[SwapChain] Added IsPresentable() to SwapChain interface.

This new function allows to detect when the native surface of a swap-chain is temporarily unavailable. This occurs when a mobile app is paused and the native surface is destroyed, while it is later re-initialized when the app resumes. Also moved all SwapChain interface declarations to Backend/SwapChain.inl header as for other interfaces with more than one or two functions.
LukasBanana · Aug 8, 2024 · 2232eb6 · 2232eb6
1 parent b78b7e3
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Showing 34 changed files with 241 additions and 127 deletions.
diff --git a/examples/Cpp/ExampleBase/ExampleBase.cpp b/examples/Cpp/ExampleBase/ExampleBase.cpp
@@ -11,6 +11,7 @@
 #include "ImageReader.h"
 #include "FileUtils.h"
 #include <stdio.h>
+#include <thread>
 
 #define STB_IMAGE_IMPLEMENTATION
 #include <stb/stb_image.h>
@@ -380,13 +381,25 @@ void ExampleBase::Run()
  bool fullscreen = false;
  const LLGL::Extent2D initialResolution = swapChain->GetResolution();
 
- #ifdef LLGL_MOBILE_PLATFORM
- while (LLGL::Surface::ProcessEvents())
- #else
+ #ifndef LLGL_MOBILE_PLATFORM
  LLGL::Window& window = LLGL::CastTo<LLGL::Window>(swapChain->GetSurface());
- while (LLGL::Surface::ProcessEvents() && !window.HasQuit() && !input.KeyDown(LLGL::Key::Escape))
  #endif
+
+ while (LLGL::Surface::ProcessEvents() && !input.KeyDown(LLGL::Key::Escape))
  {
+ #ifndef LLGL_MOBILE_PLATFORM
+ // On desktop platforms, we also want to quit the app if the close button has been pressed
+ if (window.HasQuit())
+ break;
+ #endif
+
+ // On mobile platforms, if app has paused, the swap-chain might not be presentable until the app is resumed again
+ if (!swapChain->IsPresentable())
+ {
+ std::this_thread::yield();
+ continue;
+ }
+
  #ifdef LLGL_OS_ANDROID
  if (input.KeyDown(LLGL::Key::BrowserBack))
  ANativeActivity_finish(ExampleBase::androidApp_->activity);
@@ -484,17 +497,20 @@ ExampleBase::ExampleBase(const LLGL::UTF8String& title)
  LLGL::RenderSystemDescriptor rendererDesc = g_Config.rendererModule;
 
  #if defined LLGL_OS_ANDROID
- LLGL::RendererConfigurationOpenGL cfgGL;
- if (android_app* app = ExampleBase::androidApp_)
+ if (rendererDesc.moduleName == "OpenGLES3")
  {
- rendererDesc.androidApp = app;
- cfgGL.majorVersion = 3;
- cfgGL.minorVersion = 1;
- rendererDesc.rendererConfig = &cfgGL;
- rendererDesc.rendererConfigSize = sizeof(cfgGL);
+ LLGL::RendererConfigurationOpenGL cfgGL;
+ if (android_app* app = ExampleBase::androidApp_)
+ {
+ rendererDesc.androidApp = app;
+ cfgGL.majorVersion = 3;
+ cfgGL.minorVersion = 1;
+ rendererDesc.rendererConfig = &cfgGL;
+ rendererDesc.rendererConfigSize = sizeof(cfgGL);
+ }
+ else
+ throw std::invalid_argument("'android_app' state was not specified");
  }
- else
- throw std::invalid_argument("'android_app' state was not specified");
  #endif
 
  if (g_Config.debugger)

diff --git a/include/LLGL-C/SwapChain.h b/include/LLGL-C/SwapChain.h
@@ -14,6 +14,7 @@
 #include <stdint.h>
 
 
+LLGL_C_EXPORT bool llglIsPresentable(LLGLSwapChain swapChain);
 LLGL_C_EXPORT void llglPresent(LLGLSwapChain swapChain);
 LLGL_C_EXPORT uint32_t llglGetCurrentSwapIndex(LLGLSwapChain swapChain);
 LLGL_C_EXPORT uint32_t llglGetNumSwapBuffers(LLGLSwapChain swapChain);

diff --git a/include/LLGL/Backend/SwapChain.inl b/include/LLGL/Backend/SwapChain.inl
@@ -0,0 +1,46 @@
+/*
+ * SwapChain.inl
+ *
+ * Copyright (c) 2015 Lukas Hermanns. All rights reserved.
+ * Licensed under the terms of the BSD 3-Clause license (see LICENSE.txt).
+ */
+
+virtual bool IsPresentable(
+ void
+) const override final;
+
+virtual void Present(
+ void
+) override final;
+
+virtual std::uint32_t GetCurrentSwapIndex(
+ void
+) const override final;
+
+virtual std::uint32_t GetNumSwapBuffers(
+ void
+) const override final;
+
+virtual std::uint32_t GetSamples(
+ void
+) const override final;
+
+virtual LLGL::Format GetColorFormat(
+ void
+) const override final;
+
+virtual LLGL::Format GetDepthStencilFormat(
+ void
+) const override final;
+
+virtual const LLGL::RenderPass* GetRenderPass(
+ void
+) const override;
+
+virtual bool SetVsyncInterval(
+ std::uint32_t vsyncInterval
+) override final;
+
+
+
+// ================================================================================
diff --git a/include/LLGL/SwapChain.h b/include/LLGL/SwapChain.h
@@ -76,6 +76,28 @@ class LLGL_EXPORT SwapChain : public RenderTarget
 
  /* ----- Back Buffer ----- */
 
+ /**
+ \brief Returns true if this swap-chain is ready for rendering and presenting. Otherwise, the native surface or back buffer are not available.
+ \remarks This is mostly used for mobile platforms where the surface can be temporarily destroyed when the app is paused and later re-initialized when the app resumes.
+ If this is false, no rendering to this swap-chain must be performed nor can the back buffer be presented.
+ \remarks A safe way to handle the event of a lost native surface is to skip the entire rendering when this returns false as shown below:
+ \code
+ while (LLGL::Surface::ProcessEvents()) {
+ // Skip frame if swap-chain is currently not presentable
+ if (!swapChain->IsPresentable()) {
+ std::this_thread::yield();
+ continue;
+ }
+
+ // Render frame ...
+
+ // Present swap-chain back buffer
+ swapChain->Present();
+ }
+ \endcode
+ */
+ virtual bool IsPresentable() const = 0;
+
  /**
  \brief Swaps the current back buffer with the front buffer to present it on the screen.
  \see GetCurrentSwapIndex

diff --git a/sources/Platform/Android/AndroidCanvas.cpp b/sources/Platform/Android/AndroidCanvas.cpp
@@ -34,12 +34,6 @@ bool Surface::ProcessEvents()
  if (source != nullptr)
  source->process(app, source);
 
- /* Process sensor data */
- /*if (ident == LOOPER_ID_USER)
- {
- //TODO
- }*/
-
  /* Check if we are exiting */
  if (app->destroyRequested != 0)
  return false;

diff --git a/sources/Renderer/DebugLayer/DbgCommandBuffer.cpp b/sources/Renderer/DebugLayer/DbgCommandBuffer.cpp
@@ -743,6 +743,14 @@ void DbgCommandBuffer::BeginRenderPass(
  {
  auto& swapChainDbg = LLGL_DBG_CAST(DbgSwapChain&, renderTarget);
 
+ if (!swapChainDbg.IsPresentable())
+ {
+ LLGL_DBG_ERROR(
+ ErrorType::InvalidState,
+ "cannot begin new render pass with swap chain that is not presentable"
+ );
+ }
+
  swapChainDbg.NotifyNextRenderPass(debugger_, renderPass);
 
  bindings_.swapChain = &swapChainDbg;

diff --git a/sources/Renderer/DebugLayer/DbgSwapChain.cpp b/sources/Renderer/DebugLayer/DbgSwapChain.cpp
@@ -52,6 +52,11 @@ void DbgSwapChain::SetDebugName(const char* name)
  DbgSetObjectName(*this, name);
 }
 
+bool DbgSwapChain::IsPresentable() const
+{
+ return instance.IsPresentable();
+}
+
 void DbgSwapChain::Present()
 {
  instance.Present();

diff --git a/sources/Renderer/DebugLayer/DbgSwapChain.h b/sources/Renderer/DebugLayer/DbgSwapChain.h
@@ -32,20 +32,11 @@ class DbgSwapChain final : public SwapChain
 
  public:
 
- void SetDebugName(const char* name) override;
-
- void Present() override;
-
- std::uint32_t GetCurrentSwapIndex() const override;
- std::uint32_t GetNumSwapBuffers() const override;
- std::uint32_t GetSamples() const override;
+ #include <LLGL/Backend/SwapChain.inl>
 
- Format GetColorFormat() const override;
- Format GetDepthStencilFormat() const override;
-
- bool SetVsyncInterval(std::uint32_t vsyncInterval) override;
+ public:
 
- const RenderPass* GetRenderPass() const override;
+ void SetDebugName(const char* name) override;
 
  public:
 

diff --git a/sources/Renderer/Direct3D11/D3D11SwapChain.cpp b/sources/Renderer/Direct3D11/D3D11SwapChain.cpp
@@ -79,6 +79,11 @@ void D3D11SwapChain::SetDebugName(const char* name)
  }
 }
 
+bool D3D11SwapChain::IsPresentable() const
+{
+ return true; // dummy
+}
+
 void D3D11SwapChain::Present()
 {
  const bool tearingEnabled = (tearingSupported_ && windowedMode_ && swapChainInterval_ == 0);

diff --git a/sources/Renderer/Direct3D11/D3D11SwapChain.h b/sources/Renderer/Direct3D11/D3D11SwapChain.h
@@ -29,6 +29,10 @@ class D3D11RenderSystem;
 class D3D11SwapChain final : public SwapChain
 {
 
+ public:
+
+ #include <LLGL/Backend/SwapChain.inl>
+
  public:
 
  D3D11SwapChain(
@@ -41,19 +45,6 @@ class D3D11SwapChain final : public SwapChain
 
  void SetDebugName(const char* name) override;
 
- void Present() override;
-
- std::uint32_t GetCurrentSwapIndex() const override;
- std::uint32_t GetNumSwapBuffers() const override;
- std::uint32_t GetSamples() const override;
-
- Format GetColorFormat() const override;
- Format GetDepthStencilFormat() const override;
-
- const RenderPass* GetRenderPass() const override;
-
- bool SetVsyncInterval(std::uint32_t vsyncInterval) override;
-
  public:
 
  // Copyies a subresource region from the backbuffer (color or depth-stencil) into the destination resource.

diff --git a/sources/Renderer/Direct3D12/D3D12SwapChain.cpp b/sources/Renderer/Direct3D12/D3D12SwapChain.cpp
@@ -108,6 +108,11 @@ void D3D12SwapChain::SetDebugName(const char* name)
  }
 }
 
+bool D3D12SwapChain::IsPresentable() const
+{
+ return true; // dummy
+}
+
 void D3D12SwapChain::Present()
 {
  /* Present swap-chain with vsync interval */

diff --git a/sources/Renderer/Direct3D12/D3D12SwapChain.h b/sources/Renderer/Direct3D12/D3D12SwapChain.h
@@ -36,20 +36,11 @@ class D3D12SwapChain final : public SwapChain
 
  public:
 
- void SetDebugName(const char* name) override;
-
- void Present() override;
-
- std::uint32_t GetCurrentSwapIndex() const override;
- std::uint32_t GetNumSwapBuffers() const override;
- std::uint32_t GetSamples() const override;
+ #include <LLGL/Backend/SwapChain.inl>
 
- Format GetColorFormat() const override;
- Format GetDepthStencilFormat() const override;
-
- const RenderPass* GetRenderPass() const override;
+ public:
 
- bool SetVsyncInterval(std::uint32_t vsyncInterval) override;
+ void SetDebugName(const char* name) override;
 
  public:
 

diff --git a/sources/Renderer/Metal/MTSwapChain.h b/sources/Renderer/Metal/MTSwapChain.h
@@ -31,7 +31,9 @@ class MTSwapChain final : public SwapChain
 
  public:
 
- /* ----- Common ----- */
+ #include <LLGL/Backend/SwapChain.inl>
+
+ public:
 
  MTSwapChain(
  id<MTLDevice> device,
@@ -40,19 +42,6 @@ class MTSwapChain final : public SwapChain
  const RendererInfo& rendererInfo
  );
 
- void Present() override;
-
- std::uint32_t GetCurrentSwapIndex() const override;
- std::uint32_t GetNumSwapBuffers() const override;
- std::uint32_t GetSamples() const override;
-
- Format GetColorFormat() const override;
- Format GetDepthStencilFormat() const override;
-
- const RenderPass* GetRenderPass() const override;
-
- bool SetVsyncInterval(std::uint32_t vsyncInterval) override;
-
  public:
 
  // Updates the native render pass descriptor with the specified clear values. Returns null on failure.

diff --git a/sources/Renderer/Metal/MTSwapChain.mm b/sources/Renderer/Metal/MTSwapChain.mm
@@ -75,6 +75,11 @@ - (void)mtkView:(nonnull MTKView *)view drawableSizeWillChange:(CGSize)size
  ShowSurface();
 }
 
+bool MTSwapChain::IsPresentable() const
+{
+ return true; //TODO
+}
+
 void MTSwapChain::Present()
 {
  /* Present backbuffer */

diff --git a/sources/Renderer/Null/NullSwapChain.cpp b/sources/Renderer/Null/NullSwapChain.cpp
@@ -63,6 +63,11 @@ void NullSwapChain::SetDebugName(const char* name)
  label_.clear();
 }
 
+bool NullSwapChain::IsPresentable() const
+{
+ return true; // dummy
+}
+
 void NullSwapChain::Present()
 {
  // dummy

diff --git a/sources/Renderer/Null/NullSwapChain.h b/sources/Renderer/Null/NullSwapChain.h
@@ -22,28 +22,19 @@ class NullSwapChain final : public SwapChain
 
  public:
 
- NullSwapChain(
- const SwapChainDescriptor& desc,
- const std::shared_ptr<Surface>& surface,
- const RendererInfo& rendererInfo
- );
+ #include <LLGL/Backend/SwapChain.inl>
 
  public:
 
  void SetDebugName(const char* name) override;
 
- void Present() override;
-
- std::uint32_t GetCurrentSwapIndex() const override;
- std::uint32_t GetNumSwapBuffers() const override;
- std::uint32_t GetSamples() const override;
-
- Format GetColorFormat() const override;
- Format GetDepthStencilFormat() const override;
-
- bool SetVsyncInterval(std::uint32_t vsyncInterval) override;
+ public:
 
- const RenderPass* GetRenderPass() const override;
+ NullSwapChain(
+ const SwapChainDescriptor& desc,
+ const std::shared_ptr<Surface>& surface,
+ const RendererInfo& rendererInfo
+ );
 
  private: