| // Copyright 2013 Lovell Fuller and others. | |
| // SPDX-License-Identifier: Apache-2.0 | |
| ; | |
| const is = require('./is'); | |
| /** | |
| * Blend modes. | |
| * @member | |
| * @private | |
| */ | |
| const blend = { | |
| clear: 'clear', | |
| source: 'source', | |
| over: 'over', | |
| in: 'in', | |
| out: 'out', | |
| atop: 'atop', | |
| dest: 'dest', | |
| 'dest-over': 'dest-over', | |
| 'dest-in': 'dest-in', | |
| 'dest-out': 'dest-out', | |
| 'dest-atop': 'dest-atop', | |
| xor: 'xor', | |
| add: 'add', | |
| saturate: 'saturate', | |
| multiply: 'multiply', | |
| screen: 'screen', | |
| overlay: 'overlay', | |
| darken: 'darken', | |
| lighten: 'lighten', | |
| 'colour-dodge': 'colour-dodge', | |
| 'color-dodge': 'colour-dodge', | |
| 'colour-burn': 'colour-burn', | |
| 'color-burn': 'colour-burn', | |
| 'hard-light': 'hard-light', | |
| 'soft-light': 'soft-light', | |
| difference: 'difference', | |
| exclusion: 'exclusion' | |
| }; | |
| /** | |
| * Composite image(s) over the processed (resized, extracted etc.) image. | |
| * | |
| * The images to composite must be the same size or smaller than the processed image. | |
| * If both `top` and `left` options are provided, they take precedence over `gravity`. | |
| * | |
| * Any resize, rotate or extract operations in the same processing pipeline | |
| * will always be applied to the input image before composition. | |
| * | |
| * The `blend` option can be one of `clear`, `source`, `over`, `in`, `out`, `atop`, | |
| * `dest`, `dest-over`, `dest-in`, `dest-out`, `dest-atop`, | |
| * `xor`, `add`, `saturate`, `multiply`, `screen`, `overlay`, `darken`, `lighten`, | |
| * `colour-dodge`, `color-dodge`, `colour-burn`,`color-burn`, | |
| * `hard-light`, `soft-light`, `difference`, `exclusion`. | |
| * | |
| * More information about blend modes can be found at | |
| * https://www.libvips.org/API/current/libvips-conversion.html#VipsBlendMode | |
| * and https://www.cairographics.org/operators/ | |
| * | |
| * @since 0.22.0 | |
| * | |
| * @example | |
| * await sharp(background) | |
| * .composite([ | |
| * { input: layer1, gravity: 'northwest' }, | |
| * { input: layer2, gravity: 'southeast' }, | |
| * ]) | |
| * .toFile('combined.png'); | |
| * | |
| * @example | |
| * const output = await sharp('input.gif', { animated: true }) | |
| * .composite([ | |
| * { input: 'overlay.png', tile: true, blend: 'saturate' } | |
| * ]) | |
| * .toBuffer(); | |
| * | |
| * @example | |
| * sharp('input.png') | |
| * .rotate(180) | |
| * .resize(300) | |
| * .flatten( { background: '#ff6600' } ) | |
| * .composite([{ input: 'overlay.png', gravity: 'southeast' }]) | |
| * .sharpen() | |
| * .withMetadata() | |
| * .webp( { quality: 90 } ) | |
| * .toBuffer() | |
| * .then(function(outputBuffer) { | |
| * // outputBuffer contains upside down, 300px wide, alpha channel flattened | |
| * // onto orange background, composited with overlay.png with SE gravity, | |
| * // sharpened, with metadata, 90% quality WebP image data. Phew! | |
| * }); | |
| * | |
| * @param {Object[]} images - Ordered list of images to composite | |
| * @param {Buffer|String} [images[].input] - Buffer containing image data, String containing the path to an image file, or Create object (see below) | |
| * @param {Object} [images[].input.create] - describes a blank overlay to be created. | |
| * @param {Number} [images[].input.create.width] | |
| * @param {Number} [images[].input.create.height] | |
| * @param {Number} [images[].input.create.channels] - 3-4 | |
| * @param {String|Object} [images[].input.create.background] - parsed by the [color](https://www.npmjs.org/package/color) module to extract values for red, green, blue and alpha. | |
| * @param {Object} [images[].input.text] - describes a new text image to be created. | |
| * @param {string} [images[].input.text.text] - text to render as a UTF-8 string. It can contain Pango markup, for example `<i>Le</i>Monde`. | |
| * @param {string} [images[].input.text.font] - font name to render with. | |
| * @param {string} [images[].input.text.fontfile] - absolute filesystem path to a font file that can be used by `font`. | |
| * @param {number} [images[].input.text.width=0] - integral number of pixels to word-wrap at. Lines of text wider than this will be broken at word boundaries. | |
| * @param {number} [images[].input.text.height=0] - integral number of pixels high. When defined, `dpi` will be ignored and the text will automatically fit the pixel resolution defined by `width` and `height`. Will be ignored if `width` is not specified or set to 0. | |
| * @param {string} [images[].input.text.align='left'] - text alignment (`'left'`, `'centre'`, `'center'`, `'right'`). | |
| * @param {boolean} [images[].input.text.justify=false] - set this to true to apply justification to the text. | |
| * @param {number} [images[].input.text.dpi=72] - the resolution (size) at which to render the text. Does not take effect if `height` is specified. | |
| * @param {boolean} [images[].input.text.rgba=false] - set this to true to enable RGBA output. This is useful for colour emoji rendering, or support for Pango markup features like `<span foreground="red">Red!</span>`. | |
| * @param {number} [images[].input.text.spacing=0] - text line height in points. Will use the font line height if none is specified. | |
| * @param {String} [images[].blend='over'] - how to blend this image with the image below. | |
| * @param {String} [images[].gravity='centre'] - gravity at which to place the overlay. | |
| * @param {Number} [images[].top] - the pixel offset from the top edge. | |
| * @param {Number} [images[].left] - the pixel offset from the left edge. | |
| * @param {Boolean} [images[].tile=false] - set to true to repeat the overlay image across the entire image with the given `gravity`. | |
| * @param {Boolean} [images[].premultiplied=false] - set to true to avoid premultiplying the image below. Equivalent to the `--premultiplied` vips option. | |
| * @param {Number} [images[].density=72] - number representing the DPI for vector overlay image. | |
| * @param {Object} [images[].raw] - describes overlay when using raw pixel data. | |
| * @param {Number} [images[].raw.width] | |
| * @param {Number} [images[].raw.height] | |
| * @param {Number} [images[].raw.channels] | |
| * @param {boolean} [images[].animated=false] - Set to `true` to read all frames/pages of an animated image. | |
| * @param {string} [images[].failOn='warning'] - @see {@link /api-constructor#parameters|constructor parameters} | |
| * @param {number|boolean} [images[].limitInputPixels=268402689] - @see {@link /api-constructor#parameters|constructor parameters} | |
| * @returns {Sharp} | |
| * @throws {Error} Invalid parameters | |
| */ | |
| function composite (images) { | |
| if (!Array.isArray(images)) { | |
| throw is.invalidParameterError('images to composite', 'array', images); | |
| } | |
| this.options.composite = images.map(image => { | |
| if (!is.object(image)) { | |
| throw is.invalidParameterError('image to composite', 'object', image); | |
| } | |
| const inputOptions = this._inputOptionsFromObject(image); | |
| const composite = { | |
| input: this._createInputDescriptor(image.input, inputOptions, { allowStream: false }), | |
| blend: 'over', | |
| tile: false, | |
| left: 0, | |
| top: 0, | |
| hasOffset: false, | |
| gravity: 0, | |
| premultiplied: false | |
| }; | |
| if (is.defined(image.blend)) { | |
| if (is.string(blend[image.blend])) { | |
| composite.blend = blend[image.blend]; | |
| } else { | |
| throw is.invalidParameterError('blend', 'valid blend name', image.blend); | |
| } | |
| } | |
| if (is.defined(image.tile)) { | |
| if (is.bool(image.tile)) { | |
| composite.tile = image.tile; | |
| } else { | |
| throw is.invalidParameterError('tile', 'boolean', image.tile); | |
| } | |
| } | |
| if (is.defined(image.left)) { | |
| if (is.integer(image.left)) { | |
| composite.left = image.left; | |
| } else { | |
| throw is.invalidParameterError('left', 'integer', image.left); | |
| } | |
| } | |
| if (is.defined(image.top)) { | |
| if (is.integer(image.top)) { | |
| composite.top = image.top; | |
| } else { | |
| throw is.invalidParameterError('top', 'integer', image.top); | |
| } | |
| } | |
| if (is.defined(image.top) !== is.defined(image.left)) { | |
| throw new Error('Expected both left and top to be set'); | |
| } else { | |
| composite.hasOffset = is.integer(image.top) && is.integer(image.left); | |
| } | |
| if (is.defined(image.gravity)) { | |
| if (is.integer(image.gravity) && is.inRange(image.gravity, 0, 8)) { | |
| composite.gravity = image.gravity; | |
| } else if (is.string(image.gravity) && is.integer(this.constructor.gravity[image.gravity])) { | |
| composite.gravity = this.constructor.gravity[image.gravity]; | |
| } else { | |
| throw is.invalidParameterError('gravity', 'valid gravity', image.gravity); | |
| } | |
| } | |
| if (is.defined(image.premultiplied)) { | |
| if (is.bool(image.premultiplied)) { | |
| composite.premultiplied = image.premultiplied; | |
| } else { | |
| throw is.invalidParameterError('premultiplied', 'boolean', image.premultiplied); | |
| } | |
| } | |
| return composite; | |
| }); | |
| return this; | |
| } | |
| /** | |
| * Decorate the Sharp prototype with composite-related functions. | |
| * @private | |
| */ | |
| module.exports = function (Sharp) { | |
| Sharp.prototype.composite = composite; | |
| Sharp.blend = blend; | |
| }; | |