profiler.go

package main

import (
	glfw "github.com/go-gl/glfw3"
	"github.com/jimarnold/gltext"
)

type Profiler struct {
	frameSpeed float64
	frameTimes []float64
	frame      int
	lastTime   float64
	font       *gltext.Font
}

func NewProfiler(font *gltext.Font) *Profiler {
	return &Profiler{frameTimes: make([]float64, 256), frameSpeed: 0, frame: 0, font: font}
}

func (this *Profiler) start() {
	this.lastTime = glfw.GetTime()
}

func (this *Profiler) update() {
	frameCount := len(this.frameTimes)
	now := glfw.GetTime()
	this.frameTimes[this.frame%frameCount] = now - this.lastTime
	movingAverage := 0.0
	for _, f := range this.frameTimes {
		movingAverage += f
	}
	movingAverage /= float64(frameCount)
	if this.frame%frameCount == 0 {
		this.frameSpeed = movingAverage
	}
	this.lastTime = now
	this.frame++
}

func (this *Profiler) render() {
	this.font.Printf(1.7, 0, "%f", this.frameSpeed)
}