re: [cgmo-webcgm] rotateAnimation test

[Don Larson <dlarson@cgmlarson.com>]

Forrest,

We agree with your assessment of the error in the "rotateAnimation.htm"

 

In our implementation of rotate, we overlooked the fact the the rotation

point needs to be converted from NVDC to VDC before it can be applied.

This was not caught by the RotateAPS test is because the CGM for that

test has (0,0) based VDC coordinates.

 

After we modified the rotationAnimation.htm to use rotation point

(181.7,46.0), it works correclty.

 
Regards,
Don Larson

 >
 >  All,
 >
 >  In doing some testing with the java script version of the
 >  tranformXCF-js.htm we found we were not taking into consideration that the
 >  lower left of the transformXCF.cgm was not 0,0 but -5000,0. After we
 >  changed our code to take this into consideration we no longer passed the
 >  rotateAnimation test. We believe the point of rotation in the test in not
 >  correct. The point in the htm file is (280.7,205.0) which is the vdc
 >  coordinate of the point in mm. Because the lower left of the CGM is
 >  (99,159) vdcs in mm. We believe the offset should be subtracted from the
 >  point to make it NVDC’s. The rotation point should be (181.7,46.0). This
 >  may require changes in the getTransform values, but we arenot sure of this
 >  yet.
 >
 >  Regards,
 >  Forrest