docs/core_checks.md

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[![Khronos Vulkan][1]][2]

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[2]: https://www.khronos.org/vulkan/

# Core Validation Checks

Implemented as part of the `VK_LAYER_KHRONOS_validation` layer,  this validation object is responsible for validating
the status of descriptor sets, command buffers, shader modules, pipeline states, renderpass usage, synchronization,
dynamic states, and many other types of valid usage. It is the main module responsible for validation requiring
substantial background state.

This module validates that:

- the descriptor set state and pipeline state at each draw call are consistent
- pipelines are created correctly, known when used and bound at draw time
- descriptor sets are known and consist of valid types, formats, and layout
- descriptor set regions are valid, bound, and updated appropriately
- command buffers referenced are known and valid
- command sequencing for specific state dependencies and renderpass use is correct
- memory is available
- dynamic state is correctly set.

This validation object will print errors if validation checks are not correctly met, and provide context related to
the failures.

## Memory/Resource related functionality

This validation additionally attempts to ensure that memory objects are managed correctly by the application.
These memory objects may be bound to pipelines, objects, and command buffers, and then submitted to the GPU
for work. Specifically the layer validates that:

- the correct memory objects have been bound
- memory objects are specified correctly upon command buffer submittal
- only existing memory objects are referenced
- destroyed memory objects are not referenced
- the application has confirmed any memory objects to be reused or destroyed have been properly unbound
- checks texture formats and render target formats.

Errors will be printed if validation checks are not correctly met and warnings if improper (but not illegal) use of
memory is detected.  Validation also dumps all memory references and bindings for each operation.

## Swapchain validation functionality

This area of functionality validates the use of the WSI (Window System Integration) "swapchain" extensions (e.g., `VK_EXT_KHR_swapchain` and `VK_EXT_KHR_device_swapchain`).