Q about an order of querying for physical device surface capabilities and the swap chain extension support

[valignatev]

Hi! In the Vulkan Tutorial, there is a note that It is important that we only try to query for swap chain support after verifying that the extension is available., in this section: https://vulkan-tutorial.com/Drawing_a_triangle/Presentation/Swap_chain#page_Querying-details-of-swap-chain-support

While I get that querying for the surface capabilities is kinda pointless if swap chain isn’t supported, I failed to find an explicit rule about the order of these operations in the spec. Maybe I got lost in the spec and overlooked the explanation of why it’s that important? What could happen if we check surface capabilities first, and query for swap chain support after?

[krOoze]

Do not crosspost, and see answer at https://www.reddit.com/r/vulkan/comments/dmu7vd/q_about_an_order_of_querying_for_physical_device/

[valignatev]

Is this still a cross-posting if the question is in a completely different place?

But I get your point though, and thanks a lot for the answer. I’ll paste it here anyway, so people don’t have to click around:
Here’s the part of the spec that could be violated: Vulkan® 1.1.243 - A Specification (with all registered Vulkan extensions)

“Applications must not use a VkPhysicalDevice in any command added by an extension or core version that is not supported by that physical device.”