nx_cpp_calc.nx source
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1// nx_cpp_calc.nx -- Calculates honest cost-per-page using real coverage measurements and ISO-standardized yields.
2const K_MAGIC_50000: i64 = 50000
3// nx_cpp_calc.nx -- cost-per-page (CPP) calculator: turn cartridge price + ISO yield + OUR measured real
4// coverage into honest $/page, and the genuine-vs-aftermarket savings the cartridge industry obscured for
5// years (the researcher's sources: vendors hid yields until ISO/IEC 19752/19798 standardized them; refills/
6// remanufactured = 30% of the market precisely because OEM CPP is high). Our edge: we measure REAL coverage,
7// so we give the true CPP for a user's ACTUAL documents, not just the vendor's 5%-ISO marketing number.
8//
9// PURE integer arithmetic (money in CENTS, CPP in MILLI-CENTS/page = 1/1000 cent, so 4166 = 4.166 cents/page);
10// no float, no syscalls -> never-brick #26. Grounded: ISO/IEC 19752 standard page = 5% coverage = 50000 ppm.
11// genealogy_id: project-printer-management-ipp-sclass-2026-06-20 ; license_tier: ORIGINAL
12
13// CPP at the ISO 5% standard yield. price in cents, yield in ISO pages. Returns milli-cents/page, -1 if bad.
14func nx_cpp_iso(price_cents: i64, yield_pages: i64) -> i64 {
15 if yield_pages <= 0 { return 0 - 1 }
16 if price_cents < 0 { return 0 - 1 }
17 return (price_cents * 1000) / yield_pages
18}
19
20// REAL pages a cartridge yields at OUR measured coverage (ppm). capacity = yield*50000 ppm (the 5% ISO page).
21func nx_cpp_real_pages(yield_pages: i64, coverage_ppm: i64) -> i64 {
22 if yield_pages <= 0 { return 0 - 1 }
23 if coverage_ppm <= 0 { return 0 - 1 }
24 return (yield_pages * K_MAGIC_50000) / coverage_ppm
25}
26
27// REAL CPP at OUR measured coverage. real_CPP = price * coverage_ppm / (yield * 50) milli-cents/page
28// (derivation: price / [(yield*50000)/coverage] * 1000). At 5% (50000 ppm) it equals the ISO CPP; heavier
29// pages cost proportionally more -- the HONEST per-document number the vendor's 5% marketing hides.
30func nx_cpp_real(price_cents: i64, yield_pages: i64, coverage_ppm: i64) -> i64 {
31 if yield_pages <= 0 { return 0 - 1 }
32 if coverage_ppm < 0 { return 0 - 1 }
33 if price_cents < 0 { return 0 - 1 }
34 let denom: i64 = yield_pages * 50
35 if denom <= 0 { return 0 - 1 }
36 return (price_cents * coverage_ppm) / denom
37}
38
39// savings (milli-cents/page) of aftermarket vs genuine at ISO yield. -1 if either input is bad.
40func nx_cpp_savings(genuine_cents: i64, genuine_yield: i64, after_cents: i64, after_yield: i64) -> i64 {
41 let g: i64 = nx_cpp_iso(genuine_cents, genuine_yield)
42 let a: i64 = nx_cpp_iso(after_cents, after_yield)
43 if g < 0 { return 0 - 1 }
44 if a < 0 { return 0 - 1 }
45 return g - a
46}
47
48// savings as a percent (0..100) of the genuine CPP. -1 if genuine CPP is unknown/zero.
49func nx_cpp_savings_pct(genuine_cents: i64, genuine_yield: i64, after_cents: i64, after_yield: i64) -> i64 {
50 let g: i64 = nx_cpp_iso(genuine_cents, genuine_yield)
51 let a: i64 = nx_cpp_iso(after_cents, after_yield)
52 if g <= 0 { return 0 - 1 }
53 if a < 0 { return 0 - 1 }
54 return ((g - a) * 100) / g
55}