VkFragmentShadingRateCombinerOpKHR

The equation used for each combiner operation is defined by VkFragmentShadingRateCombinerOpKHR:

typedef enum VkFragmentShadingRateCombinerOpKHR {
    VK_FRAGMENT_SHADING_RATE_COMBINER_OP_KEEP_KHR = 0,
    VK_FRAGMENT_SHADING_RATE_COMBINER_OP_REPLACE_KHR = 1,
    VK_FRAGMENT_SHADING_RATE_COMBINER_OP_MIN_KHR = 2,
    VK_FRAGMENT_SHADING_RATE_COMBINER_OP_MAX_KHR = 3,
    VK_FRAGMENT_SHADING_RATE_COMBINER_OP_MUL_KHR = 4,
} VkFragmentShadingRateCombinerOpKHR;

• VK_FRAGMENT_SHADING_RATE_COMBINER_OP_KEEP_KHR specifies a combiner operation of combine(A_xy,B_xy) = A_xy.
• VK_FRAGMENT_SHADING_RATE_COMBINER_OP_REPLACE_KHR specifies a combiner operation of combine(A_xy,B_xy) = B_xy.
• VK_FRAGMENT_SHADING_RATE_COMBINER_OP_MIN_KHR specifies a combiner operation of combine(A_xy,B_xy) = min(A_xy,B_xy).
• VK_FRAGMENT_SHADING_RATE_COMBINER_OP_MAX_KHR specifies a combiner operation of combine(A_xy,B_xy) = max(A_xy,B_xy).
• VK_FRAGMENT_SHADING_RATE_COMBINER_OP_MUL_KHR specifies a combiner operation of combine(A_xy,B_xy) = A_xy*B_xy.

where combine(A_xy,B_xy) is the combine operation, and A_xy and B_xy are the inputs to the operation.

If fragmentShadingRateStrictMultiplyCombiner is VK_FALSE, using VK_FRAGMENT_SHADING_RATE_COMBINER_OP_MUL_KHR with values of 1 for both A and B in the same dimension results in the value 2 being produced for that dimension. See the definition of fragmentShadingRateStrictMultiplyCombiner for more information.

These operations are performed in a component-wise fashion.