ClipDistance
ClipDistance
Decorating a variable with the ClipDistance built-in decoration will
make that variable contain the mechanism for controlling user clipping.
ClipDistance is an array such that the ith element of the array
specifies the clip distance for plane i.
A clip distance of 0 means the vertex is on the plane, a positive distance
means the vertex is inside the clip half-space, and a negative distance
means the vertex is outside the clip half-space.
The array variable decorated with ClipDistance is explicitly sized by
the shader.
In the last pre-rasterization
shader stage, these values will be linearly interpolated across the
primitive and the portion of the primitive with interpolated distances less
than 0 will be considered outside the clip volume.
If ClipDistance is then used by a fragment shader, ClipDistance
contains these linearly interpolated values.
Valid Usage
VUID-ClipDistance-ClipDistance-04187
The ClipDistance decoration must be used only within the
MeshEXT, MeshNV, Vertex, Fragment,
TessellationControl, TessellationEvaluation, or Geometry
Execution Model
VUID-ClipDistance-ClipDistance-04188
The variable decorated with ClipDistance within the MeshEXT,
MeshNV, or Vertex Execution Model must be declared using the
Output Storage Class
VUID-ClipDistance-ClipDistance-04189
The variable decorated with ClipDistance within the Fragment
Execution Model must be declared using the Input Storage Class
VUID-ClipDistance-ClipDistance-04190
The variable decorated with ClipDistance within the
TessellationControl, TessellationEvaluation, or Geometry
Execution Model must not be declared in a Storage Class other than
Input or Output
VUID-ClipDistance-ClipDistance-04191
The variable decorated with ClipDistance must be declared as an
array of 32-bit floating-point values