90 lines
2.4 KiB
Text
90 lines
2.4 KiB
Text
Ease :: enum {
|
|
linear;
|
|
quad;
|
|
cubic;
|
|
quart;
|
|
quint;
|
|
expo;
|
|
sine;
|
|
circ;
|
|
back;
|
|
elastic;
|
|
}
|
|
|
|
Transition :: enum {
|
|
in;
|
|
out;
|
|
in_out;
|
|
}
|
|
|
|
/*
|
|
Calculate a tween value for the given process, easing function, and transition.
|
|
|
|
The value returned can be used like so:
|
|
progress := 1.0 / time_in_seconds;
|
|
|
|
current = original + ease(progress, .cubic, .in_out);
|
|
|
|
@Note: Progress must be between 0.0 and 1.0
|
|
*/
|
|
ease :: (progress: $T, $$ease: Ease = .linear, $$transition: Transition = .in) -> T
|
|
#modify { return type_is_float(T); }
|
|
{
|
|
p := progress;
|
|
|
|
#insert -> string {
|
|
expressions :: string.[
|
|
"p", // linear
|
|
"p * p", // quad
|
|
"p * p * p", // cubic
|
|
"p * p * p * p", // quart
|
|
"p * p * p * p * p", // quint
|
|
"math.pow(2, (10 * (p - 1)))", // expo
|
|
"-math.cos(p * (math.PI * 0.5)) + 1", // sine
|
|
"-(math.sqrt(1 - (p * p)) - 1)", // circ
|
|
"p * p * (2.7 * p - 1.7)", // back
|
|
"-math.pow(2, 10 * (p - 1)) * math.sin((p - 1.075) * (math.PI * 2) / 0.3)" // elastic
|
|
];
|
|
|
|
b: basic.String_Builder;
|
|
|
|
if is_constant(ease) basic.append(*b, "#");
|
|
basic.append(*b, "if ease == {\n");
|
|
|
|
info := type_info(Ease);
|
|
for info.names {
|
|
basic.print_to_builder(*b, #string END
|
|
case .%1; %2if transition == {
|
|
case .in;
|
|
return %3;
|
|
|
|
case .out;
|
|
p = 1 - p;
|
|
return p - (%3);
|
|
|
|
case .in_out;
|
|
p *= 2;
|
|
if p < 1 {
|
|
return 0.5 * (%3);
|
|
}
|
|
|
|
p = 2 - p;
|
|
return 0.5 * (1 - (%3)) + 0.5;
|
|
}
|
|
END, it, ifx is_constant(transition) "#" else "", expressions[it_index]);
|
|
}
|
|
|
|
basic.append(*b, "}\n");
|
|
|
|
return basic.builder_to_string(*b);
|
|
}
|
|
|
|
return p;
|
|
}
|
|
|
|
|
|
#scope_file;
|
|
|
|
#import "jc";
|
|
math :: #import "Math"; // @future
|
|
basic :: #import "Basic"; // @future
|