Added SDL_HINT_VULKAN_DISPLAY

include/SDL3/SDL_hints.h

@@ -3373,6 +3373,17 @@ extern "C" {
  */
 #define SDL_HINT_VITA_TOUCH_MOUSE_DEVICE    "SDL_VITA_TOUCH_MOUSE_DEVICE"
 
+/**
+ * A variable overriding the display index used in SDL_Vulkan_CreateSurface()
+ *
+ * The display index starts at 0, which is the default.
+ *
+ * This hint should be set before calling SDL_Vulkan_CreateSurface()
+ *
+ * \since This hint is available since SDL 3.0.0.
+ */
+#define SDL_HINT_VULKAN_DISPLAY "SDL_VULKAN_DISPLAY"
+
 /**
  * Specify the Vulkan library to load.
  *

src/video/SDL_vulkan_utils.c

@@ -209,7 +209,7 @@ int SDL_Vulkan_Display_CreateSurface(void *vkGetInstanceProcAddr_,
         SDL_SetError(VK_KHR_DISPLAY_EXTENSION_NAME " extension is not enabled in the Vulkan instance.");
         goto error;
     }
-    chosenDisplayId = SDL_getenv("SDL_VULKAN_DISPLAY");
+    chosenDisplayId = SDL_GetHint(SDL_HINT_VULKAN_DISPLAY);
     if (chosenDisplayId) {
         displayId = SDL_atoi(chosenDisplayId);
     }