| 0,0 → 1,56 |
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| ART FILES BY IMAGINATION PILOTS |
| Technical overview by Daniel Marschall 15 Feb 2018 |
| |
| |
| VERSION 1.x (16-bit era, "IPE16") |
| ================================= |
| |
| Version 1.0 For game: "Blown Away" (1994) |
| * File signature "Art" + 20 NUL bytes |
| * Image names up to 23 characters |
| (unsure if the 23th byte must be a zero terminator) |
| * LZW implementation: GIF standard implementation |
| - variable code length between 9 and 12 bits |
| - clear code (256) |
| - end code (257) |
| * Pictures can only be 8-bit |
| * Each picture can either be LZW compressed (code "P") |
| or uncompressed (code "p", lower case) |
| * Decompressed/raw data: Top-down pixel data |
| * Attached: Optional palette (R,G,B), uncompressed. |
| (Sprites usually do not have a palette, so the game |
| will use the palette of the parent picture) |
| |
| Version 1.1 For games: "Panic in the Park" (1995) |
| "Where's Waldo? At the Circus" (1995) |
| * Codes for compression/raw are now "Q" and "q" instead of |
| "P" and "p" |
| * Each picture has now a relative X- and Y-offsets for 'fine-tuning'. |
| These offsets cannot be negative, though. |
| |
| VERSION 2.x (32-bit era, "IPE32") |
| ================================= |
| |
| Version 2.0 For games: "Where's Waldo? Exploring Geography" (1996) |
| "Eraser Turnabout" (1997) |
| "Virtual K'Nex" (1998) |
| * File signature "ART_DATA" |
| * Image names up to 8 characters; |
| no zero termination required after the 8 characters. |
| * LZW implementation by Mark R. Nelson and Shawn M. Regan |
| - variable code length between 9 and 13 bits |
| - clear code (256) |
| - end code (257) |
| * Pictures are divided into chunks. Each chunk can be compressed or |
| uncompressed. Limitations: |
| - Each compressed chunk (except the last one) must decode into |
| exactly 16382 (0x3FFE) bytes of uncompressed data. |
| - The size of the compressed data of a chunk must not exceed the |
| size of the original uncompressed data. |
| * The size of each chunk (raw or compressed) is limited |
| to max. 32767 Bytes (0x7FFF). |
| * Decompressed/raw data: Windows Bitmap (without file header); |
| therefore, theoretically every color depth/compression/etc. can be used. |
| For 8-bit pictures, the palette is included in the Bitmap. |
| * Re-using of parent palette is not possible. |
| Property changes: |
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| Added: svn:mime-type |
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| +text/plain |
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| \ No newline at end of property |
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