readIesProfile

function readIesProfile(text: string): IesProfile

import { readIesProfile } from '@driftengine/assets';

Parameters

In depth

Whitespace-delimited across line breaks, because that is what the format is. LM-63 attaches no meaning to a newline inside its numeric lists, and every file a manufacturer publishes wraps them — so a reader that parses line by line passes a hand-built fixture and fails on everything real. The header is the only part that is line-oriented, and it ends at TILT=.

Pure, and it takes text rather than a URL, for the reason readRadianceHdr gives: the fetching decision belongs to the consumer who has to make it, and a pure function is one that can be tested exactly.

What it costs is holding the whole grid, which for a dense fixture is a few thousand floats. What would make it wrong is a TILT other than NONE: that describes a fixture mounted at an angle with its own correction table, and applying the distribution without it would be confidently wrong rather than obviously wrong — so it is refused by name.