ID: 22323 User updated by: jukkaho at mail dot student dot oulu dot fi Reported By: jukkaho at mail dot student dot oulu dot fi -Status: Feedback +Status: Open Bug Type: GD related Operating System: Linux PHP Version: 4.3.0 New Comment:
Relevant parts are not changed in CVS so there are still no way to call gdImageSaveAlpha() with a true argument so that alpha channel is actually sent to browser. Default value is still set to 0 and has the following comment: /* 2.0.2: alpha blending is now on by default, and saving of alpha is off by default. This allows font antialiasing to work as expected on the first try in JPEGs -- quite important -- and also allows for smaller PNGs when saving of alpha channel is not really desired, which it usually isn't! */ im->saveAlphaFlag = 0; In my case it really is desired. I want to be able to produce transparent PNGs. I just don't have access in PHP to change saveAlphaFlag value. Someone could just create a new PHP image function ImageSaveAlpha($im,$bool) that passes that info to gdImageSaveAlpha (gdImagePtr im, int saveAlphaArg); I have solved my blending problems already by using undocumented functions as I have described in bug #22327. Previous Comments: ------------------------------------------------------------------------ [2003-02-20 07:30:49] [EMAIL PROTECTED] Please try using this CVS snapshot: http://snaps.php.net/php4-STABLE-latest.tar.gz For Windows: http://snaps.php.net/win32/php4-win32-STABLE-latest.zip ------------------------------------------------------------------------ [2003-02-20 04:24:57] jukkaho at mail dot student dot oulu dot fi Alpha channel in a truecolor image is only sent when im->saveAlphaFlag is true. It is by default set to false in gdImageCreateTrueColor() and there are no callers to gdImageSaveAlpha() to set it to any other value. I tested a hack where I call gdImageSaveAlpha() in PHP_FUNCTION(imagealphablending) and it worked mostly as expected. I'd guess that another function call is needed unless is it made to default behaviour and calls are embedded in PHP_FUNCTION(imagepng) etc. Only weird things that occured were that for some reason, target image alpha channel is discarded when blending other images to it. For example when blending fully transparent part over another fully transparent part resulted in a white area. White comes from destination image that's transparent too. Maybe I should open another bug for it? ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=22323&edit=1
