code wiki / _hdl_build / _pe_riff2.nx
_pe_riff2.nx source
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1// AUTHORED BY THE NISHI BUILDER (pattern: WIRE_TLV v2 le/pad) -- [type][len][body] wire walk, no Claude logic
2import "nx_syscalls.nx"
3func _pe_riff2_rdbe(b: *u8, off: i64, w: i64) -> i64 { var v: i64 = 0; var i: i64 = 0; while i < w { v = (v << 8) | (b[off + i] & 0xff); i = i + 1 } return v }
4func _pe_riff2_rdle(b: *u8, off: i64, w: i64) -> i64 { var v: i64 = 0; var i: i64 = 0; while i < w { v = v | ((b[off + i] & 0xff) << (i * 8)); i = i + 1 } return v }
5func _pe_riff2_count(b: *u8, n: i64) -> i64 {
6 var off: i64 = 0
7 var c: i64 = 0
8 while off < n {
9 if off + 8 > n { return 0 - 1 }
10 let l: i64 = _pe_riff2_rdle(b, off + 4, 4)
11 if off + 8 + l > n { return 0 - 1 }
12 off = off + 8 + l + (l & 1)
13 c = c + 1
14 }
15 return c
16}
17func _pe_riff2_find(b: *u8, n: i64, t: i64) -> i64 {
18 var off: i64 = 0
19 while off < n {
20 if off + 8 > n { return 0 - 2 }
21 let ty: i64 = _pe_riff2_rdbe(b, off + 0, 4)
22 let l: i64 = _pe_riff2_rdle(b, off + 4, 4)
23 if off + 8 + l > n { return 0 - 2 }
24 if ty == t { return off + 8 }
25 off = off + 8 + l + (l & 1)
26 }
27 return 0 - 1
28}