1 /* 2 * This file is part of libsidplayfp, a SID player engine. 3 * 4 * Copyright 2012-2014 Leandro Nini <drfiemost@users.sourceforge.net> 5 * Copyright 2010 Antti Lankila 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 20 */ 21 22 #ifndef NULLSID_H 23 #define NULLSID_H 24 25 #include "c64/c64sid.h" 26 27 #include "sidcxx11.h" 28 29 namespace libsidplayfp 30 { 31 32 /** 33 * SID chip placeholder which does nothing and returns 0xff on reading. 34 */ 35 class NullSid final : public c64sid 36 { 37 private: NullSid()38 NullSid() {} ~NullSid()39 virtual ~NullSid() {} 40 41 public: 42 /** 43 * Returns singleton instance. 44 */ getInstance()45 static NullSid *getInstance() 46 { 47 static NullSid nullsid; 48 return &nullsid; 49 } 50 reset(uint8_t)51 void reset(uint8_t) override {} 52 write(uint_least8_t,uint8_t)53 void write(uint_least8_t, uint8_t) override {} read(uint_least8_t)54 uint8_t read(uint_least8_t) override { return 0xff; } 55 GetVolumes(uint8_t & a,uint8_t & b,uint8_t & c)56 void GetVolumes(uint8_t &a, uint8_t &b, uint8_t &c) const override {a = b = c = 0;}; 57 }; 58 59 } 60 61 #endif // NULLSID_H 62