deckcraft/crates/metafile
Brandon Thomas e28851d2f1
Pictures: WMF/EMF text, pattern and hatch brushes draw; ActiveX previews show (#336)
* ActiveX controls show their pictures

A slide's p:controls are read: each control with a p:pic (the image PowerPoint shows for it,
often a WMF) becomes a picture above the slide's shapes.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

* Metafiles draw their text, pattern and hatch brushes

deckcraft-metafile (still kurbo + thiserror only, so it builds for wasm):
- Text: WMF EXTTEXTOUT/TEXTOUT and EMF EXTTEXTOUTW/EXTTEXTOUTA/SMALLTEXTOUT with the
  selected font (CREATEFONTINDIRECT, EXTCREATEFONTINDIRECTW: face, signed LOGFONT height,
  width, weight, italic, underline, strike-out, escapement, charset), text and background
  colour, background mode, TA_* alignment and TA_UPDATECP, the dx array (ETO_PDY pairs too),
  ETO_OPAQUE fills and ETO_CLIPPED clips. 8-bit strings decode through their charset
  (Windows-1252/1250/1251; symbol fonts keep their codes at U+F000; double-byte sets keep
  their advances). The neutral Item::Text carries a text-space-to-picture transform, so the
  mapping and escapement are folded in and glyphs are never mirrored.
- Brushes: WMF DIBCREATEPATTERNBRUSH, EMF CREATEDIBPATTERNBRUSHPT and CREATEMONOBRUSH, and
  BS_HATCHED, as Item::Pattern tiles in 96-dpi pixels; WMF PATBLT. The XOR / AND-pattern /
  XOR see-through shadow of old PowerPoint WMFs draws its pattern in the XOR colour.
- MFCOMMENT escapes with an embedded EMF are ignored: PowerPoint draws the WMF's records.
- Pattern pixels and text count against the byte budget; strings are capped.

deckcraft-render draws text through deckcraft-fonts with the face slide text would use
(document_face), symbol fonts mapped as bullets map them (deckcraft_text::symbol_char, now
public, with Webdings), per-character fallback, the file's advances, GDI cell metrics for
top/bottom alignment, underline/strike-out and synthetic bold/italic. Tiles below 1.5 output
pixels per cell are drawn as their average colour.

On the 24 corpus slides that show a metafile, mean abs diff against PowerPoint goes from
28.31 to 5.06 (with the OLE/ActiveX preview commits).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-10-12 22:40:56 -04:00
..
src Pictures: WMF/EMF text, pattern and hatch brushes draw; ActiveX previews show (#336) 2026-10-12 22:40:56 -04:00
Cargo.toml Pictures: WMF and EMF draw, with the metafile reader ported from WordCraft (#317) 2026-10-12 18:27:19 -04:00