EAPI double
ecore_animator_pos_map(double pos,
Ecore_Pos_Map map,
double v1,
double v2)
{
/* purely functional - locking not required */
if (pos > 1.0) pos = 1.0;
else if (pos < 0.0)
pos = 0.0;
switch (map)
{
case ECORE_POS_MAP_LINEAR:
return pos;
case ECORE_POS_MAP_ACCELERATE:
pos = 1.0 - _pos_map_sin(M_PI_2 + pos * M_PI_2);
return pos;
case ECORE_POS_MAP_DECELERATE:
pos = _pos_map_sin(pos * M_PI_2);
return pos;
case ECORE_POS_MAP_SINUSOIDAL:
pos = (1.0 - _pos_map_cos(pos * M_PI)) / 2.0;
return pos;
case ECORE_POS_MAP_ACCELERATE_FACTOR:
pos = _pos_map_accel_factor(pos, v1);
return pos;
case ECORE_POS_MAP_DECELERATE_FACTOR:
pos = 1.0 - _pos_map_accel_factor(1.0 - pos, v1);
return pos;
case ECORE_POS_MAP_SINUSOIDAL_FACTOR:
if (pos < 0.5) pos = _pos_map_accel_factor(pos * 2.0, v1) / 2.0;
else pos = 1.0 - (_pos_map_accel_factor((1.0 - pos) * 2.0, v1) / 2.0);
return pos;
case ECORE_POS_MAP_DIVISOR_INTERP:
pos = _pos_map_pow(pos, v1, (int)v2);
return pos;
case ECORE_POS_MAP_BOUNCE:
pos = _pos_map_spring(pos, (int)v2, v1);
if (pos < 0.0) pos = -pos;
pos = 1.0 - pos;
return pos;
case ECORE_POS_MAP_SPRING:
pos = 1.0 - _pos_map_spring(pos, (int)v2, v1);
return pos;
default:
return pos;
}
return pos;
}
static double
_pos_map_accel_factor(double pos,
double v1)
{
int i, fact = (int)v1;
double p, o1 = pos, o2 = pos, v;
p = 1.0 - _pos_map_sin((M_PI / 2.0) + ((pos * M_PI) / 2.0));
o2 = p;
for (i = 0; i < fact; i++)
{
o1 = o2;
o2 = o2 * p;
}
v = v1 - (double)fact;
pos = (v * o2) + ((1.0 - v) * o1);
return pos;
}
static double
_pos_map_spring(double pos,
int bounces,
double decfac)
{
int segnum, segpos, b1, b2;
double len, decay, decpos, p2;
if (bounces < 0) bounces = 0;
p2 = _pos_map_pow(pos, 0.5, 3);
len = (M_PI / 2.0) + ((double)bounces * M_PI);
segnum = (bounces * 2) + 1;
segpos = 2 * (((int)(p2 * segnum) + 1) / 2);
b1 = segpos;
b2 = segnum + 1;
if (b1 < 0) b1 = 0;
decpos = (double)b1 / (double)b2;
decay = _pos_map_accel_factor(1.0 - decpos, decfac);
return _pos_map_sin((M_PI / 2.0) + (p2 * len)) * decay;
}
