Imported existing sources

nescorelib/mappers/mapper004.cpp

@@ -0,0 +1,178 @@
+#include "mapper004.h"
+
+// local includes
+#include "nesemulator.h"
+#include "utils/datastreamutils.h"
+
+QString Mapper004::name() const
+{
+    return QStringLiteral("MMC3");
+}
+
+quint8 Mapper004::mapper() const
+{
+    return 4;
+}
+
+void Mapper004::hardReset()
+{
+    Board::hardReset();
+
+    // Flags
+    m_flagC = false;
+    m_flagP = false;
+    m_address8001 = 0;
+
+    m_prgReg[0] = 0;
+    m_prgReg[1] = 1;
+    m_prgReg[2] = prgRom8KbMask()-1;
+    m_prgReg[3] = prgRom8KbMask();
+
+    setupPRG();
+
+    // CHR
+    for (int i = 0; i < 6; i++)
+        m_chrReg[i] = 0;
+
+    // IRQ
+    m_irqEnabled = false;
+    m_irqCounter = 0;
+    m_irqReload = 0xFF;
+    m_oldIrqCounter = 0;
+    m_mmc3AltBehavior = false;
+    m_irqClear = false;
+
+//    switch (GameCartInfo.chip_type[0].ToLower())
+//    {
+//    case "mmc3a": mmc3_alt_behavior = true; break;
+//    case "mmc3b": mmc3_alt_behavior = false; break;
+//    case "mmc3c": mmc3_alt_behavior = false; break;
+//    }
+}
+
+void Mapper004::writePrg(quint16 address, quint8 value)
+{
+    switch (address & 0xE001)
+    {
+    case 0x8000:
+        m_address8001 = value & 0x7;
+        m_flagC = (value & 0x80) != 0;
+        m_flagP = (value & 0x40) != 0;
+        setupCHR();
+        setupPRG(); break;
+    case 0x8001:
+        switch (m_address8001)
+        {
+        case 0:
+        case 1:
+        case 2:
+        case 3:
+        case 4:
+        case 5:
+            m_chrReg[m_address8001] = value; setupCHR();
+            break;
+        case 6:
+        case 7:
+            m_prgReg[m_address8001 - 6] = value & prgRom8KbMask();
+            setupPRG();
+            break;
+        }
+        break;
+    case 0xA000:
+        if (m_rom.mirroring != Mirroring::Full)
+            switch1kNmt((value & 1) == 1 ? Mirroring::Horizontal : Mirroring::Vertical);
+        break;
+    case 0xA001:
+        togglePrgRamEnable(value & 0x80);
+        togglePrgRamWritableEnable((value & 0x40) == 0);
+        break;
+    case 0xC000:
+        m_irqReload = value;
+        break;
+    case 0xC001:
+        if (m_mmc3AltBehavior)
+            m_irqClear = true;
+        m_irqCounter = 0;
+        break;
+    case 0xE000:
+        m_irqEnabled = false;
+        m_emu.interrupts().removeFlag(Interrupts::IRQ_BOARD);
+        break;
+    case 0xE001:
+        m_irqEnabled = true;
+        break;
+    }
+}
+
+void Mapper004::onPpuA12RaisingEdge()
+{
+    m_oldIrqCounter = m_irqCounter;
+
+    if (m_irqCounter == 0 || m_irqClear)
+        m_irqCounter = m_irqReload;
+    else
+        m_irqCounter = m_irqCounter - 1;
+
+    if ((!m_mmc3AltBehavior || m_oldIrqCounter != 0 || m_irqClear) && m_irqCounter == 0 && m_irqEnabled)
+        m_emu.interrupts().addFlag(Interrupts::IRQ_BOARD);
+
+    m_irqClear = false;
+}
+
+void Mapper004::readState(QDataStream &dataStream)
+{
+    Board::readState(dataStream);
+
+    dataStream >> m_flagC >> m_flagP >> m_address8001 >> m_chrReg >> m_prgReg
+    // IRQ
+    >> m_irqEnabled >> m_irqCounter >> m_oldIrqCounter >> m_irqReload >> m_irqClear >> m_mmc3AltBehavior;
+}
+
+void Mapper004::writeState(QDataStream &dataStream) const
+{
+    Board::writeState(dataStream);
+
+    dataStream << m_flagC << m_flagP << m_address8001 << m_chrReg << m_prgReg
+    // IRQ
+               << m_irqEnabled << m_irqCounter << m_oldIrqCounter << m_irqReload << m_irqClear << m_mmc3AltBehavior;
+}
+
+bool Mapper004::ppuA12ToggleTimerEnabled() const
+{
+    return true;
+}
+
+bool Mapper004::ppuA12TogglesOnRaisingEdge() const
+{
+    return true;
+}
+
+void Mapper004::setupCHR()
+{
+    if (!m_flagC)
+    {
+        switch2kChr(m_chrReg[0] >> 1, CHRArea::Area0000);
+        switch2kChr(m_chrReg[1] >> 1, CHRArea::Area0800);
+        switch1kChr(m_chrReg[2], CHRArea::Area1000);
+        switch1kChr(m_chrReg[3], CHRArea::Area1400);
+        switch1kChr(m_chrReg[4], CHRArea::Area1800);
+        switch1kChr(m_chrReg[5], CHRArea::Area1C00);
+    }
+    else
+    {
+        switch2kChr(m_chrReg[0] >> 1, CHRArea::Area1000);
+        switch2kChr(m_chrReg[1] >> 1, CHRArea::Area1800);
+        switch1kChr(m_chrReg[2], CHRArea::Area0000);
+        switch1kChr(m_chrReg[3], CHRArea::Area0400);
+        switch1kChr(m_chrReg[4], CHRArea::Area0800);
+        switch1kChr(m_chrReg[5], CHRArea::Area0C00);
+    }
+}
+
+void Mapper004::setupPRG()
+{
+    switch8kPrg(m_prgReg[m_flagP ? 2 : 0], PRGArea::Area8000);
+    switch8kPrg(m_prgReg[1], PRGArea::AreaA000);
+    switch8kPrg(m_prgReg[m_flagP ? 0 : 2], PRGArea::AreaC000);
+    switch8kPrg(m_prgReg[3], PRGArea::AreaE000);
+}