#include <stdio.h>
#include <math.h>

float v[128][3];
float vn[128][3];
float f[128][3];

/** Subtracts a from b and stores the result in c.
*/
void subtract(float a[3], float b[3], float c[3])
{
	//Fill this in
}

/** Computes the cross product of a and b, storing the result in c.
*/
void cross(float a[3], float b[3], float c[3])
{
	c[0] = a[1]*b[2]-a[2]*b[1];
	c[1] = a[2]*b[0]-a[0]*b[2];
	c[2] = a[0]*b[1]-a[1]*b[0];
}

/** Sets the length of a vector to 1.0.
*/
void normalize(float a[3])
{
	float length = sqrt(a[0]*a[0] + a[1]*a[1] + a[2]*a[2]);
	a[0] /= length;
	a[1] /= length;
	a[2] /= length;
}

/** Computes the normal of a triangle specified by vertices v1, v2,
    and v3, storing the normalized result in normal.
*/
void computeNormal(float v1[3], float v2[3], float v3[3], float normal[3])
{
	//Fill this in
}

int main()
{
	//Read the vertices from input.obj into v and write them to output.obj

    //Read the faces from input.obj into f 

	//For each face f compute its normal and store it in vn

	//Write vn to output.obj

	//Write f to output.obj

	return 0;
}