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 31:30Bits 29:20Bits 19:10Bits 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 9Bits 8:0

1-bit integer part

9-bit fractional part




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