/content/animation-easing-functions.gif

easing-functions-demo.scad

include <easing-functions.scad>;

function undulate(t) = abs((t - .5) * 2);

length = 5;
fullWidth = 200;
textSize = 5;

margin = length;
textGutter = length;

fgColor = "black";
bgColor = "white";

module demo(label, weight) {
    width = weight * fullWidth;

    color(bgColor) {
        polygon(
            [
                [0, 0],
                [0, length],
                [fullWidth, length],
                [fullWidth, 0]
            ],
            paths = [[0, 1, 2, 3]]
        );
    }

    color(fgColor) {
        polygon(
            [
                [0, 0],
                [0, length],
                [width, length],
                [width, 0]
            ],
            paths = [[0, 1, 2, 3]]
        );
    }

    translate([textGutter * -1, 0, 0]) {
        text(
            label,
            size = textSize,
            halign = "right"
        );
    }
}

easing_functions = [
    ["linear", linear(undulate($t))],
    ["ease_in_quad", ease_in_quad(undulate($t))],
    ["ease_out_quad", ease_out_quad(undulate($t))],
    ["ease_in_out_quad", ease_in_out_quad(undulate($t))],
    ["ease_in_cubic", ease_in_cubic(undulate($t))],
    ["ease_out_cubic", ease_out_cubic(undulate($t))],
    ["ease_in_out_cubic", ease_in_out_cubic(undulate($t))],
    ["ease_in_quart", ease_in_quart(undulate($t))],
    ["ease_out_quart", ease_out_quart(undulate($t))],
    ["ease_in_out_quart", ease_in_out_quart(undulate($t))],
    ["ease_in_quint", ease_in_quint(undulate($t))],
    ["ease_out_quint", ease_out_quint(undulate($t))],
    ["ease_in_out_quint", ease_in_out_quint(undulate($t))],
];

for (i = [0 : len(easing_functions) -1 ]) {
    easing_function = easing_functions[i];
    name = easing_function[0];
    value = easing_function[1];

    y = (length + margin) * i * -1;

    translate([0, y, 0]) {
        demo(name, value);
    }
}

easing-functions.scad

// http://gizma.com/easing/

// no easing, no acceleration
function linear(t) = (
    t
);

// accelerating from zero velocity
function ease_in_quad(t) = (
    pow(t, 2)
);

// decelerating to zero velocity
function ease_out_quad(t) = (
    t * (2 - t)
);

// acceleration until halfway, then deceleration
function ease_in_out_quad(t) = (
    t < .5
        ? 2 * pow(t, 2)
        : -1 + (4 - 2 * t) * t
);

// accelerating from zero velocity
function ease_in_cubic(t) = (
    pow(t, 3)
);

// decelerating to zero velocity
function ease_out_cubic(t) = (
    pow(t - 1, 3) + 1
);

// acceleration until halfway, then deceleration
function ease_in_out_cubic(t) = (
    t < .5
        ? 4 * pow(t, 3)
        : (t - 1) * (2 * t - 2) * (2 * t - 2) + 1
);

// accelerating from zero velocity
function ease_in_quart(t) = (
    pow(t, 4)
);

// decelerating to zero velocity
function ease_out_quart(t) = (
    1 - (t - 1) * pow(t - 1, 3)
);

// acceleration until halfway, then deceleration
function ease_in_out_quart(t) = (
	t < .5
        ? .5 * pow(t / .5, 4)
	    : -.5 * (pow(t / .5 - 2, 4) - 2)
);

// accelerating from zero velocity
function ease_in_quint(t) = (
    pow(t, 5)
);

// decelerating to zero velocity
function ease_out_quint(t) = (
	pow((t - 1), 5) + 1
);

// acceleration until halfway, then deceleration
function ease_in_out_quint(t) = (
    t < .5
        ? .5 * pow(t / .5, 5)
        : .5 * (pow(t / .5 - 2, 5) + 2)
);