public void quad(GL gl, float[][] v)
	{
		float[] out = new float[3];
		calcNormal(v, out);
		
		gl.glBegin(GL.GL_QUADS);
			gl.glNormal3f(out[0], out[1], out[2]);
			for (int i=0; i < 4; i++)
			{
				gl.glVertex3d(v[i][0], v[i][1], v[i][2]);
			}
		gl.glEnd();
	}
	
	public void calcNormal(float[][] v, float[] out)
	{
		float[] v1 = new float[3];
		float[] v2 = new float[3];
		int x = 0;
		int y = 0;
		int z = 0;
		
		//point-difference formula (finds vector)
		v1[x] = v[0][x] - v[1][x];
		v1[y] = v[0][y] - v[1][y];
		v1[z] = v[0][z] - v[1][z];
		
		//calculate vector from point 1 to point 0
		v2[x] = v[1][x] - v[2][x];
		v2[y] = v[1][y] - v[2][y];
		v2[z] = v[1][z] - v[2][z];
		
		//cross product to give surface normal
		out[x] = v1[y]*v2[z] - v1[z]*v2[y];
		out[y] = v1[z]*v2[x] - v1[x]*v2[z];
		out[z] = v1[x]*v2[y] - v1[y]*v2[x];
		
		reduceToUnit(out);
	}
	
	public void reduceToUnit(float[] vector)
	{
		float length;
		length = (float)Math.sqrt((vector[0]*vector[0]) + (vector[1]*vector[1]) + (vector[2]*vector[2]));
		
		if (length == 0.0) { length = 1.0f; }
		
		vector[0] /= length;
		vector[1] /= length;
		vector[2] /= length;
	}