Use timestamps for image descriptor updates (#3152)

include/mbgl/vulkan/descriptor_set.hpp

@@ -60,7 +60,7 @@ public:
 
     void allocate();
 
-    void markDirty(bool value = true);
+    virtual void markDirty();
     void bind(CommandEncoder& encoder);
 
 protected:
@@ -91,7 +91,13 @@ public:
     ImageDescriptorSet(Context& context_);
     virtual ~ImageDescriptorSet() = default;
 
+    void markDirty() override;
+    const std::chrono::duration<double>& getLastModified() const { return lastModified; }
+
     void update(const std::array<gfx::Texture2DPtr, shaders::maxTextureCountPerShader>& textures);
+
+protected:
+    std::chrono::duration<double> lastModified;
 };
 
 } // namespace vulkan

include/mbgl/vulkan/texture2d.hpp

@@ -60,6 +60,7 @@ public:
     size_t numChannels() const noexcept override;
 
     bool isDirty() const { return samplerStateDirty || textureDirty; }
+    bool isModifiedAfter(const std::chrono::duration<double>& t) const { return t < lastModified; }
 
     void create() noexcept override;
 
@@ -112,6 +113,7 @@ private:
     std::shared_ptr<PremultipliedImage> imageData{nullptr};
     bool textureDirty{true};
     bool samplerStateDirty{true};
+    std::chrono::duration<double> lastModified{0};
 
     SharedImageAllocation imageAllocation;
     vk::ImageLayout imageLayout{vk::ImageLayout::eUndefined};

src/mbgl/vulkan/descriptor_set.cpp

@@ -5,6 +5,7 @@
 #include <mbgl/vulkan/texture2d.hpp>
 #include <mbgl/util/logging.hpp>
 #include <mbgl/util/instrumentation.hpp>
+#include <mbgl/util/monotonic_timer.hpp>
 
 #include <cassert>
 #include <math.h>
@@ -120,8 +121,8 @@ void DescriptorSet::allocate() {
     dirty = std::vector(descriptorSets.size(), true);
 }
 
-void DescriptorSet::markDirty(bool value) {
-    std::fill(dirty.begin(), dirty.end(), value);
+void DescriptorSet::markDirty() {
+    std::fill(dirty.begin(), dirty.end(), true);
 }
 
 void DescriptorSet::bind(CommandEncoder& encoder) {
@@ -186,7 +187,14 @@ void UniformDescriptorSet::update(const gfx::UniformBufferArray& uniforms,
 }
 
 ImageDescriptorSet::ImageDescriptorSet(Context& context_)
-    : DescriptorSet(context_, DescriptorSetType::DrawableImage) {}
+    : DescriptorSet(context_, DescriptorSetType::DrawableImage),
+      lastModified(0.0) {}
+
+void ImageDescriptorSet::markDirty() {
+    DescriptorSet::markDirty();
+
+    lastModified = util::MonotonicTimer::now();
+}
 
 void ImageDescriptorSet::update(const std::array<gfx::Texture2DPtr, shaders::maxTextureCountPerShader>& textures) {
     MLN_TRACE_FUNC();

src/mbgl/vulkan/drawable.cpp

@@ -436,8 +436,8 @@ bool Drawable::bindDescriptors(CommandEncoder& encoder) const noexcept {
         for (const auto& texture : textures) {
             if (!texture) continue;
             const auto textureImpl = static_cast<const Texture2D*>(texture.get());
-            if (textureImpl->isDirty()) {
-                impl->imageDescriptorSet->markDirty(true);
+            if (textureImpl->isModifiedAfter(impl->imageDescriptorSet->getLastModified())) {
+                impl->imageDescriptorSet->markDirty();
                 break;
             }
         }

src/mbgl/vulkan/texture2d.cpp

@@ -362,7 +362,9 @@ void Texture2D::createTexture() {
     context.renderingStats().numCreatedTextures++;
     context.renderingStats().numActiveTextures++;
     context.renderingStats().memTextures += getDataSize();
+
     textureDirty = false;
+    lastModified = util::MonotonicTimer::now();
 }
 
 void Texture2D::createSampler() {
@@ -392,6 +394,7 @@ void Texture2D::createSampler() {
     sampler = context.getBackend().getDevice()->createSampler(samplerCreateInfo);
 
     samplerStateDirty = false;
+    lastModified = util::MonotonicTimer::now();
 }
 
 void Texture2D::destroyTexture() {