AxibugEmuOnline/Core/VirtualNes.Core/Mapper/Mapper114.cs

//////////////////////////////////////////////////////////////////////////
// Mapper114                                                            //
//////////////////////////////////////////////////////////////////////////
using static VirtualNes.Core.CPU;
using static VirtualNes.MMU;
using BYTE = System.Byte;
using INT = System.Int32;


namespace VirtualNes.Core
{
    public class Mapper114 : Mapper
    {
        BYTE reg_m, reg_a;
        BYTE[] reg_b = new BYTE[8];
        BYTE reg_c;
        BYTE irq_counter;
        BYTE irq_occur;
        public Mapper114(NES parent) : base(parent)
        {
        }

        public override void Reset()

        {
            SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
            if (VROM_1K_SIZE != 0)
            {
                SetVROM_8K_Bank(0);
            }

            reg_a = reg_c = reg_m = 0;
            for (INT i = 0; i < 8; i++)
            {
                reg_b[i] = 0;
            }
            irq_counter = 0;
            irq_occur = 0;
            nes.SetRenderMethod(EnumRenderMethod.POST_RENDER);
        }

        //void Mapper114::WriteLow(WORD addr, BYTE data)
        public override void WriteLow(ushort addr, byte data)
        {
            reg_m = data;
            SetBank_CPU();
        }

        //void Mapper114::Write(WORD addr, BYTE data)
        public override void Write(ushort addr, byte data)
        {
            if (addr == 0xE003)
            {
                irq_counter = data;
            }
            else
            if (addr == 0xE002)
            {
                irq_occur = 0;
                nes.cpu.ClrIRQ(IRQ_MAPPER);
            }
            else
            {
                switch (addr & 0xE000)
                {
                    case 0x8000:
                        if ((data & 0x01) != 0) SetVRAM_Mirror(VRAM_HMIRROR);
                        else SetVRAM_Mirror(VRAM_VMIRROR);
                        break;
                    case 0xA000:
                        reg_c = 1;
                        reg_a = data;
                        break;
                    case 0xC000:
                        if (reg_c == 0)
                        {
                            break;
                        }
                        reg_b[reg_a & 0x07] = data;
                        switch (reg_a & 0x07)
                        {
                            case 0:
                            case 1:
                            case 2:
                            case 3:
                            case 6:
                            case 7:
                                SetBank_PPU();
                                break;
                            case 4:
                            case 5:
                                SetBank_CPU();
                                break;
                        }
                        reg_c = 0;
                        break;
                }
            }
        }

        //void Mapper114::Clock(INT scanline)
        public override void Clock(int cycles)
        {
            //	if( irq_occur ) {
            //		nes.cpu.IRQ_NotPending();
            //	}
        }

        //void Mapper114::HSync(INT scanline)
        public override void HSync(int scanline)
        {
            if ((scanline >= 0 && scanline <= 239) && nes.ppu.IsDispON())
            {
                if (irq_counter != 0)
                {
                    irq_counter--;
                    if (irq_counter == 0)
                    {
                        irq_occur = 0xFF;
                        nes.cpu.SetIRQ(IRQ_MAPPER);
                    }
                }
            }
        }

        void SetBank_CPU()
        {
            if ((reg_m & 0x80) != 0)
            {
                SetPROM_16K_Bank(4, reg_m & 0x1F);
            }
            else
            {
                SetPROM_8K_Bank(4, reg_b[4]);
                SetPROM_8K_Bank(5, reg_b[5]);
            }
        }

        void SetBank_PPU()
        {
            SetVROM_2K_Bank(0, reg_b[0] >> 1);
            SetVROM_2K_Bank(2, reg_b[2] >> 1);
            SetVROM_1K_Bank(4, reg_b[6]);
            SetVROM_1K_Bank(5, reg_b[1]);
            SetVROM_1K_Bank(6, reg_b[7]);
            SetVROM_1K_Bank(7, reg_b[3]);
        }

        //void Mapper114::SaveState(LPBYTE p)
        public override void SaveState(byte[] p)
        {
            for (int i = 0; i < 8; i++)
            {
                p[i] = reg_b[i];
            }

            p[8] = reg_m;
            p[9] = reg_a;
            p[10] = reg_c;
            p[11] = irq_counter;
            p[12] = irq_occur;
        }

        //void Mapper114::LoadState(LPBYTE p)
        public override void LoadState(byte[] p)
        {
            for (int i = 0; i < 8; i++)
            {
                reg_b[i] = p[i];
            }
            reg_m = p[8];
            reg_a = p[9];
            reg_c = p[10];
            irq_counter = p[11];
            irq_occur = p[12];
        }

        public override bool IsStateSave()
        {
            return true;
        }

    }
}