This is (incomplete) readme for the patch portion of the tiletool.  We'll make a nicer html version later ;-)


The header file contains a list of filenames of the individual tilesheets used by a mod.  Thus, 
a mod will have one tilehead, and up to one tilesheet per level, all contained within the same folder
as the executible.


TILEHEAD:
0    16*91    TS_File      Contains an ASCII zero terminated filename of a tilesheet.
                           The patch looks at byte 16*current_level for a filename.
                           Therefore, all levels (including levels 80, 81 and 90) must
                           reference a tilesheet file.  Currently we can do up to 32 levels,
                           but one day a patch may be made to allow more.

                           
                           
                           
The tilesheet file is loaded at the start of each level (during the fade in and fade out).
It contains information for tile info, animation, and graphics in that order.                          
                           
                           
TILESHEET:

0        2    TileCount    Number of tiles in tilesheet (keen1: TC = 910; keen2,3 = ?)
2        2    FrameCount   Number of frames in tilesheet.  (keen1: FC = 8, keen2,3 = ?)
4        2    GfxLength    Length of one plane of tile graphics.  (keen1,2,3: GL = as much as desired/will fit)
6        4    InfoLoc      Offset from beginning of file of tileinfo
10       4    AnimLoc      Offset from beginning of file of animinfo
14       4    GfxLoc       Offset from beginning of file of graphics
18      46    buffer       left empty

64    TC*6    TileInfo     TileInfo*
?   TC*8*2    AnimInfo     AnimInfo**
?     GL*4    GfxLoc	   Tile Graphics***


*TileInfo

Similar to the unmodded tileinfo.  Contains 5 planes.  The first plane (plane 0) is 910 words for the behaviour of the tiles.
The values are unchanged from keen 1-3.  Planes 1 thru 4 are blocking top, right, bottom, and left edges, respectively,
and are only one byte per tile.  In addition, the byte can signify axis-normal blocking, or sloped blocking.  Slope values
are negative and defined in the PDF file.  There is no animation plane, as this has been replaced by animation data.


TILEINFO:
0   	TC    Behaviour    Unchanged from Keen1-3
TC    	TC    Top Blocking Values 0 thru 3 unchaged from Keen1-3.  Negative values indicate various slopes.
TC*2    TC    Right         ""
TC*3    TC    Bottom        ""
TC*4    TC    Left          ""



**AnimInfo

In the unmodded keen1-3.exe, the game goes through the animation plane and processes each tile.  The data in the
animation plane is converted into offsets in video memory, which are stored in four arrays of words in main memory (one
per animation frame).  The AnimInfo is in the format of these arrays.  Because offsets can be arbitrary, one tile
can have ANY four GRAPHICS for a given frame.  For "non-animating" tiles, this graphic is the same for each
frame.  By using empty space in the executable, the patch stores animation information for 4 extra arrays,
for a total of 8 frames!  


ANIMINFO:
0     TC*2    Frame 0      Offset data for frame 0
TC*2  TC*2    Frame 1      Offset data for frame 1 
TC*4  TC*2    Frame 2      Offset data for frame 2
...
TC*14 TC*2    Frame 7      Offset data for frame 7 



***Graphics info is simply tile EGALATCH data.  It is loaded into video memory.  The patch makes use of a pointer
to the start of tile graphics that is defined during game loading.

GFXINFO:
0       GL    Blue         Data for the BLUE  plane (8 pixels per byte)
GL      GL    Green        Data for the GREEN plane (8 pixels per byte)
GL*2    GL    Red          Data for the RED   plane (8 pixels per byte)
GL*3    GL    Light        Data for the LIGHT plane (8 pixels per byte)




To be continued...