Path: utzoo!utgpu!water!watmath!clyde!att!alberta!ubc-cs!uw-beaver!cornell!rochester!pt.cs.cmu.edu!sei!ajpo!eberard From: eberard@ajpo.sei.cmu.edu (Edward Berard) Newsgroups: comp.sys.mac.programmer Subject: Rotation of Objects Keywords: Rotation, Object-Oriented Graphics, Bit-Mapped Graphics, Text Message-ID: <360@ajpo.sei.cmu.edu> Date: 19 Aug 88 09:04:05 GMT Lines: 41 I have a multi-part question concerning the rotation of objects on a Macintosh: a) Given an object-oriented graphic object (e.g., a rectangle or an oval) and a point about which it is to be rotated, what are some of the better algorithms for rotating this object? If there is more than one viable way to accomplish the rotation, what are the trade-offs? b) Given a bit-mapped graphic object (e.g., a picture or icon) and a point about which it is to be rotated, what are some of the better algorithms for rotating this object? If there is more than one viable way to accomplish this rotation, what are the trade-offs? c) Given a text object and a point about which it is to be rotated, what are some of the better algorithms for rotating this object? Do concepts such as font and style impact these algorithms? If there is more than one viable way to accomplish this rotation, what are the trade-offs? d) For each of the above, consider the user interface issues. For example, during rotation, should the user be presented with a schematic representation of the object (e.g., a dashed-line outline of the region occupied by the object)? e) Consider the impact, if any, of accomplishing the above rotations from a remote source. Specifically, suppose you had to direct the Macintosh from another computer, e.g., you are sending commands to the toolbox over an RS-232C line, Ethernet, or AppleTalk. Does this change any of your answers? What are the trade-offs? Obviously, general computer graphics rotation algorithms are available in any number of texts. However, the intent of the above questions is to narrow the focus to the Macintosh environment. I would also be interested in a discussion of directing the output of the above rotations to both Postscript and non-Postscript printers. -- Ed Berard (301) 695-6960