55 lines
1.9 KiB
JavaScript
55 lines
1.9 KiB
JavaScript
export function createRenderStep(runNextFrame) {
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let toRun = [];
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let toRunNextFrame = [];
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let numToRun = 0;
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let isProcessing = false;
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let flushNextFrame = false;
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const toKeepAlive = new WeakSet();
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const step = {
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schedule: (callback, keepAlive = false, immediate = false) => {
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const addToCurrentFrame = immediate && isProcessing;
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const buffer = addToCurrentFrame ? toRun : toRunNextFrame;
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if (keepAlive)
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toKeepAlive.add(callback);
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if (buffer.indexOf(callback) === -1) {
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buffer.push(callback);
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if (addToCurrentFrame && isProcessing)
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numToRun = toRun.length;
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}
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return callback;
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},
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cancel: (callback) => {
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const index = toRunNextFrame.indexOf(callback);
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if (index !== -1)
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toRunNextFrame.splice(index, 1);
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toKeepAlive.delete(callback);
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},
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process: (frameData) => {
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if (isProcessing) {
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flushNextFrame = true;
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return;
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}
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isProcessing = true;
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[toRun, toRunNextFrame] = [toRunNextFrame, toRun];
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toRunNextFrame.length = 0;
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numToRun = toRun.length;
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if (numToRun) {
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for (let i = 0; i < numToRun; i++) {
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const callback = toRun[i];
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callback(frameData);
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if (toKeepAlive.has(callback)) {
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step.schedule(callback);
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runNextFrame();
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}
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}
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}
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isProcessing = false;
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if (flushNextFrame) {
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flushNextFrame = false;
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step.process(frameData);
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}
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},
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};
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return step;
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}
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//# sourceMappingURL=create-render-step.js.map
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