Yeah, I pretty much asked that question of the Java group a few months ago:
https://groups.google.com/d/topic/comp.lang.java.programmer/kA2JLneZmTc/discussion On Thursday, January 17, 2013 2:29:09 PM UTC-6, strangeoptics wrote: > > Yes that's the way. I tried it out and it works. > I found also a project that has a working implementation of the inverse > Matrix and pre-transformations. > > http://publicobject.googlecode.com/svn-history/r19/whisky/src/com/publicobject/whisky/Element.java > It is a good starting point to implement my own scene graph lib. > > thx > > On Wednesday, January 16, 2013 11:46:12 PM UTC+1, bob wrote: >> >> Every object should have its own Matrix. >> >> >> Then take the inverse of that Matrix and multiply it by the screen >> coordinate. The result will be a point that can be compared with the >> coordinates of the pre-transformed object. >> >> >> >> >> >> On Wednesday, January 16, 2013 3:07:21 PM UTC-6, strangeoptics wrote: >>> >>> Hi, >>> >>> I would like to draw some objects onto a canvas that are translated and >>> rotated. >>> When I tap on the screen I need to translate the screen coordinates into >>> the drawing space of the objects to find out if they are selected. >>> >>> What is the best way to accomplish this? >>> 1) Is there a 2D Scene Grap API available? >>> 2) Do I can store the Matrix for every Object and reverse it? The >>> canvas.getMatrix() method is deprecated! >>> 3) Is there another alternative? >>> >>> thx >>> >>> -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
