/* 
flext tutorial - attributes 2

Copyright (c) 2002 Thomas Grill (xovo@gmx.net)
For information on usage and redistribution, and for a DISCLAIMER OF ALL
WARRANTIES, see the file, "license.txt," in this distribution.  

-------------------------------------------------------------------------

This is an example of an object doing various float operations
*/


// IMPORTANT: enable attribute processing (specify before inclusion of flext headers!)
// For clarity, this is done here, but you'd better specify it as a compiler definition
// FLEXT_ATTRIBUTES must be 0 or 1, 
#define FLEXT_ATTRIBUTES 1


// include flext header
#include <flext.h>

// check for appropriate flext version
#if !defined(FLEXT_VERSION) || (FLEXT_VERSION < 400)
#error You need at least flext version 0.4.0
#endif

#include <math.h>


class attr2:
	public flext_base
{
	// compulsory flext header with a class setup function
	FLEXT_HEADER_S(attr2,flext_base,setup)
 
public:
	// constructor 
	attr2();

protected:
	void m_trigger(float f);   
	
	// stored argument of operation
	float arg; 

	// stored result
	float res;

	enum operation {
		op_set,op_add,op_sub,op_mul,op_div,op_pow
	} op;

	static const t_symbol *sym_set,*sym_add,*sym_sub,*sym_div,*sym_mul,*sym_pow;

private:

	static void setup(t_class *);

	// callback for method "m_trigger" (with one float argument)
	FLEXT_CALLBACK_F(m_trigger);  

	// define attribute callbacks for variable "arg" ("ATTRVAR" means GET and SET)
	FLEXT_ATTRVAR_F(arg);  

	// define attribute callbacks for variable "res" (GET only)
	FLEXT_ATTRGET_F(res);  

	// methods for getting/setting the operation mode
	void opget(const t_symbol *&s) const; 
	void opset(const t_symbol *&s);

	// define attribute callbacks for variable "res" (GET only)
	FLEXT_CALLGET_S(opget);  
	FLEXT_CALLSET_S(opset);  
};

// instantiate the class
FLEXT_NEW("attr2",attr2)

// instantiate static variables
const t_symbol 
	*attr2::sym_set,
	*attr2::sym_add,*attr2::sym_sub,
	*attr2::sym_div,*attr2::sym_mul,
	*attr2::sym_pow;

void attr2::setup(t_class *)
{
	// Upon class creation setup some symbols
	// This is done only upon creation of of the first "attr2" object
	sym_set = MakeSymbol("=");
	sym_add = MakeSymbol("+");
	sym_sub = MakeSymbol("-");
	sym_mul = MakeSymbol("*");
	sym_div = MakeSymbol("/");
	sym_pow = MakeSymbol("**");
}


attr2::attr2():
	arg(0),res(0),  // initialize argument and result
	op(op_set)  // initialize operation
{ 
	// define inlets
	AddInAnything();  // first inlet of type anything (index 0)
	
	// define outlets
	AddOutFloat();  // one float outlet (has index 0)
	
	// register method (for floats) "m_trigger" for inlet 0
	FLEXT_ADDMETHOD(0,m_trigger);  

	// register attribute "arg" with the variable "arg"
	FLEXT_ADDATTR_VAR1("arg",arg);  

	// register attribute "result" with variable "res"
	FLEXT_ADDATTR_GET("result",res);  

	// register attribute "op" with methods "opget" and "opset"
	FLEXT_ADDATTR_VAR("op",opget,opset);  
} 

// receive an operand, do the math operation and trigger the output
void attr2::m_trigger(float f)
{
	switch(op) {
	case op_set: res = f; break;
	case op_add: res = f+arg; break;
	case op_sub: res = f-arg; break;
	case op_mul: res = f*arg; break;
	case op_div: 
		if(arg) res = f/arg; 
		else {
			post("%s - argument to division is 0: result set to 0",thisName());
			res = 0;
		}
		break;
	case op_pow: res = (float)pow(f,arg); break;
#ifdef _DEBUG
	default: ERRINTERNAL();  // operation not defined
#endif
	}
		
	// output value to outlet
	ToOutFloat(0,res); // (0 stands for the outlet index 0)
}


// report the operation mode
void attr2::opget(const t_symbol *&s) const
{

	switch(op) {
	case op_set: s = sym_set; break;
	case op_add: s = sym_add; break;
	case op_sub: s = sym_sub; break;
	case op_mul: s = sym_mul; break;
	case op_div: s = sym_div; break;
	case op_pow: s = sym_pow; break;
#ifdef _DEBUG
	default: ERRINTERNAL();  // operation not defined
#endif
	}
}

// set the operation mode
void attr2::opset(const t_symbol *&s)
{
	if(s == sym_set)
		op = op_set;
	else if(s == sym_add)
		op = op_add;
	else if(s == sym_sub)
		op = op_sub;
	else if(s == sym_mul)
		op = op_mul;
	else if(s == sym_div)
		op = op_div;
	else if(s == sym_pow)
		op = op_pow;
	else {
		post("%s - operation is not defined, set to =",thisName());
		op = op_set;
	}
}