1/*
2 * Copyright (C) 2023 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17import {Segment} from 'app/components/timeline/segment';
18import {TimeRange, Timestamp} from 'common/time';
19import {ComponentTimestampConverter} from 'common/timestamp_converter';
20
21export class Transformer {
22  private fromWidth: bigint;
23  private targetWidth: number;
24
25  private fromOffset: bigint;
26  private toOffset: number;
27
28  constructor(
29    private fromRange: TimeRange,
30    private toRange: Segment,
31    private timestampConverter: ComponentTimestampConverter,
32  ) {
33    this.fromWidth =
34      this.fromRange.to.getValueNs() - this.fromRange.from.getValueNs();
35    // Needs to be a whole number to be compatible with bigints
36    this.targetWidth = Math.round(this.toRange.to - this.toRange.from);
37
38    this.fromOffset = this.fromRange.from.getValueNs();
39    // Needs to be a whole number to be compatible with bigints
40    this.toOffset = this.toRange.from;
41  }
42
43  transform(x: Timestamp): number {
44    return (
45      this.toOffset +
46      (this.targetWidth * Number(x.getValueNs() - this.fromOffset)) /
47        Number(this.fromWidth)
48    );
49  }
50
51  untransform(x: number): Timestamp {
52    x = Math.round(x);
53    const valueNs =
54      this.fromOffset +
55      (BigInt(x - this.toOffset) * this.fromWidth) / BigInt(this.targetWidth);
56    return this.timestampConverter.makeTimestampFromNs(valueNs);
57  }
58}
59