note 58215 added to function.imagecolorat

In GD 2.x there is support for true color images complete with an alpha channel. GD 2.x has a 7-bit (0-127) alpha channel. While most people are used to an 8-bit (0-255) alpha channel, it is actually quite handy that GD's is 7-bit (0-127). Each pixel is represented by a 32-bit signed integer, with the four 8-bit bytes arranged like this: High Byte <--> Low Byte {Alpha Channel} {Red} {Green} {Blue} For a signed integer, the leftmost bit, or the highest bit, is used to indicate whether the value is negative, thus leaving only 31 bits of actual information. PHP's default integer value is a signed long into which we can store a single GD palette entry. Whether that integer is positive or negative tells us whether antialiasing is enabled for that palette entry. ---- Manual Page -- http://www.php.net/manual/en/function.imagecolorat.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+58215 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+58215&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+58215&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+58215&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+58215&report=yes&reason=useless Delete: non-english -- http://master.php.net/manage/user-notes.php?action=delete+58215&report=yes&reason=non-english Delete: already in docs -- http://master.php.net/manage/user-notes.php?action=delete+58215&report=yes&reason=already+in+docs Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+58215&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+58215&report=yes Search -- http://master.php.net/manage/user-notes.php