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CLK/Storage/Data/ZX8081.cpp

133 lines
4.4 KiB
C++

//
// ZX8081.cpp
// Clock Signal
//
// Created by Thomas Harte on 08/06/2017.
// Copyright 2017 Thomas Harte. All rights reserved.
//
#include "ZX8081.hpp"
using namespace Storage::Data::ZX8081;
static uint16_t short_at(std::size_t address, const std::vector<uint8_t> &data) {
return uint16_t(data[address] | (data[address + 1] << 8));
}
static std::shared_ptr<File> ZX80FileFromData(const std::vector<uint8_t> &data) {
// Does this look like a ZX80 file?
if(data.size() < 0x28) return nullptr;
// uint16_t next_line_number = short_at(0x2, data);
// uint16_t first_visible_line = short_at(0x13, data);
uint16_t vars = short_at(0x8, data);
uint16_t end_of_file = short_at(0xa, data);
uint16_t display_address = short_at(0xc, data);
// check that the end of file is contained within the supplied data
if(size_t(end_of_file - 0x4000) > data.size()) return nullptr;
// check for the proper ordering of buffers
if(vars > end_of_file) return nullptr;
if(end_of_file > display_address) return nullptr;
// TODO: does it make sense to inspect the tokenised BASIC?
// It starts at 0x4028 and proceeds as [16-bit line number] [tokens] [0x76],
// but I'm as yet unable to find documentation of the tokens.
// TODO: check that the line numbers declared above exist (?)
auto file = std::make_shared<File>();
file->data = data;
file->isZX81 = false;
return file;
}
static std::shared_ptr<File> ZX81FileFromData(const std::vector<uint8_t> &data) {
// Does this look like a ZX81 file?
// Look for a file name.
std::size_t data_pointer = 0;
std::vector<uint8_t> name_data;
std::size_t c = 11;
while(c < data.size() && c--) {
name_data.push_back(data[data_pointer] & 0x3f);
if(data[data_pointer] & 0x80) break;
data_pointer++;
}
if(!c) return nullptr;
data_pointer++;
if(data.size() < data_pointer + 0x405e - 0x4009) return nullptr;
// if(data[data_pointer]) return nullptr;
// uint16_t vars = short_at(data_pointer + 0x4010 - 0x4009, data);
uint16_t end_of_file = short_at(data_pointer + 0x4014 - 0x4009, data);
// uint16_t display_address = short_at(0x400c - 0x4009, data);
// check that the end of file is contained within the supplied data
if(data_pointer + end_of_file - 0x4009 > data.size()) return nullptr;
// check for the proper ordering of buffers
// if(vars > end_of_file) return nullptr;
// if(end_of_file > display_address) return nullptr;
// TODO: does it make sense to inspect the tokenised BASIC?
// It starts at 0x4028 and proceeds as [16-bit line number] [tokens] [0x76],
// but I'm as yet unable to find documentation of the tokens.
// TODO: check that the line numbers declared above exist (?)
auto file = std::make_shared<File>();
file->name = StringFromData(name_data, true);
file->data = data;
file->isZX81 = true;
return file;
}
std::shared_ptr<File> Storage::Data::ZX8081::FileFromData(const std::vector<uint8_t> &data) {
std::shared_ptr<Storage::Data::ZX8081::File> result = ZX81FileFromData(data);
if(result) return result;
return ZX80FileFromData(data);
}
// MARK: - String conversion
std::wstring Storage::Data::ZX8081::StringFromData(const std::vector<uint8_t> &data, bool is_zx81) {
std::wstring string;
wchar_t zx80_map[64] = {
' ', u'\u2598', u'\u259d', u'\u2580', u'\u2596', u'\u258c', u'\u259e', u'\u259b', u'\u2588', u'\u2584', u'\u2580', '"', u'\u00a3', '$', ':', '?',
'(', ')', '>', '<', '=', '+', '-', '*', '/', ';', ',', '.', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
};
// TODO: the block character conversions shown here are in the wrong order
wchar_t zx81_map[64] = {
' ', u'\u2598', u'\u259d', u'\u2580', u'\u2596', u'\u258c', u'\u259e', u'\u259b', u'\u2588', u'\u2584', u'\u2580', '"', u'\u00a3', '$', ':', '?',
'(', ')', '-', '+', '*', '/', '=', '>', '<', ';', ',', '.', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
};
wchar_t *map = is_zx81 ? zx81_map : zx80_map;
for(uint8_t byte : data) {
string.push_back(map[byte & 0x3f]);
}
return string;
}
std::vector<uint8_t> Storage::Data::ZX8081::DataFromString(const std::wstring &string, bool is_zx81) {
std::vector<uint8_t> data;
// TODO
(void)string;
(void)is_zx81;
return data;
}