65 lines
1.9 KiB
TypeScript
65 lines
1.9 KiB
TypeScript
/* @license
|
|
* Copyright 2019 Google LLC. All Rights Reserved.
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
|
|
const canvas: HTMLCanvasElement = document.createElement('canvas');
|
|
const context: CanvasRenderingContext2D = canvas.getContext('2d')!;
|
|
|
|
|
|
export class ImageAccessor {
|
|
static fromArrayBuffer(buffer: ArrayBuffer, width: number, height: number):
|
|
ImageAccessor {
|
|
return new ImageAccessor(
|
|
new ImageData(new Uint8ClampedArray(buffer), width, height));
|
|
}
|
|
|
|
static fromImageElement(image: HTMLImageElement): ImageAccessor {
|
|
canvas.width = image.naturalWidth;
|
|
canvas.height = image.naturalHeight;
|
|
context.drawImage(image, 0, 0);
|
|
return new ImageAccessor(
|
|
context.getImageData(0, 0, canvas.width, canvas.height));
|
|
}
|
|
|
|
toArrayBuffer(): ArrayBuffer {
|
|
const {buffer} = this.source.data;
|
|
return buffer.slice(0, buffer.byteLength) as ArrayBuffer;
|
|
}
|
|
|
|
cssColorAt(x: number, y: number): string {
|
|
if (x < 0 || y < 0 || x > (this.width - 1) || y > (this.height - 1)) {
|
|
return 'black';
|
|
}
|
|
|
|
const position = (y * this.width + x) * 4;
|
|
const array = this.source.data;
|
|
|
|
const color = `rgb(${array[position]}, ${array[position + 1]}, ${
|
|
array[position + 2]})`;
|
|
return color;
|
|
}
|
|
|
|
constructor(protected source: ImageData) {
|
|
}
|
|
|
|
get width(): number {
|
|
return this.source.width;
|
|
}
|
|
|
|
get height(): number {
|
|
return this.source.height;
|
|
}
|
|
}
|