Allow SDL GPU to opt into additional Vulkan features

include/SDL3/SDL_hints.h

@@ -4080,6 +4080,16 @@ extern "C" {
  */
 #define SDL_HINT_VULKAN_LIBRARY "SDL_VULKAN_LIBRARY"
 
+/**
+ * Specify the Vulkan API version to create the instance with.
+ *
+ * This hint should be set before creating a Vulkan window. Expects a
+ * version string delimited by underscores. E.g. 1_0_0 or 1_3_0
+ *
+ * \since This hint is available since SDL 3.xx.
+ */
+#define SDL_HINT_VULKAN_REQUEST_API_VERSION "SDL_VULKAN_REQUEST_API_VERSION"
+
 /**
  * A variable controlling how the fact chunk affects the loading of a WAVE
  * file.

src/gpu/vulkan/SDL_gpu_vulkan.c

@@ -11205,6 +11205,22 @@ static Uint8 VULKAN_INTERNAL_CreateInstance(VulkanRenderer *renderer)
     appInfo.pEngineName = "SDLGPU";
     appInfo.engineVersion = SDL_VERSION;
     appInfo.apiVersion = VK_MAKE_VERSION(1, 0, 0);
+    const char *hint = SDL_GetHint(SDL_HINT_VULKAN_REQUEST_API_VERSION);
+    if (hint) {
+        char *text = SDL_strdup(hint);
+        int numFound = 0;
+        int version[3] = { 0, 0, 0 };
+        char *saveptr = NULL;
+        char *token = SDL_strtok_r(text, "_", &saveptr);
+        while (token != NULL && numFound < 3) {
+            version[numFound] = SDL_atoi(token);
+            numFound++;
+            token = SDL_strtok_r(NULL, "_", &saveptr);
+        }
+
+        appInfo.apiVersion = VK_MAKE_VERSION(version[0], version[1], version[2]);
+        SDL_free(text);
+    }
 
     createFlags = 0;