refactor GLSLExtension.cpp & add 'param' shader preprocessor directive & add PostEffect class (WIP)

src/graphics/core/PostEffect.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <variant>
+#include <unordered_map>
+#include <glm/glm.hpp>
+
+class Shader;
+
+class PostEffect {
+public:
+    struct Param {
+        enum class Type { FLOAT, VEC2, VEC3, VEC4 };
+        using Value = std::variant<float, glm::vec2, glm::vec3, glm::vec4>;
+
+        Type type;
+
+        Param();
+        Param(Type type);
+    };
+
+    PostEffect(std::unique_ptr<Shader> shader);
+
+    void use();
+private:
+    std::unique_ptr<Shader> shader;
+    std::unordered_map<std::string, Param> params;
+};