1 files changed, 119 insertions, 0 deletions
diff --git a/src/chips/ymfm_opl2.cpp b/src/chips/ymfm_opl2.cpp
new file mode 100644
index 0000000..07705ee
--- /dev/null
+++ b/src/chips/ymfm_opl2.cpp
@@ -0,0 +1,119 @@
+/*
+ * Interfaces over Yamaha OPL3 (ym3812) chip emulators
+ *
+ * Copyright (c) 2017-2025 Vitaly Novichkov (Wohlstand)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "ymfm_opl2.h"
+#include "ymfm/ymfm_opl.h"
+#include <cstring>
+
+YmFmOPL2::YmFmOPL2() :
+    OPLChipBaseT(),
+    m_headPos(0),
+    m_tailPos(0),
+    m_queueCount(0)
+{
+    ymfm::ymfm_interface* intf = new ymfm::ymfm_interface;
+    m_intf = intf;
+    m_chip = new ymfm::ym3812(*intf);
+    setRate(m_rate);
+}
+
+YmFmOPL2::~YmFmOPL2()
+{
+    ymfm::ym3812 *chip_r = reinterpret_cast<ymfm::ym3812*>(m_chip);
+    ymfm::ymfm_interface *intf_r = reinterpret_cast<ymfm::ymfm_interface*>(m_intf);
+    delete chip_r;
+    delete intf_r;
+}
+
+void YmFmOPL2::setRate(uint32_t rate)
+{
+    OPLChipBaseT::setRate(rate);
+    ymfm::ym3812 *chip_r = reinterpret_cast<ymfm::ym3812*>(m_chip);
+    chip_r->reset();
+}
+
+void YmFmOPL2::reset()
+{
+    OPLChipBaseT::reset();
+    ymfm::ym3812 *chip_r = reinterpret_cast<ymfm::ym3812*>(m_chip);
+    chip_r->reset();
+}
+
+void YmFmOPL2::writeReg(uint16_t addr, uint8_t data)
+{
+    Reg &back = m_queue[m_headPos++];
+    back.addr = addr;
+    back.data = data;
+
+    if(m_headPos >= c_queueSize)
+        m_headPos = 0;
+
+    ++m_queueCount;
+}
+
+void YmFmOPL2::nativeGenerate(int16_t *frame)
+{
+    ymfm::ym3812 *chip_r = reinterpret_cast<ymfm::ym3812*>(m_chip);
+    ymfm::ym3812::output_data frames_i;
+
+    uint32_t addr1 = 0xffff, addr2 = 0xffff;
+    uint8_t data1 = 0, data2 = 0;
+
+    // see if there is data to be written; if so, extract it and dequeue
+    if(m_queueCount > 0)
+    {
+        const Reg &front = m_queue[m_tailPos++];
+
+        if(m_tailPos >= c_queueSize)
+            m_tailPos = 0;
+        --m_queueCount;
+
+        addr1 = 0 + 2 * ((front.addr >> 8) & 3);
+        data1 = front.addr & 0xff;
+        addr2 = addr1 + 1;
+        data2 = front.data;
+    }
+
+    // write to the chip
+    if(addr1 != 0xffff)
+    {
+        chip_r->write(addr1, data1);
+        chip_r->write(addr2, data2);
+    }
+
+    chip_r->generate(&frames_i);
+    frame[0] = static_cast<int16_t>(ymfm::clamp(frames_i.data[0] / 2, -32768, 32767));
+    frame[1] = frame[0];
+}
+
+const char *YmFmOPL2::emulatorName()
+{
+    return "YMFM OPL2";
+}
+
+bool YmFmOPL2::hasFullPanning()
+{
+    return false;
+}
+
+OPLChipBase::ChipType YmFmOPL2::chipType()
+{
+    return CHIPTYPE_OPL2;
+}