Where the artwork is used

The artwork browser includes the reference disc's 242 IFF images, plus alternate versions of files that changed across the retained Apache discs, demo and patches. Choose Version above the image to switch editions, or enable Changed between editions to find the 98 filenames with variants. Identical copies share one version, with their editions and stored dates listed below the image.

The reference-image check and alternate-image check compare decoded pixels and palettes with the original game's image loader. The browser also includes working artwork and spare files that the game never displays.

LBM is the filename extension used here for IFF bitmap images. Each image carries indexed pixels and a colour palette. The decoder handles both packed-pixel PBM and planar ILBM forms, including ByteRun1 compression.

The screenshots are palette sources

initialise_3d_palette_ loads small RGB files for the scene colours. It does not load the corresponding LBM screenshots. The surviving batch files show how some of those RGB files were exported:

rgb 3dpal /f0 /l223
rgb clear /f16 /l28
rgb overcast /f16 /l28

Direct byte comparisons give these relationships:

The other four copies of FOGDULL.LBM differ from their RGB files at 12 of these 20 palette entries. Those source images and exported palettes are different revisions. The RGB bytes are what the game uses.

FOG.LBM depicts a jet flying over terrain. Its pixels provide a scene in which to inspect colours while editing the palette; Apache renders its actual terrain and fog in 3D. CLEAR.LBM is a small sky-gradient image serving the same palette-authoring purpose.

The Abu Dabi drawing

3DPAL.LBM contains a cockpit screenshot with a hand-drawn figure holding an “Abu Dabi” sign. The figure is painted into the image pixels. Its role in the shipped files is as the carrier for the base palette: 3DPAL.BAT exports the first 224 colours, and the original engine reads 3DPAL.RGB. The doodle itself is not displayed by the game. It appears to be an artist or programmer's addition to a working image; the file does not identify its author.

The cockpit belongs to F-16 Fighting Falcon

The cockpit in the later 3DPAL.LBM is the artwork used by Digital Integration's F-16 Fighting Falcon, also sold as iF-16. Compare the full cockpit screenshot: the rounded HUD frame, the red/green angle-of-attack indicator immediately to its left, and the row of round keypad buttons beneath it align with the Apache bitmap. The identification comes from that artwork match. The original iF-16 manual describes the instrument panel in chapter 5.

The image retains only the upper-left 320 × 240 portion of the cockpit view. Its IFF BMHD records an image size of 320 × 240 and a page size of 640 × 480, consistent with the full-resolution screenshot. The “Abu Dabi” figure was drawn into this palette-working image.

The earlier discs contain a different bitmap under the same filename:

Switch between the earlier map and the later cockpit in the viewer.

The earlier file is 4,888 bytes, SHA-256 1b52a4aafe72bde16cd9a3247aadd5c07d9fa8cf092beb57f883d83777893cab; the later file is 26,866 bytes, SHA-256 af7e5c2c71a50a12641d55e92140c06cd0729343f9dc4c72e2a98c6c2172c6b2. Dates come from the preserved disc-directory records in the European v2 manifest and the reference-disc manifest. This places the F-16 artwork in a later revision of the palette source, rather than the original 1995 bitmap.

The loader is visible in initialise_3d_palette_. The captured native palette setup also records the RGB files and byte counts actually loaded.

Explosion sheets and fonts

The explosion LBMs are source sheets containing several frames. The game loads individual indexed images named AIREXP1.BMP through AIREXP15.BMP and GNDEXP1.BMP through GNDEXP33.BMP, rather than the complete LBM sheets. These BMP files contain raw pixel bytes, without Windows bitmap headers.

For example, all 64 × 64 pixels of AIREXP1.BMP match the rectangle beginning at (4, 4) in AIREXP2.LBM. All 64 × 32 pixels of GNDEXP1.BMP match the rectangle beginning at (2, 2) in GNDEXP2.LBM. Coordinates are zero-based. Other sheets preserve alternate effects and earlier artwork; a similar filename alone does not establish that a particular sheet supplied an active animation.

The effects viewer shows the individual frames and active sequences. initialise_explosions_ names the files the game loads.

FONTS/11X15.LBM is loaded directly. The menu-font constructor cuts 256 glyph cells from its grid. The font analysis shows the characters and explains their layout. UIDATA/MOUSE.LBM is also referenced by the executable's mouse code.

3DDATA/SHOT0000.LBM is a saved helicopter screenshot, with no filename reference in the reference software executable. It is part of the shipped working material, rather than a menu screen.

Other artwork changes between editions

All 98 changed filenames have differences in their decoded pixels or dimensions. Files are matched by their full, case-insensitive path within each Apache distribution. The separate Hind demo bundled on the US disc is excluded. Files unique to another edition under an entirely different filename are outside this version comparison.

tools/catalogue_resources.py rebuilds the catalogue from the retained media manifests, including discs consolidated into other directories. Original reference indices remain unchanged, so existing viewer links still select the same artwork. Additional images are stored once per distinct file hash.

Why the repeated images?

The reference-disc portion of the browser preserves its original paths. It has 242 IFF files but 230 distinct file contents, measured by SHA-256. Five groups account for the repeated files:

Korea's fog screenshots are different images, and its fog RGB palettes also differ. The shared 3DDATA directory and the individual warzone directories contain copies of the palette sources, even though the game loads the base palette from 3DDATA and fog palettes from the selected warzone. These are duplicates in the original files, not repeated extraction results.