From b1d1573702f21e3104606d6ade5f5d39ec86a33a Mon Sep 17 00:00:00 2001 From: Hannes Schulze Date: Thu, 23 Jan 2025 22:02:11 +0100 Subject: restructure project --- src/nes/cartridge.cc | 70 ---------------------------------------------------- 1 file changed, 70 deletions(-) delete mode 100644 src/nes/cartridge.cc (limited to 'src/nes/cartridge.cc') diff --git a/src/nes/cartridge.cc b/src/nes/cartridge.cc deleted file mode 100644 index 861dc13..0000000 --- a/src/nes/cartridge.cc +++ /dev/null @@ -1,70 +0,0 @@ -#include "nes/cartridge.hh" -#include - -namespace nes -{ - namespace - { - constexpr auto prg_rom_bank_size = std::size_t{ 16 * 1024 }; - constexpr auto chr_rom_bank_size = std::size_t{ 8 * 1024 }; - constexpr auto ram_bank_size = std::size_t{ 8 * 1024 }; - } // namespace - - auto cartridge::from_data(void const* data, std::size_t const length) -> cartridge - { - // See: https://www.nesdev.org/wiki/INES - - auto const bytes = static_cast(data); - auto res = cartridge{}; - res.is_valid_ = true; - - // Parse header. - if (length < 16) { return cartridge{}; } - if (bytes[0] != 'N' || bytes[1] != 'E' || bytes[2] != 'S' || bytes[3] != 0x1A) { return cartridge{}; } - auto const prg_rom_banks = bytes[4]; - auto const chr_rom_banks = bytes[5]; - auto const control_1 = bytes[6]; - auto const control_2 = bytes[7]; - auto const ram_banks = (bytes[8] != 0) ? bytes[8] : 1; - auto const has_trainer = (control_1 & 0b00000100) != 0; - - res.mapper_number_ = - (control_1 & 0b11110000) >> 4 | - (control_2 & 0b11110000) >> 0; - res.name_table_arrangement_ = (control_1 & 0b00000001) != 0 - ? name_table_arrangement::vertical - : name_table_arrangement::horizontal; - - // Load program data. - auto offset = std::size_t{ 16 }; - if (has_trainer) { offset += 512; } - - auto const prg_rom_size = prg_rom_banks * prg_rom_bank_size; - if (length < offset + prg_rom_size) { return cartridge{}; } - res.prg_rom_ = std::vector(&bytes[offset], &bytes[offset + prg_rom_size]); - - offset += prg_rom_size; - - auto const chr_rom_size = chr_rom_banks * chr_rom_bank_size; - if (length < offset + chr_rom_size) { return cartridge{}; } - res.chr_rom_ = std::vector(&bytes[offset], &bytes[offset + chr_rom_size]); - - res.ram_ = std::vector(ram_banks * ram_bank_size, std::uint8_t{ 0 }); - - 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{}; } - - stream.seekg(0, std::ios::end); - auto const length = stream.tellg(); - stream.seekg(0, std::ios::beg); - auto data = std::vector(length); - stream.read(reinterpret_cast(data.data()), data.size()); - - return from_data(data.data(), data.size()); - } -} // namespace nes \ No newline at end of file -- cgit v1.3.1