         vn_mid_width = .4[vn_tilde_vair, vn_tilde_stem];
        vn_mid_width = .4[vn_tilde_vair, stem];
        pos1(vn_tilde_vair, theta + 90);
        pos2(vn_tilde_vair, theta + 90);
        pos3(vn_tilde_vair, theta + 90);
        pos4(vn_tilde_vair, theta + 90);
        z2 - z1 = z4 - z3 = min(vn_mid_width - .8crisp - .2vn_tt_corr, .3w)*dir theta;
        lft x1r = w - rt x4l = 0;
        bot y1l = 0;
        top y4r = vround(top y4r + max(.3vn_tilde_h, y2r + .25vn_tilde_vair) - bot y4l);
        pair delta;
        ypart delta = min(3*(y3l - y1l), 1.6h);
        delta = whatever*dir theta;
        filldraw z1l .. controls(z1l + delta) and (z3l - delta)
            .. z3l .. z4l -- z4r .. controls(z4r - delta) and (z2r + delta)
            .. z2r .. z1r -- cycle; % stroke
    else:
        pickup fine.nib;
        vn_tilde_vair := min(vair, .5vn_tilde_h);
        pos1(vn_tilde_vair, 180);
        pos2(vn_tilde_vair, 90);
        pos3(.5[vn_tilde_vair, slab], 90);
        pos4(vn_tilde_vair, 90);
        pos5(vn_tilde_vair, 180);
        lft x1r = w - rt x5l = 0;
        x2 - x1 = x3 - x2 = x4 - x3 = x5 - x4;
        bot y1 = bot y4l = 0;
        top y2r = top y5 = h;
        y3 = .5[y2, y4];
        filldraw stroke z1e{up} ... z2e{right} .. z3e .. {right}z4e ... {up}z5e;
    fi % stroke
    vn_set_ac_join(tilde_, .5w, .5w#, 0);
    penlabels(1, 2, 3, 4, 5);
end_accent;

vn_dot_diam# := max(.8max(dot_size#, cap_curve#), flare#);
define_whole_blacker_pixels(vn_dot_diam);
vn_bot(dot_) := max(vn_accent_gap#,  .7vn_dot_diam#) + vn_dot_diam#;

define_accent_dimens(
    dot_,
    vn_dot_diam#,
    vn_dot_diam#
);

begin_accent(dot_);
    pickup tiny.nib;
    pos1(h, 0);
    pos2(h, 90);
    lft x1l = 0;
    x1 = x2;
    top y2r = h;
    y1 = 1/2[y2l, y2r];
    dot(1, 2);  % dot
    vn_set_ac_join(dot_, .5w, .5w#, .5h#);
    penlabels(1, 2);
end_accent;


if not square_dots:
    vn_horn_dot_size# := min(dot_size#, .3x_height#);
%     vn_horn_dot_size# := 1.2stem# + .1vn_tt_corr#;
    vn_horn_stem# := if vn_tt_corr# = 0: 1.3 fi vair#;
    vn_ohorn_width# := vn_horn_dot_size# + .1stem# + .2vn_tt_corr#;
    vn_ohorn_height# := 1.6vn_horn_dot_size# + .2vn_tt_corr#;
    vn_uhorn_width# := vn_horn_dot_size#  + .2u# +
                   if case_ = small: .1u# + .4stem# - .2vn_slant_width_corr#
                   else:             .4cap_hair# fi;
    vn_uhorn_height# := 1.7vn_horn_dot_size#;
else:
    vn_horn_dot_size# := max(dot_size#, .8cap_curve#);
    vn_horn_stem# := .7vn_horn_dot_size#;
    vn_ohorn_width# := vn_horn_dot_size# + .3stem# + .3u#;
    vn_ohorn_height# := 1.7vn_horn_dot_size#;
    vn_uhorn_width# := vn_horn_dot_size# + .5stem# + .3u#;
    vn_uhorn_height# := 1.8vn_horn_dot_size#;
fi

vn_horn_top# := vn_letter_height# + vn_horn_dot_size#;

define_accent_dimens(
    ohorn_,
    vn_ohorn_width#,
    vn_ohorn_height#
);

begin_accent(ohorn_);
    vn_draw_horn(ohorn_, vn_horn_dot_size#, vn_horn_stem#, 45);
    vn_bot(ohorn_) := vn_horn_top# - vn_height(ohorn_);
end_accent;

define_accent_dimens(
    uhorn_,
    vn_uhorn_width#,
    vn_uhorn_height#
);

begin_accent(uhorn_);
    vn_draw_horn(uhorn_, vn_horn_dot_size#,
        if case_ <> small: min(vn_horn_stem#, hair#) else: vn_horn_stem# fi, 0);
    vn_bot(uhorn_) := vn_horn_top# - vn_height(uhorn_);
end_accent;

vn_ac_top := vn_max_ac_top#;

if serifs:
    vn_breve_acute_gap# := -.02x_height# + .3stem# + .1vn_tt_corr#;
else:
    vn_breve_acute_gap# := .15x_height# - .4stem#;
    vn_acute_botwidth# := vn_acute_hair#/sind(vn_acute_theta); % arcording to ss acute
fi

define_double_accent(
    breve_, acute_,
    if serifs:
        .8vn_left_side(breve_) + .2vn_tt_corr#
    else:
        vn_left_side(breve_) - .5vn_acute_botwidth# - .5u#
    fi,
    vn_breve_acute_gap#
);

define_double_accent(
    breve_, grave_,
    vn_align_right(breve_, grave_)
    if serifs:
        - .7vn_right_side(breve_)
        - vn_sl_shift(breve_)
        - .2vn_tt_corr#
    else:
        - vn_right_side(breve_)
        + .7vn_acute_botwidth#
        - vn_sl_shift(breve_)
    fi,
    vn_breve_acute_gap#
);

define_double_accent(
    breve_, hook_,
    vn_align_join(breve_, hook_),
    vn_breve_acute_gap#
);

vn_breve_tilde_gap# := .04x_height# + .3stem# + .1vn_tt_corr#;

define_double_accent(
    breve_, tilde_,
    vn_align_join(breve_, tilde_),
    vn_breve_tilde_gap#
);

if not serifs:
vn_acute_botshift# := .5vn_acute_hair#/sind(vn_acute_theta) +
                  .7vn_acute_stem#/sind(vn_acute_theta) + u#; % arcording to ss acute
fi

define_double_accent(
    circumflex_, acute_,
    if serifs:
        .3vn_left_side(circumflex_)
        + .2vn_tt_corr#
    else:
        vn_left_side(circumflex_)
        - vn_acute_botshift#
    fi,
    vn_breve_acute_gap#
);

define_double_accent(
    circumflex_, grave_,
    vn_align_right(circumflex_, grave_)
    if serifs:
         - .3vn_right_side(circumflex_)
         - vn_sl_shift(circumflex_)
         - .2vn_tt_corr#
    else:
         - vn_right_side(circumflex_)
         + vn_acute_botshift#
         - vn_sl_shift(circumflex_)
    fi,
    vn_breve_acute_gap#
);

define_double_accent(
    circumflex_, hook_,
    vn_align_join(circumflex_, hook_)
    if serifs:
        + .3vn_right_side(circumflex_)
        - vn_sl_shift(circumflex_)
        - .2vn_tt_corr#
    else:
         + .7vn_right_side(circumflex_)
         - vn_sl_shift(circumflex_)
    fi,
    vn_breve_acute_gap#
);

define_double_accent(
    circumflex_, tilde_,
    vn_align_join(circumflex_, tilde_),
    vn_breve_tilde_gap#
);

vn_double_ac_top := vn_max_ac_top#;

endinput;
