nigel@nigel:~/beryl-svn/beryl/trunk$ svn diff
Index: beryl-plugins/src/rotate.c
===================================================================
--- beryl-plugins/src/rotate.c  (revision 675)
+++ beryl-plugins/src/rotate.c  (working copy)
@@ -550,7 +550,7 @@
         else if (rs->xrot > 180.0f / size)
             xrot = rs->xrot - 360.0f / size;
     }
-
+fprintf(stderr, "xrot = %f.\n", xrot);
     adjust = -xrot * 0.05f * rs->acceleration;
     amount = fabs (xrot);
     if (amount < 10.0f)
[1]+  Done                    beryl-manager
nigel@nigel:~/beryl-svn/beryl/trunk$ 

First a normal rotate:

nigel@nigel:~/beryl-svn/beryl/trunk$ xrot = 90.000000.
xrot = 89.704689.
xrot = 89.133492.
xrot = 88.187241.
xrot = 86.969429.
xrot = 85.562759.
xrot = 83.936508.
xrot = 82.189659.
xrot = 80.269455.

And now a crazy one:

nigel@nigel:~/beryl-svn/beryl/trunk$ xrot = 90.000000.
xrot = 89.732811.
xrot = 89.215927.
xrot = 88.427048.
xrot = 87.411140.
xrot = 86.185562.
xrot = 84.767258.
xrot = 83.252426.
xrot = 81.585114.
xrot = 79.779800.
xrot = 77.850479.
xrot = 75.810616.
xrot = 73.673180.
xrot = 71.567596.
xrot = 69.392326.
xrot = 67.157845.
xrot = 64.874138.
xrot = 62.163467.
xrot = 59.418240.
xrot = 56.122265.
xrot = 52.813061.
xrot = 49.504383.
xrot = 46.209122.
xrot = 43.854855.
xrot = 41.524387.
xrot = 39.222790.
xrot = 126.954727.
xrot = 124.471359.
xrot = 121.793121.
xrot = 117.830086.
xrot = 113.654465.
xrot = 199.470200.
xrot = 194.799438.
xrot = 190.115875.
xrot = 185.071518.
xrot = 269.462372.
xrot = 263.235413.
xrot = 256.746582.
xrot = 249.780762.
xrot = 332.391663.
xrot = 324.321777.
xrot = 314.457733.
xrot = 303.981842.
xrot = 382.973267.
xrot = 371.156738.
xrot = 362.136658.
xrot = 352.661865.
xrot = 424.010071.
xrot = 412.399109.
xrot = 400.225098.
xrot = 383.762115.
xrot = 366.769043.
xrot = 352.028168.
xrot = 336.998505.
xrot = 321.056641.
xrot = 304.957367.
xrot = 287.360596.
xrot = 269.741119.
xrot = 256.152161.
xrot = 242.638733.
xrot = 229.236877.
xrot = 215.065948.
xrot = 201.086182.
xrot = 187.330841.
xrot = 170.346252.
xrot = 153.731171.
xrot = 142.099548.
xrot = 130.780457.
xrot = 119.787354.
xrot = 105.516724.
xrot = 91.725830.
xrot = 79.501587.
xrot = 67.755615.
xrot = 57.479004.
xrot = 47.656067.
xrot = 38.736633.
xrot = 30.253662.
xrot = 22.206299.
xrot = 12.863586.
xrot = 4.669800.
xrot = -2.482056.
xrot = -8.415100.
xrot = -11.899292.
xrot = -14.802246.
xrot = -17.277466.
xrot = -19.907776.
xrot = -22.193420.
xrot = -24.444397.
xrot = -26.404968.
xrot = -27.670288.
xrot = -28.760193.
xrot = -29.688843.
xrot = -30.441406.
xrot = -31.058228.
xrot = -31.545837.
xrot = -31.937073.
xrot = -32.204041.
xrot = -32.353699.
xrot = -32.392883.
xrot = -32.328430.
xrot = -32.166931.
xrot = -31.906616.
xrot = -31.559570.
xrot = -31.132263.
xrot = -30.663513.
xrot = -30.131348.
xrot = -29.541504.
xrot = -28.876343.
xrot = -28.160706.
xrot = -27.399170.
xrot = -26.676514.
xrot = -25.920532.
xrot = -25.135193.
xrot = -24.324341.
xrot = -23.491943.
xrot = -22.641907.
xrot = -21.442322.
xrot = -20.230652.
xrot = -18.965637.
xrot = -17.703674.
xrot = -16.549255.
xrot = -15.412231.
xrot = -14.206848.
xrot = -13.036255.
xrot = -11.952026.
xrot = -10.916138.
xrot = -10.091980.
xrot = -9.316528.
xrot = -8.692749.
xrot = -8.107727.
xrot = -7.559387.
xrot = -6.931641.
xrot = -6.344971.
xrot = -5.897339.
xrot = -5.480164.
xrot = -5.091370.
xrot = -4.648682.
xrot = -4.237183.
xrot = -3.924866.
xrot = -3.635132.
xrot = -3.366455.
xrot = -3.048035.
xrot = -2.753540.
xrot = -2.540771.
xrot = -2.344482.
xrot = -2.163269.
xrot = -1.949585.
xrot = -1.752869.
xrot = -1.611389.
xrot = -1.481445.
xrot = -1.362000.
xrot = -1.252319.
xrot = -1.151489.
xrot = -1.058777.
xrot = -0.949951.
xrot = -0.850220.
xrot = -0.776123.
xrot = -0.708313.
xrot = -0.646301.
xrot = -0.576477.
xrot = -0.512695.
xrot = -0.465637.
xrot = -0.422729.
xrot = -0.383728.
xrot = -0.340027.
xrot = -0.300293.
xrot = -0.272156.
xrot = -0.246643.
xrot = -0.223572.
xrot = -0.193359.
xrot = -0.166077.
xrot = -0.144348.
xrot = -0.124878.
xrot = -0.111267.
xrot = -0.099060.