A solid generator allows multiple identical solids to be produced in
respective ones of the tiles of a rectangular array of tiles. The tiles
may occupy a whole frame, may be shifted relative to the edges of the
frame. One row of tiles may be shifted relative to another row. The array
may be passed across the frame. The tiles may occupy a part of the frame.
A single ramp is defined by R=Ah+Bv_C where A, B and C are signed values,
h=pixels along a line and v=lines. Values of A, B and C for various tiles
are stored in registers C1, C2, C3, FB1, FB2, FB3 and used in relation to
the individual tiles.
