# 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](native-image-check.json) and [alternate-image check](native-version-check.json) 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:

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

Direct byte comparisons give these relationships:

| Source image | Colours exported from its palette | Runtime use |
| --- | --- | --- |
| `3DDATA/3DPAL.LBM` | 0–223, exactly matching the 672-byte `3DPAL.RGB` | Base scene palette |
| `3DDATA/CLEAR.LBM` | 16–28, exactly matching the 39-byte `CLEAR.RGB` | Clear-sky colours |
| `3DDATA/OVERCAST.LBM` | 16–28, exactly matching the 39-byte `OVERCAST.RGB` | Overcast-sky colours |
| Each `FOG.LBM` | 135–154, exactly matching its 60-byte `FOG.RGB` | Clear-weather fog colours |
| `KOREA.WZ/FOGDULL.LBM` | 135–154, exactly matching its 60-byte `FOGDULL.RGB` | Overcast fog colours |

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](index.html#0) 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](https://www.old-games.com/screenshot/4244-12-f-16-fighting-falcon-a.jpg): 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](https://shared.akamai.steamstatic.com/store_item_assets/steam/apps/3020280/manuals/bce40bf28f556caebef0a0e62d10991689492edc/iF16Manual.PDF) 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:

| Editions in our collection | Stored file date | Image |
| --- | --- | --- |
| September 1996 European and US editions, October 1996 Japanese edition, and the US disc's Hind demo | 2 March 1995 | Small map on a magenta background |
| September 1998, October 2000 and November 2000 editions, including their warzone copies | 22 May 1997 | F-16 cockpit screenshot with the Abu Dabi drawing |

Switch between the [earlier map](index.html#0/1) and the [later cockpit](index.html#0/0) 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](../media/cd_1996_09_eu_v2.json) and [the reference-disc manifest](../media/cd_2000_10_eu.json). 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_](../engine/decompiled/00489d14_initialise_3d_palette_.c). The [captured native palette setup](../models/materials.json) 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](../effects/index.html) shows the individual frames and active sequences. [initialise_explosions_](../engine/decompiled/004a6530_initialise_explosions_.c) 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](../fonts/index.html) 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

| Files | Versions to compare |
| --- | --- |
| [OVERCAST.LBM](index.html#15/1) | The 1996 discs have a 320 × 200 grey sky gradient; the later discs have a 640 × 480 image with a different palette and the gradient in its upper-left area. |
| [TITLE.LBM](index.html#224) | European, US and demo title artwork. The US image also exists as `A_TITLE.LBM` on the reference disc. |
| [LOG.LBM](index.html#186/1), [NETWORK.LBM](index.html#196/1) | Earlier artwork from the German DOS edition. |
| [MAIN.LBM](index.html#194/1), [QUICK_OP.BBM](index.html#208/1), [TOPTEN.LBM](index.html#226/1), [IM.LBM](index.html#248/1) | Demo and retail menu images. BBM uses the same IFF image format and is included in the comparison. |
| [MOUSE.LBM](index.html#238/1) | The demo has a 640 × 480 sheet; retail has a 320 × 64 cursor strip. |
| `MANUAL/PAGE*.LBM` | English, German and French pages, including six filenames absent from the reference disc. |

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:

| Image | Byte-identical copies |
| --- | --- |
| `3DPAL.LBM` | `3DDATA`, `CYPRUS.WZ`, `FORT.WZ`, `KOREA.WZ`, `YEMEN.WZ` |
| `FOG.LBM` | `3DDATA`, `CYPRUS.WZ`, `FORT.WZ`, `YEMEN.WZ` |
| `FOGDULL.LBM` | `3DDATA`, `CYPRUS.WZ`, `FORT.WZ`, `YEMEN.WZ` |
| `CONTENTS.LBM` | `MANUAL`, `MENUSCRN` |
| `INDEX.LBM` | `MANUAL`, `MENUSCRN` |

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.