Re: Quickdraw, graphics questions

[rees@cs.pitt.edu (Ted Rees)]

Noel Rappin (noel@gaia.gatech.edu) wrote:
: A am attempting to create something similar to a draw program in MCL,
: and I have the following basic questions that I hope someone here can
: answer:

: 1)  MCL does not seem to support color QuickDraw at all -- is there
: someone or someplace that has implemented this?

: 2)  MCL provides two functions for bitmaps, make-bitmap and copy-bits.
: Neither of these is ever called with a view, and it doesn't seem like
: you can draw into them, so how do you get information into a bitmap.

: 3)  With that in mind, what is the best way to do "rubber-banding" in
: MCL -- where, for example, the line you are drawing is updated on the
: screen as you drag the mouse, without destroying the underlying
: picture.

MCL's QuickDraw support is mostly a thin veneer over the basic QuickDraw
calls.  Look in the library folder for the QuickDraw.lisp file to see how
it's done.  Almost every MCL QuickDraw function focuses the view first
which means that any code that is not trivial will focus it repeatedly and
tend to be rather slow.  You can use their code as model for your own.