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<?php |
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/** |
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* Module Name: Beautiful Math |
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* Module Description: Use LaTeX markup 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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* Feature: 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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/** |
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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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|
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function latex_markup( $content ) { |
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$textarr = wp_html_split( $content ); |
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|
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$regex = '% |
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\$latex(?:=\s*|\s+) |
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((?: |
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[^$]+ # Not a dollar |
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| |
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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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|
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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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|
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if ( false === stripos( $element, '$latex' ) ) { |
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continue; |
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} |
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|
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$element = preg_replace_callback( $regex, 'latex_src', $element ); |
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} |
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|
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return implode( '', $textarr ); |
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} |
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|
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function latex_src( $matches ) { |
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$latex = $matches[1]; |
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|
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$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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|
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|
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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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|
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return latex_render( $latex, $fg, $bg, $s ); |
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} |
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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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|
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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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|
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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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|
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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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/** |
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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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|
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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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/** |
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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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|
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add_filter( 'no_texturize_shortcodes', 'latex_no_texturize' ); |
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|
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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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|
