vkGetQueryPoolResults

To retrieve status and results for a set of queries, call:

VkResult vkGetQueryPoolResults(
    VkDevice device,
    VkQueryPool queryPool,
    uint32_t firstQuery,
    uint32_t queryCount,
    size_t dataSize,
    void* pData,
    VkDeviceSize stride,
    VkQueryResultFlags flags);

• device is the logical device that owns the query pool.
• queryPool is the query pool managing the queries containing the desired results.
• firstQuery is the initial query index.
• queryCount is the number of queries to read.
• dataSize is the size in bytes of the buffer pointed to by pData.
• pData is a pointer to an application-allocated buffer where the results will be written
• stride is the stride in bytes between results for individual queries within pData.
• flags is a bitmask of VkQueryResultFlagBits specifying how and when results are returned.

Any results written for a query are written according to a layout dependent on the query type.

If no bits are set in flags, and all requested queries are in the available state, results are written as an array of 32-bit unsigned integer values. Behavior when not all queries are available is described below.

If VK_QUERY_RESULT_WITH_AVAILABILITY_BIT is set, results for all queries in queryPool identified by firstQuery and queryCount are copied to pData, along with an extra availability or status value written directly after the results of each query and interpreted as an unsigned integer. A value of zero indicates that the results are not yet available, otherwise the query is complete and results are available. The size of the availability or status values is 64 bits if VK_QUERY_RESULT_64_BIT is set in flags. Otherwise, it is 32 bits.

If VK_QUERY_RESULT_WITH_STATUS_BIT_KHR is set, results for all queries in queryPool identified by firstQuery and queryCount are copied to pData, along with an extra status value written directly after the results of each query and interpreted as a signed integer. A value of zero indicates that the results are not yet available. Positive values indicate that the operations within the query completed successfully, and the query results are valid. Negative values indicate that the operations within the query completed unsuccessfully.

VkQueryResultStatusKHR defines specific meaning for values returned here, though implementations are free to return other values.

If the status value written is negative, indicating that the operations within the query completed unsuccessfully, then all other results written by this command are undefined: unless otherwise specified for any of the results of the used query type.

Results for any available query written by this command are final and represent the final result of the query. If VK_QUERY_RESULT_PARTIAL_BIT is set, then for any query that is unavailable, an intermediate result between zero and the final result value is written for that query. Otherwise, any result written by this command is undefined:.

If VK_QUERY_RESULT_64_BIT is set, results and, if returned, availability or status values for all queries are written as an array of 64-bit values. If the queryPool was created with VK_QUERY_TYPE_PERFORMANCE_QUERY_KHR, results for each query are written as an array of the type indicated by VkPerformanceCounterKHR::storage for the counter being queried. Otherwise, results and availability or status values are written as an array of 32-bit values. If an unsigned integer query’s value overflows the result type, the value may either wrap or saturate. If the maintenance7 feature is enabled, for an unsigned integer query, the 32-bit result value must be equal to the 32 least significant bits of the equivalent 64-bit result value. If a signed integer query’s value overflows the result type, the value is undefined:. If a floating-point query’s value is not representable as the result type, the value is undefined:.

If VK_QUERY_RESULT_WAIT_BIT is set, this command defines an execution dependency with any earlier commands that writes one of the identified queries. The first synchronization scope includes all instances of vkCmdEndQuery, vkCmdEndQueryIndexedEXT, vkCmdWriteTimestamp2, and vkCmdWriteTimestamp that reference any query in queryPool indicated by firstQuery and queryCount. The second synchronization scope includes the host operations of this command.

If VK_QUERY_RESULT_WAIT_BIT is not set, vkGetQueryPoolResultsmay return VK_NOT_READY if there are queries in the unavailable state.

If `VK_QUERY_RESULT_WITH_AVAILABILITY_BIT` is set, `stride`
:normative{type="must"} be large enough to contain the unsigned integer representing
availability