all: update present semaphores

Now two sems are provided by Window::acquireNext()
It fixes the validator errors and (I hope) clarifies a little how
  syncronization via semaphores  works

Author: kzubatov

samples/shadowmap/Renderer.cpp

@@ -139,7 +139,7 @@ void Renderer::drawFrame()
   // but only on some platforms (not windows+nvidia, sadly).
   if (nextSwapchainImage)
   {
-    auto [image, view, availableSem] = *nextSwapchainImage;
+    auto [image, view, availableSem, readyForPresentSem] = *nextSwapchainImage;
 
     ETNA_CHECK_VK_RESULT(currentCmdBuf.begin(vk::CommandBufferBeginInfo{}));
     {
@@ -167,7 +167,8 @@ void Renderer::drawFrame()
     }
     ETNA_CHECK_VK_RESULT(currentCmdBuf.end());
 
-    auto renderingDone = commandManager->submit(std::move(currentCmdBuf), std::move(availableSem));
+    auto renderingDone = commandManager->submit(
+      std::move(currentCmdBuf), std::move(availableSem), std::move(readyForPresentSem));
 
     const bool presented = window->present(std::move(renderingDone), view);
 

tasks/local_shadertoy1/App.cpp

@@ -111,7 +111,8 @@ void App::drawFrame()
   // because it kills the swapchain, so we skip frames in this case.
   if (nextSwapchainImage)
   {
-    auto [backbuffer, backbufferView, backbufferAvailableSem] = *nextSwapchainImage;
+    auto [backbuffer, backbufferView, backbufferAvailableSem, backbufferReadyForPresent] =
+      *nextSwapchainImage;
 
     ETNA_CHECK_VK_RESULT(currentCmdBuf.begin(vk::CommandBufferBeginInfo{}));
     {
@@ -158,10 +159,14 @@ void App::drawFrame()
     ETNA_CHECK_VK_RESULT(currentCmdBuf.end());
 
     // We are done recording GPU commands now and we can send them to be executed by the GPU.
-    // Note that the GPU won't start executing our commands before the semaphore is
-    // signalled, which will happen when the OS says that the next swapchain image is ready.
-    auto renderingDone =
-      commandManager->submit(std::move(currentCmdBuf), std::move(backbufferAvailableSem));
+    // Note that the GPU won't start executing our commands before the backbufferAvailableSem
+    // semaphore is signalled, which will happen when the OS says that the next swapchain image is
+    // ready, and the result image will be ready for present after backbufferReadyForPresent is
+    // signalled by GPU
+    auto renderingDone = commandManager->submit(
+      std::move(currentCmdBuf),
+      std::move(backbufferAvailableSem),
+      std::move(backbufferReadyForPresent));
 
     // Finally, present the backbuffer the screen, but only after the GPU tells the OS
     // that it is done executing the command buffer via the renderingDone semaphore.

tasks/model_bakery/renderer/Renderer.cpp

@@ -101,7 +101,7 @@ void Renderer::drawFrame()
 
   if (nextSwapchainImage)
   {
-    auto [image, view, availableSem] = *nextSwapchainImage;
+    auto [image, view, availableSem, readyForPresentSem] = *nextSwapchainImage;
 
     ETNA_CHECK_VK_RESULT(currentCmdBuf.begin(vk::CommandBufferBeginInfo{}));
     {
@@ -123,7 +123,8 @@ void Renderer::drawFrame()
     }
     ETNA_CHECK_VK_RESULT(currentCmdBuf.end());
 
-    auto renderingDone = commandManager->submit(std::move(currentCmdBuf), std::move(availableSem));
+    auto renderingDone = commandManager->submit(
+      std::move(currentCmdBuf), std::move(availableSem), std::move(readyForPresentSem));
 
     const bool presented = window->present(std::move(renderingDone), view);