Variable Font wght Axis Value Check

Check actual variable-font wght range and exact declared named instances, retaining original out-of-range flag despite clamped value; no universal weight-name mapping or outline availability claim.

Description

A variable font’s declared weight range and named instances define separate checks.

A variable font’s declared weight range and named instances define separate checks. Clamping does not erase the original range violation.^[1]

Enter finite requested value, positive ordered two-value bounds and named weights within bounds. Return inclusive range flag, clamped value and exact original-value named-instance match.

When to use Variable Font wght Axis Value Check

Use Variable Font wght Axis Value Check when you need to evaluate the supplied records under the calculation and evidence rules below. No universal weight names, font-file extraction or actual outline support is established.

Prepare measured font or typeset-layout values and the explicit design policy requested. For text or font bytes, use the supported syntax explained below.

How to use Variable Font wght Axis Value Check and understand its results

Prepare measured font or typeset-layout values and the explicit design policy requested. For text or font bytes, use the supported syntax explained below.
Enter requestedAxisWeight, declaredAxisBounds, declaredNamedInstanceWeights using the field table and calculation rules, then run the tool.
Read axisValueWithinFontBounds, resolvedClampedAxisValue, exactNamedInstanceFound. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
requestedAxisWeight	Requested axis weight	number	Required
declaredAxisBounds	Declared axis bounds	list of number	Required
declaredNamedInstanceWeights	Declared named instance weights	list of number	Required

Enter finite requested value, positive ordered two-value bounds and named weights within bounds. Return inclusive range flag, clamped value and exact original-value named-instance match.

clamped=max(minimum,min(maximum,requested))

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
axisValueWithinFontBounds	Axis value within font bounds	boolean
resolvedClampedAxisValue	Resolved clamped axis value	number
exactNamedInstanceFound	Exact named instance found	boolean

json

{
  "input": {
    "requestedAxisWeight": 550,
    "declaredAxisBounds": [
      300,
      700
    ],
    "declaredNamedInstanceWeights": [
      400,
      600
    ]
  },
  "output": {
    "axisValueWithinFontBounds": true,
    "resolvedClampedAxisValue": 550,
    "exactNamedInstanceFound": false
  }
}

Limitations and assumptions

No universal weight names, font-file extraction or actual outline support is established.

Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Numeric lists are limited to 10,000 entries; string lists to 128 strings of at most 128 characters each. The rules above may impose smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors. A successfully returned false flag is an evaluated outcome; its meaning is explained above.

Alternative or Complementary methods

Use x-Height Ratio From Font File: A font’s x-height ratio relates a native metric to units per em. Missing native metrics should be represented separately from measured outline height. For a complementary task, use Font Stretch Percent Width Axis: Width-axis calibration compares text advances under two settings. Pooled advances answer a different question from averaging sample percentages.

References

Variable Font wght Axis Value Check — tool.io

Similar or alternative tools

x-Height Ratio From Font File
A font’s x-height ratio relates a native metric to units per em. Missing native metrics should be represented separately from measured outline height.
Font Stretch Percent Width Axis
Width-axis calibration compares text advances under two settings. Pooled advances answer a different question from averaging sample percentages.