110 lines
2.3 KiB
C
110 lines
2.3 KiB
C
#include "mapper000.h"
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#include <stdlib.h>
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#include <stdio.h>
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struct Mapper000* createMapper000(Byte prg_rom_size, Byte chr_rom_size, FILE* fp)
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{
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struct Mapper000* mapper = (struct Mapper000*)malloc(sizeof(struct Mapper000));
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if (mapper == NULL)
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{
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fprintf(stderr, "Failed to create Mapper 000. Aborting\n");
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exit(-1);
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}
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mapper->prg_rom_size = prg_rom_size;
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mapper->prg_rom = (Byte*)calloc(prg_rom_size, 0x4000);
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if (mapper->prg_rom == NULL)
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{
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fprintf(stderr, "Failed to allocate cartridge PRG ROM. Aborting\n");
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exit(-1);
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}
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mapper->chr_rom_size = chr_rom_size;
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mapper->chr_rom = (Byte*)calloc(chr_rom_size, 0x2000);
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if (mapper->chr_rom == NULL)
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{
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fprintf(stderr, "Failed to allocate cartridge CHR ROM. Aborting\n");
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exit(-1);
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}
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fread(mapper->prg_rom, 0x4000, prg_rom_size, fp);
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fread(mapper->chr_rom, 0x2000, chr_rom_size, fp);
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return mapper;
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}
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void destroyMapper000(struct Mapper000* mapper)
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{
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free(mapper->chr_rom);
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free(mapper->prg_rom);
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free(mapper);
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}
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Byte Mapper000_ReadCPU(void* mapper, Word address)
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{
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struct Mapper000* sMapper = (struct Mapper000*)mapper;
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Byte val = 0x00;
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if (address >= 0x6000 && address < 0x8000)
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{
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fprintf(stderr, "This Mapper 000 implementation doesnt support FamilyBasic PRG RAM\n");
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exit(-1);
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}
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else if (address >= 0x8000)
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{
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Word effectiveAddress = address - 0x8000;
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effectiveAddress %= 0x4000 * (sMapper->prg_rom_size == 1);
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val = sMapper->prg_rom[effectiveAddress];
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}
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else
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{
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fprintf(stderr, "Cartridge read access violation by the CPU at $%04X\n", address);
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exit(-1);
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}
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return val;
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}
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Byte Mapper000_ReadPPU(void* mapper, Word address)
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{
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struct Mapper000* sMapper = (struct Mapper000*)mapper;
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Byte val = 0x00;
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if (address >= 0x2000)
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{
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fprintf(stderr, "Cartridge read access violation by the PPU at $%04X\n", address);
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exit(-1);
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}
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else
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{
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val = sMapper->chr_rom[address];
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}
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return val;
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}
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void Mapper000_WriteCPU(void* mapper, Word address, Byte value)
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{
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// nothing
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}
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void Mapper000_WritePPU(void* mapper, Word address, Byte value)
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{
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// nothing
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}
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void Mapper000_GetPatternTableTexture(void* mapper, SDL_Texture* texture, int index)
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{
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struct Mapper000* sMapper = (struct Mapper000*)mapper;
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int pitch;
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void* pixels;
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SDL_LockTexture(texture, NULL, &pixels, &pitch);
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SDL_memcpy(pixels, sMapper->chr_rom + (size_t)0x1000 * index, 0x1000);
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SDL_UnlockTexture(texture);
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}
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