Date: Sun, 11 Feb 2007 09:44:11 -0500 (EST) From: Daniel Eischen <deischen@freebsd.org> To: "Eugene M. Kim" <freebsd.org@ab.ote.we.lv> Cc: hackers@freebsd.org Subject: Re: sin()/cos()/tan() for kernel code? '_ 'a Message-ID: <Pine.GSO.4.64.0702110941580.19880@sea.ntplx.net> In-Reply-To: <45CED641.7020608@ab.ote.we.lv> References: <45CED641.7020608@ab.ote.we.lv>
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On Sun, 11 Feb 2007, Eugene M. Kim wrote: > 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? Can't you do this in userland? Teach moused? -- DE
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