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-rw-r--r--lib/nes/sys/cartridge.cc60
1 files changed, 18 insertions, 42 deletions
diff --git a/lib/nes/sys/cartridge.cc b/lib/nes/sys/cartridge.cc
index 43f9430..fcb7e84 100644
--- a/lib/nes/sys/cartridge.cc
+++ b/lib/nes/sys/cartridge.cc
@@ -5,68 +5,44 @@
namespace nes::sys
{
- cartridge::cartridge(status const status)
- : status_{ status }
- {
- }
-
- auto cartridge::from_data(void const* data, u32 const length) -> cartridge
+ cartridge::cartridge(u8 const* data, u32 const length)
{
// See: https://www.nesdev.org/wiki/INES
auto const bytes = static_cast<u8 const*>(data);
- auto res = cartridge{ status::success };
// Parse header.
- if (length < header_length) { return cartridge{ status::error_invalid_ines_data }; }
+ if (length < header_length) { return; }
auto const h = header{ bytes };
if (h.get_magic_0() != 'N' || h.get_magic_1() != 'E' || h.get_magic_2() != 'S' || h.get_magic_3() != 0x1A)
{
- return cartridge{ status::error_invalid_ines_data };
+ return;
}
auto const mapper_number = static_cast<u8>((h.get_mapper_high() << 4) | (h.get_mapper_low() << 0));
- res.mapper_ = &mapper::get(mapper_number);
- res.name_table_arrangement_ = h.get_name_table_arrangement();
+ mapper_ = &mapper::get(mapper_number);
+ name_table_arrangement_ = h.get_name_table_arrangement();
// Load program data.
auto offset = u32{ 16 };
if (h.get_has_trainer()) { offset += 512; }
- res.prg_rom_size_ = h.get_prg_rom_banks() * prg_rom_bank_size;
- if (length < offset + res.prg_rom_size_) { return cartridge{ status::error_invalid_ines_data }; }
- if (res.prg_rom_size_ > max_prg_rom_size) { return cartridge{ status::error_invalid_ines_data }; }
- std::copy_n(&bytes[offset], res.prg_rom_size_, res.prg_rom_);
+ prg_rom_size_ = h.get_prg_rom_banks() * prg_rom_bank_size;
+ if (length < offset + prg_rom_size_) { return; }
+ if (prg_rom_size_ > max_prg_rom_size) { return; }
+ std::copy_n(&bytes[offset], prg_rom_size_, prg_rom_);
- offset += res.prg_rom_size_;
+ offset += prg_rom_size_;
- res.chr_rom_size_ = h.get_chr_rom_banks() * chr_rom_bank_size;
- if (length < offset + res.chr_rom_size_) { return cartridge{ status::error_invalid_ines_data }; }
- if (res.chr_rom_size_ > max_chr_rom_size) { return cartridge{ status::error_invalid_ines_data }; }
- std::copy_n(&bytes[offset], res.chr_rom_size_, res.chr_rom_);
-
- res.ram_size_ = std::max(h.get_ram_banks(), 1u) * ram_bank_size;
- if (res.ram_size_ > max_ram_size) { return cartridge{ status::error_invalid_ines_data }; }
-
- if (auto const status = res.get_mapper().validate(res); status != status::success)
- {
- return cartridge{ status };
- }
-
- return res;
- }
-
- auto cartridge::from_file(std::string_view const path) -> cartridge
- {
- auto stream = std::ifstream{ path, std::ios::binary };
- if (!stream.good()) { return cartridge{ status::error_system_error }; }
+ chr_rom_size_ = h.get_chr_rom_banks() * chr_rom_bank_size;
+ if (length < offset + chr_rom_size_) { return; }
+ if (chr_rom_size_ > max_chr_rom_size) { return; }
+ std::copy_n(&bytes[offset], chr_rom_size_, chr_rom_);
- stream.seekg(0, std::ios::end);
- auto const length = stream.tellg();
- stream.seekg(0, std::ios::beg);
- auto data = std::vector<u8>(static_cast<u32>(length));
- stream.read(reinterpret_cast<char*>(data.data()), length);
+ ram_size_ = std::max(h.get_ram_banks(), 1u) * ram_bank_size;
+ if (ram_size_ > max_ram_size) { return; }
- return from_data(data.data(), static_cast<u32>(length));
+ status_ = get_mapper().validate(*this);
+ if (status_ != status::success) { return; }
}
} // namespace nes::sys \ No newline at end of file