Reimplement drawing system with vertex buffers.

Now with 10000% more performance.

src/FlatLayerVisualisation.hpp

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <vector>
+
+#include "LayerData.hpp"
+#include "LayerVisualisation.hpp"
+
+namespace fmri
+{
+    class FlatLayerVisualisation : public LayerVisualisation
+    {
+    public:
+        explicit FlatLayerVisualisation(const LayerData& layer);
+
+        void render() override;
+
+    private:
+        std::size_t faceCount;
+        std::vector<float> vertexBuffer;
+        std::vector<float> colorBuffer;
+        std::vector<int> indexBuffer;
+    };
+}