If the system has CLEW installed (which is detected by recently
added FindCLEW routines) then OpenSubduv would be compiled against
this library.
It makes binaries and libraries more portable across the systems,
so it's possible to run the same binary on systems with and without
OpenCL SDK installed.
The most annoying part of the change is updating examples to load
OpenCL libraries, but ideally code around controllers and interface
creation is to be de-duplicated anyway.
Based on the pull request #303 from Martijn Berger
- add a framebuffer to gl_hud with programmable image shader
- add optional SSAO image shader to the new framebuffer
- add screenshot to png functionality
- implement in glViewer
note: ptexViewer and some others still need refactoring to use the new hud capabilities