A system and methods for implementing histogram computation, for example, into
the rasterization pipeline of a 3-D graphics system, are provided. With the histogram
computation mechanism, statistical histogram data may be generated for input data
of any kind or retrieved from any source that may be specified in a 2-D array or
specified in an immediate fashion to specialized data processing hardware. Depending
on the nature of the input data, the data may be filtered before passing the data
to data processing hardware for further processing. The data processing hardware
may then apply an additional function to the input data set before calculation
of the histogram data. Then, at some point, the data processing hardware may apply
a function to the data to map the derived data to a real-valued function that can
then be quantized to a histogram element in the range specified from zero to the
number of histogram elements minus one. The corresponding element in this histogram
is then incremented according to the data received as it passes through the graphics
processor. Advantageously, relatively expensive host computing resources are conserved,
and developers are insulated from the tedious details required of implementing
histogram computation from the ground up each time it becomes desirable to compute
histogram data in connection with an application.
