1 files changed, 84 insertions, 0 deletions
diff --git a/src/layer_context.hh b/src/layer_context.hh
new file mode 100644
index 0000000..228efa3
--- /dev/null
+++ b/src/layer_context.hh
@@ -0,0 +1,84 @@
+#ifndef LAYER_CONTEXT_HH_
+#define LAYER_CONTEXT_HH_
+
+#include <mutex>
+#include <variant>
+
+#include "device_context.hh"
+#include "instance_context.hh"
+#include "queue_context.hh"
+
+// The purpose of this file is to provide a definition for the highest level
+// entry point struct of our vulkan state.
+//
+// All Context structs have deleted copy/move constructors. This is because we
+// want to be extremely explicit with how/when we delete things, and this allows
+// us to use destructors for cleanup without much worry about weird copies
+// floating around. Most contexts will probably live inside std::unique_ptr's as
+// a result so they can be used in standard containers.
+
+namespace low_latency {
+
+template <typename T>
+concept DispatchableType =
+    std::same_as<std::remove_cvref_t<T>, VkInstance> ||
+    std::same_as<std::remove_cvref_t<T>, VkDevice> ||
+    std::same_as<std::remove_cvref_t<T>, VkPhysicalDevice> ||
+    std::same_as<std::remove_cvref_t<T>, VkQueue>;
+
+struct LayerContext {
+  public:
+    using ContextVariant = std::variant<std::unique_ptr<DeviceContext>,
+                                        std::unique_ptr<InstanceContext>>;
+
+  public:
+    std::mutex mutex;
+    std::unordered_map<void*, ContextVariant> contexts;
+    std::uint64_t current_frame = 0;
+
+  public:
+    LayerContext();
+    LayerContext(const LayerContext&) = delete;
+    LayerContext(LayerContext&&) = delete;
+    LayerContext operator==(const LayerContext&) = delete;
+    LayerContext operator==(LayerContext&&) = delete;
+    ~LayerContext();
+
+  public:
+    template <DispatchableType T> static void* get_key(const T& dt) {
+        return *reinterpret_cast<void**>(dt);
+    }
+
+    template <typename T, DispatchableType DispatchableType>
+        requires(!std::same_as<T, QueueContext>)
+    T& get_context(const DispatchableType& dt) {
+        const auto key = get_key(dt);
+
+        const auto it = this->contexts.find(key);
+        assert(it != std::end(this->contexts));
+
+        const auto ptr = std::get_if<std::unique_ptr<T>>(&it->second);
+        assert(ptr && *ptr);
+
+        return **ptr;
+    }
+
+    // QueueContext's are actually owned by a device so look there instead.
+    template <typename T, DispatchableType DispatchableType>
+        requires(std::same_as<T, QueueContext>)
+    T& get_context(const DispatchableType& dt) {
+
+        const auto& device_context = this->get_context<DeviceContext>(dt);
+        const auto& queue_context = device_context.queue_contexts;
+
+        const auto it = device_context.queue_contexts.find(dt);
+        assert(it != std::end(queue_context));
+
+        const auto& ptr = it->second;
+        return *ptr;
+    }
+};
+
+}; // namespace low_latency
+
+#endif
+\ No newline at end of file