Microsoft DirectX 8.0 (C++) |
Microsoft® Direct3D® for Microsoft DirectX® 8.0 supports additional parameters to control the rendering of point sprites (point primitives). These parameters enable points to be of variable size and have a full texture map applied. The size of each point is determined by an application-specified size combined with a distance-based function computed by Direct3D. The application can specify point size either as per-vertex or by setting D3DRS_POINTSIZE, which applies to points without a per-vertex size. The point size is expressed in camera space units, with the exception of when the application is passing post-transformed flexible vertex format (FVF) vertices. In this case, the distance-based function is not applied and the point size is expressed in units of pixels on the render target.
The texture coordinates computed and used when rendering points depends on the setting of D3DRS_POINTSPRITEENABLE. When this value is set to TRUE, the texture coordinates are set so that each point displays the full-texture. In general, this is only useful when points are significantly larger than one pixel. When D3DRS_POINTSPRITEENABLE is set to FALSE, each point's vertex texture coordinate is used for the entire point.