DDS textures can now be saved, not just opened: uncompressed (BGRA, BGRX, L8, A8L8; lossless) or BC1/BC2/BC3 (DXT1/3/5) from a clean-room block encoder, with an optional box-filtered mip chain, in the legacy header. Save As and Save a Copy ask with DDS Options; scripts pass `ddsCompression`/`ddsMipmaps` (file commands, control `app.save`, RPC `doc.save`, MCP `doc_save`/`doc_export`), and the CLI takes `--dds-compression`/`--dds-mipmaps`. Targa and DDS answers travel together as `FormatChoices` through the Save As flow.
Review follow-ups:
- File › Save behind DDS or Targa Options records a plain Save with its answer, and replaying `file.save` applies it (#3531).
- The block encoder finds the principal axis from every channel, so a channel that varies on its own can't hide the others' variation.
- DDS joins the shared round-trip suite; the header is built before the output buffer is allocated.
- Enter on a focused Cancel in DDS, Targa or TIFF Options cancels instead of saving.
A read-only DirectDraw Surface codec on the model of PCX: the top mip
level of a 2D texture, uncompressed (channel masks, RGB or luminance,
8 to 32 bits) or BC1/BC2/BC3 (DXT1/3/5), with the legacy or the DX10
header. Cubemaps, arrays, volumes and other formats are refused with
an Unsupported error naming what was found; every header field is
treated as hostile (checked sizes, limits before allocating, no
indexing on file offsets).
Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>