Jason Shen jason-shen

## HaversinFormula.go
// haversin(θ) function
func hsin(theta float64) float64 {
	return math.Pow(math.Sin(theta/2), 2)
}

// Distance function returns the distance (in meters) between two points of
//     a given longitude and latitude relatively accurately (using a spherical
//     approximation of the Earth) through the Haversin Distance Formula for
//     great arc distance on a sphere with accuracy for small distances
//

## instructions.md

      
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                jason-shen
                / instructions.md
            
            
              Created
              May 25, 2023 08:21
                — forked from matthewjberger/instructions.md
            
              
                Install a nerd font on ubuntu
              
          
    1.) Download a Nerd Font
2.) Unzip and copy to ~/.fonts
3.) Run the command fc-cache -fv to manually rebuild the font cache

  
## gstreamermixer.md

      
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                jason-shen
                / gstreamermixer.md
            
            
              Last active
              July 31, 2022 17:01
            
              
                gstreamer video mix
              
          
    #gstreamer mixer
gst-launch-1.0 -e \
videomixer name=mix background=1 \
        sink_1::xpos=0   sink_1::ypos=0 \
        sink_2::xpos=200 sink_2::ypos=0 \
        sink_3::xpos=0 sink_3::ypos=100 \
        sink_4::xpos=200 sink_4::ypos=100 \
    ! autovideosink \


## cert-commands.txt
//Self-Signed Certificate for using with VS Code Live Server

//Save both files in a location you will remember

1. create a private key
openssl genrsa -aes256 -out localhost.key 2048
// you will be prompted to provide a password
//this will create localhost.key (call it whatever you like)

2. create the certificate

## vim_cheatsheet.md

      
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                jason-shen
                / vim_cheatsheet.md
            
            
              Created
              February 21, 2022 11:04
                — forked from awidegreen/vim_cheatsheet.md
            
              
                Vim shortcuts
              
          
    Introduction


C-a == Ctrl-a
M-a == Alt-a

General

:q        close
:w        write/saves
:wa[!]    write/save all windows [force]
:wq       write/save and close


## webrtc_simulcast.js
document.getElementById("btn").onclick = async () => {
  await run();
}

async function run() {
  let stream = await navigator.mediaDevices.getUserMedia({ video: true, audio: false });

  /* sender */
  let sender = new RTCPeerConnection();
  sender.onicecandidate = e => receiver.addIceCandidate(e.candidate);

## caddy https
Caddy is ready to serve your site over HTTPS:

Point your domain's A/AAAA DNS records at this machine.
Upload your site's files to /var/www/html.
Edit your Caddyfile at /etc/caddy/Caddyfile:
Replace :80 with your domain name
Change the site root to /var/www/html
Reload the configuration: systemctl reload caddy
Visit your site!

## Docker Compose + NATS example
FROM golang:1.6.2

COPY . /go

RUN go get github.com/nats-io/nats
RUN go build api-server.go

EXPOSE 8080
ENTRYPOINT ["/go/api-server"]

## ws.go
	httpsServer := &http.Server{
		Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			hj, isHJ := w.(http.Hijacker)
			if r.Header.Get("Upgrade") == "websocket" && isHJ {
				c, br, err := hj.Hijack()
				if err != nil {
					log.Printf("websocket websocket hijack: %v", err)
					http.Error(w, err.Error(), 500)
					return
				}

## volume_meter.html
<!DOCTYPE html>
<html lang="en">
    <head>
        <title> </title>
        <link rel="stylesheet" type="text/css" href="http://cdn.jsdelivr.net/min/1.5/min.min.css">
        <style>
        body,textarea,input,select {
            background:0;
            border-radius:0;
            font:16px sans-serif;
	// haversin(θ) function
	func hsin(theta float64) float64 {
	return math.Pow(math.Sin(theta/2), 2)
	}

	// Distance function returns the distance (in meters) between two points of
	// a given longitude and latitude relatively accurately (using a spherical
	// approximation of the Earth) through the Haversin Distance Formula for
	// great arc distance on a sphere with accuracy for small distances
	//
	//Self-Signed Certificate for using with VS Code Live Server

	//Save both files in a location you will remember

	1. create a private key
	openssl genrsa -aes256 -out localhost.key 2048
	// you will be prompted to provide a password
	//this will create localhost.key (call it whatever you like)

	2. create the certificate
	document.getElementById("btn").onclick = async () => {
	await run();
	}

	async function run() {
	let stream = await navigator.mediaDevices.getUserMedia({ video: true, audio: false });

	/* sender */
	let sender = new RTCPeerConnection();
	sender.onicecandidate = e => receiver.addIceCandidate(e.candidate);
	Caddy is ready to serve your site over HTTPS:

	Point your domain's A/AAAA DNS records at this machine.
	Upload your site's files to /var/www/html.
	Edit your Caddyfile at /etc/caddy/Caddyfile:
	Replace :80 with your domain name
	Change the site root to /var/www/html
	Reload the configuration: systemctl reload caddy
	Visit your site!
	FROM golang:1.6.2

	COPY . /go

	RUN go get github.com/nats-io/nats
	RUN go build api-server.go

	EXPOSE 8080
	ENTRYPOINT ["/go/api-server"]
	httpsServer := &http.Server{
	Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	hj, isHJ := w.(http.Hijacker)
	if r.Header.Get("Upgrade") == "websocket" && isHJ {
	c, br, err := hj.Hijack()
	if err != nil {
	log.Printf("websocket websocket hijack: %v", err)
	http.Error(w, err.Error(), 500)
	return
	}
	<!DOCTYPE html>
	<html lang="en">
	<head>
	<title> </title>
	<link rel="stylesheet" type="text/css" href="http://cdn.jsdelivr.net/min/1.5/min.min.css">
	<style>
	body,textarea,input,select {
	background:0;
	border-radius:0;
	font:16px sans-serif;