Re: [boost] RE: A preliminary proposal: AGG project

From: Beman Dawes (bdawes_at_[hidden])
Date: 2002-05-06 09:43:33

At 01:49 AM 5/6/2002, Mika Heiskanen wrote:
 >
 >Joel de Guzman wrote:
 >
 >> I agree with most of what you said. However, you are implying that
 >> standard libraries should not use platform specific APIs. This is
 >> certainly not true. As an example, how do you think are standard
 >> files and streams implemented anyway? Ultimately, it should map
 >> to the underlying platform where it is deployed. The key point here
 >> is that these calls are opaque and hidden from the client. The cross-
 >> platform API shields the client from the platform.
 >
 >There has probably been poor wording by me. I am specifically opposed to 
a
 >standard library which would may line, polygon etc rendering requests to
 >some platform specific API, whether it is hardware or software. All
 >rendering should by done by the library itself. It is the users
 >responsibility to then copy the pixel buffer to a display. By allowing 
the
 >user to configure the representation of the pixel buffer the copying may
 >then involve a direct memcpy via some platform specific call.

Please understand that standard library proposals today can't be just "good 
ideas".  They have to be shown to work in practical computing environments.

Thus for the standard committee to accept a library that leaves some 
responsibility to the user (like copying the pixel buffer to a display), it 
would have to be shown that this is something a potential user can easily 
and efficiently do, and the best way to demonstrate this is by proving 
demonstration code for actual operating systems and graphics packages.

So even if the core proposal itself is not concerned with interfaces to 
common operating systems or graphics packages, practical examples and tests 
should allow display on common platforms, IMO.

--Beman