Sprite and Layers System Register
From SpecNext Wiki
| Number | TBRegisterNumber::$15 |
|---|---|
| Readable | TBRegisterReadable::Yes |
| Writable | TBRegisterWritable::Yes |
| Short Description | [[ShortDesc::Enables/disables Sprites and Lores Layer, and chooses priority of sprites and Layer 2.]] |
Bitmapped as follows:
| Bit | Function |
|---|---|
| 7 | Enable Lores Layer |
| 6 | If 1, the sprite rendering order is reversed, i.e. sprite 0 is on top |
| 5 | If 1, the clipping works even in "over border" mode (doubling X-axis coordinates of clip window) |
| 3-4 | If %00, ULA is drawn under Layer 2 and Sprites; if %01, it is drawn between them, if %10 it is drawn over both |
| 2 | If 1, Layer 2 is drawn over Sprites, else sprites drawn over layer 2 |
| 1 | Enable sprites over border (0 after reset) |
| 0 | Enable sprite visibility (0 after reset) |
When both "over border" (bit 1) and "clipping over border" (bit 5) is enabled, the Sprite clipping window {{#ask: TBRegisterNumber::$19 }} ($19) X-axis coordinates are "doubled", and coordinates origin is moved from pixel [0,0] position to sprite [0,0] position ([-32,-32] pixel position). For example: setting clip coordinates as {x1:5, x2:155, y1:7, y2:248} will make sprites visible in area [10,7]..[309,248] (inclusively) in sprite coordinates.