Sprite Attribute Upload
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Revision as of 15:09, 18 August 2017 by wiki>Hyphz
| Number | $xx57 |
|---|---|
| Decimal | |
| Short desc. | Uploads sprite positions, visibility and effect flags. |
| Bit Mask | |
| Readable | No |
| Writable | Yes |
| Subsystem | Sprites |
Uploads attributes of the sprite slot selected by Sprite Status/Slot Select ($303B / 12347). Attributes are in 4 byte blocks sent in the following order; after sending 4 bytes the address auto-increments to the next sprite. This auto-increment is independent of other sprite ports. The 4 bytes are as follows:
Byte 1 is the low bits of the X position. Legal X positions are 0-319 if sprites are allowed over the border or 32-287 if not. The MSB is in byte 3.
Byte 2 is the Y position. Legal Y positions are 0-255 if sprites are allowed over the border or 32-223 if not.
Byte 3 is bitmapped:
| Bit | Description |
|---|---|
| 4-7 | Palette offset, added to each palette index from pattern before drawing |
| 3 | Enable X mirror |
| 2 | Enable Y mirror |
| 1 | Enable rotation |
| 0 | MSB of X coordinate |
Byte 4 is also bitmapped:
| Bit | Description |
|---|---|
| 7 | Enable visibility |
| 6 | Reserved |
| 5-0 | Pattern index ("Name") |