A bit more refactoring to expose the begin/end transactional nature.

vk_descriptors.cpp

@@ -2,7 +2,6 @@
 
 void DescriptorLayoutBuilder::add_binding(uint32_t binding, VkDescriptorType type)
 {
-
   VkDescriptorSetLayoutBinding newbind{
     .binding = binding,
       .descriptorType = type,

vk_engine.cpp

@@ -71,8 +71,7 @@ void VulkanEngine::cleanup()
   loadedEngine = nullptr;
 }
 
-void VulkanEngine::draw()
+Transaction VulkanEngine::begin_transaction() {
-{
   // ZED: begin command transaction
   // wait until the gpu has finished rendering the last frame. Timeout of 1 second
   VK_CHECK(vkWaitForFences(_device, 1, &get_current_frame()._renderFence, true, 1000000000));
@@ -90,59 +89,17 @@ void VulkanEngine::draw()
 
   VK_CHECK(vkBeginCommandBuffer(cmd, &cmdBeginInfo));
 
+  return {cmd, swapchainImageIndex};
+}
 
-
+void VulkanEngine::commit_transaction(Transaction& t) {
-
+  VK_CHECK(vkEndCommandBuffer(t.cmd));
-
-
-  // ZED: draw the things
-  _drawExtent.width = _drawImage.imageExtent.width;
-  _drawExtent.height = _drawImage.imageExtent.height;
-
-  // transition our main draw image into general layout so we can write into it
-  // we will overwrite it all so we dont care about what was the older layout
-  vkutil::transition_image(cmd, _drawImage.image, VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_GENERAL);
-
-  draw_background(cmd);
-
-  // ZED: ?
-  vkutil::transition_image(cmd, _drawImage.image, VK_IMAGE_LAYOUT_GENERAL, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);
-
-
-
-
-  // ZED: ?
-  vkutil::transition_image(cmd, _swapchainImages[swapchainImageIndex], VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
-
-  vkutil::copy_image_to_image(cmd, _drawImage.image,
-      _swapchainImages[swapchainImageIndex],
-      _drawExtent, _swapchainExtent);
-
-
-
-  // ZED: ?
-  vkutil::transition_image(cmd, _swapchainImages[swapchainImageIndex], VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
-
-  _gui.draw_imgui(_swapchainExtent, cmd,  _swapchainImageViews[swapchainImageIndex]);
-  // ZED: end drawing the things
-
-
-
-
-
-
-  // ZED: finalize image and commit command buffer
-  vkutil::transition_image(cmd, _swapchainImages[swapchainImageIndex], VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_PRESENT_SRC_KHR);
-
-  VK_CHECK(vkEndCommandBuffer(cmd));
-
-
 
   // ZED: submit command to queue
   //prepare the submission to the queue.
   //we want to wait on the _presentSemaphore, as that semaphore is signaled when the swapchain is ready
   //we will signal the _renderSemaphore, to signal that rendering has finished
-  VkCommandBufferSubmitInfo cmdinfo = vkinit::command_buffer_submit_info(cmd);
+  VkCommandBufferSubmitInfo cmdinfo = vkinit::command_buffer_submit_info(t.cmd);
 
   VkSemaphoreSubmitInfo waitInfo = vkinit::semaphore_submit_info(VK_PIPELINE_STAGE_2_COLOR_ATTACHMENT_OUTPUT_BIT_KHR,get_current_frame()._swapchainSemaphore);
   VkSemaphoreSubmitInfo signalInfo = vkinit::semaphore_submit_info(VK_PIPELINE_STAGE_2_ALL_GRAPHICS_BIT, get_current_frame()._renderSemaphore);
@@ -164,7 +121,7 @@ void VulkanEngine::draw()
     .pWaitSemaphores = &get_current_frame()._renderSemaphore,
     .swapchainCount = 1,
     .pSwapchains = &_swapchain,
-    .pImageIndices = &swapchainImageIndex,
+    .pImageIndices = &t.swapchainImageIndex,
   };
 
   VK_CHECK(vkQueuePresentKHR(_graphicsQueue, &presentInfo));
@@ -173,6 +130,44 @@ void VulkanEngine::draw()
   _frameNumber++;
 }
 
+void VulkanEngine::draw()
+{
+  auto t = begin_transaction();
+
+  // ZED: draw the things
+  _drawExtent.width = _drawImage.imageExtent.width;
+  _drawExtent.height = _drawImage.imageExtent.height;
+
+  // transition our main draw image into general layout so we can write into it
+  // we will overwrite it all so we dont care about what was the older layout
+  vkutil::transition_image(t.cmd, _drawImage.image, VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_GENERAL);
+
+  draw_background(t.cmd);
+
+  // ZED: ?
+  vkutil::transition_image(t.cmd, _drawImage.image, VK_IMAGE_LAYOUT_GENERAL,
+      VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);
+
+  // ZED: ?
+  vkutil::transition_image(t.cmd, _swapchainImages[t.swapchainImageIndex],
+      VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
+
+  vkutil::copy_image_to_image(t.cmd, _drawImage.image,
+      _swapchainImages[t.swapchainImageIndex],
+      _drawExtent, _swapchainExtent);
+
+  // ZED: ?
+  vkutil::transition_image(t.cmd, _swapchainImages[t.swapchainImageIndex], VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
+
+  _gui.draw_imgui(_swapchainExtent, t.cmd,  _swapchainImageViews[t.swapchainImageIndex]);
+  // ZED: end drawing the things
+
+  // ZED: finalize image and commit command buffer
+  vkutil::transition_image(t.cmd, _swapchainImages[t.swapchainImageIndex], VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_IMAGE_LAYOUT_PRESENT_SRC_KHR);
+
+  commit_transaction(t);
+}
+
 void VulkanEngine::run()
 {
   //main loop
@@ -393,7 +388,7 @@ void VulkanEngine::init_descriptors() {
     { VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1 }
   };
 
-  globalDescriptorAllocator.init_pool(_device, 10, sizes);
+  _globalDescriptorAllocator.init_pool(_device, 10, sizes);
 
   // make the descriptor set layout for our compute draw
   {
@@ -404,14 +399,14 @@ void VulkanEngine::init_descriptors() {
 
   // other code
   //allocate a descriptor set for our draw image
-  _drawImageDescriptors = globalDescriptorAllocator.allocate(_device,_drawImageDescriptorLayout);
+  _drawImageDescriptors = _globalDescriptorAllocator.allocate(_device,_drawImageDescriptorLayout);
 
   VkDescriptorImageInfo imgInfo{
     .imageView = _drawImage.imageView,
     .imageLayout = VK_IMAGE_LAYOUT_GENERAL,
   };
   
-  VkWriteDescriptorSet drawImageWrite = {
+  VkWriteDescriptorSet drawImageWrite{
     .sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET,
     .dstSet = _drawImageDescriptors,
     .dstBinding = 0,
@@ -424,7 +419,7 @@ void VulkanEngine::init_descriptors() {
 
   //make sure both the descriptor allocator and the new layout get cleaned up properly
   _mainDeletionQueue.push_function([&]() {
-      globalDescriptorAllocator.destroy_pool(_device);
+      _globalDescriptorAllocator.destroy_pool(_device);
 
       vkDestroyDescriptorSetLayout(_device, _drawImageDescriptorLayout, nullptr);
     });

vk_engine.h

@@ -7,6 +7,11 @@
 #include <vk_descriptors.h>
 #include "vk_gui.h"
 
+struct Transaction {
+  VkCommandBuffer cmd;
+  uint32_t swapchainImageIndex = 0;
+};
+
 struct DeletionQueue {
   std::deque<std::function<void()>> deletors;
 
@@ -42,7 +47,7 @@ public:
   VkPipeline _gradientPipeline;
   VkPipelineLayout _gradientPipelineLayout;
 
-  DescriptorAllocator globalDescriptorAllocator;
+  DescriptorAllocator _globalDescriptorAllocator;
   VkDescriptorSet _drawImageDescriptors;
   VkDescriptorSetLayout _drawImageDescriptorLayout;
 
@@ -108,6 +113,9 @@ public:
 
   void immediate_submit(std::function<void(VkCommandBuffer cmd)>&& function);
 
+  Transaction begin_transaction();
+  void commit_transaction(Transaction& cmd);
+
 private:
   void init_vulkan();
   void init_swapchain();