63 lines
2.4 KiB
JavaScript
63 lines
2.4 KiB
JavaScript
"use strict";
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.PNG = exports.PngType = void 0;
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var tslib_1 = require("tslib");
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var upng_1 = tslib_1.__importDefault(require("@pdf-lib/upng"));
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var getImageType = function (ctype) {
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if (ctype === 0)
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return PngType.Greyscale;
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if (ctype === 2)
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return PngType.Truecolour;
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if (ctype === 3)
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return PngType.IndexedColour;
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if (ctype === 4)
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return PngType.GreyscaleWithAlpha;
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if (ctype === 6)
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return PngType.TruecolourWithAlpha;
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throw new Error("Unknown color type: " + ctype);
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};
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var splitAlphaChannel = function (rgbaChannel) {
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var pixelCount = Math.floor(rgbaChannel.length / 4);
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var rgbChannel = new Uint8Array(pixelCount * 3);
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var alphaChannel = new Uint8Array(pixelCount * 1);
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var rgbaOffset = 0;
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var rgbOffset = 0;
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var alphaOffset = 0;
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while (rgbaOffset < rgbaChannel.length) {
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rgbChannel[rgbOffset++] = rgbaChannel[rgbaOffset++];
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rgbChannel[rgbOffset++] = rgbaChannel[rgbaOffset++];
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rgbChannel[rgbOffset++] = rgbaChannel[rgbaOffset++];
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alphaChannel[alphaOffset++] = rgbaChannel[rgbaOffset++];
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}
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return { rgbChannel: rgbChannel, alphaChannel: alphaChannel };
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};
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var PngType;
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(function (PngType) {
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PngType["Greyscale"] = "Greyscale";
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PngType["Truecolour"] = "Truecolour";
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PngType["IndexedColour"] = "IndexedColour";
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PngType["GreyscaleWithAlpha"] = "GreyscaleWithAlpha";
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PngType["TruecolourWithAlpha"] = "TruecolourWithAlpha";
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})(PngType = exports.PngType || (exports.PngType = {}));
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var PNG = /** @class */ (function () {
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function PNG(pngData) {
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var upng = upng_1.default.decode(pngData);
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var frames = upng_1.default.toRGBA8(upng);
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if (frames.length > 1)
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throw new Error("Animated PNGs are not supported");
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var frame = new Uint8Array(frames[0]);
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var _a = splitAlphaChannel(frame), rgbChannel = _a.rgbChannel, alphaChannel = _a.alphaChannel;
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this.rgbChannel = rgbChannel;
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var hasAlphaValues = alphaChannel.some(function (a) { return a < 255; });
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if (hasAlphaValues)
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this.alphaChannel = alphaChannel;
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this.type = getImageType(upng.ctype);
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this.width = upng.width;
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this.height = upng.height;
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this.bitsPerComponent = 8;
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}
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PNG.load = function (pngData) { return new PNG(pngData); };
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return PNG;
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}());
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exports.PNG = PNG;
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//# sourceMappingURL=png.js.map
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