Sticky bit: Difference between revisions
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The "sticky bit" is one of the per-sprite attributes stored in the [[Sprites|Sprite Control Bank 3]] (bit 6). | The "sticky bit" (or "chain bit") is one of the per-sprite attributes stored in the [[Sprites|Sprite Control Bank 3]] (bit 6). | ||
{{16BitRegister|Y position|9|'''[[Sticky bit]]''' | {{16BitRegister|Y position|9|'''[[Sticky bit]]'''|1|Sprite size|6}} | ||
Setting it to 1 makes the corresponding sprite "stick" to the precedent one. | Setting it to 1 makes the corresponding sprite "stick" to the right of the precedent one. This allows moving groups of sprites easily, by just updating one coordinate pair. | ||
The | The [[LSPC]] will automatically place a chained sprite to the right of the previous one. It will inherit the same Y position, the same height and the same vertical shrinking coefficient. All attributes are ignored except the horizontal shrinking coefficient. | ||
Changing the driving sprite's attributes will change all those of the consecutively chained sprites, but the values will remain unchanged in [[VRAM]]. | |||
Changing driven sprites attributes won't affect it until its sticky bit is reset. | |||
[[Category:Video system]] | [[Category:Video system]] | ||
Latest revision as of 22:45, 23 June 2018
The "sticky bit" (or "chain bit") is one of the per-sprite attributes stored in the Sprite Control Bank 3 (bit 6).
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| Def | Y position | Sticky bit | Sprite size | |||||||||||||
Setting it to 1 makes the corresponding sprite "stick" to the right of the precedent one. This allows moving groups of sprites easily, by just updating one coordinate pair.
The LSPC will automatically place a chained sprite to the right of the previous one. It will inherit the same Y position, the same height and the same vertical shrinking coefficient. All attributes are ignored except the horizontal shrinking coefficient.
Changing the driving sprite's attributes will change all those of the consecutively chained sprites, but the values will remain unchanged in VRAM.
Changing driven sprites attributes won't affect it until its sticky bit is reset.