XR Layout
This section applies only to Windows 7 and later operating systems.
XR is a fixed-point 1.9 format. The value is biased by -0.5, which results in a dynamic range of approximately [-0.5,1.5]. The fixed point representation implies a scale of 2x to shift the decimal point one place to the right.
Each XR element occupies one 32-bit DWORD, which is laid out as shown in the following table regardless of host CPU endianness.
| Bits 31:30 | Bits 29:20 | Bits 19:10 | Bits 9:0 |
|---|---|---|---|
Alpha channel |
Blue channel |
Green channel |
Red channel |
Each of the red, green and blue channels is laid out as shown in the following table.
| Bit 9 | Bits 8:0 |
|---|---|
1-bit integer part |
9-bit fractional part |