Date: Sun, 11 Feb 2007 00:39:29 -0800 From: "Eugene M. Kim" <freebsd.org@ab.ote.we.lv> To: hackers@freebsd.org Subject: sin()/cos()/tan() for kernel code? '_ 'a Message-ID: <45CED641.7020608@ab.ote.we.lv>
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Hello all, I am writing a mouse device driver for my Wacom tablet (Intuos 2 9x12). The tablet comes with a mouse and I managed to get valid coordinate data from the device. However, unlike usual mice, the coordinate system is tied not to the orientation of the mouse itself, but to the tablet, which acts much like a "mouse pad". So, for example, if I rotate the mouse 30 degrees to the left and move it left and right, the mouse cursor would move not horizontally, but to 2- or 8-o'clock. Fortunately the mouse also provides orientation data along with coordinate data, so the correct cursor movement could be calculated from it. The problem: The calculation needs trigonometry, but there seems to be no math library support in the kernel (I ran "grep -w cos" on the -CURRENT source tree, which turned nothing up). Does anyone have an idea on how to do this? Cheers, Eugene
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