public static GameMemory OpenFile(string filename)
{
byte[] file = ReadFile(filename);
int length = file.Length;
if(length < headerSize)
{
throw new ArgumentException($"{filename} is not a valid story file");
}
ImmutableByteWrapper wrapper = new ImmutableByteWrapper(file);
byte high = wrapper.ReadAddress(Bits.AddressOfHighByte(baseOffset));
byte low = wrapper.ReadAddress(Bits.AddressOfLowByte(baseOffset));
int dynamicSegmentLength = (256 * high) + low;
if(dynamicSegmentLength > length)
{
throw new ArgumentException($"{filename} is not a valid story file");
}
byte[] dynamicPart = new byte[dynamicSegmentLength];
Array.Copy(file, dynamicPart, dynamicSegmentLength);
byte[] staticPart = new byte[length - dynamicSegmentLength];
Array.Copy(file, dynamicSegmentLength, staticPart, 0, length - dynamicSegmentLength);
return new GameMemory(staticPart, new ImmutableByteWrapper(dynamicPart));
}
private static string ReadAsUtf8String(ImmutableByteWrapper bulkEdits)
{
byte[] asRead = new byte[bulkEdits.Length];
for (int i = 0; i < bulkEdits.Length; i++)
{
asRead[i] = bulkEdits.ReadAddress(new ByteAddress(i));
}
return Encoding.UTF8.GetString(asRead);
}
private static void TestMemoryBase()
{
byte[] bytes = Encoding.UTF8.GetBytes("Hello World");
ImmutableByteWrapper initialState = new ImmutableByteWrapper(bytes);
ByteAddress address1 = new ByteAddress(1);
ImmutableByteWrapper edited = initialState.WriteToAddress(address1, 0x00);
//owerwrite "world"
byte[] newBytes = Encoding.UTF8.GetBytes("woid!");
IEnumerable<int> sixThruTen = Enumerable.Range(6, 5);
var multiEdits = sixThruTen.Select(val =>
{
var address = new ByteAddress(val);
var toWrite = newBytes[val - 6];
return new Tuple<ByteAddress, byte>(address, toWrite);
});
ImmutableByteWrapper bulkEdits = initialState.WriteMultipleAddress(multiEdits);
var toPrint = ReadAsUtf8String(bulkEdits);
var oldToPrint = ReadAsUtf8String(initialState);
Console.WriteLine($"Initial state has {oldToPrint} and bulk edited has {toPrint}");
int length = initialState.Length;
Console.WriteLine(edited.ReadAddress(address1));
Console.WriteLine(initialState.ReadAddress(address1));
}