Difference between revisions of "Sprite Pattern Upload"
(core 2.00.23 changes) |
(The pattern slot auto-increment is now officially wrapping around from 63 to 0.) |
||
| Line 9: | Line 9: | ||
Used to upload sprite patterns. Sprite patterns are 16x16 (256 bytes for 8 bit colour and 128 bytes for 4 bit colour sprites) and are sent in English reading order. Each byte is the offset, 0-255 (or two 0-15 for 4-bit graphics), within the active sprite palette. After sending 256 bytes, the target pattern slot is auto-incremented. This auto-increment is independent of other sprite registers. | Used to upload sprite patterns. Sprite patterns are 16x16 (256 bytes for 8 bit colour and 128 bytes for 4 bit colour sprites) and are sent in English reading order. Each byte is the offset, 0-255 (or two 0-15 for 4-bit graphics), within the active sprite palette. After sending 256 bytes, the target pattern slot is auto-incremented. This auto-increment is independent of other sprite registers. | ||
| − | Auto-increment from pattern slot 63 | + | Auto-increment from pattern slot 63 will wrap to slot 0 (only 64 pattern slots will be available in foreseeable future, and if ever extended, there will be separate configuration bit to enable more than 64 pattern slots). |
| − | With 4 bit sprites each pattern slot contains effectively two patterns, each 128 bytes long, the sub-pattern displayed is selected by | + | With 4 bit sprites each pattern slot contains effectively two patterns, each 128 bytes long, the sub-pattern displayed is selected by "N6" bit in 5th sprite-attribute byte. |
| + | |||
| + | With 4 bit graphics the top bits (of each pattern byte) 7-4 are "left" pixel on display and bits 3-0 are "right next to it" pixel on display (in default mode, no mirror, no rotate). | ||
Revision as of 02:51, 11 February 2019
| Number | $xx5B |
|---|---|
| Decimal | |
| Short desc. | Used to upload the pattern of the selected sprite. |
| Bit Mask | %---- ---- 0101 1011 ?? |
| Readable | No |
| Writable | Yes |
| Subsystem | Sprites |
Used to upload sprite patterns. Sprite patterns are 16x16 (256 bytes for 8 bit colour and 128 bytes for 4 bit colour sprites) and are sent in English reading order. Each byte is the offset, 0-255 (or two 0-15 for 4-bit graphics), within the active sprite palette. After sending 256 bytes, the target pattern slot is auto-incremented. This auto-increment is independent of other sprite registers.
Auto-increment from pattern slot 63 will wrap to slot 0 (only 64 pattern slots will be available in foreseeable future, and if ever extended, there will be separate configuration bit to enable more than 64 pattern slots).
With 4 bit sprites each pattern slot contains effectively two patterns, each 128 bytes long, the sub-pattern displayed is selected by "N6" bit in 5th sprite-attribute byte.
With 4 bit graphics the top bits (of each pattern byte) 7-4 are "left" pixel on display and bits 3-0 are "right next to it" pixel on display (in default mode, no mirror, no rotate).