canvas-image

CanvasImage - scripting animation on canvas

npm install canvas-image
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CanvasImage

Create animations with indepedent movements out of images.

Example

<canvas id='canvas' width=240 height=120></canvas>

var CanvasImage = require('canvas-image');
$(window).ready(function() {
    var anim = new CanvasImage.Animation;
    var canvas = document.getElementById('canvas');
    var bar = new CanvasImage;
    bar
    .setDimensions(canvas)
    .setFrames(100)
    .setImg('foo.png',401,436)
    .setAnchor('center')
    .setScaling({easing:'sinusoidal',start:0.5,end:1});
    anim.animate([bar],canvas);
});

.setFrames(num)

Set the number of frames to specify the duration of the effects

.setFrames(40) // 40 frames worth of effects

.setDimensions(canvas)

Pass this function with a canvas element that has the width and height you intend to draw on.

.setImg('imgsrc.png',width,height)

Pass the img path, the width, and the height of the image.

.setAnchor

Achor will affect the rotate, scaling, and movement animations such that they occur around the anchor point instead of the midpoint. You can either call .setAnchor('center') or .setAnchor({x:24,y:155}) for example to anchor at (24,155).

.setRotate

Specify start rotation and end rotation in degrees.

.setRotate({start:0, end:180}); // start at 0 degrees and end at 180degrees.

// or

.setRotate({start:0, end:45, easing:'linear'})


// Check out [node-easing](https://github.com/rook2pawn/node-easing)

You can also pass an "endToEnd" flag to tell the easer to go back and forth, i.e. {start:0, end: 45, easing:'linear', endToEnd:true}

.setOpacity

Governs opacity. start values can range from 0 to 1 and end values can range from 0 to 1.

.setScaling

Governs scaling. start values can range from 0 to any number, and end values can range from 0 to any number. 1 = 100% scaling (no scaling).

.setMovement

.setMovement({start:{x:0,y:0},end:{x:100,y:100}});

// goes from 0,0, to 100,100

ANIMATION PACKAGE

var anim = new CanvasImage.Animation

ANIMATION Methods

anim.animate(list,canvasElement,cb)

.animate will take a list of CanvasImage elements, draw them on the supplied canvasElement, then when the animation is finished, will execute the supplied callback if there is one. Here's an example

var CanvasImage = require('canvas-image');
var bar = new CanvasImage;
var cat = new CanvasImage;
var anim = new CanvasImage.Animation;
bar
.setDimensions(canv)
.setFrames(15)
.setImg('foo.png',199,32)
.setAnchor('center')
.setRotate({easing:'linear',start:0,end:360})
.setMovement({start:{x:-100,y:-100},end:{x:0,y:0}})
.setScaling({easing:'linear',start:0.2,end:1});
cat
.setDimensions(canv)
.setFrames(15)
.setImg('bar.png',135,32)
.setAnchor('center')
.setMovement({start:{x:100,y:100},end:{x:-200,y:0}})
.setScaling({easing:'linear',start:0.2,end:1});

var mycanvas = document.getElementById('mycanvas');
anim.animate([bar,cat],mycanvas,function() {
    anim.dimmer(mycanvas);
});

In this example, bar and cat are two indepedent CanvasImage elements that have positional, rotationl, and movement, and scaling elements over time. anim.animate takes these two and renders them onto a canvas with id mycanvas. Then, when the animation is finished, the callback is called and there is a convenience method called .dimmer that takes a canvas element and quickly reduces the opacity to 0 in a brief animation.

anim.dimmer(canvasElement)

Takes a canvas element and reduces the opacity from 100% to 0% in a brief animation.

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