This step modifies fragment coverage values based on the values in the
pSampleMask array member of
VkPipelineMultisampleStateCreateInfo, as described previously in
section Section 9.2, “Graphics Pipelines”.
pSampleMask contains an array of static coverage information that is
ANDed with the coverage information generated during rasterization.
Bits that are zero disable coverage for the corresponding sample.
Bit B of mask word M corresponds to sample 32 × M
+ B.
The array is sized to a length of ⌈ rasterizationSamples /
32 ⌉ words.
If pSampleMask is NULL, it is treated as if the mask has all bits
enabled, i.e. no coverage is removed from fragments.
The elements of the sample mask array are of type VkSampleMask,
each representing 32 bits of coverage information:
typedef uint32_t VkSampleMask;