Add all the files

src/imgui/imgui_extension.h

@@ -0,0 +1,14 @@
+#pragma once
+#include "imgui.h"
+
+void ImRotateStart();
+ImVec2 ImRotationCenter();
+void ImRotateEnd(float rad, ImVec2 center = ImRotationCenter());
+
+inline ImVec2 operator-(const ImVec2& l, const ImVec2& r) { return{ l.x - r.x, l.y - r.y }; }
+inline bool operator<(const ImVec2& lhs, const ImVec2& rhs) { return lhs.x < rhs.x; }
+inline bool operator>=(const ImVec2& lhs, const ImVec2& rhs) { return lhs.x >= rhs.x; }
+
+void ImGui_PrecacheFonts();
+ImFont* ImGui_GetFont(float size);
+void ImGui_UpdateWindowInformation(bool mainWindow);