1 files changed, 148 insertions, 0 deletions
diff --git a/plugins/sid/sidplay-libs/resid/wave.cpp b/plugins/sid/sidplay-libs/resid/wave.cpp
new file mode 100644
index 00000000..6f5ec5dd
--- /dev/null
+++ b/plugins/sid/sidplay-libs/resid/wave.cpp
@@ -0,0 +1,148 @@
+//  ---------------------------------------------------------------------------
+//  This file is part of reSID, a MOS6581 SID emulator engine.
+//  Copyright (C) 2002  Dag Lem <resid@nimrod.no>
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//  ---------------------------------------------------------------------------
+
+#define __WAVE_CC__
+#include "wave.h"
+
+RESID_NAMESPACE_START
+
+// ----------------------------------------------------------------------------
+// Constructor.
+// ----------------------------------------------------------------------------
+WaveformGenerator::WaveformGenerator()
+{
+  sync_source = this;
+
+  set_chip_model(MOS6581);
+
+  reset();
+}
+
+
+// ----------------------------------------------------------------------------
+// Set sync source.
+// ----------------------------------------------------------------------------
+void WaveformGenerator::set_sync_source(WaveformGenerator* source)
+{
+  sync_source = source;
+  source->sync_dest = this;
+}
+
+
+// ----------------------------------------------------------------------------
+// Set chip model.
+// ----------------------------------------------------------------------------
+void WaveformGenerator::set_chip_model(chip_model model)
+{
+  if (model == MOS6581) {
+    wave__ST = wave6581__ST;
+    wave_P_T = wave6581_P_T;
+    wave_PS_ = wave6581_PS_;
+    wave_PST = wave6581_PST;
+  }
+  else {
+    wave__ST = wave8580__ST;
+    wave_P_T = wave8580_P_T;
+    wave_PS_ = wave8580_PS_;
+    wave_PST = wave8580_PST;
+  }
+}
+
+
+// ----------------------------------------------------------------------------
+// Register functions.
+// ----------------------------------------------------------------------------
+void WaveformGenerator::writeFREQ_LO(reg8 freq_lo)
+{
+  freq = freq & 0xff00 | freq_lo & 0x00ff;
+}
+
+void WaveformGenerator::writeFREQ_HI(reg8 freq_hi)
+{
+  freq = (freq_hi << 8) & 0xff00 | freq & 0x00ff;
+}
+
+void WaveformGenerator::writePW_LO(reg8 pw_lo)
+{
+  pw = pw & 0xf00 | pw_lo & 0x0ff;
+}
+
+void WaveformGenerator::writePW_HI(reg8 pw_hi)
+{
+  pw = (pw_hi << 8) & 0xf00 | pw & 0x0ff;
+}
+
+void WaveformGenerator::writeCONTROL_REG(reg8 control)
+{
+  waveform = (control >> 4) & 0x0f;
+  ring_mod = control & 0x04;
+  sync = control & 0x02;
+
+  reg8 test_next = control & 0x08;
+
+  // Test bit set.
+  // The accumulator and the shift register are both cleared.
+  // NB! The shift register is not really cleared immediately. It seems like
+  // the individual bits in the shift register start to fade down towards
+  // zero when test is set. All bits reach zero within approximately
+  // $2000 - $4000 cycles.
+  // This is not modeled. There should fortunately be little audible output
+  // from this peculiar behavior.
+  if (test_next) {
+    accumulator = 0;
+    shift_register = 0;
+  }
+  // Test bit cleared.
+  // The accumulator starts counting, and the shift register is reset to
+  // the value 0x7ffff8.
+  // NB! The shift register will not actually be set to this exact value if the
+  // shift register bits have not had time to fade to zero.
+  // This is not modeled.
+  else if (test) {
+    shift_register = 0x7ffff8;
+  }
+
+  test = test_next;
+
+  // The gate bit is handled by the EnvelopeGenerator.
+}
+
+reg8 WaveformGenerator::readOSC()
+{
+  return output() >> 4;
+}
+
+// ----------------------------------------------------------------------------
+// SID reset.
+// ----------------------------------------------------------------------------
+void WaveformGenerator::reset()
+{
+  accumulator = 0;
+  shift_register = 0x7ffff8;
+  freq = 0;
+  pw = 0;
+
+  test = 0;
+  ring_mod = 0;
+  sync = 0;
+
+  msb_rising = false;
+}
+
+RESID_NAMESPACE_STOP