.. _program_listing_file_Src_GraphicsEngineVulkan_common_ImageLayoutHelper.hpp:

Program Listing for File ImageLayoutHelper.hpp
==============================================

|exhale_lsh| :ref:`Return to documentation for file <file_Src_GraphicsEngineVulkan_common_ImageLayoutHelper.hpp>` (``Src/GraphicsEngineVulkan/common/ImageLayoutHelper.hpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #pragma once
   
   #include <vulkan/vulkan.hpp>
   
   namespace Kataglyphis {
   
   // Access mask a layout transition's src/dst side needs for the given layout.
   // Shared by every image-layout transition in the engine so there is exactly
   // one place that answers "what access does this layout imply".
   constexpr vk::AccessFlags accessFlagsForImageLayout(vk::ImageLayout layout)
   {
       switch (layout) {
       case vk::ImageLayout::ePreinitialized:
           return vk::AccessFlagBits::eHostWrite;
       case vk::ImageLayout::eTransferDstOptimal:
           return vk::AccessFlagBits::eTransferWrite;
       case vk::ImageLayout::eTransferSrcOptimal:
           return vk::AccessFlagBits::eTransferRead;
       case vk::ImageLayout::eColorAttachmentOptimal:
           return vk::AccessFlagBits::eColorAttachmentWrite;
       case vk::ImageLayout::eDepthStencilAttachmentOptimal:
           return vk::AccessFlagBits::eDepthStencilAttachmentWrite;
       case vk::ImageLayout::eShaderReadOnlyOptimal:
           return vk::AccessFlagBits::eShaderRead;
       case vk::ImageLayout::eGeneral:
           return vk::AccessFlagBits::eShaderRead | vk::AccessFlagBits::eShaderWrite
                  | vk::AccessFlagBits::eColorAttachmentWrite | vk::AccessFlagBits::eTransferRead
                  | vk::AccessFlagBits::eTransferWrite;
       default:
           return vk::AccessFlags();
       }
   }
   
   // Pipeline stage a layout transition's src/dst side needs for the given
   // layout. eDepthStencilAttachmentOptimal and eShaderReadOnlyOptimal
   // deliberately return eAllCommands rather than the narrower
   // eEarlyFragmentTests/eFragmentShader: that is what lets a transition be
   // recorded on a queue other than the graphics queue.
   constexpr vk::PipelineStageFlags pipelineStageForLayout(vk::ImageLayout oldImageLayout)
   {
       switch (oldImageLayout) {
       case vk::ImageLayout::eTransferDstOptimal:
       case vk::ImageLayout::eTransferSrcOptimal:
           return vk::PipelineStageFlagBits::eTransfer;
       case vk::ImageLayout::eColorAttachmentOptimal:
           return vk::PipelineStageFlagBits::eColorAttachmentOutput;
       case vk::ImageLayout::eDepthStencilAttachmentOptimal:
           return vk::PipelineStageFlagBits::eAllCommands;// We do this to allow queue
                                                          // other than graphic return
                                                          // vk::PipelineStageFlagBits::eEarlyFragmentTests;
       case vk::ImageLayout::eShaderReadOnlyOptimal:
           return vk::PipelineStageFlagBits::eAllCommands;// We do this to allow queue
                                                          // other than graphic return
                                                          // vk::PipelineStageFlagBits::eFragmentShader;
       case vk::ImageLayout::ePreinitialized:
           return vk::PipelineStageFlagBits::eHost;
       case vk::ImageLayout::eUndefined:
           return vk::PipelineStageFlagBits::eTopOfPipe;
       case vk::ImageLayout::eGeneral:
           return vk::PipelineStageFlagBits::eAllCommands;
       default:
           return vk::PipelineStageFlagBits::eBottomOfPipe;
       }
   }
   
   }// namespace Kataglyphis