add array index to descriptor struct

vulkan.d

@@ -232,16 +232,18 @@ struct Buffer
 
 struct Descriptor
 {
+	union
+	{
+		Buffer     buf;
+		Image      image;
+		ImageView  view;
+		BufferView buf_view;
+		VkSampler  sampler;
+	}
   DescType     type;
   u32          binding;
-  union
-  {
-    Buffer     buf;
-    Image      image;
-    ImageView  view;
-    BufferView buf_view;
-    VkSampler  sampler;
-  }
+	u32          index;
+	bool         array_elem;
 }
 
 enum MipmapMode : VkSamplerMipmapMode
@@ -2021,6 +2023,11 @@ PrepareWrite(Vulkan* vk, VkWriteDescriptorSet* write, DescSet set, Descriptor* d
   write.dstBinding      = desc.binding;
   write.descriptorCount = 1;
 
+	if(desc.array_elem)
+	{
+		write.dstArrayElement = desc.index;
+	}
+
   switch(desc.type) with(DescType)
   {
     case Image, StorageImage, InputAttach:
@@ -2038,7 +2045,7 @@ PrepareWrite(Vulkan* vk, VkWriteDescriptorSet* write, DescSet set, Descriptor* d
         info.buffer       = desc.buf.buffer;
         info.offset       = cast(VkDeviceSize)0;
         info.range        = cast(VkDeviceSize)desc.buf.size;
-        write.pBufferInfo = info;
+				write.pBufferInfo = info;
       } break;
     case UniformTexelBuf, StorageTexelBuf:
       {