\ProvidesFile{pgf-go-lines.sty}[2026/10/23 v0.2026.10.23 pgf-go: arrows and lines]
\ExplSyntaxOn

%FLECHAS Y LINEAS ENTRE DOS INTERSECCIONES: \arrow[<opciones>]{<desde>}{<hasta>} Y \line[...]{...}{...}.
%SOLO EXISTEN DENTRO DE goban (COMO \mark; \line ES UN COMANDO DE LaTeX). SE DIBUJAN EN LA CAPA DE LAS
%MARCAS, ENCIMA DE LAS PIEDRAS, RECORTADAS A LA PARTE VISIBLE. EL HALO (DEL COLOR DEL FONDO DEL TABLERO)
%LAS SEPARA DE LAS PIEDRAS. TAMBIEN LAS USA \sgf (AR Y LN).

%LAS DOS TIENEN EL MISMO ESTILO, CADA UNA EN SU ARBOL: /pgfgo/arrow Y /pgfgo/line. #1: arrow O line.
%CLAVES: /pgfgo/{arrow, line}/{color, width, opacity, dash, shorten, bend, halo, forget}
%CLAVES: /pgfgo/{arrow, line}/halo/{true, false, color, width}
\cs_new_protected:Npn \__pgfgo_lines_new:n #1 {
	\tl_new:c {l__pgfgo_ #1 _color_tl}
	\dim_new:c {l__pgfgo_ #1 _width_dim}
	\tl_new:c {l__pgfgo_ #1 _opacity_tl}
	\tl_new:c {l__pgfgo_ #1 _dash_tl}
	\dim_new:c {l__pgfgo_ #1 _shorten_dim}
	\fp_new:c {l__pgfgo_ #1 _bend_fp}
	\bool_new:c {l__pgfgo_ #1 _halo_bool}
	\tl_new:c {l__pgfgo_ #1 _halo_color_tl}
	\dim_new:c {l__pgfgo_ #1 _halo_width_dim}
	\keys_define:nn {pgfgo / #1} {
		color				.tl_set:c		= {l__pgfgo_ #1 _color_tl},
		color				.initial:n	= {black},
		width				.dim_set:c	= {l__pgfgo_ #1 _width_dim},
		width				.initial:n	= {1.2pt},
		opacity			.tl_set:c		= {l__pgfgo_ #1 _opacity_tl},
		opacity			.initial:n	= {1},
		%EL TRAZO: solid, dashed O dotted (EL HALO ES SIEMPRE CONTINUO).
		dash				.choices:nn	= {solid, dashed, dotted} {\tl_set_eq:cN {l__pgfgo_ #1 _dash_tl} \l_keys_choice_tl},
		dash				.initial:n	= {solid},
		%ACORTA LOS DOS EXTREMOS (POR EJEMPLO, PARA NO TAPAR LAS PIEDRAS).
		shorten			.dim_set:c	= {l__pgfgo_ #1 _shorten_dim},
		shorten			.initial:n	= {0pt},
		%UN ARCO: SALE GIRADA bend GRADOS A LA IZQUIERDA (NEGATIVO, A LA DERECHA), COMO bend left DE TikZ.
		bend				.fp_set:c		= {l__pgfgo_ #1 _bend_fp},
		bend				.initial:n	= {0},
		halo				.code:n			= {\keys_set:nn {pgfgo / #1 / halo} {##1}},
		halo				.default:n	= {true},
		forget			.code:n			= {\bool_set_false:N \l_pgfgo_goban_remember_mark_bool},
		forget			.groups:n		= {preset},
	}
	\keys_define:nn {pgfgo / #1 / halo} {
		true				.code:n			= {\bool_set_true:c {l__pgfgo_ #1 _halo_bool}},
		false				.code:n			= {\bool_set_false:c {l__pgfgo_ #1 _halo_bool}},
		%SIN color, EL DEL FONDO DEL TABLERO.
		color				.tl_set:c		= {l__pgfgo_ #1 _halo_color_tl},
		width				.dim_set:c	= {l__pgfgo_ #1 _halo_width_dim},
		width				.initial:n	= {0.8pt},
	}
	\bool_set_true:c {l__pgfgo_ #1 _halo_bool}
}
\__pgfgo_lines_new:n {arrow}
\__pgfgo_lines_new:n {line}

%LA PUNTA DE LAS FLECHAS (UNA PUNTA DE arrows.meta) Y EN QUE EXTREMOS VA: end O both.
\tl_new:N \l__pgfgo_arrow_tip_tl
\bool_new:N \l__pgfgo_arrow_both_bool
\keys_define:nn {pgfgo / arrow} {
	tip					.tl_set:N		= \l__pgfgo_arrow_tip_tl,
	tip					.initial:n	= {Stealth},
	tips				.choices:nn	= {end, both}
		{\bool_set:Nn \l__pgfgo_arrow_both_bool {\str_if_eq_p:Vn \l_keys_choice_tl {both}}},
	tips				.initial:n	= {end},
}
\cs_generate_variant:Nn \str_case:nn {vn}

\keys_define:nn {pgfgo} {
	arrow				.code:n			= {\keys_set:nn {pgfgo / arrow} {#1}},
	line				.code:n			= {\keys_set:nn {pgfgo / line} {#1}},
}

%LA RECTA DE (#1,#2) A (#3,#4) O, CON bend, LA CURVA: COMO EN TikZ, LOS PUNTOS DE CONTROL ESTAN A 0.3915
%DE LA DISTANCIA, EN LAS DIRECCIONES DE SALIDA Y DE LLEGADA (GIRADAS bend Y -bend).
\fp_new:N \l__pgfgo_lines_bend_fp
\cs_new_protected:Npn \__pgfgo_lines_path:nnnn #1#2#3#4 {
	\pgfpathmoveto {\pgfpointxy{#1}{#2}}
	\fp_compare:nNnTF {\l__pgfgo_lines_bend_fp} = {0}
		{\pgfpathlineto {\pgfpointxy{#3}{#4}}}
		{
			\pgfpathcurveto
				{\pgfpointxy
					{\fp_eval:n {#1 + 0.3915 * ((#3 - #1) * cosd(\l__pgfgo_lines_bend_fp) - (#4 - #2) * sind(\l__pgfgo_lines_bend_fp))}}
					{\fp_eval:n {#2 + 0.3915 * ((#3 - #1) * sind(\l__pgfgo_lines_bend_fp) + (#4 - #2) * cosd(\l__pgfgo_lines_bend_fp))}}}
				{\pgfpointxy
					{\fp_eval:n {#3 - 0.3915 * ((#3 - #1) * cosd(\l__pgfgo_lines_bend_fp) + (#4 - #2) * sind(\l__pgfgo_lines_bend_fp))}}
					{\fp_eval:n {#4 - 0.3915 * ((#4 - #2) * cosd(\l__pgfgo_lines_bend_fp) - (#3 - #1) * sind(\l__pgfgo_lines_bend_fp))}}}
				{\pgfpointxy{#3}{#4}}
		}
}

%LA PUNTA DE arrows.meta CRECE CON EL GROSOR DE LA LINEA (SOBRE TODO A LO LARGO): EL HALO DE UNA FLECHA NO
%PUEDE SER LA MISMA FLECHA MAS GRUESA. ES LA FLECHA DIBUJADA 32 VECES, CORRIDA EL ANCHO DEL HALO EN CADA
%DIRECCION: ASI RODEA IGUAL A CUALQUIER PUNTA. LOS COSENOS Y SENOS DE LAS 32 DIRECCIONES SE CALCULAN UNA
%SOLA VEZ, COMO LOS CALCULA \pgfpointpolar ({<COSENO>}{<SENO>} EN CADA ELEMENTO).
\seq_new:N \g__pgfgo_lines_halo_seq
\int_step_inline:nnn {0} {31} {
	\pgfmathparse {#1 * 11.25}
	\tl_set_eq:NN \l_tmpa_tl \pgfmathresult
	\use:c {pgfmathcos@} {\l_tmpa_tl}
	\tl_set_eq:NN \l_tmpb_tl \pgfmathresult
	\use:c {pgfmathsin@} {\l_tmpa_tl}
	\seq_gput_right:Ne \g__pgfgo_lines_halo_seq {{\l_tmpb_tl} {\pgfmathresult}}
}

%EL HALO DE UNA FLECHA (#1: arrow) DE (#2,#3) A (#4,#5), CON EL GROSOR DE LA FLECHA YA FIJADO. CADA COPIA
%SOLO CAMBIA LA TRANSFORMACION, QUE ES LOCAL: ALCANZA UN GRUPO DE TEX (SIN ABRIR UN AMBITO EN EL PDF).
\dim_new:N \l__pgfgo_lines_halo_dim
\cs_new_protected:Npn \__pgfgo_lines_arrow_halo:nnnnn #1#2#3#4#5 {
	\pgfmathsetlength \l__pgfgo_lines_halo_dim {\dim_use:c {l__pgfgo_ #1 _halo_width_dim}}
	\seq_map_inline:Nn \g__pgfgo_lines_halo_seq {
		\group_begin:
			\pgftransformshift {\__pgfgo_lines_halo_shift:nn ##1}
			\__pgfgo_lines_path:nnnn {#2} {#3} {#4} {#5}
			\pgfusepath{stroke}
		\group_end:
	}
}
%UN PUNTO DE PGF: EL ANCHO DEL HALO EN LA DIRECCION DE COSENO #1 Y SENO #2.
\cs_new_protected:Npn \__pgfgo_lines_halo_shift:nn #1#2 {
	\dim_gset:cn {pgf@x} {#1 \l__pgfgo_lines_halo_dim}
	\dim_gset:cn {pgf@y} {#2 \l__pgfgo_lines_halo_dim}
}

%DIBUJA UNA FLECHA O UNA LINEA (#1: arrow O line) CON LAS OPCIONES #2, DE (#3,#4) A (#5,#6). CON
%partial = auto, LOS EXTREMOS SON PARTE DE LO DIBUJADO.
\cs_new_protected:Npn \pgfgo_line_parsed:nnnnnn #1#2#3#4#5#6 {
	\bool_lazy_and:nnF {\int_compare_p:nNn {#3} = {#5}} {\int_compare_p:nNn {#4} = {#6}} {
		\bool_if:NT \l_pgfgo_goban_partial_auto_bool {
			\pgfgo_kernel_extent_add:nn {#3} {#4}
			\pgfgo_kernel_extent_add:nn {#5} {#6}
		}
		\group_begin:
			\keys_set_exclude_groups:nnn {pgfgo / #1} {preset} {#2}
			\fp_set_eq:Nc \l__pgfgo_lines_bend_fp {l__pgfgo_ #1 _bend_fp}
			\pgfonlayer{pgfgo_layer_mark}
			\pgfscope
				\pgfgo_goban_clip:n {
					\pgfpathrectanglecorners
						{\pgfpointxy{\int_use:N \l_pgfgo_goban_from_x_int - 0.5}{\int_use:N \l_pgfgo_goban_from_y_int - 0.5}}
						{\pgfpointxy{\int_use:N \l_pgfgo_goban_to_x_int + 0.5}{\int_use:N \l_pgfgo_goban_to_y_int + 0.5}}
				}
				\pgfsetroundcap
				\pgfsetroundjoin
				\str_if_eq:nnT {#1} {arrow} {
					\pgfsetarrowsend{\tl_use:N \l__pgfgo_arrow_tip_tl}
					\bool_if:NT \l__pgfgo_arrow_both_bool {\pgfsetarrowsstart{\tl_use:N \l__pgfgo_arrow_tip_tl}}
				}
				\dim_compare:nNnF {\dim_use:c {l__pgfgo_ #1 _shorten_dim}} = {0pt} {
					\pgfsetshortenstart{\dim_use:c {l__pgfgo_ #1 _shorten_dim}}
					\pgfsetshortenend{\dim_use:c {l__pgfgo_ #1 _shorten_dim}}
				}
				\bool_if:cT {l__pgfgo_ #1 _halo_bool} {
					\tl_if_empty:cTF {l__pgfgo_ #1 _halo_color_tl}
						{\tl_set_eq:NN \l__pgfgo_lines_halo_tl \l_pgfgo_goban_border_fill_color_tl}
						{\tl_set_eq:Nc \l__pgfgo_lines_halo_tl {l__pgfgo_ #1 _halo_color_tl}}
					\pgfscope
						\pgfsetstrokecolor {\l__pgfgo_lines_halo_tl}
						\pgfsetfillcolor {\l__pgfgo_lines_halo_tl}
						\str_if_eq:nnTF {#1} {arrow} {
							\pgfsetlinewidth {\dim_use:c {l__pgfgo_ #1 _width_dim}}
							\__pgfgo_lines_arrow_halo:nnnnn {#1} {#3} {#4} {#5} {#6}
						}{
							\pgfsetlinewidth {\dim_eval:n {\dim_use:c {l__pgfgo_ #1 _width_dim} + \dim_use:c {l__pgfgo_ #1 _halo_width_dim} * 2}}
							\__pgfgo_lines_path:nnnn {#3} {#4} {#5} {#6}
							\pgfusepath{stroke}
						}
					\endpgfscope
				}
				\pgfsetlinewidth {\dim_use:c {l__pgfgo_ #1 _width_dim}}
				\pgfsetstrokecolor {\tl_use:c {l__pgfgo_ #1 _color_tl}}
				\pgfsetfillcolor {\tl_use:c {l__pgfgo_ #1 _color_tl}}
				\pgfsetstrokeopacity {\tl_use:c {l__pgfgo_ #1 _opacity_tl}}
				\pgfsetfillopacity {\tl_use:c {l__pgfgo_ #1 _opacity_tl}}
				\str_case:vn {l__pgfgo_ #1 _dash_tl} {
					{dashed}	{\pgfsetdash {{3\pgflinewidth} {2\pgflinewidth}} {0pt}}
					{dotted}	{\pgfsetdash {{0pt} {2\pgflinewidth}} {0pt}}
				}
				\__pgfgo_lines_path:nnnn {#3} {#4} {#5} {#6}
				\pgfusepath{stroke}
			\endpgfscope
			\endpgfonlayer
		\group_end:
	}
}

%#1: arrow O line, #2: OPCIONES, #3 Y #4: LAS DOS INTERSECCIONES.
\tl_new:N \l__pgfgo_lines_from_tl
\tl_new:N \l__pgfgo_lines_halo_tl
\cs_new_protected:Npn \pgfgo_line:nnnn #1#2#3#4 {
	\group_begin:
		\keys_set_groups:nnn {pgfgo / #1} {preset} {#2}
		\pgfgo_kernel_point:nTF {#3} {
			\tl_set_eq:NN \l__pgfgo_lines_from_tl \l_pgfgo_kernel_point_tl
			\pgfgo_kernel_point:nTF {#4}
				{\__pgfgo_lines_draw:nnVV {#1} {#2} \l__pgfgo_lines_from_tl \l_pgfgo_kernel_point_tl}
				{\msg_warning:nnn {pgfgo} {unknown-coordinate} {#4}}
		} {\msg_warning:nnn {pgfgo} {unknown-coordinate} {#3}}
	\group_end:
}
%#3 Y #4: {x}{y} DE CADA EXTREMO. SI HAY QUE RECORDARLA, TAMBIEN VA A LA MEMORIA.
\cs_new_protected:Npn \__pgfgo_lines_draw:nnnn #1#2#3#4 {
	\pgfgo_remember:Nnn \l_pgfgo_goban_remember_mark_bool {#1}
		{\exp_not:N \pgfgo_line_parsed:nnnnnn {#1} {\exp_not:n {#2}} #3 #4}
	\pgfgo_line_parsed:nnnnnn {#1} {#2} #3 #4
}
\cs_generate_variant:Nn \__pgfgo_lines_draw:nnnn {nnVV}

%\arrow Y \line SE ACTIVAN SOLO DENTRO DE goban (VER pgf-go-goban.sty).
\NewDocumentCommand{\__pgfgo_arrow_command}{O{}mm}{\pgfgo_line:nnnn {arrow} {#1} {#2} {#3}}
\NewDocumentCommand{\__pgfgo_line_command}{O{}mm}{\pgfgo_line:nnnn {line} {#1} {#2} {#3}}

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