On Thu, Apr 05, 2007 at 04:09:59AM +0000, [EMAIL PROTECTED] wrote: > > > > all in all this isnt a simple solution. the only way i see to > > > handle both methods is to have 2 calls. 1 to add a point relative > > > to origin and one to specify it absolutely. > > > > Two calls makes sense, but I think internally the point list > > should be relative to the object origin, and then convert to > > absolute coords at render time. This would allow us to do some > > sore of scaling based on object size (although some error would > > be introduced if the points were specified in abs coords). > > In order to eliminate cummulative errors, the vertex coords > must be stored as input (possibly modulo integer translations). > In order to minimize confusion from multiple coord systems > (and every time you have any kind of transformation, you basically > create a new coord system), or things like eg. mixing calls to add > points with calls to move/resize/rotate the obj (something which > I think ought to be avoided in usage), the inputs must have an > 'absolute' interpretation - either absolute rel to the canvas, > or absolute rel to an (untransformed) 'obj coord system'. > > I'd have to say that I think it would be best if the inputs > were taken rel to the (untransformed) obj, and nothing else. The > object size would grow with points added, or with resizing (scaling > the poly), and the bounding rect would change with rotations, etc.. > But the input vertex coords would have an absolute interpretation > as being rel to the (untransformed) obj.
All of this is exactly what I had in mind, with an additional call that took points in absolute canvas coords and then converted them to object coords (at the current location/rotation/scaling). The use case I had in mind for such a function would be to add points based on mouse input. It would basically just do px,py = canvas_coords_to_polygon_coords(cx, cy) polygon_point_add(px,py) So, maybe we would just need the functions that map between the two coordinate spaces :) Brian ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ enlightenment-devel mailing list enlightenment-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/enlightenment-devel
