Italic Angle Degrees Slant Classifier

Classify measured signed slant geometrically with explicit caller upright tolerance; positive means right in caller convention, no font italic-feature or stylistic authenticity diagnosis.

Description

Slant direction is a geometric observation under a declared sign convention.

Slant direction is a geometric observation under a declared sign convention. It does not identify whether a font is stylistically italic.^[1]

Enter nonempty angles strictly between −90° and 90° and nonnegative tolerance. Return original zero-based index groups and ordinary median signed angle.

When to use Italic Angle Degrees Slant Classifier

Use Italic Angle Degrees Slant Classifier when you need to evaluate the supplied records under the calculation and evidence rules below. Positive means right in the caller convention; no italic feature or outline authenticity is verified.

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 Italic Angle Degrees Slant Classifier 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 outlineSignedSlantAnglesDegrees, callerUprightToleranceDegrees using the field table and calculation rules, then run the tool.
Read leftLeaningIndices, rightLeaningIndices, uprightIndices, medianSignedSlantDegrees. 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
outlineSignedSlantAnglesDegrees	Outline signed slant angles degrees	list of number	Required
callerUprightToleranceDegrees	Caller upright tolerance degrees	number	Required

Enter nonempty angles strictly between −90° and 90° and nonnegative tolerance. Return original zero-based index groups and ordinary median signed angle.

left if angle<−tolerance; right if angle>tolerance; otherwise upright

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

Output field	Meaning	Value type
leftLeaningIndices	Left leaning indices	list of number
rightLeaningIndices	Right leaning indices	list of number
uprightIndices	Upright indices	list of number
medianSignedSlantDegrees	Median signed slant degrees	number

json

{
  "input": {
    "outlineSignedSlantAnglesDegrees": [
      -12,
      -10,
      0
    ],
    "callerUprightToleranceDegrees": 1
  },
  "output": {
    "leftLeaningIndices": [
      0,
      1
    ],
    "rightLeaningIndices": [],
    "uprightIndices": [
      2
    ],
    "medianSignedSlantDegrees": -10
  }
}

Limitations and assumptions

Positive means right in the caller convention; no italic feature or outline authenticity is verified.

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.

Alternative or Complementary methods

Use Ascender/Descender Extents Checker: Glyph ink may extend beyond declared ascent and descent. Signed outline coordinates and positive descent magnitude have different roles. For a complementary task, use Oldstyle Figure Alignment Checker: Oldstyle-figure evidence can include descenders and varied tops. Observed geometry alone cannot verify an activated font feature.

References

Italic Angle Degrees Slant Classifier — tool.io

Similar or alternative tools

Ascender/Descender Extents Checker
Glyph ink may extend beyond declared ascent and descent. Signed outline coordinates and positive descent magnitude have different roles.
Oldstyle Figure Alignment Checker
Oldstyle-figure evidence can include descenders and varied tops. Observed geometry alone cannot verify an activated font feature.