Global Mapper SDK
Sets the user data to associate with the layer. This value can be retrieved by calling GM_GetLayerInfo. This is useful if you want to tie some structure or value to a particular layer without maintaining your own separate layer to value mapping.
Syntax
C++
Copy
GM_DLL_EXPORTED GM_Error_t32 __stdcall GM_SetLayerUserData
(
GM_LayerHandle_t32 aLayer, // layer to set user data for
void* aUserData // user data pointer/value to associate with layer
)