glyphs-mcp-italic-first-pass

name	glyphs-mcp-italic-first-pass
description	Use this skill when the task is to create a first-pass italic or oblique set from roman glyphs, selected glyphs, or one current glyph by copying layers and applying a guarded slant.

Glyphs MCP italic first pass

Use this skill for a guarded roman-to-italic first pass. It accelerates the work; it does not claim optical completion.

Core rules

• Prefer the Paths / Outlines profile for review-only work, or Editing when applying.
• Read current font, master, and selection before mutation.
• Default angle is 12.0 degrees unless the user specifies another value.
• Interpret angle as a Glyphs source/Transformations angle: positive values lean Latin outlines to the right. In exported OpenType/UFO metadata, the corresponding post.italicAngle / slnt value is negative (+12 in Glyphs source convention maps to about -12 in exported font convention).
• Before outline work, verify the target italic master's italicAngle from get_font_masters equals +angle within 0.01; do not use slantAngle, which reports the separate postscriptSlantAngle custom parameter.
• If the target master italicAngle differs, run set_master_italic_angle with dry_run=true, show the before/after, and only set it with confirm=true after explicit approval.
• Copy roman paths into the italic master and skew only those copied paths.
• Copy components as live components, but do not skew component transforms or component outlines; component shapes should resolve from their own italic master layers.
• Default compatibility_mode is preserve_if_possible; path compatibility is useful but not required.
• Before slant_mode="cursivy", run review_master_stem_metrics for the target italic master.
• If Cursivy stems are missing, ask whether to set stems, measure suggestions, use raw slant, or stop.
• Run review_italic_first_pass before apply_italic_first_pass.
• Always run apply_italic_first_pass with dry_run=true before any mutating call.
• Only mutate after explicit approval with confirm=true.
• Never auto-save the font.

Workflow

1. Read context:
   • get_selected_font_and_master
   • get_font_masters
   • get_selected_glyphs when scope may be selection-based
2. Resolve scope:
   • current_glyph
   • selected_glyphs
   • glyph_names
   • all_glyphs
3. Resolve source roman and target italic masters.
4. Verify target master italic angle:
   • call get_font_masters
   • find the target master by target_master_id
   • compare its italicAngle to +angle within 0.01
   • if different, call set_master_italic_angle with dry_run=true
   • summarize the before/after and wait for approval before calling set_master_italic_angle with confirm=true
5. If using Cursivy:
   • call review_master_stem_metrics
   • if missing, call set_master_stem_metrics only after approval and with dry_run=true first
6. Call review_italic_first_pass.
7. Summarize:
   • glyph count and blocked glyphs
   • missing stems
   • protected glyph warnings
   • compatibility mode and compatibility issues
   • live component preservation and any component warnings
   • target glyphs that would be created
8. If the user approves, call apply_italic_first_pass with dry_run=true.
9. After approval of the dry run, call apply_italic_first_pass with confirm=true.
10. Re-read or summarize returned results and list glyphs that still need manual optical work.

Defaults

Use these defaults unless the user says otherwise:

{
  "scope": "selected_glyphs",
  "angle": 12.0,
  "slant_mode": "cursivy",
  "stem_policy": "require_existing",
  "compatibility_mode": "preserve_if_possible",
  "copy_options": {
    "paths": true,
    "components": true,
    "anchors": true,
    "metrics": true
  },
  "origin": 3,
  "backup": true
}

Component Position Handling

When copy_options.components=true, preserve components as live components. Do not decompose them and do not skew their outlines, scale, rotation, or internal transform, because component glyphs are expected to have their own italic master drawings.

However, component placement must follow the same slant geometry as paths. After copying a component, adjust only its x translation according to its y translation:

new_x = old_x + tan(angle) * old_y

Use the Glyphs source angle convention from this skill. If old_y == 0, leave the x position unchanged.

This keeps baseline components unmoved while shifting components placed above or below the baseline so they align with the slanted path geometry.

Manual review reminders

Warn that mechanically slanted glyphs need review, especially a, e, f, g, k, v, w, x, y, punctuation, brackets, braces, quotes, and symbols.

Kerning replacement is not part of this v1 skill. If the user wants kerning copied from roman to italic, treat it as a separate follow-up workflow.

Deeper references

• Command set
• Glyphs Transformations docs
• Stem metrics docs