Entry | |
---|---|
R0 | Flags: |
Bit 0: Synchronise | |
Bit 1: Synchronise if unclaimed | |
R1 | Render operation: |
0 = No-op | |
1 = Copy rectangle | |
2 = Fill rectangle | |
R2 | Pointer to operation parameter block |
R4 | Bits 0-23: 13 (reason code) |
Bits 24-31: Display number |
Exit | |
---|---|
R4 | 0 |
- | All other registers preserved |
The kernel issues this call to instruct the driver to perform a hardware-accelerated rendering task. The appropriate driver should respond to the call in the following manner:
The kernel has no generic fallback in place for if this call is left unclaimed. Fallbacks are handled on a case-by-case basis in the VDU drivers. Therefore any user software which wishes to make use of hardware acceleration should either do so via the VDU interface (e.g. use block copy/fill OS_Plot operations), or call GraphicsV directly and use their own software fallback for any unsupported operations. Just because one call succeeds it does not guarantee that the next call will succeed, or that a call made with slightly different parameters will succeed.