OpenGL and DirectX are graphics libraries used for all sorts of
graphics applications, from games to architectural drawing. To use them, you have to write code that talks with the library in terms of graphics primitives like spheres
or strips of polygons. The most demanding scientific applications can benefit from
being written with low-level graphics libraries, but it is rarely something you
would want to undertake yourself. In the sample DirectX code below, you draw a line
by building its points.
for ( int splineIdx=0; splineIdx<4; splineIdx++ ) {
p[splineIdx] = new Vector3(coords[splineIdx,0],coords[splineIdx,1],
coords[splineIdx,2]);
}
m_device.DrawUserPrimitives(PrimitiveType.LineStrip, p, 0, m_vertexCnt);
DirectX is a Microsoft-specific library, offering slightly better speed on Windows.
OpenGL is on every Windows machine, as well, but is cross-platform. The great John
Carmack (of Quake fame) said he didn't know why you would want to take three days
to learn DirectX when you can learn OpenGL in a day. If you aren't named John Carmack,
it might take you longer to learn, but OpenGL is the more straightforward of these
two main options.
