PointCoord
PointCoord
Decorating a variable with the PointCoord
built-in decoration will make
that variable contain the coordinate of the current fragment within the
point being rasterized, normalized to the size of the point with origin in
the upper left corner of the point, as described in
Basic Point Rasterization.
If the primitive the fragment shader invocation belongs to is not a point,
then the variable decorated with PointCoord
contains an undefined:
value.
Depending on how the point is rasterized, PointCoord
may never reach
(0,0) or (1,1).
Valid Usage
VUID-PointCoord-PointCoord-04311
The PointCoord
decoration must be used only within the
Fragment
Execution
Model
VUID-PointCoord-PointCoord-04312
The variable decorated with PointCoord
must be declared using the
Input
Storage
Class
VUID-PointCoord-PointCoord-04313
The variable decorated with PointCoord
must be declared as a
two-component vector of 32-bit floating-point values