ColecoJoystickIO.cc

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#include "ColecoJoystickIO.hh"
#include "MSXMotherBoard.hh"
#include "Reactor.hh"
#include "JoystickPort.hh"
#include "Math.hh"
#include "enumerate.hh"
#include "serialize.hh"
 
namespace openmsx {
 
ColecoJoystickIO::ColecoJoystickIO(const DeviceConfig& config)
        : MSXDevice(config)
        , keyboard(
                config.getMotherBoard(),
                config.getMotherBoard().getScheduler(),
                config.getMotherBoard().getCommandController(),
                config.getMotherBoard().getReactor().getEventDistributor(),
                config.getMotherBoard().getMSXEventDistributor(),
                config.getMotherBoard().getStateChangeDistributor(),
                Keyboard::MATRIX_CVJOY,
                config)
{
        MSXMotherBoard& motherBoard = getMotherBoard();
        auto time = getCurrentTime();
        for (auto [i, port] : enumerate(ports)) {
                port = &motherBoard.getJoystickPort(unsigned(i));
                // Clear strobe bit, or MSX joysticks will stay silent.
                port->write(0xFB, time);
        }
        reset(time);
}
 
void ColecoJoystickIO::reset(EmuTime::param /*time*/)
{
        joyMode = 0;
}
 
byte ColecoJoystickIO::peekIO(word port, EmuTime::param time) const
{
        const int joyPort = (port >> 1) & 1;
        const byte joyStatus = ports[joyPort]->read(time);
        const byte* keys = keyboard.getKeys();
 
        if (joyMode == 0) {
                // Combine keypad rows, convert to high-active and drop unused bits.
                // Note: The keypad can only return one button press, but I don't know
                //       what happens if you press two buttons at once.
                unsigned keypadStatus = ~(
                        keys[joyPort * 2 + 2] | (keys[joyPort * 2 + 3] << 8)
                        ) & 0xFFF;
                constexpr byte keyEnc[] = {
                        0xF, 0xA, 0xD, 0x7, 0xC, 0x2, 0x3, 0xE, 0x5, 0x1, 0xB, 0x9, 0x6
                        };
                return keyEnc[Math::findFirstSet(keypadStatus)]
                     | 0x30 // not connected
                     | ((joyStatus << 1) & (keys[joyPort] >> 1) & 0x40); // trigger B
        } else {
                // Map MSX joystick direction bits to Coleco bits.
                byte value =
                          ( joyStatus       & 0x01) // up
                        | ((joyStatus >> 2) & 0x02) // right
                        | ((joyStatus << 1) & 0x04) // down
                        | ((joyStatus << 1) & 0x08) // left
                        | 0x30 // not connected
                        | ((joyStatus << 2) & 0x40) // trigger A
                        ;
                        // Note: ColEm puts 0 in bit 7.
                        //       I don't know why this is different from bit 4 and 5.
                // Combine with row 0/1 of keyboard matrix.
                return value & (keys[joyPort] | ~0x4F);
        }
}
 
byte ColecoJoystickIO::readIO(word port, EmuTime::param time)
{
        return peekIO(port, time);
}
 
void ColecoJoystickIO::writeIO(word port, byte /*value*/, EmuTime::param /*time*/)
{
        joyMode = (port >> 6) & 1;
}
 
template<typename Archive>
void ColecoJoystickIO::serialize(Archive& ar, unsigned version)
{
        ar.template serializeBase<MSXDevice>(*this);
        ar.serialize("joyMode", joyMode);
        if (ar.versionAtLeast(version, 2)) {
                ar.serialize("keyboard", keyboard);
        }
}
INSTANTIATE_SERIALIZE_METHODS(ColecoJoystickIO);
REGISTER_MSXDEVICE(ColecoJoystickIO, "ColecoJoystick");
 
} // namespace openmsx