Reduce usage of local buffer in GEVulkanDrawCall

lib/graphics_engine/src/ge_vulkan_draw_call.cpp

@@ -1024,15 +1024,20 @@ void GEVulkanDrawCall::createVulkanData()
         flags |= VK_BUFFER_USAGE_INDIRECT_BUFFER_BIT;
         extra_size = 200 * sizeof(VkDrawIndexedIndirectCommand);
     }
+    // Use VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT | VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
+    // or a staging buffer when buffer is small
     m_dynamic_data = new GEVulkanDynamicBuffer(flags,
         extra_size + sizeof(GEVulkanCameraUBO),
         GEVulkanDriver::getMaxFrameInFlight(),
+        GEVulkanDynamicBuffer::supportsHostTransfer() ? 0 :
         GEVulkanDriver::getMaxFrameInFlight());
 
     flags = VK_BUFFER_USAGE_STORAGE_BUFFER_BIT;
+    // Using VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT | VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT
+    // will be a lot slower when there are many objects (like particles)
     m_sbo_data = new GEVulkanDynamicBuffer(flags, getInitialSBOSize(),
-        GEVulkanDriver::getMaxFrameInFlight(),
+        GEVulkanDriver::getMaxFrameInFlight(), 0,
-        GEVulkanDriver::getMaxFrameInFlight());
+        false/*enable_host_transfer*/);
 }   // createVulkanData
 
 // ----------------------------------------------------------------------------

lib/graphics_engine/src/ge_vulkan_dynamic_buffer.cpp

@@ -14,9 +14,11 @@ int GEVulkanDynamicBuffer::m_supports_host_transfer = -1;
 GEVulkanDynamicBuffer::GEVulkanDynamicBuffer(VkBufferUsageFlags usage,
                                              size_t initial_size,
                                              unsigned host_buffer_size,
-                                             unsigned local_buffer_size)
+                                             unsigned local_buffer_size,
+                                             bool enable_host_transfer)
+                     : m_usage(usage),
+                       m_enable_host_transfer(enable_host_transfer)
 {
-    m_usage = usage;
     m_size = m_real_size = initial_size;
 
     m_host_buffer.resize(host_buffer_size, VK_NULL_HANDLE);
@@ -51,8 +53,9 @@ start:
     host_info.flags = VMA_ALLOCATION_CREATE_HOST_ACCESS_SEQUENTIAL_WRITE_BIT |
         VMA_ALLOCATION_CREATE_MAPPED_BIT;
     host_info.preferredFlags = VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
-    if ((with_transfer && m_supports_host_transfer == 1) ||
+    if (((with_transfer && m_supports_host_transfer == 1) ||
-        (with_transfer && m_supports_host_transfer == -1))
+        (with_transfer && m_supports_host_transfer == -1)) &&
+        m_enable_host_transfer)
     {
         host_info.flags |=
             VMA_ALLOCATION_CREATE_HOST_ACCESS_ALLOW_TRANSFER_INSTEAD_BIT;
@@ -66,7 +69,8 @@ start:
         return;
     }
 
-    if (with_transfer && m_supports_host_transfer == -1)
+    if (with_transfer && m_enable_host_transfer &&
+        m_supports_host_transfer == -1)
     {
         vmaGetAllocationMemoryProperties(vk->getVmaAllocator(), host_memory,
             &prop);

lib/graphics_engine/src/ge_vulkan_dynamic_buffer.hpp

@@ -19,10 +19,12 @@ private:
 
     std::vector<void*> m_mapped_addr;
 
-    VkBufferUsageFlags m_usage;
-
     size_t m_size, m_real_size;
 
+    const VkBufferUsageFlags m_usage;
+
+    const bool m_enable_host_transfer;
+
     static int m_supports_host_transfer;
     // ------------------------------------------------------------------------
     void initHostBuffer(unsigned frame, bool with_transfer);
@@ -34,7 +36,8 @@ public:
     // ------------------------------------------------------------------------
     GEVulkanDynamicBuffer(VkBufferUsageFlags usage, size_t initial_size,
                           unsigned host_buffer_size,
-                          unsigned local_buffer_size);
+                          unsigned local_buffer_size,
+                          bool enable_host_transfer = true);
     // ------------------------------------------------------------------------
     ~GEVulkanDynamicBuffer();
     // ------------------------------------------------------------------------
@@ -60,6 +63,12 @@ public:
     std::vector<VmaAllocation>& getLocalMemory()     { return m_local_memory; }
     // ------------------------------------------------------------------------
     std::vector<void*>& getMappedAddr()               { return m_mapped_addr; }
+    // ------------------------------------------------------------------------
+    /** This can only be called after creating an instance with
+     *  local_buffer_size == 0 first, which is always done in
+     *  GEVulkan2dRenderer::createTrisBuffers. */
+    static bool supportsHostTransfer()
+                                      { return m_supports_host_transfer == 1; }
 
 };   // GEVulkanDynamicBuffer