Specifies the combine operation used when merging multiple fragment shading rates (pipeline, primitive, attachment).
In Variable Rate Shading, the final shading rate is produced by two sequential combine operations. First, the pipeline rate and primitive rate are combined using the first operation. Then the result is combined with the attachment rate using the second operation. Each operation works component‑wise on the width and height of the shading rate. The final result is clamped to a set of device‑supported rates.
| Keep | Specifies a combiner operation that keeps the first input (A). Equivalent to combine(A,B) = A. |
| Replace | Specifies a combiner operation that replaces with the second input (B). Equivalent to combine(A,B) = B. |
| Min | Specifies a combiner operation component‑wise minimum. Equivalent to combine(A,B) = min(A,B). |
| Max | Specifies a combiner operation component‑wise maximum. Equivalent to combine(A,B) = max(A,B). |
| Mul | Specifies a combiner operation Component‑wise multiplication. Equivalent to combine(A,B) = A * B. (In DirectX 12, specifies a combiner operation addition with clamp. Equivalent to combine(A,B) = min(maxRate, A + B)) |
| Count | The count of ShadingRateCombinerOp. |