Get a mipmap (as a ZMAP handle) for a given map.
ZMAP CExtAPI::map_GetMipmapLevel(ZMAP hMap, long MipLevel);
| Name | Type | Comment |
|---|---|---|
| hMap | ZMAP | A handle to a map variable, a mipmap of which is to be retrieved. |
| MipLevel | long | The sub-sampling factor of the desired mipmap. See comments below. |
A null pointer if the desired mipmap does not exist, or if an error occurred. Otherwise, a non-null handle to a map variable is returned.
MipLevel is the ratio of the side-lengths of the full-resolution map (referenced by hMap) to the side-lengths of the desired mipmap. So, for example, if you want to retrieve the mipmap that is one-quarter of the resolution of the full-res map, enter a MipLevel if 4.
Note, however, that not all values of MipLevel are allowed. Allowed values are given by:
MipLevel = ResStep ^ n
Where: