rsc3/doc-schelp/HelpSource/Classes/Gradient.scrbl

119 lines
2.1 KiB
Racket

#lang scribble/manual
@(require (for-label racket))
@title{Gradient}
A linear color fade between two colors@section{categories}
GUI>Accessories
@section{related}
Classes/Color, Classes/HiliteGradient
@section{description}
@section{note}
The use of Gradient is strong::not supported yet::. When Gradient is used in place of Color, the average gradient color will be used instead. ::
@section{classmethods}
@section{method}
new
@section{argument}
color1
An instance of link::Classes/Color::.
@section{argument}
color2
An instance of link::Classes/Color::.
@section{argument}
direction
@racketblock[\h:: or ]
@racketblock[\v:: for horizontal and vertical respectively. Default value is ]
@racketblock[\h::.
]
@section{argument}
steps
The resolution of the gradient. Default value is 64.
@section{instancemethods}
@section{method}
at
Retrieve the colour at position
@racketblock[pos::, typically a value between zero and one. ]
@racketblock[at(0):: is ]
@racketblock[color1::, and ]
@racketblock[at(1):: is ]
@racketblock[color2::.
]
@section{argument}
pos
@section{examples}
@racketblock[
// basic usage
(
w = Window.new.front;
w.view.background = Gradient(Color.yellow,Color.white);
)
// change direction and resolution
(
w = Window.new.front;
w.view.background = Gradient(Color.red,Color.white,\v, 5);
)
// almost unnoticeable variations can be pleasant
(
w = Window.new.front;
v = CompositeView(w, Rect(50,50,300,300));
c = Color.rand;
d = c.vary(0.15);
v.background = Gradient(c, d, \v);
[c, d].postln
)
(
var w, k, c, d, e, c1, c2, f, g;
w = Window.new.front;
k = Slider2D(w, Rect(50,50,300,300));
f = {
c = Color.rand;
d = c.vary(0.5);
e = d.vary(0.5);
};
g = {
c1 = d.hueBlend(e, k.y).round(0.01);
c2 = c.hueBlend(e, k.x).round(0.01);
k.background = Gradient(c1, c2, \v)
};
f.value; g.value;
k.action = g;
k.mouseUpAction = { [c1, c2].postln };
k.keyDownAction = f; // hit any key for new color
)
// an example using gradient indirectly to update window colour
(
w=Window.new.front;
g = Gradient(Color.red,Color.green);
Task{
(0, 0.01 .. 1).do{|pos|
w.view.background = g.at(pos);
0.01.wait;
};
}.play(AppClock)
)
::
]