core: remove unused Metal RendererBackend state-cache methods (#4519)

include/mln/mtl/renderer_backend.hpp

@@ -17,16 +17,12 @@ class ProgramParameters;
 namespace mtl {
 
 using ProcAddress = void (*)();
-using FramebufferID = uint32_t;
 
 class RendererBackend : public gfx::RendererBackend {
 public:
     RendererBackend(gfx::ContextMode);
     ~RendererBackend() override;
 
-    /// Called prior to rendering to update the internally assumed MetalMetal  state.
-    virtual void updateAssumedState() = 0;
-
     /// One-time shader initialization
     void initShaders(gfx::ShaderRegistry&, const ProgramParameters& programParameters) override;
 
@@ -40,26 +36,6 @@ protected:
     /// Reads the color pixel data from the currently bound framebuffer.
     PremultipliedImage readFramebuffer(const Size&);
 
-    /// A constant to signal that a framebuffer is bound, but with an unknown ID.
-    static constexpr const FramebufferID ImplicitFramebufferBinding = std::numeric_limits<FramebufferID>::max();
-
-    /// Tells the renderer that the Metal state has already been set by the windowing toolkit.
-    /// It sets the internal assumed state to the supplied values.
-    void assumeFramebufferBinding(FramebufferID fbo);
-    void assumeViewport(int32_t x, int32_t y, const Size&);
-    void assumeScissorTest(bool);
-
-    /// Returns true when assumed framebuffer binding hasn't changed from the implicit binding.
-    bool implicitFramebufferBound();
-
-public:
-    /// Triggers a Metal state update if the internal assumed state doesn't
-    /// match the supplied values.
-    void setFramebufferBinding(FramebufferID fbo);
-    void setViewport(int32_t x, int32_t y, const Size&);
-    void setScissorTest(bool);
-
-protected:
     MTLDevicePtr device;
     MTLCommandQueuePtr commandQueue;
     bool baseVertexInstanceDrawingSupported = false;

platform/default/include/mln/mtl/headless_backend.hpp

@@ -15,7 +15,6 @@ public:
                     SwapBehaviour = SwapBehaviour::NoFlush,
                     gfx::ContextMode = gfx::ContextMode::Unique);
     ~HeadlessBackend() override;
-    void updateAssumedState() override;
     gfx::Renderable& getDefaultRenderable() override;
     PremultipliedImage readStillImage() override;
     MTL::Texture* getMetalTexture();

platform/default/src/mln/mtl/headless_backend.cpp

@@ -87,10 +87,6 @@ void HeadlessBackend::ensureResource() {
     }
 }
 
-void HeadlessBackend::updateAssumedState() {
-    // no-op
-}
-
 PremultipliedImage HeadlessBackend::readStillImage() {
     return getResource<HeadlessRenderableResource>().readStillImage();
 }

platform/glfw/metal_backend.h

@@ -14,7 +14,6 @@ public:
     mln::gfx::Renderable &getDefaultRenderable() override;
     void activate() override;
     void deactivate() override;
-    void updateAssumedState() override;
     void setSize(mln::Size size_);
     mln::Size getSize() const;
 };

platform/glfw/metal_backend.mm

@@ -127,7 +127,6 @@ mln::gfx::Renderable& MetalBackend::getDefaultRenderable() { return *this; }
 
 void MetalBackend::activate() {}
 void MetalBackend::deactivate() {}
-void MetalBackend::updateAssumedState() {}
 
 void MetalBackend::setSize(mln::Size size_) {
   size = size_;

platform/ios/src/MLNMapView+Metal.h

@@ -26,11 +26,6 @@ private:
   void deactivate() override;
   // End implementation of mln::gfx::RendererBackend
 
-  // Implementation of mln::gl::RendererBackend
-public:
-  void updateAssumedState() override;
-  // End implementation of mln::gl::Rendererbackend
-
   // Implementation of MLNMapViewImpl
 public:
   mln::gfx::RendererBackend& getRendererBackend() override { return *this; }

platform/ios/src/MLNMapView+Metal.mm

@@ -208,15 +208,6 @@ void MLNMapViewMetalImpl::deactivate() {
   }
 }
 
-/// This function is called before we start rendering, when iOS invokes our rendering method.
-/// iOS already sets the correct framebuffer and viewport for us, so we need to update the
-/// context state with the anticipated values.
-void MLNMapViewMetalImpl::updateAssumedState() {
-  auto& resource = getResource<MLNMapViewMetalRenderableResource>();
-  assumeFramebufferBinding(ImplicitFramebufferBinding);
-  assumeViewport(0, 0, resource.framebufferSize());
-}
-
 UIImage* MLNMapViewMetalImpl::snapshot() {
   auto& resource = getResource<MLNMapViewMetalRenderableResource>();
   return nil;  // TODO: resource.mtlView.snapshot;

platform/macos/src/MLNMapView+Metal.h

@@ -26,11 +26,6 @@ private:
   void deactivate() override;
   // End implementation of mln::gfx::RendererBackend
 
-  // Implementation of mln::gl::RendererBackend
-public:
-  void updateAssumedState() override;
-  // End implementation of mln::gl::Rendererbackend
-
   // Implementation of MLNMapViewImpl
 public:
   mln::gfx::RendererBackend& getRendererBackend() override { return *this; }

platform/macos/src/MLNMapView+Metal.mm

@@ -158,15 +158,6 @@ void MLNMapViewMetalImpl::deactivate() {
   }
 }
 
-/// This function is called before we start rendering, when iOS invokes our rendering method.
-/// iOS already sets the correct framebuffer and viewport for us, so we need to update the
-/// context state with the anticipated values.
-void MLNMapViewMetalImpl::updateAssumedState() {
-  auto& resource = getResource<MLNMapViewMetalRenderableResource>();
-  assumeFramebufferBinding(ImplicitFramebufferBinding);
-  assumeViewport(0, 0, resource.framebufferSize());
-}
-
 mln::PremultipliedImage MLNMapViewMetalImpl::readStillImage() {
   // return readFramebuffer(mapView.framebufferSize); // TODO: RendererBackend::readFramebuffer
   return {};

src/mln/mtl/renderer_backend.cpp

@@ -60,22 +60,6 @@ PremultipliedImage RendererBackend::readFramebuffer(const Size& size) {
     return PremultipliedImage(size);
 }
 
-void RendererBackend::assumeFramebufferBinding(const mtl::FramebufferID) {}
-
-void RendererBackend::assumeViewport(int32_t, int32_t, const Size&) {}
-
-void RendererBackend::assumeScissorTest(bool) {}
-
-bool RendererBackend::implicitFramebufferBound() {
-    return false;
-}
-
-void RendererBackend::setFramebufferBinding(const mtl::FramebufferID) {}
-
-void RendererBackend::setViewport(int32_t, int32_t, const Size&) {}
-
-void RendererBackend::setScissorTest(bool) {}
-
 /// @brief Register a list of types with a shader registry instance
 /// @tparam ...ShaderID Pack of BuiltIn:: shader IDs
 /// @param registry A shader registry instance