/**
* This profile uses the first half of the penumbral gradient as a start
* and then scales linearly.
*/
static double
SmoothLinearProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
double res, nv;
if (acc > 1.0f)
acc -= 1.0f; /*this is so acc = 1 is no acceleration */
else
return 1.0f;
nv = (velocity - threshold) * acc * 0.5f;
if (nv < 0) {
res = 0;
}
else if (nv < 2) {
res = CalcPenumbralGradient(nv * 0.25f) * 2.0f;
}
else {
nv -= 2.0f;
res = nv * 2.0f / M_PI /* steepness of gradient at 0.5 */
+ 1.0f; /* gradient crosses 2|1 */
}
res += vel->min_acceleration;
return res;
}
/**
* acceleration function similar to classic accelerated/unaccelerated,
* but with smooth transition in between (and towards zero for adaptive dec.).
*/
static double
SimpleSmoothProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
if (velocity < 1.0f)
return CalcPenumbralGradient(0.5 + velocity * 0.5) * 2.0f - 1.0f;
if (threshold < 1.0f)
threshold = 1.0f;
if (velocity <= threshold)
return 1;
velocity /= threshold;
if (velocity >= acc)
return acc;
else
return 1.0f + (CalcPenumbralGradient(velocity / acc) * (acc - 1.0f));
}
/**
* acceleration function similar to classic accelerated/unaccelerated,
* but with smooth transition in between (and towards zero for adaptive dec.).
*/
static float
SimpleSmoothProfile(
DeviceVelocityPtr pVel,
float velocity,
float threshold,
float acc)
{
if(velocity < 1.0f)
return CalcPenumbralGradient(0.5 + velocity*0.5) * 2.0f - 1.0f;
if(threshold < 1.0f)
threshold = 1.0f;
if (velocity <= threshold)
return 1;
velocity /= threshold;
if (velocity >= acc)
return acc;
else
return 1.0f + (CalcPenumbralGradient(velocity/acc) * (acc - 1.0f));
}
/**
* From 0 to threshold, the response graduates smoothly from min_accel to
* acceleration. Beyond threshold it is exactly the specified acceleration.
*/
static double
SmoothLimitedProfile(DeviceIntPtr dev,
DeviceVelocityPtr vel,
double velocity, double threshold, double acc)
{
double res;
if (velocity >= threshold || threshold == 0.0f)
return acc;
velocity /= threshold; /* should be [0..1[ now */
res = CalcPenumbralGradient(velocity) * (acc - vel->min_acceleration);
return vel->min_acceleration + res;
}
