Refactor: Extract VertexLoader from command_processor.cpp.

Preparation for a similar concept to Dolphin or PPSSPP. These can be JIT-ed and cached.

src/video_core/vertex_loader.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include "video_core/pica.h"
+#include "video_core/shader/shader.h"
+
+namespace Pica {
+
+class MemoryAccesses {
+    /// Combine overlapping and close ranges
+    void SimplifyRanges() {
+        for (auto it = ranges.begin(); it != ranges.end(); ++it) {
+            // NOTE: We add 32 to the range end address to make sure "close" ranges are combined, too
+            auto it2 = std::next(it);
+            while (it2 != ranges.end() && it->first + it->second + 32 >= it2->first) {
+                it->second = std::max(it->second, it2->first + it2->second - it->first);
+                it2 = ranges.erase(it2);
+            }
+        }
+    }
+
+public:
+    /// Record a particular memory access in the list
+    void AddAccess(u32 paddr, u32 size) {
+        // Create new range or extend existing one
+        ranges[paddr] = std::max(ranges[paddr], size);
+
+        // Simplify ranges...
+        SimplifyRanges();
+    }
+
+    /// Map of accessed ranges (mapping start address to range size)
+    std::map<u32, u32> ranges;
+};
+
+class VertexLoader {
+public:
+    void Setup(const Pica::Regs &regs);
+    void LoadVertex(int index, int vertex, Shader::InputVertex &input, MemoryAccesses &memory_accesses);
+
+    u32 GetPhysicalBaseAddress() const { return base_address; }
+    int GetNumTotalAttributes() const { return num_total_attributes; }
+private:
+    u32 vertex_attribute_sources[16];
+    u32 vertex_attribute_strides[16] = {};
+    Regs::VertexAttributeFormat vertex_attribute_formats[16] = {};
+    u32 vertex_attribute_elements[16] = {};
+    u32 vertex_attribute_element_size[16] = {};
+    bool vertex_attribute_is_default[16];
+    u32 base_address;
+    int num_total_attributes;
+};
+
+}  // namespace Pica