SPIR-V Built-In
FrontFacing
Front face determination of a fragment
FrontFacing
Decorating a variable with the FrontFacing built-in decoration will
make that variable contain whether the fragment is front or back facing.
This variable is non-zero if the current fragment is considered to be part
of a front-facing polygon primitive or of a
non-polygon primitive and is zero if the fragment is considered to be part
of a back-facing polygon primitive.
Valid Usage
VUID-FrontFacing-FrontFacing-04229
The FrontFacing decoration must be used only within the
Fragment Execution Model
VUID-FrontFacing-FrontFacing-04230
The variable decorated with FrontFacing must be declared using the
Input Storage Class
VUID-FrontFacing-FrontFacing-04231
The variable decorated with FrontFacing must be declared as a
boolean value