With one discount applied under the table, the gross column summed to 315,60
against a total of 284,04. Nothing was miscalculated — the discount simply came
after — but a reader who adds up a column found a document that does not agree
with itself, and no way to tell which figure was the real one. On an invoice
that is not a presentation detail.
A discount or surcharge now sits on its line, percentage or fixed amount, and
is inside that line's total. The label under the line is built from the same
value that did the arithmetic, so the words cannot end up describing a
different number than the one printed beside them.
The invoice-wide adjustment stays in the arithmetic for anything that genuinely
applies to the whole document, but nothing uses it by default.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
TCPDF 6, deliberately, after installing 7 and finding out what it is. Version 7
is not a newer TCPDF; it is a compatibility shim over tc-lib-pdf whose own
mapping table lists 115 of 293 methods as stubs, and whose font package ships
no font files at all — the first render died on a missing helvetica.json. The
6.x line carries a hundred and sixty-five fonts, a working writeHTML and real
header and footer hooks, and is what everybody means by TCPDF.
The body is a Blade template handed to writeHTML rather than a hundred Cell()
calls with millimetre coordinates, because this table has to be adjusted the
first time somebody sees it on paper, and nobody adjusts the second kind.
InvoiceMath is integer cents end to end, and rounds once. A percentage applied
line by line and rounded each time drifts from the same percentage applied to
the sum — three lines at 3,33 € less 10 % is 99 cents that way and 100 cents
the honest way, and the customer's calculator is what finds it. Gross is always
derived from net and never the reverse: taking VAT back out of a gross figure
returns a different number often enough to matter. A discount and a surcharge
are one operation with opposite signs, so nothing has to remember which of two
flags means which.
Quantities are thousandths, because hours, gigabytes and part-months are all
real, and are printed with the trailing zeroes stripped — "12,000 Std." reads
as a defect.
Every line shows quantity, unit price net, total net AND total gross: this goes
to businesses and to consumers, and each reads a different column first.
Verifying it took two goes and both failures were mine. `strings` over a PDF set
in a Unicode font finds nothing, because the text is stored as subset glyph ids
— the check has to render in a core font to be a check at all. And two of the
strings I then declared missing were simply expectations I had got wrong.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
nexxo