public:
	virtual void            AddEntityTextOverlay(int ent_index, int line_offset, float duration, int r, int g, int b, int a, const char* format, ...) = 0;
	virtual void            AddBoxOverlay(const Vector& origin, const Vector& mins, const Vector& max, QAngle const& orientation, int r, int g, int b, int a, float duration) = 0;
	virtual void            AddSphereOverlay(const Vector& vOrigin, float flRadius, int nTheta, int nPhi, int r, int g, int b, int a, float flDuration) = 0;
	virtual void            AddTriangleOverlay(const Vector& p1, const Vector& p2, const Vector& p3, int r, int g, int b, int a, bool noDepthTest, float duration) = 0;
	virtual void            __unkn() = 0;
	virtual void            AddLineOverlay(const Vector& origin, const Vector& dest, int r, int g, int b, bool noDepthTest, float duration) = 0;
	virtual void            AddTextOverlay(const Vector& origin, float duration, const char* format, ...) = 0;
	virtual void            AddTextOverlay(const Vector& origin, int line_offset, float duration, const char* format, ...) = 0;
	virtual void            AddScreenTextOverlay(float flXPos, float flYPos, float flDuration, int r, int g, int b, int a, const char* text) = 0;
	virtual void            AddSweptBoxOverlay(const Vector& start, const Vector& end, const Vector& mins, const Vector& max, const QAngle& angles, int r, int g, int b, int a, float flDuration) = 0;
	virtual void            AddGridOverlay(const Vector& origin) = 0;
	virtual void            AddCoordFrameOverlay(const matrix3x4_t& frame, float flScale, int vColorTable[3][3] = NULL) = 0;
	virtual int             ScreenPosition(const Vector& point, Vector& screen) = 0;
	virtual int             ScreenPosition(float flXPos, float flYPos, Vector& screen) = 0;
	virtual OverlayText_t* GetFirst(void) = 0;
	virtual OverlayText_t* GetNext(OverlayText_t* current) = 0;
	virtual void            ClearDeadOverlays(void) = 0;
	virtual void            ClearAllOverlays() = 0;
	virtual void            AddTextOverlayRGB(const Vector& origin, int line_offset, float duration, float r, float g, float b, float alpha, const char* format, ...) = 0;
	virtual void            AddTextOverlayRGB(const Vector& origin, int line_offset, float duration, int r, int g, int b, int a, const char* format, ...) = 0;
	virtual void            AddLineOverlayAlpha(const Vector& origin, const Vector& dest, int r, int g, int b, int a, bool noDepthTest, float duration) = 0;
	virtual void            AddBoxOverlay2(const Vector& origin, const Vector& mins, const Vector& max, QAngle const& orientation, const uint8_t* faceColor, const uint8_t* edgeColor, float duration) = 0;
	virtual void            PurgeTextOverlays() = 0;
	virtual void            DrawPill(const Vector& mins, const Vector& max, float& diameter, int r, int g, int b, int a, float duration) = 0;
	void AddCapsuleOverlay(Vector& mins, Vector& maxs, float pillradius, int r, int g, int b, int a, float duration)
	{
		GetVFunc<void(__thiscall*)(void*, Vector&, Vector&, float&, int, int, int, int, float)>(this, 23)(this, mins, maxs, pillradius, r, g, b, a, duration);
	}

private:
	inline void AddTextOverlay(const Vector& origin, int line_offset, float duration, int r, int g, int b, int a, const char* format, ...) {} /* catch improper use of bad interface. Needed because '0' duration can be resolved by compiler to NULL format string (i.e., compiles but calls wrong function) */