content: /*
   * HalfNES by Andrew Hoffman
   * Licensed under the GNU GPL Version 3. See LICENSE file
   */
  package com.grapeshot.halfnes.mappers;
  
  import com.grapeshot.halfnes.utils;
  import java.util.Arrays;
  
  /**
   *
   * @author Andrew
   */
  public class AfterburnerMapper extends Mapper {
      //the Afterburner mapper is special in that it uses ROM name tables
  
      private int bank = 0x0;
      boolean useromnt = false;
      int romnt1, romnt2;
  
      @Override
      public void loadrom() throws BadMapperException {
          //needs to be in every mapper. Fill with initial cfg
          super.loadrom();
          //movable bank, should really be random. eh, effort
          for (int i = 0; i < 16; ++i) {
              prg_map[i] = (1024 * i) & (prgsize - 1);
          }
          //fixed bank
          for (int i = 1; i <= 16; ++i) {
              prg_map[32 - i] = prgsize - (1024 * i);
          }
          for (int i = 0; i < 8; ++i) {
              chr_map[i] = (1024 * i) & (chrsize - 1);
          }
      }
  
      @Override
      public final void cartWrite(int addr, int data) {
          if (addr < 0x8000 || addr > 0xffff) {
              super.cartWrite(addr, data);
              return;
          } else if (addr <= 0x8fff) {
              setppubank(2, 0, data);
          } else if (addr <= 0x9fff) {
              setppubank(2, 2, data);
          } else if (addr <= 0xafff) {
              setppubank(2, 4, data);
          } else if (addr <= 0xbfff) {
              setppubank(2, 6, data);
          } else if (addr <= 0xcfff) {
              romnt1 = data | 0x80;
          } else if (addr <= 0xdfff) {
              romnt2 = data | 0x80;
          } else if (addr <= 0xefff) {
              useromnt = ((data & (utils.BIT4)) != 0);
              setmirroring(((data & (utils.BIT0)) != 0) ? MirrorType.H_MIRROR : MirrorType.V_MIRROR);
          } else if (addr <= 0xffff) {
              bank = data & 0xf;
              //remap PRG bank (1st bank switchable, 2nd bank mapped to LAST bank)
              for (int i = 0; i < 16; ++i) {
                  prg_map[i] = (1024 * (i + 16 * bank)) & (prgsize - 1);
              }
          }
      }
  
      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 * ((banksize * banknum) + i)) % chrsize;
          }
      }
  
      public int ppuRead(int addr) {
          if (addr < 0x2000) {
              return chr[chr_map[addr >> 10] + (addr & 1023)];
          } else {
              switch (addr & 0xc00) {
                  case 0:
                      return (useromnt ? chr[(addr & 0x3ff) + (romnt1 * 1024)] : nt0[addr & 0x3ff]);
                  case 0x400:
                      return (useromnt ? chr[(addr & 0x3ff) + (romnt2 * 1024)] : nt1[addr & 0x3ff]);
                  case 0x800:
                      return (useromnt ? chr[(addr & 0x3ff) + (romnt2 * 1024)] : nt2[addr & 0x3ff]);
                  case 0xc00:
                  default:
                      if (addr >= 0x3f00) {
                          addr &= 0x1f;
                          if (addr >= 0x10 && ((addr & 3) == 0)) {
                              addr -= 0x10;
                          }
                          return ppu.pal[addr];
                      } else {
                          return (useromnt ? chr[(addr & 0x3ff) + (romnt1 * 1024)] : nt3[addr & 0x3ff]);
                      }
              }
          }
      }
  }
  