smoothstep() examples
https://en.wikipedia.org/wiki/Smoothstep is a core function that exists in GLSL (shader programming). Here you can find it ported to java.
Example of soft limits and interaction
// An example of setting left and right limits for motion
// This comes from my live performance software, in which I want to control
// Peasycam's distance with a knob. I want freedom to move, but I also
// want to set certain limits so I don't get too close or too far (as it has happened
// in previous performances :) At the same time, I don't want to "hit an invisible wall"
// when zooming in or out, I want that it progressively ignores my orders if I'm doing
// the wrong thing.
float xPos = 450;
float xSpeed = 0;
void setup() {
size(900, 300, P2D);
}
void draw() {
background(255);
ellipse(xPos, 150, 50, 50);
xSpeed = map(mouseX, 0, width, -20, 20);
if(xSpeed < 0) {
// If going left, limit speed when in given range
// The closer we are to the edge, the stronger the speed reduction.
// Values below 150 become 0. Above 400 they become 1.
xSpeed *= smootherstep(150, 400, xPos);
} else {
// If going right, limit speed when in given range
// Values below 700 become 1, above 850 they become 0
xSpeed *= 1-smootherstep(700, 850, xPos);
}
xPos += xSpeed;
}
float smoothstep(float edge0, float edge1, float x) {
x = constrain((x - edge0) / (edge1 - edge0), 0, 1);
return x * x * (3 - 2 * x);
}
float smootherstep(float edge0, float edge1, float x) {
x = constrain((x - edge0) / (edge1 - edge0), 0, 1);
return x * x * x * (x * (x * 6 - 15) + 10);
}
Example using smoothstep() for easing
void setup() {
size(900, 300, P2D);
}
void draw() {
background(255);
// Make a normalized triangle wave with a period of 400 frames
float x = abs((frameCount % 400) - 200) / 200.0;
ellipse(100 + x * 500, 50, 50, 50); // linear
ellipse(100 + smoothstep(0, 1, x) * 500, 150, 50, 50); // smooth
ellipse(100 + smootherstep(0, 1, x) * 500, 250, 50, 50); // smoother
}
float smoothstep(float edge0, float edge1, float x) {
x = constrain((x - edge0) / (edge1 - edge0), 0, 1);
return x * x * (3 - 2 * x);
}
float smootherstep(float edge0, float edge1, float x) {
x = constrain((x - edge0) / (edge1 - edge0), 0, 1);
return x * x * x * (x * (x * 6 - 15) + 10);
}
