/
composite.ts
123 lines (105 loc) · 3.59 KB
/
composite.ts
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
/*
* Copyright (c) 2016-present Invertase Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this library 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.
*/
import * as superstruct from 'superstruct';
import * as utils from '../utils';
import { OperationBuilder } from '../types';
import { imageBlend, imageGravity } from './types';
import { readFileSync } from 'fs';
import { AssertionError } from 'assert';
/**
* The user visible name of this operation.
*/
const name = 'composite';
/**
* Composite an image over the base image. The image to composite must be the same size
* or smaller than the base image.
* If both `top` and `left` options are provided, they take precedence over `gravity`.
*/
const struct = superstruct.object({
operation: superstruct.literal(name),
/**
* HTTP URL or GCS bucket path (to a public file) of the file you wish to overlay.
*/
input: superstruct.string(),
/**
* How to blend the overlay image with the base image.
* Defaults to 'over'.
*/
blend: superstruct.defaulted(superstruct.enums([...imageBlend]), 'over'),
/**
* Gravity at which to place the overlay image. (optional, default 'centre').
*/
gravity: superstruct.optional(superstruct.enums([...imageGravity])),
/**
* Zero-indexed offset in pixels from the top edge.
*/
top: superstruct.optional(utils.coerceStringToInt(superstruct.integer())),
/**
* Zero-indexed offset in pixels from the left edge.
*/
left: superstruct.optional(utils.coerceStringToInt(superstruct.integer())),
/**
* If true, repeat the overlay image across the entire image with the given gravity.
*/
tile: superstruct.optional(utils.coerceStringToBoolean()),
/**
* Set to true to avoid pre-multiplying the image below.
*/
premultiplied: superstruct.optional(utils.coerceStringToBoolean()),
/**
* Number representing the DPI for vector overlay image. (optional, default 72)
*/
density: superstruct.defaulted(
utils.coerceStringToInt(superstruct.integer()),
72,
),
});
export type OperationComposite = superstruct.Infer<typeof struct>;
export const operationComposite: OperationBuilder = {
name,
struct,
/**
* Custom builder since we use `composite` to overlay text as an svg.
*/
async build(operation) {
const options = operation.options as OperationComposite;
// TODO replace this and actually get file from GCP storage
const overlayFileBuffer = readFileSync(`${process.cwd()}${options.input}`);
if (options.left && options.top == undefined) {
throw new AssertionError({
message: `Options for the '${operation.operation}' operation are invalid: if 'left' is specified then 'top' must also be provided.`,
});
}
if (options.top && options.left == undefined) {
throw new AssertionError({
message: `Options for the '${operation.operation}' operation are invalid: if 'top' is specified then 'left' must also be provided.`,
});
}
return [
{
method: 'composite',
arguments: [
[
{
...options,
input: Buffer.from(overlayFileBuffer),
},
],
],
},
];
},
};