Paintworks file format: Difference between revisions
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m (add compressed info) |
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Uncompressed images are simply screen dumps as one might expect. |
Uncompressed images are simply screen dumps as one might expect. |
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− | Compressed images are |
+ | Compressed images are a two step process, RLE decoding and re-ordering. |
+ | RLE decompression: |
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+ | |||
+ | /* Written by Lonny Pursell - placed in to Public Domain 1/28/2017 */ |
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+ | void decode_rle(uint8 *data, uint8 *bmap, uint32 bms) { |
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+ | uint8 cmd, chr; |
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+ | uint16 i; |
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+ | uint32 src=0, dst=0, cnt=0; |
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+ | do { |
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+ | cmd = data[src++]; |
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+ | if (cmd & 0x80) { /* literal? */ |
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+ | cmd = cmd & 0x7f; |
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+ | memcpy(&bmap[dst], &data[src], (uint32)cmd); |
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+ | dst = dst + (uint32)cmd; |
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+ | src = src + (uint32)cmd; |
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+ | } else { /* repeat? */ |
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+ | chr = data[src++]; |
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+ | for (i=0; i<cmd; i++) { |
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+ | bmap[dst++] = chr; |
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+ | } |
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+ | } |
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+ | cnt = cnt + cmd; |
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+ | } while (cnt<bms); |
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+ | } |
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+ | |||
+ | The resulting bitmap is arranged as follows: |
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+ | |||
+ | ST low resolution: |
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+ | All of plane 0..., all of plane 1..., all of plane 2..., all of plane 3... |
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+ | ST medium resolution |
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+ | All of plane 0..., all of plane 1... |
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+ | ST high resolution: |
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+ | No rendering required. |
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</pre> |
</pre> |
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Back to [[ST Picture Formats]] |
Back to [[ST Picture Formats]] |
Revision as of 23:23, 28 January 2017
Paintworks *.SC0 *.CL0 (st low resolution) *.SC1 *.CL1 (st medium resolution) *.SC2 *.CL2 (st high resolution) *.PG0 (st low resolution, double high) *.PG1 (st medium resolution, double high) *.PG2 (st high resolution, double high) Early versions of Paintworks were called N-Vision. These are often mistaken as NEOchrome files. One should not rely on the file extension to determine the contents. 1 word file id [0x00] recommend using 'secondary file id' for identification 1 word resolution [0 = low, 1 = medium, 2 = high] recommend using 'flags' to determine resolution 16 words palette 12 bytes file name, usually [" . "] 1 word ? 1 word ? 1 word ? 9 bytes secondary file id ["ANvisionA"] 1 byte flags, bit field: cxrrtttt c = compression flag [1 = compressed] x = not used r = resolution [0 = low, 1 = medium, 2 = high] t = type [0 = page, 1 = screen, 2 = clipart, 4 = pattern] page = double high, thus 320x400, 640x400, 640x800 screen = standard st resolutions clipart = standard st resolutions pattern = no documentation at this time 64 bytes ? --------- 128 bytes total for header ? image data: Uncompressed images are simply screen dumps as one might expect. Compressed images are a two step process, RLE decoding and re-ordering. RLE decompression: /* Written by Lonny Pursell - placed in to Public Domain 1/28/2017 */ void decode_rle(uint8 *data, uint8 *bmap, uint32 bms) { uint8 cmd, chr; uint16 i; uint32 src=0, dst=0, cnt=0; do { cmd = data[src++]; if (cmd & 0x80) { /* literal? */ cmd = cmd & 0x7f; memcpy(&bmap[dst], &data[src], (uint32)cmd); dst = dst + (uint32)cmd; src = src + (uint32)cmd; } else { /* repeat? */ chr = data[src++]; for (i=0; i<cmd; i++) { bmap[dst++] = chr; } } cnt = cnt + cmd; } while (cnt<bms); } The resulting bitmap is arranged as follows: ST low resolution: All of plane 0..., all of plane 1..., all of plane 2..., all of plane 3... ST medium resolution All of plane 0..., all of plane 1... ST high resolution: No rendering required.
Back to ST Picture Formats