feat: add map background color

include/render/Renderer.h

@@ -29,6 +29,8 @@ private:
     std::unique_ptr<WorldShader> m_WorldShader;
     std::unique_ptr<EntityShader> m_EntityShader;
 
+    glm::vec3 m_BackgroundColor;
+
     bool m_IsometricView = true;
     float m_IsometricShade = m_IsometricView;
     glm::vec2 m_CamPos{};
@@ -49,6 +51,8 @@ public:
     void setCamPos(const glm::vec2& newPos);
     void setIsometricView(bool isometric); // false = 2D       true = Isometric
 
+    void setBackgroundColor(const glm::vec3& color) { m_BackgroundColor = color; }
+
     glm::vec2 getCursorWorldPos(const glm::vec2& cursorPos, float aspectRatio, float zoom, float windowWidth, float windowHeight);
 private:
     void updateIsometricView();