Gives the ability to retrieve param annotations. Blocks wrapped in <>
following a parameter.
For example:
float slider < float max_value = 10.0; float min_value = 0.0; >;
These blocks are not for shading purposes but to help describe the
shader's gui as in the example above.
Adds graphics api functions for retrieving annotations:
size_t gs_param_get_num_annotations(const gs_eparam_t *param);
gs_eparam_t *gs_param_get_annotation_by_idx(const gs_eparam_t *param,
size_t annotation);
gs_eparam_t *gs_param_get_annotation_by_name(const gs_eparam_t *param,
const char *name);