%%     Copyright (C) 2020-2022 by Nan Geng <nangeng@nwafu.edu.cn>
%% --------------------------------------------------------------------------
%%
%%     This work may be distributed and/or modified under the
%%     conditions of the LaTeX Project Public License, either
%%     version 1.3c of this license or (at your option) any later
%%     version. This version of this license is in
%%        http://www.latex-project.org/lppl/lppl-1-3c.txt
%%     and the latest version of this license is in
%%        http://www.latex-project.org/lppl.txt
%%     and version 1.3 or later is part of all distributions of
%%     LaTeX version 2005/12/01 or later.
%%
%%     This work has the LPPL maintenance status "maintained".
%%
%%     The Current Maintainer of this work is Nan Geng.
%%
%% --------------------------------------------------------------------------
%%
\NeedsTeXFormat{LaTeX2e}[2020/10/01]
\RequirePackage{expl3}
\ProvidesExplPackage{circledtext}{2022-04-28}{v1.1.0}
  {Typeset circled text with l3draw}

\RequirePackage { xtemplate, l3keys2e, l3draw, xparse }

% 保证TeXLive的向下兼容
\cs_if_free:NT \box_ht_plus_dp:N
  {
    \cs_new_protected:Npn \box_ht_plus_dp:N #1
      { \tex_dimexpr:D \box_ht:N #1 + \box_dp:N #1 \scan_stop: }
  }

% 带圈文字用户接口
% #1 *号命令，实现阴文
% #2 格式选项
% #3 文字
\NewDocumentCommand{\circledtext}{ s O{} m }
  {
    \group_begin:
      \IfBooleanTF{ #1 }
        {
          \bool_set_true:N  \l__circledtext_negative_bool
        }{
          \bool_set_false:N \l__circledtext_negative_bool
        }
      \__circledtext_handle:nn { #2 } { #3 }
    \group_end:
  }

% 是否反白标志
\bool_new:N   \l__circledtext_negative_bool

% 基字符盒子
\box_new:N    \l__circledtext_basebox_box

% 字符盒子类型
\tl_new:N     \l__circledtext_char_box_type_tl
% 字符盒子类型列表
\clist_new:N  \g__circledtext_char_box_list_clist

% 缩放方式
\tl_new:N     \l__circledtext_resize_method_tl
% 缩放方式列表
\clist_new:N  \g__circledtext_resize_method_clist

% 基字符盒子正方形连长
\dim_new:N    \l__circledtext_char_box_size_dim
% 基字符盒子正方形外接圆半径
\dim_new:N    \l__circledtext_char_box_radius_dim
% 基字符宽度
\dim_new:N    \l__circledtext_char_width_dim
% 基字符高度
\dim_new:N    \l__circledtext_char_height_dim
% 字符(串)盒子宽度
\dim_new:N    \l__circledtext_box_width_dim
% 字符(串)盒子高度
\dim_new:N    \l__circledtext_box_height_dim
% 字符(串)外框线宽
\dim_new:N    \l__circledtext_box_linewidth_dim
% 字符(串)内部十字、米字装饰线线宽
\dim_new:N    \l__circledtext_cross_linewidth_dim
% 字符(串)深度(带格式)
\dim_new:N    \l__circledtext_char_dp_dim

% 字符(串)盒子容器
\coffin_new:N \l__circledtext_str_box_coffin
% 字符框盒子容器
\coffin_new:N \l__circledtext_box_coffin
% 字符盒子容器
\coffin_new:N \l__circledtext_char_coffin
% 临时盒子容器
\coffin_new:N \l__circledtext_tmpa_coffin
% 临时盒子容器
\coffin_new:N \l__circledtext_tmpb_coffin

% 基字符宽度
\dim_new:N    \charboxwd
% 基字符高度
\dim_new:N    \charboxht

% 待处理字符(串)
\tl_new:N     \l__circledtext_chars_tl
% 字符(串)排版格式
\tl_new:N     \l__circledtext_character_format_tl
% 内部十字、米字装饰线颜色点边框颜色比例
\int_new:N    \l__circledtext_cross_color_ratio_int
\int_set:Nn   \l__circledtext_cross_color_ratio_int { 30 }
% 字符(串)的字形类型(实线、虚线等)
\int_new:N    \l__circledtext_charstroke_type_int

% 字体自身缩放比例
\fp_new:N     \l__circledtext_char_shrink_fp

% 填充色辅助函数
\cs_new_nopar:Nn \__circledtext_aux_color_boxfill:
  { }

% 盒子由l3draw实现，
% 设计思路和部分源码来自zitie宏包(\url{https://www.ctan.org/pkg/zitie})。

% 颜色命名函数
% #1 颜色名称
% #2 颜色表达式
\cs_set_nopar:Npn \__circledtext_color_select:nn #1#2
  {
    \color_set:nn {#1} {#2}
  }
\cs_generate_variant:Nn \__circledtext_color_select:nn {nx}

% 颜色命名函数
% #1 颜色名称
% #2 颜色空间
% #3 颜色分量值
\cs_set_nopar:Npn \__circledtext_color_select:nnn #1#2#3
  {
    \color_set:nnn {#1} {#2} {#3}
  }
\cs_generate_variant:Nn \__circledtext_color_select:nnn {nnx}

% 计算基字符的宽和高
\cs_new:Npn \__circledtext_calc_basechar_w_h:
  {
    \dim_set:Nn \l__circledtext_char_width_dim
      {
        \box_wd:N \l__circledtext_basebox_box
      }
    \dim_set:Nn \l__circledtext_char_height_dim
      {
        \box_ht_plus_dp:N \l__circledtext_basebox_box
      }
  }

% 盒子容器总高度计算函数
\cs_new_nopar:Npn \__circledtext_coffin_ht_plus_dp:N #1
  {
    \coffin_ht:N #1 + \coffin_dp:N #1
  }

% 计算基字符外框大小(外接正方形边长和外接圆半径)
\cs_new:Npn \__circledtext_calc_char_box_size:
  {
    % 设置基字符格式的基字符盒子
    \hbox_set:Nn \l_tmpa_box
      {
        \tl_use:N \l__circledtext_character_format_tl
        \tl_use:N \c__circledtext_basechar_tl
      }

    % 盒子宽度
    \dim_set:Nn \l_tmpa_dim
      {
        \box_wd:N \l_tmpa_box
      }
    % 盒子高度
    \dim_set:Nn \l_tmpb_dim
      {
        \box_ht_plus_dp:N \l_tmpa_box
      }

    % 盒子深度
    \dim_set:Nn \l__circledtext_char_dp_dim
      {
        \box_dp:N \l_tmpa_box
      }

    % 正方形边长
    \dim_compare:nNnTF \l_tmpa_dim > \l_tmpb_dim
      {
        \dim_gset_eq:NN \l__circledtext_char_box_size_dim \l_tmpa_dim
      }
      {
        \dim_gset_eq:NN \l__circledtext_char_box_size_dim \l_tmpb_dim
      }

    % 设置基字符盒子正方形宽和高(相等)
    \dim_gset_eq:NN \charboxwd \l__circledtext_char_box_size_dim
    \dim_gset_eq:NN \charboxht \l__circledtext_char_box_size_dim

    % 外接圆半径
    \dim_gset:Nn \l__circledtext_char_box_radius_dim
      {
        \fp_to_dim:n
          {
            \fp_eval:n { \l__circledtext_char_box_size_dim * sqrt(2)/ 2 }
          }
      }
  }

% 字符盒子构造类型函数名称生成函数
% 名称中6个参数分别表示：
% #1 左下角x坐标
% #2 左下角y坐标
% #3 右上角x坐标
% #4 右上角y坐标
% #5 x方向缩放比例(扩展保留参数)
% #6 y方向缩放比例(扩展保留参数)
\cs_new_nopar:Npn \__circledtext_char_box_type:n #1
  {
    __circledtext_char_box_construct_type_ #1 :nnnnnn
  }
% 字符盒子构造类型函数名称命令生成函数
% 名称命令中6个参数分别表示：
% #1 左下角x坐标
% #2 左下角y坐标
% #3 右上角x坐标
% #4 右上角y坐标
% #5 x方向缩放比例(扩展保留参数)
% #6 y方向缩放比例(扩展保留参数)
\cs_new_nopar:Npn \__circledtext_char_box_type_c:n #1
  {
    \use:c
      {
        __circledtext_char_box_construct_type_ #1 :nnnnnn
      }
  }

% 字符盒子构造类型函数生成器函数
% #1 类型名称
\cs_new:Npn \__circledtext_new_char_box_construct:nn #1
  {
    % 将类型名称记入clist
    \clist_put_right:Nn \g__circledtext_char_box_list_clist {#1}
    % 类似\cs_new:cn __circledtext_char_box_construct_type_none:nnnnnn
    \cs_new:cn { \__circledtext_char_box_type:n {#1} }
  }

% 定义字符边框盒子类型

% 无边框
\__circledtext_new_char_box_construct:nn { none } { }

% 填充正方形
\__circledtext_new_char_box_construct:nn { __filledsquare }
  {
    \cs_if_eq:NNF \__circledtext_aux_color_boxfill: \c_empty_tl
      {
        \__circledtext_aux_color_boxfill:
        \draw_scope_begin:
          \bool_if:NTF \l__circledtext_negative_bool
            {
              \color_fill:n { circledtextcharcolor }
            }{
              \color_fill:n { circledtextboxfill   }
            }
          \draw_transform_shift:n { (#3-#3*#5)/2, (#4-#4*#6)/2 }
          \draw_path_rectangle:nn { #1, #2 } { #3*#5, #4*#6 }
          \draw_path_use_clear:n { fill }
        \draw_scope_end:
      }
  }

% 反色填充正方形
\__circledtext_new_char_box_construct:nn { __negfilledsquare }
  {
    \cs_if_eq:NNF \__circledtext_aux_color_boxfill: \c_empty_tl
      {
        \__circledtext_aux_color_boxfill:
        \draw_scope_begin:
          \bool_if:NTF \l__circledtext_negative_bool
            {
              \color_fill:n { circledtextboxfill   }
            }{
              \color_fill:n { circledtextcharcolor }
            }
          \draw_transform_shift:n { (#3-#3*#5)/2, (#4-#4*#6)/2 }
          \draw_path_rectangle:nn { #1, #2 } { #3*#5, #4*#6 }
          \draw_path_use_clear:n { fill }
        \draw_scope_end:
      }
  }

% 正方形填充内切圆
\__circledtext_new_char_box_construct:nn { __innerfilledcircle }
  {
    \cs_if_eq:NNF \__circledtext_aux_color_boxfill: \c_empty_tl
      {
        \__circledtext_aux_color_boxfill:
        \draw_scope_begin:
          \bool_if:NTF \l__circledtext_negative_bool
            {
              \color_fill:n { circledtextcharcolor }
            }{
              \color_fill:n { circledtextboxfill   }
            }
          \draw_path_circle:nn { #3/2, #4/2 } { #3*#5/2 }
          \draw_path_use_clear:n { fill }
        \draw_scope_end:
      }
  }

% 正方形填充外接圆
\__circledtext_new_char_box_construct:nn { __outerfilledcircle }
  {
    \cs_if_eq:NNF \__circledtext_aux_color_boxfill: \c_empty_tl
      {
        \__circledtext_aux_color_boxfill:
        \draw_scope_begin:
          \bool_if:NTF \l__circledtext_negative_bool
            {
              \color_fill:n { circledtextcharcolor }
            }{
              \color_fill:n { circledtextboxfill   }
            }
          \draw_path_circle:nn { #3/2, #4/2 } { \l__circledtext_char_box_radius_dim*#5 }
          \draw_path_use_clear:n { fill }
        \draw_scope_end:
      }
  }

% 正方形边框
\__circledtext_new_char_box_construct:nn { __squarebox }
  {
    \draw_scope_begin:
      \color_stroke:n { circledtextcharboxcolor   }
      \draw_transform_shift:n { (#3-#3*#5)/2, (#4-#4*#6)/2 }
      \draw_path_rectangle:nn { #1, #2 } { #3*#5, #4*#6 }
      \draw_path_use_clear:n { stroke }
    \draw_scope_end:
  }

% 正方形内切圆边框
\__circledtext_new_char_box_construct:nn { __innercirclebox }
  {
    \__circledtext_aux_color_boxfill:
    \draw_scope_begin:
      \color_stroke:n { circledtextcharboxcolor   }
      \draw_path_circle:nn { #3/2, #4/2 } { #3*#5/2 }
      \draw_path_use_clear:n { stroke }
    \draw_scope_end:
  }

% 正方形外接圆边框
\__circledtext_new_char_box_construct:nn { __outercirclebox }
  {
    \draw_scope_begin:
      \color_stroke:n { circledtextcharboxcolor }
      \draw_path_circle:nn { #3/2, #4/2 }
        { \l__circledtext_char_box_radius_dim*#5 }
      \draw_path_use_clear:n { stroke }
    \draw_scope_end:
  }

% 正方形斜十字线(正方形对角连线)
\__circledtext_new_char_box_construct:nn { __dcross }
  {
    \draw_scope_begin:
      \tl_if_empty:NF \l__circledtext_dash_pattern_tl
        {
          \exp_args:No \draw_dash_pattern:nn { \l__circledtext_dash_pattern_tl } { 0pt }
        }
      \draw_linewidth:n{ \l__circledtext_cross_linewidth_dim }
      \color_stroke:n { circledtextcrosscolor }
      \draw_transform_shift:n { (#3-#3*#5)/2, (#4-#4*#6)/2 }
      \draw_path_moveto:n { #1   ,    #2 }
      \draw_path_lineto:n { #3*#5, #4*#6 }
      \draw_path_moveto:n { #1   , #4*#6 }
      \draw_path_lineto:n { #3   , #2*#5 }
      \draw_path_use_clear:n { stroke }
    \draw_scope_end:
  }

% 正方形正十字线(正方形对边中点连线)
\__circledtext_new_char_box_construct:nn { __scross }
  {
    \draw_scope_begin:
      \tl_if_empty:NF \l__circledtext_dash_pattern_tl
        {
          \exp_args:No \draw_dash_pattern:nn { \l__circledtext_dash_pattern_tl } { 0pt }
        }
      \draw_linewidth:n{ \l__circledtext_cross_linewidth_dim }
      \color_stroke:n { circledtextcrosscolor }
      \draw_transform_shift:n { (#3-#3*#5)/2, (#4-#4*#6)/2 }
      \draw_path_moveto:n { #3*#5/2,      #2 }
      \draw_path_lineto:n { #3*#5/2,   #4*#6 }
      \draw_path_moveto:n { #1     , #4*#6/2 }
      \draw_path_lineto:n { #3*#5  , #4*#6/2 }
      \draw_path_use_clear:n { stroke }
    \draw_scope_end:
  }

% 内切圆斜十字线(需要求交点)
\__circledtext_new_char_box_construct:nn { __innerdcross }
  {
    \draw_scope_begin:
      \tl_if_empty:NF \l__circledtext_dash_pattern_tl
        {
          \exp_args:No \draw_dash_pattern:nn { \l__circledtext_dash_pattern_tl } { 0pt }
        }
      \draw_linewidth:n{ \l__circledtext_cross_linewidth_dim }
      \color_stroke:n { circledtextcrosscolor }
      \draw_path_moveto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #1, #2 } % line's first point
            { #3, #4 } % line's second point
            { #3/2, #4/2 } { #3*#5/2 }
            {1}  % index of intersect
        }
      \draw_path_lineto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #1, #2 } % line's first point
            { #3, #4 } % line's second point
            { #3/2, #4/2 } { #3*#5/2 }
            {2}  % index of intersect
        }
      \draw_path_moveto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #1, #4 } % line's first point
            { #3, #2 } % line's second point
            { #3/2, #4/2 } { #3*#5/2 }
            {1}  % index of intersect
        }
      \draw_path_lineto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #1, #4 } % line's first point
            { #3, #2 } % line's second point
            { #3/2, #4/2 } { #3*#5/2 }
            {2}  % index of intersect
        }
      \draw_path_use_clear:n { stroke }
    \draw_scope_end:
  }

% 外接圆正十字线(需要求交点)
\__circledtext_new_char_box_construct:nn { __outercross }
  {
    \draw_scope_begin:
      \tl_if_empty:NF \l__circledtext_dash_pattern_tl
        {
          \exp_args:No \draw_dash_pattern:nn { \l__circledtext_dash_pattern_tl } { 0pt }
        }
      \draw_linewidth:n{ \l__circledtext_cross_linewidth_dim }
      \color_stroke:n { circledtextcrosscolor }
      \draw_path_moveto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #3/2, #2 } % line's first point
            { #3/2, #4 } % line's second point
            { #3/2, #4/2 } { \l__circledtext_char_box_radius_dim*#5 }
            {1}  % index of intersect
        }
      \draw_path_lineto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #3/2, #2 } % line's first point
            { #3/2, #4 } % line's second point
            { #3/2, #4/2 } { \l__circledtext_char_box_radius_dim*#5 }
            {2}  % index of intersect
        }
      \draw_path_moveto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #1, #4/2 } % line's first point
            { #3, #4/2 } % line's second point
            { #3/2, #4/2 } { \l__circledtext_char_box_radius_dim*#5 }
            {1}  % index of intersect
        }
      \draw_path_lineto:n
        {
          \draw_point_intersect_line_circle:nnnnn
            { #1, #4/2 } % line's first point
            { #3, #4/2 } % line's second point
            { #3/2, #4/2 } { \l__circledtext_char_box_radius_dim*#5 }
            {2}  % index of intersect
        }
      \draw_path_use_clear:n { stroke }
    \draw_scope_end:
  }

% 填充内切圆叠加内切圆边框
\__circledtext_new_char_box_construct:nn { o }
  {
    \__circledtext_char_box_type_c:n { __innerfilledcircle } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innercirclebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 填充内切圆叠加正方形正十字线与内切圆边框
\__circledtext_new_char_box_construct:nn { o+ }
  {
    \__circledtext_char_box_type_c:n { __innerfilledcircle } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __scross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innercirclebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 填充内切圆叠加内切圆斜十字线与内切圆边框
\__circledtext_new_char_box_construct:nn { ox }
  {
    \__circledtext_char_box_type_c:n { __innerfilledcircle } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innerdcross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innercirclebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 填充内切圆叠加内切圆正斜十字线与内切圆边框
\__circledtext_new_char_box_construct:nn { ox+ }
  {
    \__circledtext_char_box_type_c:n { __innerfilledcircle } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innerdcross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __scross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innercirclebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 内切圆斜十字线叠加正十字线
\__circledtext_new_char_box_construct:nn { x+ }
  {
    \__circledtext_char_box_type_c:n { __innerdcross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __scross } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 填充正方形叠加正方形边框
\__circledtext_new_char_box_construct:nn { O }
  {
    \__circledtext_char_box_type_c:n { __filledsquare } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __squarebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 填充正方形叠加正方形正十字线与正方形边框
\__circledtext_new_char_box_construct:nn { O+ }
  {
    \__circledtext_char_box_type_c:n { __filledsquare } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __scross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __squarebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 填充正方形叠加正方形斜十字线与正方形边框
\__circledtext_new_char_box_construct:nn { OX }
  {
    \__circledtext_char_box_type_c:n { __filledsquare } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __dcross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __squarebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 填充正方形叠加正方形斜正十字线与正方形边框
\__circledtext_new_char_box_construct:nn { OX+ }
  {
    \__circledtext_char_box_type_c:n { __filledsquare } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __dcross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __scross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __squarebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 正方形斜十字线叠加正十字线
\__circledtext_new_char_box_construct:nn { X+ }
  {
    \__circledtext_char_box_type_c:n { __dcross } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __scross } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 内切圆叠加同心82%内切圆边框
\__circledtext_new_char_box_construct:nn { oo }
  {
    \__circledtext_char_box_type_c:n { __innerfilledcircle } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innercirclebox } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innercirclebox } {#1} {#2} {#3} {#4} {0.82} {0.82}
  }

% 反色正方形叠加内切填充圆
\__circledtext_new_char_box_construct:nn { Oo }
  {
    \__circledtext_char_box_type_c:n { __negfilledsquare } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __innerfilledcircle } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __squarebox } {#1} {#2} {#3} {#4} {#5} {#6}
  }

% 正方形叠加同心82%正方形边框
\__circledtext_new_char_box_construct:nn { OO }
  {
    \__circledtext_char_box_type_c:n { __filledsquare } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __squarebox } {#1} {#2} {#3} {#4} {#5} {#6}
    \__circledtext_char_box_type_c:n { __squarebox } {#1} {#2} {#3} {#4} {0.82} {0.82}
  }
\msg_new:nnn { circledtext } { box-exists } { The~ box~ type~ `#1~ not~ exists. }

% 缩放类型名称生成函数
\cs_new_nopar:Npn \__circledtext_resize:n #1
  {
    __circledtext_processor_resize_ #1 :w
  }

% 缩放类型函数名称命令生成函数
\cs_new_nopar:Npn \__circledtext_resize_c:n #1
  {
    \use:c
      {
        __circledtext_processor_resize_ #1 :w
      }
  }

% 缩放代码生成函数
% #1 dim长度变量1
% #2 dim长度变量2
% #3 缩放代码1
% #4 缩放代码2
% #5 缩放代码3
% 如果 #1 > 0           ，取#3代码
% 如果 #1 <= 0 且#2 > 0 ，取#4代码
% 如果 #1 <= 0 且#2 <= 0，取#5代码
\cs_new:Npn \__circledtext_dim_gezero_dispatch:NNnnn #1#2 #3#4#5
  {
    \dim_compare:nNnTF #1 > \c_zero_dim
      { #3 }
      {
        \dim_compare:nNnTF #2 > \c_zero_dim
          { #4 } { #5 }
      }
  }

% 缩放代码生成函数
% #1 dim长度变量1
% #2 dim长度变量2
% #3 缩放代码1
% #4 缩放代码2
% #5 缩放代码3
% #6 缩放代码4
% 如果 #1 > 0  且 #2 > 0 ，取#3代码
% 如果 #1 > 0  且 #2 <= 0，取#4代码
% 如果 #1 <= 0 且 #2 > 0 ，取#5代码
% 如果 #1 <= 0 且 #2 <= 0，取#6代码
\cs_new:Npn \__circledtext_dim_gezero_dispatch:NNnnnn #1#2 #3#4#5#6
  {
    \dim_compare:nNnTF #1 > \c_zero_dim
      {
        \dim_compare:nNnTF #2 > \c_zero_dim
          { #3 } { #4 }
      }
      {
        \dim_compare:nNnTF #2 > \c_zero_dim
          { #5 } { #6 }
      }
  }

% 缩放代码生成函数(分别按高度、宽度或实际尺寸缩放)
\cs_new:Npn \__circledtext_force_size_dispatch:nnn % height, width, none
  {
    \__circledtext_dim_gezero_dispatch:NNnnn \l__circledtext_height_dim
      \l__circledtext_width_dim
  }

% 缩放代码生成函数(分别按高宽、高度、宽度或实际尺寸缩放)
\cs_new:Npn \__circledtext_force_size_dispatch:nnnn % both, height, width, none
  {
    \__circledtext_dim_gezero_dispatch:NNnnnn \l__circledtext_box_height_dim
      \l__circledtext_box_width_dim
  }

% 构造缩放类型
\cs_new:Npn \__circledtext_new_resize_method:nn #1
  {
    \clist_put_right:Nn \g__circledtext_resize_method_clist {#1}
    \cs_new:cpn { \__circledtext_resize:n {#1} }
  }

% 无缩放
\__circledtext_new_resize_method:nn { none } { }

% 按实际参数缩放
\__circledtext_new_resize_method:nn { real }
  {
    \__circledtext_force_size_dispatch:nnnn
      {% 盒子宽高缩放
        \coffin_resize:Nnn \l__circledtext_box_coffin
                           \l__circledtext_box_width_dim
                           \l__circledtext_box_height_dim
      }
      {% 指定高度为比例缩放
        \coffin_scale:Nnn \l__circledtext_box_coffin
          {
            \dim_ratio:nn { \l__circledtext_box_height_dim }
                          { \__circledtext_coffin_ht_plus_dp:N \l__circledtext_box_coffin }
          }
          {
            \dim_ratio:nn { \l__circledtext_box_height_dim }
                          { \__circledtext_coffin_ht_plus_dp:N \l__circledtext_box_coffin }
          }
      }
      {% 指定宽度为比例缩放
        \coffin_scale:Nnn \l__circledtext_box_coffin
          {
            \dim_ratio:nn { \l__circledtext_box_width_dim }
                          { \coffin_wd:N \l__circledtext_box_coffin }
          }
          {
            \dim_ratio:nn { \l__circledtext_box_width_dim }
                          { \coffin_wd:N \l__circledtext_box_coffin }
          }
      }
      {% 实际宽、高比例缩放
        \coffin_scale:Nnn \l__circledtext_box_coffin
                          { \l__circledtext_x_scale_tl }
                          { \l__circledtext_y_scale_tl }
      }
  }

% 按基字符参数缩放
\__circledtext_new_resize_method:nn { base }
  {
    \__circledtext_force_size_dispatch:nnnn
      {% 按指定盒子宽高缩放
        \coffin_resize:Nnn \l__circledtext_box_coffin
                           \l__circledtext_box_width_dim
                           \l__circledtext_box_height_dim
      }
      {% 基字符宽高乘以高度比例缩放
        \coffin_resize:Nnn \l__circledtext_box_coffin
           {
             \l__circledtext_char_width_dim * \dim_ratio:nn { \l__circledtext_box_height_dim }
               { \__circledtext_coffin_ht_plus_dp:N \l__circledtext_box_coffin }
           }
           {
             \l__circledtext_box_height_dim
           }
      }
      {% 基字符宽高乘以宽度比例缩放
        \coffin_resize:Nnn \l__circledtext_box_coffin
           {
             \l__circledtext_box_width_dim
           }
           {
             \l__circledtext_char_height_dim * \dim_ratio:nn { \l__circledtext_box_width_dim }
               { \coffin_wd:N \l__circledtext_box_coffin }
           }
      }
      {% 基字符乘比例系数后缩放
        \coffin_resize:Nnn \l__circledtext_box_coffin
           {
             \l__circledtext_x_scale_tl \l__circledtext_char_width_dim
           }
           {
             \l__circledtext_y_scale_tl \l__circledtext_char_height_dim
           }
      }
  }
\msg_new:nnn { circledtext } { resize-type } { using~ `#1'~ resize. }

% 笔画设置函数
\cs_new:Npn \__circledtext_chars_stroke:nn #1#2
  {
    \special { pdf:code ~ q ~ #1 } #2 \special { pdf:code ~ Q }
  }
% 笔画构造函数
\cs_new_protected:Npn \__circledtext_chars_stroke_construct:n #1
  {
    \int_case:nn {\l__circledtext_charstroke_type_int}
      {
        {1}{ #1 }
        {2}{
          \__circledtext_chars_stroke:nn { 1 ~ Tr ~ 0.10 ~ w ~ [] ~ 0 ~ d ~ 1 ~ J } {#1}
        }
        {3}{
          \__circledtext_chars_stroke:nn { 1 ~ Tr ~ 0.10 ~ w ~ [1~1] ~ 0 ~ d ~ 1 ~ J } {#1}
        }
        {4}{
          \__circledtext_chars_stroke:nn { 3 ~ Tr } {#1}
        }

      }
  }
\cs_generate_variant:Nn  \__circledtext_chars_stroke_construct:n { V }
\cs_generate_variant:Nn  \__circledtext_chars_stroke_construct:n { x }

% key_value选项设计
\keys_define:nn { circledtext }
  {
    % 基字符
    basechar  .code:n = { \tl_gset:Nx \c__circledtext_basechar_tl {#1}
                          \__circledtext_calc_basechar_w_h:
                        },
    % 字符格式
    charf .code:n = { \tl_gset:Nn \l__circledtext_character_format_tl {#1}
                      \__circledtext_calc_char_box_size:
                    },
    % charf .initial:n = \normalsize ,
    % 边框类型
    boxtype .code:n = { \exp_args:NNx \clist_if_in:NnTF
                            \g__circledtext_char_box_list_clist {#1}
                            { \tl_set:Nx \l__circledtext_char_box_type_tl {#1} }
                            { \msg_error:nnx { circledtext } { box-exists } {#1} }
                        % \__circledtext_calc_char_box_size:
                      },
    % 缩放方式
    resize    .code:n = { \exp_args:NNx \clist_if_in:NnTF
                            \g__circledtext_resize_method_clist {#1}
                            { \tl_set:Nx \l__circledtext_resize_method_tl {#1} }
                            { \msg_error:nnx { circledtext } { resize-method } {#1} }
                        },
    % 缩放参数
    xscale .tl_set:N = \l__circledtext_x_scale_tl ,
    xscale .initial:n = 1 ,
    yscale .tl_set:N = \l__circledtext_y_scale_tl ,
    yscale .initial:n = 1 ,
    scale  .meta:n = { xscale = #1 , yscale = #1 } ,
    width  .dim_set:N = \l__circledtext_box_width_dim ,
    height .dim_set:N = \l__circledtext_box_height_dim ,

    % 字符边框线宽
    boxlinewidth .dim_set:N = \l__circledtext_box_linewidth_dim ,
    boxlinewidth .initial:n = 0.4pt ,
    % 十字线线宽
    crosslinewidth .dim_set:N = \l__circledtext_cross_linewidth_dim ,
    crosslinewidth .initial:n = 0.3pt ,

    % 边框线颜色
    boxcolor  .code:n = { \tl_set:Nx \l_tmpa_tl {
                          #1 ! \int_use:N \l__circledtext_cross_color_ratio_int }
                          \__circledtext_color_select:nn { circledtextcharboxcolor } {#1}
                          \__circledtext_color_select:nx { circledtextcrosscolor }
                                                         { \l_tmpa_tl }
                        } ,
    boxcolor  .initial:n = black ,
    boxcolor* .code:n = { \tl_set:Nx \l_tmpa_tl {
                          #1 ! \int_use:N \l__circledtext_cross_color_ratio_int }
                          \__circledtext_color_select:nnn { circledtextcharboxcolor } #1
                          \__circledtext_color_select:nnx { circledtextcrosscolor }
                                                          \l_tmpa_tl
                        } ,
    % 十字线颜色点边框颜色的比例(必须在boxcolor后)
    crosscolorratio  .code:n = { \int_set:Nn \l__circledtext_cross_color_ratio_int { #1 }
                                 \__circledtext_color_select:nn { circledtextcrosscolor }
                                   { circledtextcharboxcolor ! #1 }
                               },
    crosscolorratio  .initial:n = 30,

    % 字符颜色
    charcolor  .code:n = { \__circledtext_color_select:nn { circledtextcharcolor } {#1}
                           \tl_if_eq:nnT { #1 } { black }
                             {
                               \__circledtext_color_select:nn { circledtextboxfill }
                                                          { white }
                               \cs_set_nopar:Npn \__circledtext_aux_color_boxfill:
                                  { \color_fill:n { white } }
                             }
                         } ,
    charcolor  .initial:n = black ,
    charcolor* .code:n = { \__circledtext_color_select:nnn { circledtextcharcolor } #1 } ,
    color  .meta:n = { boxcolor = #1, crosscolor = #1,  charcolor = #1 } ,
    color* .meta:n = { boxcolor* = #1, crosscolor = #1,  charcolor* = #1 } ,
    % 字符盒子背景填充颜色
    boxfill  .code:n = { \exp_args:Nx \tl_if_empty:nTF {#1}
                           {
                             \__circledtext_color_select:nn { circledtextboxfill }
                                                        { white }
                             \cs_set_nopar:Npn \__circledtext_aux_color_boxfill:
                                { \color_fill:n { white } }
                           }{ \__circledtext_color_select:nn { circledtextboxfill } {#1}
                              \cs_set_nopar:Npn \__circledtext_aux_color_boxfill:
                                { \color_fill:n {#1} }
                           }
                        } ,
    boxfill  .initial:n = {} ,
    boxfill* .code:n = { \__circledtext_color_select:nnn { circledtextboxfill } #1
                           \cs_set_nopar:Npn \__circledtext_aux_color_boxfill:
                             { \color_fill:nn #1 }
                         } ,
    % 笔画参数
    charstroke .choice:,
    charstroke .value_required:n = true,
    charstroke .choices:nn =
      { none, solid, dashed, invisible }
      { \int_set_eq:NN \l__circledtext_charstroke_type_int \l_keys_choice_int },
    charstroke .initial:n = none,
    % 虚线样式
    dashpattern .tl_set:N = \l__circledtext_dash_pattern_tl ,
    dashpattern .initial:n = { } ,

    % 字符自身缩放比例
    charshrink  .fp_set:N  = \l__circledtext_char_shrink_fp ,
    charshrink  .initial:n = 0.75,

    unknown .code:n = { \msg_error:nn { circledtext } { unknown-option } }
  }
\msg_new:nnn { circledtext } { unknown-option }
  { package~ option~ "\l_keys_key_tl"~ is~ unknown. }

% 根据编译引擎设置基字符
\sys_if_engine_xetex:TF
  {
    \keys_set:nn { circledtext }
      {
        basechar = 好,
      }
  }{
    \sys_if_engine_luatex:TF
      {
        \keys_set:nn { circledtext }
          {
            basechar = 好,
          }
      }{
        \keys_set:nn { circledtext }
          {
            basechar = x,
          }
      }
  }

\keys_set:nn { circledtext }
  {
    charf    = \normalsize,
    boxtype  = o,
    resize   = none,
  }

% 选项设置用户接口
\NewDocumentCommand \circledtextset { m }
  {
    \keys_set:nn { circledtext } {#1}
  }

% 构建字符盒子，如字符为空，则用基字符构造
% #1 需要处理的字符(串)
\cs_new:Npn \__circledtext_single_char_construct:N #1
  {
    \tl_if_empty:NTF #1
      {
        \hcoffin_set:Nn \l__circledtext_char_coffin
          {
            \__circledtext_single_handle:N \c__circledtext_basechar_tl
          }
      }{
        \hcoffin_set:Nn \l__circledtext_char_coffin
          {
            \__circledtext_single_handle:N #1
          }
      }
  }

% 构建带圈文字内部函数
% #1 选项内容
% #2 需要处理的字符(串)
\cs_new:Npn \__circledtext_handle:nn #1#2
  {
    \group_begin:
      % 选项设置
      \keys_set:nn { circledtext } { #1 }

      % 设置字符串
      \tl_gset:Nx \l__circledtext_chars_tl {#2}

      % 构造盒子
      \__circledtext_single_char_construct:N \l__circledtext_chars_tl

      % 复制盒子准备缩放与输出
      \coffin_set_eq:NN \l__circledtext_box_coffin \l__circledtext_char_coffin

      % % 测量盒子容器总高度(用内切圆则不需要)
      % \dim_set:Nn \l_tmpa_dim
      %   { \__circledtext_coffin_ht_plus_dp:N \l__circledtext_box_coffin }
      % % 缩放字符盒子容器到字符大小
      % \coffin_scale:Nnn \l__circledtext_box_coffin
      %   {
      %     \dim_ratio:nn { \charboxht } { \l_tmpa_dim }
      %   }
      %   {
      %     \dim_ratio:nn { \charboxht } { \l_tmpa_dim }
      %   }

      % 根据指定的方式缩放盒子
      \__circledtext_resize_c:n { \l__circledtext_resize_method_tl }

      % 下沉距离=字符深度+外框线宽
      \dim_add:Nn \l__circledtext_char_dp_dim { \l__circledtext_box_linewidth_dim }

      % 输出盒子(下沉深度距离)
      \coffin_typeset:Nnnnn \l__circledtext_box_coffin
        { l } { b } { 0pt } { -\l__circledtext_char_dp_dim }
    \group_end:
  }

% 字符处理句柄函数
% #1 需要处理的字符(串)变量
\cs_new:Npn \__circledtext_single_handle:N #1
  {
    \group_begin:
      \tl_set:Nf \l__circledtext_curr_char_tl {#1}
      \__circledtext_single_construct:N \l__circledtext_curr_char_tl
    \group_end:
  }

% 构造带圈字符
% #1 需要处理的字符(串)变量
\cs_new:Npn \__circledtext_single_construct:N #1
  {
    % 按指定的格式和内容构造一个字符盒子容器
    \hcoffin_set:Nn \l__circledtext_box_coffin
      {
        \bool_if:NTF \l__circledtext_negative_bool
          {
            \color_select:n { circledtextboxfill   }
          }{
            \color_select:n { circledtextcharcolor }
          }
        \tl_use:N \l__circledtext_character_format_tl
        \__circledtext_chars_stroke_construct:n { #1 }
      }

    % 构造字符盒子容器边框
    \__circledtext_single_box_construct:
  }

% 字符盒子及边框组合盒子容器构造函数
\cs_new:Npn \__circledtext_single_box_construct:
  {
    % 根据文字内容计算缩放比例
    \dim_set:Nn \l_tmpa_dim
      { \coffin_wd:N \l__circledtext_box_coffin }
    \dim_set:Nn \l_tmpb_dim
      { \__circledtext_coffin_ht_plus_dp:N \l__circledtext_box_coffin }
    \dim_compare:nNnF \l_tmpa_dim > \l_tmpb_dim
      {
        \dim_set_eq:NN \l_tmpa_dim \l_tmpb_dim
      }

    % 缩放字符盒子容器
    \coffin_scale:Nnn \l__circledtext_box_coffin
      {
        \dim_ratio:nn { \charboxwd } { \l_tmpa_dim }
      }
      {
        \dim_ratio:nn { \charboxht } { \l_tmpa_dim }
      }

    % 按指定缩放系数对字符盒子容器进行缩放
    \coffin_scale:Nnn \l__circledtext_box_coffin
      { \l__circledtext_char_shrink_fp }
      { \l__circledtext_char_shrink_fp }

    % 绘制外框并拼装结果
    \draw_begin:
      \draw_linewidth:n { \l__circledtext_box_linewidth_dim }

      \draw_path_scope_begin:
        \__circledtext_char_box_type_c:n { \l__circledtext_char_box_type_tl }
          { 0 } { 0 } { \charboxwd } { \charboxht } { 1.0 } { 1.0 }
        \draw_transform_shift:n {\charboxwd / 2.0, \charboxht / 2.0 }
        \draw_coffin_use:Nnn \l__circledtext_box_coffin { hc } { vc }
      \draw_path_scope_end:
    \draw_end:
  }

\endinput