GraphicsV 17 (changes)
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GraphicsV
» GraphicsV 17
Graphics Vector (42)
| Entry | |
|---|---|
| R4 | Bits 0-23: 17 (reason code) |
| Bits 24-31: Driver number |
| Exit | |
|---|---|
| R0 | Pointer to list of pixel formats |
| R1 | Number of formats |
| R4 | 0 |
| - | All other registers preserved |
Use
This call is used to read a full list of the pixel formats supported by the device. This call uses the NColour, ModeFlags and Log2BPP Mode Variable Numbers to describe the supported pixel formats. Each entry in the returned list a is a 3-word structure with the following format:
| Word | Value |
|---|---|
| 0 | NColour value |
| 1 | |
| 2 | Log2BPP value |
Notes
See Valid Mode Variable Combinations for a list of all valid pixel formats currently understood by the OS.
This call should be used in preference to using GraphicsV 8 to read the supported pixel formats. However for backwards compatibility, drivers must ensure that GraphicsV 8 always returns a suitable value; i.e. just a mask of the VIDC20/RISC OS 3.5 compatible pixel formats that the driver supports.
See also
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