| 1 |
<?php |
| 2 |
/** |
| 3 |
* Module Name: Beautiful Math |
| 4 |
* Module Description: Use the LaTeX markup language to write mathematical equations and formulas. |
| 5 |
* Sort Order: 12 |
| 6 |
* First Introduced: 1.1 |
| 7 |
* Requires Connection: No |
| 8 |
* Auto Activate: No |
| 9 |
* Module Tags: Writing |
| 10 |
* Feature: Writing |
| 11 |
* Additional Search Queries: latex, math, equation, equations, formula, code |
| 12 |
*/ |
| 13 |
|
| 14 |
/** |
| 15 |
* LaTeX support. |
| 16 |
* |
| 17 |
* Backward compatibility requires support for both "[latex][/latex]", and |
| 18 |
* "$latex $" shortcodes. |
| 19 |
* |
| 20 |
* $latex e^{\i \pi} + 1 = 0$ -> [latex]e^{\i \pi} + 1 = 0[/latex] |
| 21 |
* $latex [a, b]$ -> [latex][a, b][/latex] |
| 22 |
*/ |
| 23 |
|
| 24 |
function latex_markup( $content ) { |
| 25 |
$textarr = wp_html_split( $content ); |
| 26 |
|
| 27 |
$regex = '% |
| 28 |
\$latex(?:=\s*|\s+) |
| 29 |
((?: |
| 30 |
[^$]+ # Not a dollar |
| 31 |
| |
| 32 |
(?<=(?<!\\\\)\\\\)\$ # Dollar preceded by exactly one slash |
| 33 |
)+) |
| 34 |
(?<!\\\\)\$ # Dollar preceded by zero slashes |
| 35 |
%ix'; |
| 36 |
|
| 37 |
foreach ( $textarr as &$element ) { |
| 38 |
if ( '' == $element || '<' === $element[0] ) { |
| 39 |
continue; |
| 40 |
} |
| 41 |
|
| 42 |
if ( false === stripos( $element, '$latex' ) ) { |
| 43 |
continue; |
| 44 |
} |
| 45 |
|
| 46 |
$element = preg_replace_callback( $regex, 'latex_src', $element ); |
| 47 |
} |
| 48 |
|
| 49 |
return implode( '', $textarr ); |
| 50 |
} |
| 51 |
|
| 52 |
function latex_src( $matches ) { |
| 53 |
$latex = $matches[1]; |
| 54 |
|
| 55 |
$bg = latex_get_default_color( 'bg' ); |
| 56 |
$fg = latex_get_default_color( 'text', '000' ); |
| 57 |
$s = 0; |
| 58 |
|
| 59 |
|
| 60 |
$latex = latex_entity_decode( $latex ); |
| 61 |
if ( preg_match( '/.+(&fg=[0-9a-f]{6}).*/i', $latex, $fg_matches ) ) { |
| 62 |
$fg = substr( $fg_matches[1], 4 ); |
| 63 |
$latex = str_replace( $fg_matches[1], '', $latex ); |
| 64 |
} |
| 65 |
if ( preg_match( '/.+(&bg=[0-9a-f]{6}).*/i', $latex, $bg_matches ) ) { |
| 66 |
$bg = substr( $bg_matches[1], 4 ); |
| 67 |
$latex = str_replace( $bg_matches[1], '', $latex ); |
| 68 |
} |
| 69 |
if ( preg_match( '/.+(&s=[0-9-]{1,2}).*/i', $latex, $s_matches ) ) { |
| 70 |
$s = (int) substr( $s_matches[1], 3 ); |
| 71 |
$latex = str_replace( $s_matches[1], '', $latex ); |
| 72 |
} |
| 73 |
|
| 74 |
return latex_render( $latex, $fg, $bg, $s ); |
| 75 |
} |
| 76 |
|
| 77 |
function latex_get_default_color( $color, $default_color = 'ffffff' ) { |
| 78 |
global $themecolors; |
| 79 |
return isset($themecolors[$color]) ? $themecolors[$color] : $default_color; |
| 80 |
} |
| 81 |
|
| 82 |
function latex_entity_decode( $latex ) { |
| 83 |
return str_replace( array( '<', '>', '"', ''', '&', '&', "\n", "\r" ), array( '<', '>', '"', "'", '&', '&', ' ', ' ' ), $latex ); |
| 84 |
} |
| 85 |
|
| 86 |
function latex_render( $latex, $fg, $bg, $s = 0 ) { |
| 87 |
$url = "//s0.wp.com/latex.php?latex=" . urlencode( $latex ) . "&bg=" . $bg . "&fg=" . $fg . "&s=" . $s; |
| 88 |
$url = esc_url( $url ); |
| 89 |
$alt = str_replace( '\\', '\', esc_attr( $latex ) ); |
| 90 |
|
| 91 |
return '<img src="' . $url . '" alt="' . $alt . '" title="' . $alt . '" class="latex" />'; |
| 92 |
} |
| 93 |
|
| 94 |
/** |
| 95 |
* The shortcode way. The attributes are the same as the old ones - 'fg' and 'bg', instead of foreground |
| 96 |
* and background, and 's' is for the font size. |
| 97 |
* |
| 98 |
* Example: [latex s=4 bg=00f fg=ff0]\LaTeX[/latex] |
| 99 |
*/ |
| 100 |
function latex_shortcode( $atts, $content = '' ) { |
| 101 |
extract( shortcode_atts( array( |
| 102 |
's' => 0, |
| 103 |
'bg' => latex_get_default_color( 'bg' ), |
| 104 |
'fg' => latex_get_default_color( 'text', '000' ) |
| 105 |
), $atts, 'latex' ) ); |
| 106 |
|
| 107 |
return latex_render( latex_entity_decode( $content ), $fg, $bg, $s ); |
| 108 |
} |
| 109 |
|
| 110 |
/** |
| 111 |
* LaTeX needs to be untexturized |
| 112 |
*/ |
| 113 |
function latex_no_texturize( $shortcodes ) { |
| 114 |
$shortcodes[] = 'latex'; |
| 115 |
return $shortcodes; |
| 116 |
} |
| 117 |
|
| 118 |
add_filter( 'no_texturize_shortcodes', 'latex_no_texturize' ); |
| 119 |
|
| 120 |
add_filter( 'the_content', 'latex_markup', 9 ); // before wptexturize |
| 121 |
add_filter( 'comment_text', 'latex_markup', 9 ); // before wptexturize |
| 122 |
add_shortcode( 'latex', 'latex_shortcode' ); |
| 123 |
|
