ELSA Synergy 2000, Руководство пользователя

Страница: 28 / 50

Graphics know-how
|
| ELSA Synergy 2000 |
28
EN
found 3D interfaces. The functional differences between the interfaces are
slight. Your
ELSA Synergy 2000 supports the following APIs.
4.2.2 Direct3D
As a development of Mode X and DirectDraw under Windows 3.1x, Direct3D
is a branch of the DirectX multimedia family which was developed directly for
Windows to accelerate the slow 3D display characteristics of the operating
system. Direct3D cooperates with DirectDraw in two-dimensional display. A
typical situation would be, for instance, rendering a 3D object while Direct-
Draw is placing a two-dimensional background bitmap.
Immediate mode and retained mode
As can be assumed from the two terms, immediate mode is a programming
mode that is close to the hardware. Retained mode, on the other hand, is a
programming mode that is largely predefined through an API interface. What
does this mean in detail? Looking at the two systems hierarchically, the
immediate mode is also known as the low-level mode. The programming
interface level is close to the hardware level and permits the programmer
direct access to special functions in the hardware component concerned. The
retained mode (high-level mode) makes it possible, for example, to load a
defined 3D object with textures into a Windows application. Here it can be
manipulated and moved using simple API commands. Translation takes place
in real time, without the need to know the technical structure of the object.
For further information see the Internet site www.microsoft.com/directx .
4.2.3 The OpenGL API
Since the OpenGL API was introduced in 1992, it has grown into the industry's
leading cross-platform 2D and 3D graphics API and its presence continues to
grow every day.
The OpenGL API is platform-independent and makes a distinction between
immediate and display list modes. A display list stores specific sequences
that can be recalled again later. The object descriptions can then be taken
directly from the list, resulting in very high performance. However, if objects
need to be manipulated frequently, the display list will have to be generated
again from new. The OpenGL API provides a wide range of graphics features,
from rendering a simple geometric point, line, or filled polygon, to the most
sophisticated representations of curved surfaces with lighting and texture