C16 Internal.txt

::----- C16 Internal.txt -----::
The format of Compressed sprite files 
Author: Alima Adams
Date:	24th Feb 1999
Updated: Daniel Silverstone (4th Jul 1999)

glossary of sorts:
Compressed format sprite files have the file name format *.c16
*new* = additional to usual S16 format
*changed* = altered from the usual S16 format 

1. File 16 bit Pixel format:
	 this could could be 555 (0) or 565 (1) 				uint32
	 Also the next bit (bit 1) is set if the sprite is a 16bit C16.
		the engine assumes that if bit1 is clear, it is an 8bit C16

2. Number of sprites in the file  :						uint16

3. S16 header for each sprite:
	the offset of pixel data for current sprite
	this is taken from the start of the file				uint32
	the width of the sprite							uint16
	the height of the sprite						uint16

4.*new*	Scanlines: 
	offsets to each line in the file (excluding the first line which
	is covered by myOffset. again these are from the start of the file	uint32
	
5. *changed* pixel data for each sprite:
	This takes the form of "uint8 tag " to encode runs of pixels.
	The tag is a word - the lowest bit is 0 if the run is transparent
			  - the lowest bit is 1 if the run is colour 
			  - the other fifteen bits are the number of pixels in the run
	If the tag depicts a run of colour then it will be followed by the
	specified number of colour pixel data (in 16 bit format).
	If the tag depicts a run of black then there will be no pixels
	following the tag.
	Note that since the tag is fifteen bits we can encode runs of up to 32767 pixels
	at a time.
	There are "sprite Height" lines of data for each sprite. 
	Each line terminates with a zero tag (16 bits).