Mipmapped Volume Rendering

TODO

HanProgressReport

1. Multi volume support
2. Reimplement Pixel Buffer Object
3. Move configuration file parsing from BrickManager class to MeshRend class (done)
4. Move duplicated code in QuadInfo and CubeInfo class to BrickInfo super class (done)
5. Reimplement Multi-channel support (done)
   • modify texture memory allocation to handle single channel
   • vvGLSL class
6. Modify downsampler with padding
   • the current downsampler does not pad empty data when a brick is not of a regular size. Nancy and I implemented in this way because it was easier than padding. However, this causes lots of problems from the reader part, mostly additional checking codelet whether a brick has a regular size, e.g. 128, or smaller than that. Due to the exception, we need couple more variables for boundary bricks of which size is usually smaller than the brick size. By padding, these inefficient and unnecessary data can be removed.
7. XML format for configuration file
   • the current version read a special configuration format, which is not flexible and hard to understand the format. It would be good if we can reformat the configuration file with an XML schema, as we did in covise. A new format will affect downSampler*D, meshRend::loadConfigFile() and requires a new interface to pass the information between classes.