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