Vulkan: Incorrect default for missing orco

When orcos are not available in the geometry data it is bound with
a default buffer. This buffer was initialized with only zeros. But
orcos required to read the 0, 0, 0, 1.

Fixes `render/shader/tex_voronoi.blend` render test.

Pull Request: https://projects.blender.org/blender/blender/pulls/126838

source/blender/gpu/vulkan/vk_context.cc

@@ -55,13 +55,6 @@ VKContext::~VKContext()
 void VKContext::sync_backbuffer()
 {
   VKDevice &device = VKBackend::get().device;
-  if (ghost_context_) {
-    if (!is_init_) {
-      is_init_ = true;
-      device.init_dummy_buffer(*this);
-    }
-  }
-
   if (ghost_window_) {
     GHOST_VulkanSwapChainData swap_chain_data = {};
     GHOST_GetVulkanSwapChainFormat((GHOST_WindowHandle)ghost_window_, &swap_chain_data);

source/blender/gpu/vulkan/vk_context.hh

@@ -36,8 +36,6 @@ class VKContext : public Context, NonCopyable {
   /* Reusable data. Stored inside context to limit reallocations. */
   render_graph::VKResourceAccessInfo access_info_ = {};
 
-  bool is_init_ = false;
-
   VKThreadData &thread_data_;
 
  public:

source/blender/gpu/vulkan/vk_device.cc

@@ -40,7 +40,7 @@ void VKDevice::deinit()
     return;
   }
 
-  dummy_buffer_.free();
+  dummy_buffer.free();
   samplers_.free();
 
   {
@@ -95,6 +95,7 @@ void VKDevice::init(void *ghost_context)
   init_pipeline_cache();
 
   samplers_.init();
+  init_dummy_buffer();
 
   debug::object_label(vk_handle(), "LogicalDevice");
   debug::object_label(queue_get(), "GenericQueue");
@@ -191,16 +192,16 @@ void VKDevice::init_pipeline_cache()
   vkCreatePipelineCache(vk_device_, &create_info, vk_allocation_callbacks, &vk_pipeline_cache_);
 }
 
-void VKDevice::init_dummy_buffer(VKContext &context)
+void VKDevice::init_dummy_buffer()
 {
-  if (dummy_buffer_.is_allocated()) {
-    return;
-  }
-
-  dummy_buffer_.create(sizeof(float4x4),
-                       GPU_USAGE_DEVICE_ONLY,
-                       VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT);
-  dummy_buffer_.clear(context, 0);
+  dummy_buffer.create(sizeof(float4x4),
+                      GPU_USAGE_DEVICE_ONLY,
+                      VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT);
+  debug::object_label(dummy_buffer.vk_handle(), "DummyBuffer");
+  /* Default dummy buffer. Set the 4th element to 1 to fix missing orcos. */
+  float data[16] = {
+      0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0};
+  dummy_buffer.update(static_cast<void *>(data));
 }
 
 void VKDevice::init_glsl_patch()

source/blender/gpu/vulkan/vk_device.hh

@@ -153,9 +153,6 @@ class VKDevice : public NonCopyable {
   /* Workarounds */
   VKWorkarounds workarounds_;
 
-  /** Buffer to bind to unbound resource locations. */
-  VKBuffer dummy_buffer_;
-
   std::string glsl_patch_;
   Vector<VKThreadData *> thread_data_;
 
@@ -163,6 +160,8 @@ class VKDevice : public NonCopyable {
   render_graph::VKResourceStateTracker resources;
   VKDiscardPool orphaned_data;
   VKPipelinePool pipelines;
+  /** Buffer to bind to unbound resource locations. */
+  VKBuffer dummy_buffer;
 
   /**
    * This struct contains the functions pointer to extension provided functions.
@@ -257,12 +256,6 @@ class VKDevice : public NonCopyable {
 
   bool is_initialized() const;
   void init(void *ghost_context);
-  /**
-   * Initialize a dummy buffer that can be bound for missing attributes.
-   *
-   * Dummy buffer can only be initialized after the command buffer of the context is retrieved.
-   */
-  void init_dummy_buffer(VKContext &context);
   void reinit();
   void deinit();
 
@@ -314,11 +307,6 @@ class VKDevice : public NonCopyable {
   void context_unregister(VKContext &context);
   Span<std::reference_wrapper<VKContext>> contexts_get() const;
 
-  const VKBuffer &dummy_buffer_get() const
-  {
-    return dummy_buffer_;
-  }
-
   void memory_statistics_get(int *r_total_mem_kb, int *r_free_mem_kb) const;
   void debug_print();
 
@@ -337,6 +325,11 @@ class VKDevice : public NonCopyable {
    */
   void init_functions();
 
+  /**
+   * Initialize a dummy buffer that can be bound for missing attributes.
+   */
+  void init_dummy_buffer();
+
   /* During initialization the backend requires access to update the workarounds. */
   friend VKBackend;
 };

source/blender/gpu/vulkan/vk_vertex_attribute_object.cc

@@ -62,7 +62,7 @@ void VKVertexAttributeObject::bind(
   Array<bool> visited_bindings(bindings.size());
   visited_bindings.fill(false);
 
-  const VKBuffer &dummy = VKBackend::get().device.dummy_buffer_get();
+  const VKBuffer &dummy = VKBackend::get().device.dummy_buffer;
   for (VkVertexInputAttributeDescription attribute : attributes) {
     if (visited_bindings[attribute.binding]) {
       continue;