Fix some robustness issues in the examples (#5984)

* examples: Make hello-world example exit gracefully if VK cannot be initialized

- Check if VK API function pointers are valid before using them
- Return 0 and exit if VK initialization fails
- Enable hello-world example

* examples: Fixes for ray-tracing examples

- Assert that accelleration structure buffer is not nullptr
- Check if buffer creation succeeded before proceeding
 - This makes initialization not hang, but it still fails.
   Therefore, the test expectations are just updated to point to another issue.
- Enable ray-tracing tests on Windows

1 files changed, 8 insertions, 1 deletions

diff --git a/examples/hello-world/main.cpp b/examples/hello-world/main.cpp
index 7e84d83e5..7e4211b12 100644
--- a/examples/hello-world/main.cpp
+++ b/examples/hello-world/main.cpp
@@ -80,7 +80,11 @@ int main(int argc, char* argv[])
 
 int HelloWorldExample::run()
 {
-    RETURN_ON_FAIL(initVulkanInstanceAndDevice());
+    // If VK failed to initialize, skip running but return success anyway.
+    // This allows our automated testing to distinguish between essential failures and the
+    // case where the application is just not supported.
+    if (int result = initVulkanInstanceAndDevice())
+        return (vkAPI.device == VK_NULL_HANDLE) ? 0 : result;
     RETURN_ON_FAIL(createComputePipelineFromShader());
     RETURN_ON_FAIL(createInOutBuffers());
     RETURN_ON_FAIL(dispatchCompute());
@@ -511,6 +515,9 @@ int HelloWorldExample::printComputeResults()
 
 HelloWorldExample::~HelloWorldExample()
 {
+    if (vkAPI.device == VK_NULL_HANDLE)
+        return;
+
     vkAPI.vkDestroyPipeline(vkAPI.device, pipeline, nullptr);
     for (int i = 0; i < 3; i++)
     {