Functions on VEC2

 

VEC2 is declared as typedef double VEC2[2]; and the following functions are available:

double g_abs2 (double a, double b)
g_sqrt(a*a + b*b)

double g_vec2_abs (VEC2 v)
returns the length of v

void g_vec2_add (VEC2 u, VEC2 v, VEC2 w)
u = v + w

double g_vec2_angle (VEC2 v,VEC2 w)
returns the signed angle of v and w

void g_vec2_assign (VEC2 v, VEC2 w)
v = w

void g_vec2_dec (VEC2 v, VEC2 w)
v -= w

double g_vec2_det (VEC2 v,VEC2 w)
returns v[0]*w[1]-v[1]*w[0]

double g_vec2_dist (VEC2 v,VEC2 w)
returns the distance of the two points in R2

void g_vec2_inc (VEC2 v, VEC2 w)
v += w

void g_vec2_mult (VEC2 v,double d)
multiplies v by the number r

void g_vec2_rot90 (VEC2 v, VEC2 w)
v = w rotated by 90 degree

void g_vec2_set (VEC2 v, double a, double b)
v = (a,b)

void g_vec2_set_zero (VEC2 v)
v = (0,0)

double g_vec2_skp (VEC2 v,VEC2 w)
returns the scalar product of v and w

double g_vec2_sqrabs (VEC2 v)
returns the square length of v

double g_vec2_sqrdist (VEC2 v,VEC2 w)
returns the square distance of two points

void g_vec2_sub (VEC2 u, VEC2 v, VEC2 w)
u = v - w

double g_vec2_sub_skp (VEC2 v,VEC2 w,VEC2 n)
returns the scalar product of v - w and n