Generic implementation of summed area tables with Rust
You can find more information about summed area tables on Wikipedia.
http://en.wikipedia.org/wiki/Summedareatable
rust
let src: DMat<usize> = DMat::new_ones(10,10);
let table = src.calculate_summed_area_table();
rust
assert_eq!(100, table.get_sum((0,0),(9,9)));
assert_eq!(50, table.get_sum((0,0),(9,4)));
assert_eq!(25, table.get_sum((0,0),(4,4)));
You can implement the SummedAreaTableSource
trait for your own types if you want them to have the calculate_summed_area_table()
method. You also need to implement the SourceValue
trait for the value type of your source.
This is how the library does it for DMat<usize>
type.
```rust
impl SourceValue
impl SummedAreaTableSource