VULKAN Staging buffer example

glararan

Hi,

I would like to use staging buffer to get better performance. My intent is to render terrain. My issue is that I dont see rendered vertices using indices method.

I use this hierarchy

MainWindow : QMainWindow
- MapView : QVulkanWindow
  - MapViewRenderer : QVulkanWindowRenderer
    - World
      - MapTile (here I perform draw calls for terrain rendering)

For now I use this code to create Vertex & Indices buffer via Staging buffers

        VK_CHECK_RESULT(vkManager.createBuffer(VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, vertexBufferSize, &vertexStaging.buffer, &vertexStaging.memory, verticesList.data()));
        VK_CHECK_RESULT(vkManager.createBuffer(VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, indexBufferSize, &indexStaging.buffer, &indexStaging.memory, indices.data()));
	VK_CHECK_RESULT(vkManager.createBuffer(VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, vertexBufferSize, &model.vertices.buffer, &model.vertices.memory));
	VK_CHECK_RESULT(vkManager.createBuffer(VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, indexBufferSize, &model.indices.buffer, &model.indices.memory));

	// Copy from staging buffers
        VkCommandBuffer copyCommandBuffer = vkManager.createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);

	VkBufferCopy copyRegion = {};

	copyRegion.size = vertexBufferSize;

	vkManager.deviceFuncs->vkCmdCopyBuffer(copyCommandBuffer, vertexStaging.buffer, model.vertices.buffer, 1, &copyRegion);

	copyRegion.size = indexBufferSize;

	vkManager.deviceFuncs->vkCmdCopyBuffer(copyCommandBuffer, indexStaging.buffer, model.indices.buffer, 1, &copyRegion);

    vkManager.flushCommandBuffer(copyCommandBuffer, true);

I am creating my own Command Buffer but I dont know if that's correct design for QVulkanWindowRenderer. In all examples I dont see own command buffer creation. Should I use QVulkanWindow currentCommandBuffer() ? I couldn't find any github project using Qt 5.11 with Vulkan :/

Source code is available here

glararan

Now I am getting

QVulkanWindow: Device lost
qt.vulkan: Releasing all resources due to device lost
qt.vulkan: Releasing swapchain

What could lead to this? If I comment out this code it works.

deviceFuncs->vkCmdDrawIndexed(commandBuffer, model.indexCount, 1, 0, 0, 0);

Can I somehow enable logging? Or debug it, why it crash?

glararan

I found solution.. I was setting wrong
VkPipelineMultisampleStateCreateInfo instead QVulkanWindow::getSampleCountFlagBits() I used VK_SAMPLE_COUNT_1_BIT