qzdoom/libraries/timidityplus/timiditypp/timidity_file.h

/*
    TiMidity++ -- File interface for the pure sequencer.
    Copyright (C) 2019 Christoph Oelckers

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/ 

#pragma once
#include <stdio.h>
#include <vector>
#include <string>

namespace TimidityPlus
{

struct timidity_file
{
	std::string filename;

	virtual ~timidity_file() {}
	virtual char* gets(char* buff, int n) = 0;
	virtual long read(void* buff, int32_t size, int32_t nitems) = 0;
	virtual long seek(long offset, int whence) = 0;
	virtual long tell() = 0;
};

class SoundFontReaderInterface
{
public:
	virtual struct timidity_file* open_timidityplus_file(const char* fn) = 0;
	virtual void timidityplus_add_path(const char* path) = 0;
};


// A minimalistic sound font reader interface. Normally this should be replaced with something better tied into the host application.
#ifdef USE_BASE_INTERFACE	

// Base version of timidity_file using stdio's FILE.
struct timidity_file_FILE : public timidity_file
{
	FILE* f = nullptr;

	~timidity_file_FILE()
	{
		if (f) fclose(f);
	}
	char* gets(char* buff, int n) override
	{
		if (!f) return nullptr;
		return fgets(buff, n, f);
	}
	long read(void* buff, int32_t size, int32_t nitems) override
	{
		if (!f) return 0;
		return (long)fread(buff, size, nitems, f);
	}
	long seek(long offset, int whence) override
	{
		if (!f) return 0;
		return fseek(f, offset, whence);
	}
	long tell() override
	{
		if (!f) return 0;
		return ftell(f);
	}
};

class BaseSoundFontReader : public SoundFontReaderInterface
{
	std::vector<std::string> paths;
	
	bool IsAbsPath(const char *name)
	{
		if (name[0] == '/' || name[0] == '\\') return true;
		#ifdef _WIN32
			/* [A-Za-z]: (for Windows) */
			if (isalpha(name[0]) && name[1] == ':') return true;
		#endif /* _WIN32 */
		return 0;
	}

	struct timidity_file* open_timidityplus_file(const char* fn)
	{
		FILE *f = nullptr;
		std::string fullname;
		if (!fn) 
		{
			f = fopen("timidity.cfg", "rt");
			fullname = "timidity.cfg";
		}
		else
		{
			if (!IsAbsPath(fn))
			{
				for(int i = (int)paths.size()-1; i>=0; i--)
				{
					fullname = paths[i] + fn;
					f = fopen(fullname.c_str(), "rt");
					break;
				}
			}
			if (!f) f = fopen(fn, "rt");
		}
		if (!f) return nullptr;
		auto tf = new timidity_file_FILE;
		tf->f = f;
		tf->filename = fullname;
		return tf;
	}
	
	void timidityplus_add_path(const char* path) 
	{
		std::string p  = path;
		if (p.back() != '/' && p.back() != '\\') p += '/';	// always let it end with a slash.
		paths.push_back(p);
	}
};
#endif

}