perm filename PAGE16[00,BGB] blob
sn#046248 filedate 1973-06-05 generic text, type T, neo UTF8
~F85. LEVEL NODE FORMAT.
_____________________________________________
word | CW | CCW |
0 | level ring | 3
_____|___________________|___________________|
word | DAD | SON |
1 | image | 1st polygon | 3
_____|___________________|___________________|
word | type | reloc |
2 | | 33 0200 |
_____|___________________|___________________|
word | | |
3 | --- | --- | 0
_____|___________________|___________________|
word | ALT | ncnt |
4 | (1st fusion shape)|threshold cut level| 2
_____|___________________|___________________|
word | | |
5 | --- | --- | 0
_____|___________________|___________________|
word | | |
6 | --- | --- | 0
_____|___________________|___________________|
Every level belongs to an image pointed to by the DAD link;
the ring of levels of an image is formed in the CW and CCW links;
the son of a level is its first polygon and that first polygon is
the upper left most polygon of the level.
The ncnt datum of a level contains its threshold cut value,
which is an integer between -1 and 63. The -1 level is always
generated, and it contains a single polygon with four sides. The -1
level's polygon is called the border polygon; the fiction being that
every point beyond the edges of the televsion picture has an
intensity value of -2, which is blacker than black.
The ALT link of a level contains a temporary pointer to that
level's ring of fusion shapes during polygon compare time mating.
~I1973,800;F8- 16 -