content: package com.grapeshot.halfnes.mappers;
  
  import com.grapeshot.halfnes.*;
  
  public class Mapper182 extends Mapper {
      //Pirate MMC3 clone with scrambled registers
  
      private int whichbank = 0;
      private boolean prgconfig = false;
      private boolean chrconfig = false;
      private int irqctrreload = 0;
      private int irqctr = 0;
      private boolean irqenable = false;
      private boolean irqreload = false;
      private int bank6 = 0;
      private int[] chrreg = {0, 0, 0, 0, 0, 0};
      private boolean interrupted = false;
  
      @Override
      public void loadrom() throws BadMapperException {
          //needs to be in every mapper. Fill with initial cfg
          super.loadrom();
          for (int i = 1; i <= 32; ++i) {
              prg_map[32 - i] = prgsize - (1024 * i);
          }
  
          for (int i = 0; i < 8; ++i) {
              chr_map[i] = 0;
          }
          setbank6();
          //cpuram.setPrgRAMEnable(false);
      }
  
      @Override
      public final void cartWrite(int addr, int data) {
          if (addr < 0x8000 || addr > 0xffff) {
              super.cartWrite(addr, data);
              return;
          }
          //bankswitches here
          //different register for even/odd writes
          if (((addr & (utils.BIT0)) != 0)) {
              //odd registers
              if ((addr >= 0x8000) && (addr <= 0x9fff)) {
                  //mirroring setup
                  setmirroring(((data & (utils.BIT0)) != 0) ? MirrorType.H_MIRROR : MirrorType.V_MIRROR);
              } else if ((addr >= 0xA000) && (addr <= 0xBFFF)) {
                  //prg ram write protect
                  //cpuram.setPrgRAMEnable(!utils.getbit(data, 7));
              } else if ((addr >= 0xC000) && (addr <= 0xDFFF)) {
                  //any value here reloads irq counter _@ end of scanline_
                  irqreload = true;
                  irqctrreload = data;
              } else if ((addr >= 0xE000) && (addr <= 0xFFFF)) {
                  //any value here enables interrupts
                  irqenable = true;
              }
          } else {
              //even registers
              if ((addr >= 0xA000) && (addr <= 0xBFFF)) {
                  //bank select
                  whichbank = data & 7;
                  prgconfig = ((data & (utils.BIT4)) != 0);
                  //if bit is false, 8000-9fff swappable and c000-dfff fixed to 2nd to last bank
                  //if bit is true, c000-dfff swappable and 8000-9fff fixed to 2nd to last bank
                  chrconfig = ((data & (utils.BIT5)) != 0);
                  //if false: 2 2k banks @ 0000-0fff, 4 1k banks in 1000-1fff
                  //if true: 4 1k banks @ 0000-0fff, 2 2k banks @ 1000-1fff
                  setupchr();
                  setbank6(); //OOPS FORGOT THIS I GUESS
              } else if ((addr >= 0xC000) && (addr <= 0xDFFF)) {
                  //bank select
                  switch (whichbank) {
                      case 0:
                          chrreg[0] = data;
                          setupchr();
                          break;
                      case 1:
                          chrreg[3] = data;
                          setupchr();
                          break;
                      case 2:
                          chrreg[1] = data;
                          setupchr();
                          break;
                      case 3:
                          chrreg[5] = data;
                          setupchr();
                          break;
                      case 4:
                          bank6 = data;
                          setbank6();
                          break;
                      case 5:
                          //bank 5 always swappable, always in same place
                          for (int i = 0; i < 8; ++i) {
                              prg_map[i + 8] = (1024 * (i + (data * 8))) % prgsize;
                          }
                          break;
                      case 6:
                          chrreg[2] = data;
                          setupchr();
                          break;
                      case 7:
                          chrreg[4] = data;
                          setupchr();
                          break;
                  }
              } else if ((addr >= 0xE000) && (addr <= 0xFFFF)) {
                  //any value here disables IRQ and acknowledges
                  if (interrupted) {
                      --cpu.interrupt;
                  }
                  interrupted = false;
                  irqenable = false;
                  irqctr = irqctrreload;
              }
          }
      }
  
      private void setupchr() {
          if (chrconfig) {
  
              setppubank(1, 0, chrreg[2]);
              setppubank(1, 1, chrreg[3]);
              setppubank(1, 2, chrreg[4]);
              setppubank(1, 3, chrreg[5]);
              //Lowest bit of bank number IS IGNORED for the 2k banks
              setppubank(2, 4, (chrreg[0] >> 1) << 1);
              setppubank(2, 6, (chrreg[1] >> 1) << 1);
  
          } else {
              setppubank(1, 4, chrreg[2]);
              setppubank(1, 5, chrreg[3]);
              setppubank(1, 6, chrreg[4]);
              setppubank(1, 7, chrreg[5]);
  
              setppubank(2, 0, (chrreg[0] >> 1) << 1);
              setppubank(2, 2, (chrreg[1] >> 1) << 1);
          }
      }
  
      private void setbank6() {
          if (!prgconfig) {
              //map c000-dfff to last bank, 8000-9fff to selected bank
              for (int i = 0; i < 8; ++i) {
                  prg_map[i] = (1024 * (i + (bank6 * 8))) % prgsize;
                  prg_map[i + 16] = ((prgsize - 16384) + 1024 * i);
              }
          } else {
              //map 8000-9fff to last bank, c000 to dfff to selected bank
              for (int i = 0; i < 8; ++i) {
                  prg_map[i] = ((prgsize - 16384) + 1024 * i);
                  prg_map[i + 16] = (1024 * (i + (bank6 * 8))) % prgsize;
              }
          }
      }
  
      @Override
      public void notifyscanline(int scanline) {
          //Scanline counter
          if (scanline > 239 && scanline != 261) {
              //clocked on LAST line of vblank and all lines of frame. Not on 240.
              return;
          }
          if (!ppu.mmc3CounterClocking()) {
              return;
          }
  
          if (irqreload) {
              irqreload = false;
              irqctr = irqctrreload;
          }
  
          if (irqctr-- <= 0) {
              if (irqctrreload == 0) {
                  return;
                  //irqs stop being generated if reload set to zero
              }
              if (irqenable && !interrupted) {
                  ++cpu.interrupt;
                  interrupted = true;
              }
              irqctr = irqctrreload;
          }
      }
  
      private void setppubank(int banksize, int bankpos, int banknum) {
  //        System.err.println(banksize + ", " + bankpos + ", "+ banknum);
          for (int i = 0; i < banksize; ++i) {
              chr_map[i + bankpos] = (1024 * ((banknum) + i)) % chrsize;
          }
      }
  }
  