Illustration of two different strategies for reading data from source arrays (see Section 3.2.2).
The grids represent the source data and the black grid cells represent the data required to populate the Target domain. The “pixel-by-pixel” strategy reads data from each individual black cell one-by-one, using a separate read operation for each required cell. The “bounding-box” strategy (left) reads all the black and grey cells in a single read operation; the grey cells are then discarded. The “scanline” strategy (right) uses a separate read operation for all cells with the same j coordinate, on the assumption that each operation is reading a contiguous block of data from disk; again the grey cells are discarded.