HAL_Video_ReadPaletteEntry
Hardware Abstraction Layer
HAL entry points from RISC OS
ยป HAL_Video_ReadPaletteEntry
HAL_Video_ReadPaletteEntry
(HAL entry #42)
uint HAL_Video_ReadPaletteEntry(uint type, uint pcolour, uint index)
| Entry | |
|---|---|
| type | 0 for normal palette entry |
| 1 for border colour | |
| 2 for pointer colour | |
| >=3 reserved | |
| pcolours | Palette to block of palette entry colours in BBGGRRSS format (Blue,Green,Red,Supremacy) |
| index | Index of entry |
| Exit | |
|---|---|
| - | Returns effective BBGGRRSS |
Use
This is an internal call for OS use only and should not be used by user software. User software should use GraphicsV instead of interacting with the HAL directly.
Returns the effective palette entry after taking into account any hardware restrictions in the video controller, assuming it was originally programmed with the value pcolour.
Indices are in the range 0..255 for normal, 0 for border, 0..3 for pointer colours. Note that RISC OS only makes calls using 1..3 for the pointer, and pointer colour 0 is assumed to be transparent.
Depending on hardware capabilities, HALs may have to remember current settings (eg. bits per pixel) or keep soft copies of entries. Because this call supplies the original pcolour, this need is minimised (some HALs can just return pcolour or a directly modified pcolour).