diff options
Diffstat (limited to 'lib/nes/mapper.cc')
| -rw-r--r-- | lib/nes/mapper.cc | 172 |
1 files changed, 0 insertions, 172 deletions
diff --git a/lib/nes/mapper.cc b/lib/nes/mapper.cc deleted file mode 100644 index 08af1ae..0000000 --- a/lib/nes/mapper.cc +++ /dev/null @@ -1,172 +0,0 @@ -#include "nes/mapper.hh" -#include "nes/cartridge.hh" - -namespace nes -{ - namespace - { - // ------------------------------------------------------------------------------------------------------------- - // NROM - // ------------------------------------------------------------------------------------------------------------- - - class mapper_nrom final : public mapper - { - public: - explicit mapper_nrom() = default; - - auto validate(cartridge& cartridge) -> status override - { - if (cartridge.get_ram_length() != 0x2000) - { - return status::error_invalid_ines_data; - } - - if (cartridge.get_prg_rom_length() != 0x4000 && cartridge.get_prg_rom_length() != 0x8000) - { - return status::error_invalid_ines_data; - } - - if (cartridge.get_chr_rom_length() != 0x2000) - { - return status::error_invalid_ines_data; - } - - return status::success; - } - - auto read_cpu(address const addr, cartridge& cartridge) -> std::uint8_t override - { - if (addr <= address{ 0x5FFF }) - { - return 0x0; - } - if (addr <= address{ 0x7FFF }) - { - return cartridge.get_ram()[addr.get_absolute() - 0x6000]; - } - if (addr <= address{ 0xBFFF }) - { - auto const rel = addr.get_absolute() - 0x8000u; - return cartridge.get_prg_rom()[rel]; - } - if (addr <= address{ 0xFFFF }) - { - auto rel = addr.get_absolute() - 0xC000u; - if (cartridge.get_prg_rom_length() > 0x4000) { rel += 0x4000; } - return cartridge.get_prg_rom()[rel]; - } - - return 0x0; - } - - auto write_cpu(address const addr, std::uint8_t const value, cartridge& cartridge) -> void override - { - if (addr <= address{ 0x5FFF }) - { - return; - } - if (addr <= address{ 0x7FFF }) - { - cartridge.get_ram_mut()[addr.get_absolute() - 0x6000] = value; - return; - } - } - - auto read_ppu(address const addr, cartridge& cartridge, std::uint8_t const* vram) -> std::uint8_t override - { - if (addr <= address{ 0x1FFF }) - { - auto const rel = addr.get_absolute(); - return cartridge.get_chr_rom()[rel]; - } - if (addr <= address{ 0x3EFF }) - { - return vram[mirrored_vram_address(addr, cartridge)]; - } - - return 0x0; - } - - auto write_ppu(address const addr, std::uint8_t const value, cartridge& cartridge, std::uint8_t* vram) -> void override - { - if (addr <= address{ 0x1FFF }) - { - return; - } - if (addr <= address{ 0x3EFF }) - { - vram[mirrored_vram_address(addr, cartridge)] = value; - return; - } - } - - private: - static auto mirrored_vram_address(address const addr, cartridge const& cartridge) -> unsigned - { - auto const rel = addr.get_absolute() % 0x1000u; - - switch (cartridge.get_name_table_arrangement()) - { - case name_table_arrangement::horizontal: - // $2000 = $2400, $2800 = $2c00 - if (rel <= 0x3FF) { return 0x000u + (rel % 0x400u); } - if (rel <= 0x7FF) { return 0x000u + (rel % 0x400u); } - if (rel <= 0xBFF) { return 0x400u + (rel % 0x400u); } - if (rel <= 0xFFF) { return 0x400u + (rel % 0x400u); } - break; - case name_table_arrangement::vertical: - // $2000 = $2800, $2400 = $2c00 - if (rel <= 0x3FF) { return 0x000u + (rel % 0x400u); } - if (rel <= 0x7FF) { return 0x400u + (rel % 0x400u); } - if (rel <= 0xBFF) { return 0x000u + (rel % 0x400u); } - if (rel <= 0xFFF) { return 0x400u + (rel % 0x400u); } - break; - } - - return 0; - } - }; - - // ------------------------------------------------------------------------------------------------------------- - // Invalid - // ------------------------------------------------------------------------------------------------------------- - - class mapper_invalid final : public mapper - { - public: - explicit mapper_invalid() = default; - - auto validate(cartridge&) -> status override { return status::error_unsupported_mapper; } - auto read_cpu(address, cartridge&) -> std::uint8_t override { return 0; } - auto write_cpu(address, std::uint8_t, cartridge&) -> void override {} - auto read_ppu(address, cartridge&, std::uint8_t const*) -> std::uint8_t override { return 0; } - auto write_ppu(address, std::uint8_t, cartridge&, std::uint8_t*) -> void override {} - }; - } // namespace - - // ----------------------------------------------------------------------------------------------------------------- - // Instances - // ----------------------------------------------------------------------------------------------------------------- - - auto mapper::invalid() -> mapper& - { - static auto instance = mapper_invalid{}; - return instance; - } - - auto mapper::get(std::uint8_t const number) -> mapper& - { - switch (number) - { - case 0x00: - { - static auto instance = mapper_nrom{}; - return instance; - } - default: - { - return invalid(); - } - } - } -} // namespace nes
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