  We report on a new general relativistic computational model enhancing, in
various respects, the capability of presently available tools for fitting
spectra of X-ray sources. The new model is intended for spectral analysis of
black-hole accretion discs. Our approach is flexible enough to allow easy
modifications of intrinsic emissivity profiles. Axial symmetry is not assumed,
although it can be imposed in order to reduce computational cost of data
fitting. The main current application of our code is within the XSPEC
data-fitting package, however, its applicability goes beyond that: the code can
be compiled in a stand-alone mode, capable of examining time-variable spectral
features and doing polarimetry of sources in the strong-gravity regime. Basic
features of our approach are described in a separate paper (Dovciak, Karas &
Yaqoob 2004). Here we illustrate some of its applications in more detail. We
concentrate ourselves on various aspects of line emission and Compton
reflection, including the current implementation of the lamp-post model as an
example of a more complicated form of intrinsic emissivity.
