#include "texture_eval.h"

#include <iostream>
using namespace std;

eval_item texture_routine::eval(const vector3d& pt)
{
	eval_item tmps[NUM_TMPS], accum, ept(pt);
	std::stack<int> loops;
	for(size_t i=0; i<steps.size(); i++)
	{
		step&s = steps[i];
		const eval_item *s0 = &accum, *s1 = &accum, *s2 = &accum;
		eval_item *dst = &accum;

//		std::cout << "STARTS" << endl;
//		std::cout << s.src0 << endl;

		if(s.src0 == POINT_INDEX) s0 = &ept;
		if(s.src0 >= TEMP_START && s.src0 < TEMP_END)
			s0 = &tmps[s.src0 - TEMP_START];
		if(s.src0 >= CONST_START && s.src0 < CONST_END)
			s0 = &consts[s.src0 - CONST_START];

//		std::cout << s.src1 << endl;

		if(s.src1 == POINT_INDEX) s1 = &ept;
		if(s.src1 >= TEMP_START && s.src1 < TEMP_END)
			s1 = &tmps[s.src1 - TEMP_START];
		if(s.src1 >= CONST_START && s.src1 < CONST_END)
			s1 = &consts[s.src1 - CONST_START];

//		std::cout << s.src2 << endl;

		if(s.src2 == POINT_INDEX) s2 = &ept;
		if(s.src2 >= TEMP_START && s.src2 < TEMP_END)
			s2 = &tmps[s.src2 - TEMP_START];
		if(s.src2 >= CONST_START && s.src2 < CONST_END)
			s2 = &consts[s.src2 - CONST_START];

//		std::cout << s.dest << endl;

		if(s.dest >= TEMP_START && s.dest < TEMP_END)
			dst = &tmps[s.dest - TEMP_START];

//		std::cout << s.func << endl;
//		std::cout << "ENDS" << endl;

		switch(s.func)
		{
		case add_: *dst = eval_add(*s0, *s1); break;
		case sub_: *dst = eval_sub(*s0, *s1); break;
		case mul_: *dst = eval_mul(*s0, *s1); break;
		case div_: *dst = eval_div(*s0, *s1); break;
		case dot_: *dst = eval_dot(*s0, *s1); break;
		case cross_: *dst = eval_cross(*s0, *s1); break;
		case mod_: *dst = eval_mod(*s0, *s1); break;
		case sin_: *dst = eval_func(*s0, sin); break;
		case cos_: *dst = eval_func(*s0, cos); break;
		case tan_: *dst = eval_func(*s0, tan); break;
		case exp_: *dst = eval_func(*s0, exp); break;
		case log_: *dst = eval_func(*s0, log); break;
		case neg_: *dst = eval_func(*s0, neg); break;
		case pow_: *dst = eval_pow(*s0, *s1); break;
		case atan2_: *dst = eval_atan2(*s0, *s1); break;
		case if_:
			if(!non_zero(*s0))
				i = s.src1 - 1; // increments adds one
			break;
 		case endif_: /* do nothing */ break;
		case while_:
			if(!non_zero(*s0))
				i = s.src1; // inc to after endwhile
			break;
 		case endwhile_: i = s.src0 - 1; break;
		case inc_: *dst = eval_func(*s0, eval_inc); break;
		case dec_: *dst = eval_func(*s0, eval_dec); break;
		case pack_: *dst = eval_pack(*s0, *s1, *s2); break;
		case getx_: *dst = eval_getx(*s0); break;
		case gety_: *dst = eval_gety(*s0); break;
		case getz_: *dst = eval_getz(*s0); break;
		case eq_: *dst = eval_eq(*s0, *s1); break;
		case lt_: *dst = eval_lt(*s0, *s1); break;
		case gt_: *dst = eval_lt(*s1, *s0); break;
		case ne_: *dst = eval_not(eval_eq(*s0, *s1)); break;
		case ge_: *dst = eval_not(eval_lt(*s0, *s1)); break;
		case le_: *dst = eval_not(eval_lt(*s1, *s0)); break;
		case invalid_: break;
		}
	}
	return tmps[0];
}