<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)"> <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> Hi all,<o:p></o:p> <o:p> </o:p>             A question to ask.<o:p></o:p>             We know the premultiplied alpha will be used sometimes in blend. Is that used in the graphics driver?<o:p></o:p>             Take an example:<o:p></o:p>                         If we use a XRenderComposite() function to do the rendering:<o:p></o:p>                                    XRenderComposite(dyp, PictOpOver, picture_1x1[0].pict, mask_20x20[0].pict, win->pict, 0, 0, 0, 0, 50, 50, 40, 40);<o:p></o:p>                                     And the picture_1x1[0] is a ARGB picture with an alpha value; mask_20x20[0] is a A8 picture with an alpha value.<o:p></o:p>                         How the driver(do_composite) handle this two alpha value?<o:p></o:p> <o:p> </o:p> <o:p> </o:p> Thanks,<o:p></o:p> Frank<o:p></o:p> </div> </body> </html>