def band

stelliferous@0.0.2.0 · kernel_window.bend:18

import Base

18# Rows read by output positions [offset, offset + span), kept inside the parent
19# window [parent_first, parent_first + parent_rows). A band has at least one row,
20# and its first row stays a stride multiple.
21def band(+parent_first: U32,+parent_rows: U32,+height: U32,+kernel: U32,+stride: U32,+padding: U32,+output_width: U32,+offset: U32,+span: U32) -> Band:
22  +parent_end = (parent_first + parent_rows : U32)
23  +top = ((parent_end - 1) / stride * stride : U32)
24  +first = U32.max(parent_first,U32.min(first_row(stride,padding,(offset / output_width : U32)),top))
25  +last = end_row(height,kernel,stride,padding,((offset + span - 1) / output_width : U32))
26  Band{first,(U32.min(parent_end,U32.max(last,(first + 1 : U32))) - first : U32)}