Mine

void player_update(){		GLfloat v[3] = {	player.lx - player.x,						player.ly - player.y,						player.lz - player.z};		GLfloat * c = player.matrix;	GLfloat * v1 = player.velocity;	GLfloat v2[2];		/* multiply the view vector by the transformation matrix */	v[0] = c[0] * v[0] + c[4] * v[1] + c[8] * v[2] + c[12];	v[1] = c[1] * v[0] + c[5] * v[1] + c[9] * v[2] + c[13];	v[2] = c[2] * v[0] + c[6] * v[1] + c[10] * v[2] + c[14];			/* now do the same for the velocity vector except ignore any y transforms*/	v2[0] = c[0] * v1[0] + c[8] * v1[2] + c[12];	v2[1] = c[2] * v1[0] + c[10] * v1[2] + c[14];		debug("v2=[%f, %f]", v2[0], v2[2]);		player.x+=v2[0];	player.z+=v2[1];	player.lx+=v2[0];	player.lz+=v2[1];			sengine_lookat(player.x, 				   player.y, 				   player.z, 				   player.x+v[0], 				   player.y+v[1], 				   player.z+v[2]);}