diff --git a/spec.html b/spec.html index e838f2a..065b50e 100644 --- a/spec.html +++ b/spec.html @@ -1961,25 +1961,65 @@

Layout of operators

then:
  1. -

    - Use the - MathVariants - table to try and find a glyph of height at least - DisplayOperatorMinHeight. - If none is found, fall back to the - largest non-base glyph. If none is found, fall back to - the layout algorithm of . -

    + If it is not possible to shape a stretchy glyph + corresponding to c in the block direction + with the + first available font + then fall back to the + layout algorithm of . +
    + Here we treat a non-[=embellished operator/stretchy=] [=embellished operator/largeop=] + glyph as stretchy with target dimension DisplayOperatorMinHeight. +
  2. - The min-content inline size, - max-content inline size, - inline size and block metrics of the math content - are given by the - glyph found. + The min-content inline size and + max-content inline size of the math content + are set to the preferred inline size of a glyph + stretched along the block axis.
  3. - Paint the glyph. + The inline size, + ink line-ascent, + ink line-descent, + line-ascent and + line-descent + of the math content + are obtained by the algorithm to + shape a stretchy glyph + to block dimension + DisplayOperatorMinHeight. + The inline size of the math content is the width of + the stretchy glyph. The stretchy glyph is shifted + towards the line-under by a value Δ so that its + center aligns with the center of the target when + [=embellished operator/symmetric=]: + the ink ascent of the math content is + the ascent of the stretchy glyph − Δ + and the ink descent of the math content is + the descent of the stretchy glyph + Δ. + +
    + The point of Δ here is simply to vertically align the operator when [=embellished operator/symmetric=]. +
    +
  4. +
  5. + The painting of the operator is performed by the + algorithm to shape a stretchy glyph + stretched to block dimension + DisplayOperatorMinHeight + and at position determined by the previous box metrics + shifted by Δ towards the line-over.