skia2/modules/canvaskit/htmlcanvas/pattern.js
Kevin Lubick a064c2812e [canvaskit] Make SkImageShader from SkImage
This removes a few src/ includes as well, to avoid using private
implementations like we did.

Change-Id: Ic9a21d04a131c30e17dfca6d8ea45bdefd362aa7
Bug: skia:
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206062
Reviewed-by: Mike Reed <reed@google.com>
2019-04-04 13:42:41 +00:00

68 lines
1.8 KiB
JavaScript

function CanvasPattern(image, repetition) {
this._shader = null;
// image should be an SkImage returned from HTMLCanvas.decodeImage()
this._image = image;
this._transform = CanvasKit.SkMatrix.identity();
if (repetition === '') {
repetition = 'repeat';
}
switch(repetition) {
case 'repeat-x':
this._tileX = CanvasKit.TileMode.Repeat;
// Skia's 'clamp' mode repeats the last row/column
// which looks very very strange.
// Decal mode does just transparent copying, which
// is exactly what the spec wants.
this._tileY = CanvasKit.TileMode.Decal;
break;
case 'repeat-y':
this._tileX = CanvasKit.TileMode.Decal;
this._tileY = CanvasKit.TileMode.Repeat;
break;
case 'repeat':
this._tileX = CanvasKit.TileMode.Repeat;
this._tileY = CanvasKit.TileMode.Repeat;
break;
case 'no-repeat':
this._tileX = CanvasKit.TileMode.Decal;
this._tileY = CanvasKit.TileMode.Decal;
break;
default:
throw 'invalid repetition mode ' + repetition;
}
// Takes a DOMMatrix like object. e.g. the identity would be:
// {a:1, b: 0, c: 0, d: 1, e: 0, f: 0}
// @param {DOMMatrix} m
this.setTransform = function(m) {
var t = [m.a, m.c, m.e,
m.b, m.d, m.f,
0, 0, 1];
if (allAreFinite(t)) {
this._transform = t;
}
}
this._copy = function() {
var cp = new CanvasPattern()
cp._tileX = this._tileX;
cp._tileY = this._tileY;
return cp;
}
this._dispose = function() {
if (this._shader) {
this._shader.delete();
this._shader = null;
}
}
this._getShader = function(currentTransform) {
// Ignore currentTransform since it will be applied later
this._dispose();
this._shader = this._image.makeShader(this._tileX, this._tileY, this._transform);
return this._shader;
}
}