ELSA Synergy 2000, Руководство пользователя

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area where the image that appears on the monitor is located. This pre-
vents the process of image drawing being visible. The duplicate storage
method is also known as double buffering.
Buffer swapping: Display on the monitor
Two possibilities exist for transferring a completed image from the back to
the front buffer, and thus to the display. The obvious method is to copy the
contents to the front buffer one byte at a time, a process known as “blitting”.
Page flipping is significantly faster: in this case the content of the buffer is
not rewritten—the addresses of the front and back buffers are simply
exchanged. As a result, only tiny data volumes are transferred.
The buffer swapping will only ever be performed once the image drawing pro-
cess in the back buffer is completed. This procedure should be repeated at
least 20 times a second to give a smooth representation of 3D scenarios. In
this context, we speak of frames per second (fps). This is a very important
value especially for 3D applications. A cinema film runs at 24fps.
4.2 3D interfaces
Software interfaces, including 3D interfaces, are known as APIs (Application
Programming Interface). The question is what these interfaces are used for
and how they work.
In simple terms: They make developers' work easier. In the past it was nec-
essary to address the various hardware components directly in programming
if you wanted to exploit their capabilities to the full. The APIs are a kind of
translator operating between the hardware and the software.
The specification of standard definitions was the precondition for the proper
function of these translation routines. These definitions are implemented by
the hardware manufacturers during development and optimized for the hard-
ware concerned. Developers can implement complex procedures relatively
easily by using these definitions. They can use a uniform command set when
programming and do not need to know the characteristics specific to the
hardware.
4.2.1 What APIs are available?
There are a good dozen more or less commonly found 3D APIs. However, in
recent years, two formats have established themselves as the favorites:
Direct 3D and OpenGL API. ELSA graphics boards support these commonly