I'll try a summary: WASM shaper is part of Harfbuzz, a text shaping engine for font rendering. It allows embedding WASM code in the font for influencing the way text is rendered into glyphs.
> The WASM code inside a font is expected to export a function called shape which takes five int32 arguments and returns an int32 status value.
> ..The general goal of WASM shaping involves receiving and manipulating a buffer contents structure, which is an array of infos and positions (as defined below). Initially this buffer will represent an input string in Unicode codepoints. By the end of your shape function, it should represent a set of glyph IDs and their positions.
> The WASM code inside a font is expected to export a function called shape which takes five int32 arguments and returns an int32 status value.
> ..The general goal of WASM shaping involves receiving and manipulating a buffer contents structure, which is an array of infos and positions (as defined below). Initially this buffer will represent an input string in Unicode codepoints. By the end of your shape function, it should represent a set of glyph IDs and their positions.