Apparently, searching the forum and the internet for help regarding derivations of sf::InputStream was fruitless, so hello! I've just registered, to ask some help for making my own stream class.
I tried following the tutorial here:
http://www.sfml-dev.org/tutorials/2.0/system-stream.phpMy class is basically a copy and paste of it, and I want to simply be able to read and decrypt my own encrypted files. As of now, though, it does nothing in special, I have left the encrypting methods empty for testing. Problem is: I haven't been able to load anything with it. Every time I try to call a loadFromStream from a sf::Font or sf::Texture, be it for a .jpg or a .png on the latter, the application crashes. What could be it? Is there already a working sf::InputStream derivation out there?
Here are my codes, you can even try to to compile them by yourself. No custom libraries and all. I wonder if it's a problem of my machine?
#pragma once
// "EncryptedStream.h"
// ---
#include <string>
#include <cstdio>
#include <stdexcept>
#include <SFML/System/InputStream.hpp>
namespace ds {
class FileCouldntOpen : public std::runtime_error {
public:
FileCouldntOpen(const std::string& filePath);
const std::string& filePath() const;
private:
std::string m_filePath;
};
// ---
void encryptFile (const std::string& inputPath, const std::string& outputPath);
class EncryptedStream : public sf::InputStream {
public:
EncryptedStream();
EncryptedStream(const EncryptedStream&) =delete;
EncryptedStream(const std::string& filePath);
~EncryptedStream();
void open (const std::string& filePath);
void close();
sf::Int64 read (void*, sf::Int64);
sf::Int64 seek (sf::Int64 position);
sf::Int64 tell();
sf::Int64 getSize();
private:
void decrypt (char*, int);
std::FILE* m_file;
};
}
#include <do/EncryptedStream.h>
// "EncryptedStream.cpp"
// ---
namespace ds {
FileCouldntOpen::FileCouldntOpen(const std::string& filePath)
: m_filePath(filePath),
std::runtime_error("Couldn't open " + filePath)
{ }
const std::string& FileCouldntOpen::filePath() const {
return m_filePath;
}
// ---
EncryptedStream::EncryptedStream()
: m_file(nullptr)
{ }
EncryptedStream::EncryptedStream
(const std::string& filePath)
{
open(filePath);
}
void EncryptedStream::open (const std::string& filePath) {
if (m_file)
std::fclose(m_file);
m_file = std::fopen(filePath.c_str(), "rb");
if (!m_file)
throw FileCouldntOpen(filePath);
}
void EncryptedStream::close() {
if (m_file)
std::fclose(m_file);
}
void encrypt (const std::string& inputPath, const std::string& outputPath) {
// ...
}
void EncryptedStream::decrypt (char* data, int size) {
// ...
}
// ---
sf::Int64 EncryptedStream::read (void* data, sf::Int64 size) {
if (m_file) {
sf::Int64 result = std::fread(data, 1, static_cast<std::size_t>(size), m_file);
decrypt(static_cast<char*>(data), size);
return result;
}
else {
return -1;
}
}
sf::Int64 EncryptedStream::seek (sf::Int64 position) {
if (m_file) {
std::fseek(m_file, static_cast<std::size_t>(position), SEEK_SET);
return tell();
}
else {
return -1;
}
}
sf::Int64 EncryptedStream::tell() {
if (m_file)
return std::ftell(m_file);
else
return -1;
}
sf::Int64 EncryptedStream::getSize() {
if (m_file) {
sf::Int64 position = tell();
std::fseek(m_file, 0, SEEK_END);
sf::Int64 size = tell();
seek(position);
return size;
}
else {
return -1;
}
}
// ---
EncryptedStream::~EncryptedStream() {
if (m_file)
std::fclose(m_file);
}
}
