VideoOverlay_Vet (changes)
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VideoOverlay
» SWI Calls
» VideoOverlay_Vet
VideoOverlay_Vet
(SWI &59CC6)
| 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 | Task handle |
| Exit | |
|---|---|
| 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 | Maximum width overlay can be scaled to |
| R5 | 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.
The ability for a driver to create an overlay may be influenced by the current screen mode, how much video memory is free, and the properties of any other overlays that may currently be in use. Therefore Therefore, the results of this call may be invalidated if any of those influencing factors change.
See also
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