49 lines
2.3 KiB
JavaScript
49 lines
2.3 KiB
JavaScript
"use strict";
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let promise;
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async function detectVideoAlphaMode() {
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promise ?? (promise = (async () => {
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const canvas = document.createElement("canvas");
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const gl = canvas.getContext("webgl");
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if (!gl) {
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return "premultiply-alpha-on-upload";
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}
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const video = await new Promise((resolve) => {
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const video2 = document.createElement("video");
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video2.onloadeddata = () => resolve(video2);
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video2.onerror = () => resolve(null);
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video2.autoplay = false;
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video2.crossOrigin = "anonymous";
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video2.preload = "auto";
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video2.src = "data:video/webm;base64,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";
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video2.load();
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});
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if (!video) {
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return "premultiply-alpha-on-upload";
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}
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const texture = gl.createTexture();
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gl.bindTexture(gl.TEXTURE_2D, texture);
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const framebuffer = gl.createFramebuffer();
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gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
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gl.framebufferTexture2D(
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gl.FRAMEBUFFER,
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gl.COLOR_ATTACHMENT0,
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gl.TEXTURE_2D,
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texture,
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0
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);
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gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, false);
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gl.pixelStorei(gl.UNPACK_COLORSPACE_CONVERSION_WEBGL, gl.NONE);
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gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, video);
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const pixel = new Uint8Array(4);
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gl.readPixels(0, 0, 1, 1, gl.RGBA, gl.UNSIGNED_BYTE, pixel);
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gl.deleteFramebuffer(framebuffer);
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gl.deleteTexture(texture);
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gl.getExtension("WEBGL_lose_context")?.loseContext();
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return pixel[0] <= pixel[3] ? "premultiplied-alpha" : "premultiply-alpha-on-upload";
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})());
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return promise;
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}
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export { detectVideoAlphaMode };
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//# sourceMappingURL=detectVideoAlphaMode.mjs.map
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