playcanvas/build/playcanvas.dbg/src/extras/mini-stats/cpu-timer.js

Open-source WebGL/WebGPU 3D engine for the web

import { now } from '../../core/time.js';

class CpuTimer {
    // mark the beginning of the frame
    begin(name) {
        if (!this.enabled) {
            return;
        }
        // end previous frame timings
        if (this._frameIndex < this._frameTimings.length) {
            this._frameTimings.splice(this._frameIndex);
        }
        const tmp = this._prevTimings;
        this._prevTimings = this._timings;
        this._timings = this._frameTimings;
        this._frameTimings = tmp;
        this._frameIndex = 0;
        this.mark(name);
    }
    // mark
    mark(name) {
        if (!this.enabled) {
            return;
        }
        const timestamp = now();
        // end previous mark
        if (this._frameIndex > 0) {
            const prev = this._frameTimings[this._frameIndex - 1];
            prev[1] = timestamp - prev[1];
        } else if (this._timings.length > 0) {
            const prev = this._timings[this._timings.length - 1];
            prev[1] = timestamp - prev[1];
        }
        if (this._frameIndex >= this._frameTimings.length) {
            this._frameTimings.push([
                name,
                timestamp
            ]);
        } else {
            const timing = this._frameTimings[this._frameIndex];
            timing[0] = name;
            timing[1] = timestamp;
        }
        this._frameIndex++;
    }
    get timings() {
        // remove the last time point from the list (which is the time spent outside
        // of PlayCanvas)
        return this._timings.slice(0, -1).map((v)=>v[1]);
    }
    constructor(app){
        this._frameIndex = 0;
        this._frameTimings = [];
        this._timings = [];
        this._prevTimings = [];
        this.unitsName = 'ms';
        this.decimalPlaces = 1;
        this.enabled = true;
        app.on('frameupdate', this.begin.bind(this, 'update'));
        app.on('framerender', this.mark.bind(this, 'render'));
        app.on('frameend', this.mark.bind(this, 'other'));
    }
}

export { CpuTimer };