Sprite Attribute 2 (with INC) Register: Difference between revisions
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Core 2.00.26 changes |
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After write into sprite-attribute "byte 3" ({{PortNo|$xx57}}), the {{NextRegNo|$34}} is incremented (with all consequences stemming from such action). If the sprite | After write into sprite-attribute "byte 3" ({{PortNo|$xx57}}), the {{NextRegNo|$34}} is incremented (with all consequences stemming from such action). If the sprite 127 was modified, the result of the increment is officially "undefined behaviour", and code should explicitly set valid 0..127 sprite index before next sprite-attribute manipulation. | ||
Revision as of 09:10, 27 January 2019
| Number | TBRegisterNumber::$77 |
|---|---|
| Readable | TBRegisterReadable::No |
| Writable | TBRegisterWritable::Yes |
| Short Description | [[ShortDesc::Same as {{#ask:
TBRegisterNumber::$37 }} ($37) (write third byte of sprite-attributes), plus increments {{#ask: TBRegisterNumber::$34 }} ($34)]] |
Byte 3 is bitmapped:
| Bit | Description |
|---|---|
| 4-7 | Palette offset, added to each palette index from pattern before drawing |
| 3 | Enable X mirror |
| 2 | Enable Y mirror |
| 1 | Enable rotation |
| 0 | MSB of X coordinate |
After write into sprite-attribute "byte 3" ({{#ask: PortNumber::$xx57 }} ($xx57{{#ask: PortNumber::$xx57 |mainlabel=- |headers=hide |intro= / |?NumberDec#- }})), the {{#ask: TBRegisterNumber::$34 }} ($34) is incremented (with all consequences stemming from such action). If the sprite 127 was modified, the result of the increment is officially "undefined behaviour", and code should explicitly set valid 0..127 sprite index before next sprite-attribute manipulation.