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Diffstat (limited to 'plugins/jetpack/modules/latex.php')
| -rw-r--r-- | plugins/jetpack/modules/latex.php | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/plugins/jetpack/modules/latex.php b/plugins/jetpack/modules/latex.php new file mode 100644 index 00000000..340dfa9f --- /dev/null +++ b/plugins/jetpack/modules/latex.php @@ -0,0 +1,122 @@ +<?php +/** + * Module Name: Beautiful Math + * Module Description: Use the LaTeX markup language to write mathematical equations and formulas. + * Sort Order: 12 + * First Introduced: 1.1 + * Requires Connection: No + * Auto Activate: No + * Module Tags: Writing + * Feature: Writing + * Additional Search Queries: latex, math, equation, equations, formula, code + */ + +/** + * LaTeX support. + * + * Backward compatibility requires support for both "[latex][/latex]", and + * "$latex $" shortcodes. + * + * $latex e^{\i \pi} + 1 = 0$ -> [latex]e^{\i \pi} + 1 = 0[/latex] + * $latex [a, b]$ -> [latex][a, b][/latex] + */ + +function latex_markup( $content ) { + $textarr = wp_html_split( $content ); + + $regex = '% + \$latex(?:=\s*|\s+) + ((?: + [^$]+ # Not a dollar + | + (?<=(?<!\\\\)\\\\)\$ # Dollar preceded by exactly one slash + )+) + (?<!\\\\)\$ # Dollar preceded by zero slashes + %ix'; + + foreach ( $textarr as &$element ) { + if ( '' == $element || '<' === $element[0] ) { + continue; + } + + if ( false === stripos( $element, '$latex' ) ) { + continue; + } + + $element = preg_replace_callback( $regex, 'latex_src', $element ); + } + + return implode( '', $textarr ); +} + +function latex_src( $matches ) { + $latex = $matches[1]; + + $bg = latex_get_default_color( 'bg' ); + $fg = latex_get_default_color( 'text', '000' ); + $s = 0; + + + $latex = latex_entity_decode( $latex ); + if ( preg_match( '/.+(&fg=[0-9a-f]{6}).*/i', $latex, $fg_matches ) ) { + $fg = substr( $fg_matches[1], 4 ); + $latex = str_replace( $fg_matches[1], '', $latex ); + } + if ( preg_match( '/.+(&bg=[0-9a-f]{6}).*/i', $latex, $bg_matches ) ) { + $bg = substr( $bg_matches[1], 4 ); + $latex = str_replace( $bg_matches[1], '', $latex ); + } + if ( preg_match( '/.+(&s=[0-9-]{1,2}).*/i', $latex, $s_matches ) ) { + $s = (int) substr( $s_matches[1], 3 ); + $latex = str_replace( $s_matches[1], '', $latex ); + } + + return latex_render( $latex, $fg, $bg, $s ); +} + +function latex_get_default_color( $color, $default_color = 'ffffff' ) { + global $themecolors; + return isset($themecolors[$color]) ? $themecolors[$color] : $default_color; +} + +function latex_entity_decode( $latex ) { + return str_replace( array( '<', '>', '"', ''', '&', '&', "\n", "\r" ), array( '<', '>', '"', "'", '&', '&', ' ', ' ' ), $latex ); +} + +function latex_render( $latex, $fg, $bg, $s = 0 ) { + $url = "//s0.wp.com/latex.php?latex=" . urlencode( $latex ) . "&bg=" . $bg . "&fg=" . $fg . "&s=" . $s; + $url = esc_url( $url ); + $alt = str_replace( '\\', '\', esc_attr( $latex ) ); + + return '<img src="' . $url . '" alt="' . $alt . '" title="' . $alt . '" class="latex" />'; +} + +/** + * The shortcode way. The attributes are the same as the old ones - 'fg' and 'bg', instead of foreground + * and background, and 's' is for the font size. + * + * Example: [latex s=4 bg=00f fg=ff0]\LaTeX[/latex] + */ +function latex_shortcode( $atts, $content = '' ) { + extract( shortcode_atts( array( + 's' => 0, + 'bg' => latex_get_default_color( 'bg' ), + 'fg' => latex_get_default_color( 'text', '000' ) + ), $atts, 'latex' ) ); + + return latex_render( latex_entity_decode( $content ), $fg, $bg, $s ); +} + +/** + * LaTeX needs to be untexturized + */ +function latex_no_texturize( $shortcodes ) { + $shortcodes[] = 'latex'; + return $shortcodes; +} + +add_filter( 'no_texturize_shortcodes', 'latex_no_texturize' ); + +add_filter( 'the_content', 'latex_markup', 9 ); // before wptexturize +add_filter( 'comment_text', 'latex_markup', 9 ); // before wptexturize +add_shortcode( 'latex', 'latex_shortcode' ); |