#include "stdio.h"
#include "stdlib.h"
#include "math.h"
#include "dotAndCrossProduct.h"

#define X 0
#define Y 1
#define Z 2

//draws one triangle
int drawTriangle(FILE *outfile, double coords1[], double coords2[], double coords3[]){
	double vectn[] = {0,0,0};	// normal vector
	double vectnlenin = 0;		// normal vector length inverse
	double vect1[] = {0,0,0};	// vector between coordinates 1 & 2
	double vect2[] = {0,0,0};	// vector between coordinates 1 & 3

	vect1[0] = coords1[0] - coords2[0];
	vect1[1] = coords1[1] - coords2[1];
	vect1[2] = coords1[2] - coords2[2];
	vect2[0] = coords1[0] - coords3[0];
	vect2[1] = coords1[1] - coords3[1];
	vect2[2] = coords1[2] - coords3[2];

	crossProduct(vectn, vect1, vect2);
/*	if((!isnormal(vectn[0]) && vectn[0] != 0) || (!isnormal(vectn[1]) && vectn[1] != 0) || (!isnormal(vectn[2]) && vectn[2] != 0)){
		printf("Troublemaker:\n\n");
		printf("vectn = %f, %f, %f\n\n", vectn[0], vectn[1], vectn[2]);
		printf("vect1 = %f, %f, %f\n", vect1[0], vect1[1], vect1[2]);
		printf("vect2 = %f, %f, %f\n\n", vect2[0], vect2[1], vect2[2]);
		printf("point1 = %f, %f, %f\n", coords1[0], coords1[1], coords1[2]);
		printf("point2 = %f, %f, %f\n", coords2[0], coords2[1], coords2[2]);
		printf("point3 = %f, %f, %f\n\n\n", coords3[0], coords3[1], coords3[2]);
	}
*/	
	vectnlenin = 1 / sqrt((vectn[0]*vectn[0]) + (vectn[1]*vectn[1]) + (vectn[2]*vectn[2]));
	vectn[0] = vectn[0] * vectnlenin;
	vectn[1] = vectn[1] * vectnlenin;
	vectn[2] = vectn[2] * vectnlenin;

	fprintf(outfile, "  facet normal %g %g %g\n", vectn[X], vectn[Y], vectn[Z]);
	fprintf(outfile, "    outer loop\n");

	fprintf(outfile, "      vertex %g %g %g\n", coords1[X], coords1[Y], coords1[Z]);
	fprintf(outfile, "      vertex %g %g %g\n", coords2[X], coords2[Y], coords2[Z]);
	fprintf(outfile, "      vertex %g %g %g\n", coords3[X], coords3[Y], coords3[Z]);

	fprintf(outfile, "    endloop\n");
	fprintf(outfile, "  endfacet\n");
	return 0;
}

//draws one triangle and allows you to precompute the normal vector
int drawTriangleWithNormal(FILE *outfile, double coords1[], double coords2[], double coords3[], double vectn[]){
	fprintf(outfile, "  facet normal %g %g %g\n", vectn[X], vectn[Y], vectn[Z]);
	fprintf(outfile, "    outer loop\n");

	fprintf(outfile, "      vertex %g %g %g\n", coords1[X], coords1[Y], coords1[Z]);
	fprintf(outfile, "      vertex %g %g %g\n", coords2[X], coords2[Y], coords2[Z]);
	fprintf(outfile, "      vertex %g %g %g\n", coords3[X], coords3[Y], coords3[Z]);

	fprintf(outfile, "    endloop\n");
	fprintf(outfile, "  endfacet\n");
	return 0;
}

//must be printed at the start of the file
int startSTL(FILE *outfile){
	fprintf(outfile, "solid Mesh\n");
	return 0;
}

//must be printed at the end of the file
int endSTL(FILE *outfile){
	fprintf(outfile, "endsolid Mesh");
}