adjust buffer size and poke stride to make things finally work

src/Mesh.hs

@@ -36,7 +36,8 @@ uploadMesh
   -> m Mesh
 uploadMesh vertices allocator = do
   let bufferCreateInfo = Vk.zero
-        { Vk.size  = fromIntegral $ sizeOf (Vertex (V3 0 0 0) (V3 0 0 0 ) (V4 0 0 0 0))
+        { Vk.size  = fromIntegral $
+          V.length loadMeshes * sizeOf (Vertex (V3 0 0 0) (V3 0 0 0 ) (V4 0 0 0 0))
         , Vk.usage = Vk.BUFFER_USAGE_VERTEX_BUFFER_BIT
         }
       allocationCreateInfo = Vk.zero
@@ -57,7 +58,7 @@ uploadMesh vertices allocator = do
     (\_ -> VMA.unmapMemory allocator (bufferAllocation $ meshBuffer mesh))
 
   liftIO $ mapM_ (\(idx, vertex) ->
-    poke (castPtr (dataPtr `plusPtr` idx)) vertex
+    poke (castPtr (dataPtr `plusPtr` (idx * sizeOf vertex))) vertex
     )
     (zip [0..] (V.toList vertices))