GraphicsV 26 (changes)
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GraphicsV
» GraphicsV 26
Graphics Vector (42)
| Entry | |
|---|---|
| R0 | Pointer to Mode Selector Block describing the required properties of the overlay |
| R1 | Aspect ratio to use when calculating returned min/max scale values |
| Top 16 bits = width | |
| Bottom 16 bits = height | |
| R2 | Flags |
| Bit 0: Overlay must support scaling | |
| Bits 1-31 reserved, should be zero | |
| R3 | Mask of which heads the overlay is to be used with |
| R4 | Bits 0-23: 26 (reason code) |
| Bits 24-31: Driver number |
| Exit | |
|---|---|
| R0 | Overlay number |
| R1 | Flags: |
| Bits 0-7: Overlay type (0 = Z-Order, 1 = Basic, 2+ reserved) | |
| Bits 8-31: Reserved | |
| R2 | Minimum width overlay can be scaled to |
| R3 | Minimum height overlay can be scaled to |
| R4 | 0 |
| R5 | Maximum width overlay can be scaled to |
| R6 | Maximum height overlay can be scaled to |
| - | All other registers preserved |
Use
Allows the user to check whether an overlay with the specified properties can be created, and if so, what capabilities it will have. If the overlay can’t be supported, the driver should not claim the call.
When vetting the settings, the driver should take into account any restrictions that result from the current system configuration. E.g. if all overlays are currently in use, no Vet call should succeed. Or conversely, if a Vet call succeeds, so too should a corresponding Create call.
See also
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