Uploaded Transform Tests

[Ulrich Läsche <ulrich@cgmtech.de>]

All,

 

I have uploaded the following tests on the ftp server:

 

translateAPS:   Update VDC -> NDVC

rotateAPS:        Update VDC -> NDVC

scaleAPS:        Update VDC -> NDVC

 

transformAPS:              New Test

transformAnimation:      New Test

translateAnimation:       New Test

rotateAnimation:            New Test

 

I will send the setRedraw2 test tomorrow.  Regarding the submitted tests, two comments apply:

 

1) The Animation ran so quickly on the screen that we built in some kind of timer setting to slow it down.  Please look at it and tell me if it makes sense.  Timing should not really be part of the tests but needs to be there to show a reasonable animation behavior.

 

2) We strongly suggest now to add a reference point to the Scale Function, as was suggested by Forrest (see mail below), but then dismissed as SVG didn’t have it either.  However, the use case we discussed at Seattle was, for example, to show fluid flow in a pipe with an expanding rectangle object.  To do that, you will have to program the following sequence each time the “fluid” rectangle expands:

 

setRedraw (disable)

translateAPS (to NVDC origin)

scaleAPS

translateAPS (to original position)

setRedraw (enable).

 

You need to move the object to the origin to perform a proper scaling transformation and to avoid seeing this happen on the screen you need the setRedraw call.  This is not only awkward to program but also inconsistent.  For the rotate function we added the reference point, otherwise you would have to run a similar sequence as described above.  Most likely, rather than using Scale users would go directly to Transform.  I don’t know why SVG didn’t implement the Scale reference point but, may be, the envisioned use case was different.  The submitted scaleAPS sample contains already a scale reference point to show how it works.

 

Please tell me your opinion.

 

Regards

Ulrich

 

 

-----Ursprüngliche Nachricht-----
Von: Forrest Carpenter [mailto:forrest@sdicgm.com]
Gesendet: Monday, January 26, 2009 3:55 PM
An: 'Lofton Henderson'; 'WebCGM'
Betreff: RE: AW: [cgmo-webcgm] scale transform

 

Lofton,

 

I am OK with the scale function scaling around the (0,0) point in NVDCs. If this is the intent then we do not need to add a point to the scale function. It might make things simpler for users, but it would not be required.

 

Regards,

Forrest