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Add Lynx documentation to sp65

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git-svn-id: svn://svn.cc65.org/cc65/trunk@5916 b7a2c559-68d2-44c3-8de9-860c34a00d81
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karri 2012-11-06 06:24:17 +00:00
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@ -254,6 +254,58 @@ bytes). There are no additional attributes for this conversion.
<sect1>Lynx sprite<p>
Lynx can handle 1, 2, 3 and 4 bits per pixel indexed sprites. The maximum size
of a sprite is roughly 508 pixels but in reality the Lynx screen is only 160 by
102 pixels which makes very large sprites useless.
The number per pixels is taken from the number of colors of the input bitmap.
There are a few attributes that you can give to the conversion software.
<descrip>
<tag/mode/
The first is what kind of encoding to use for the sprite. The attribute for
this is called "mode" and the possible values are "literal", "packed" or
"transparent". The default is "packed" if no mode is specified.
The "literal" is a totally literal mode with no packing. In this mode the
number of pixels per scanline will be a multiple of 8 both right and left from
the action point.
If the source bitmap edge ends with a color where the least significant bit is
one then there will be an extra 8 zero bits on that scan line.
So if you are using totally literal sprites and intend to change them at
runtime then please add a single pixel border far left and far right with
zeros in order to prevent graphical glitches in the game.
The standard encoding is called "packed". In this mode the sprite is packed
using run-length encoding and literal coding mixed for optimisation to
produce a small sprite.
The last encoding mode "transparent" is like packed. But here we know that
the index 0 will be transparent so we can clip off all 0 pixels from the left
and right edge of the sprite. This will produce the smallest sprite possible
on the Lynx. The sprite is not rectangular anymore.
<tag/ax/
The sprite is painted around the Anchor point. The anchor point x can be
between 0 and the width of the sprite - 1. If anchor point x is zero then
painting the sprite in location 10,20 will set the left edge of the sprite
10 pixels from the left of the Lynx screen. When the sprite is scaled by
hardware the anchor point stays in place and the sprite grows or shrinks
around the anchor point. The default value is 0 (left).
<tag/ay/
The sprite is painted around the Anchor point. The anchor point y can be
between 0 and the height of the sprite - 1. If anchor point y is zero then
painting the sprite in location 10,20 will set the top of the sprite 20
pixels from the top of the Lynx screen. When the sprite is scaled by
hardware the anchor point stays in place and the sprite grows or shrinks
around the anchor point. The default value is 0 (top).
</descrip>
<sect1>VIC2 sprite<p>