Merge pull request #55 from theckman/new_spinner_gifs

Update README spinner gifs, add tooling + notes used to create them

.gitignore

@@ -14,3 +14,12 @@ coverage.txt
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
+
+# README GIF generation files
+*.mov
+*.mp4
+*.gif
+*.prproj
+
+# OS files
+.DS_Store

examples/demo/README.md

@@ -0,0 +1,44 @@
+# demo
+
+This program is the helper used to create the gifs in the README. What follows
+are notes for when I do this in the future.
+
+### Overview
+
+The software in this `demo` folder is used to demonstrate all of the spinners
+that exist, and to help generate the GIFs used for the README.md file in the
+root of this repo.
+
+There are two helper scripts in the `scripts/` folder. `ffmpeg.sh` helps with
+converting the h.264 .mp4 files into .gif files. The `rename.go` program then
+helps rename those .gif files into the right name for committing to the
+repository.
+
+The GIFs are stored in a sister GitHub repository, [github.com/theckman/yacspin-gifs](https://github.com/theckman/yacspin-gifs)
+to avoid cluttering up this repo with binary files (images).
+
+#### Checklist
+
+- [ ] start a screen recording of the terminal using Apple QuickTime Player
+- [ ] start the demo program (`main.go`) and let it run entirely before stopping the QuickTime recording
+- [ ] load the .mov file into Adobe Preimere, and cut the clip down into the individual 10 second clips of each spinner
+- [ ] turn the clips in the original Sequence into Subsequences
+- [ ] use media encoder to export those subsequences to their own files, matching source with Adaptive High Bitrate
+- [ ] use the `scripts/ffmpeg.sh` script to convert the `.mp4` files into `.gif` files
+- [ ] `go run` the `scripts/rename.go` program, to rename the `.gif` files to match the names we expect
+
+#### QuickTime Capture Sizes
+
+When using the Apple QuickTime Player to capture the screen recording, you can
+have it only capture a specific area of the screen. These are the capture sizes
+I played with on my Apple 16" M1 Max MBP laptop.
+
+Please note, that the video files rendered from these captures tend to have
+about 2x the resolution. Keep that in mind when deciding how large of an area
+you want to capture.
+
+Capture Size (pixels) | Font Size
+----------------------|----------
+650w x 24h | 18
+340w x 12h | 10
+1300w x 47h | 38

examples/demo/main.go

@@ -0,0 +1,66 @@
+// This program was used to generate the gifs in the README file
+
+package main
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"runtime"
+	"runtime/debug"
+	"syscall"
+	"time"
+
+	"github.com/theckman/yacspin"
+)
+
+func main() {
+	// disable GC
+	debug.SetGCPercent(-1)
+
+	cfg := yacspin.Config{
+		Frequency:       200 * time.Millisecond,
+		CharSet:         yacspin.CharSets[36],
+		SuffixAutoColon: true,
+		Suffix:          " example spinner",
+		Message:         "initial message",
+		Colors:          []string{"fgYellow"},
+	}
+
+	spinner, err := yacspin.New(cfg)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to create spinner: %v\n", err)
+		os.Exit(1)
+	}
+
+	// handle SIGINT / SIGTERM without needing terminal reset
+	sigc := make(chan os.Signal, 2)
+	signal.Notify(sigc, syscall.SIGINT, syscall.SIGTERM)
+	go func() {
+		<-sigc
+		_ = spinner.Stop()
+		os.Exit(0)
+	}()
+
+	// run GC once before we start to render
+	runtime.GC()
+
+	time.Sleep(3 * time.Second)
+
+	for i := 0; i < len(yacspin.CharSets); i++ {
+		spinner.Message("initial message")
+
+		// interesting charsets for recording sizing: 19, 36
+		_ = spinner.CharSet(yacspin.CharSets[i])
+
+		_ = spinner.Start()
+
+		time.Sleep(5 * time.Second)
+
+		spinner.Message("updated message")
+
+		time.Sleep(5 * time.Second)
+
+		_ = spinner.Stop()
+	}
+}

examples/demo/scripts/ffmpeg.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+####
+#
+# Convert *.mp4 files in the current directory to GIFs at 10 FPS
+#
+####
+
+function main() {
+    for file in *.mp4;
+    do
+        basename=$(echo "${file}" | sed -e 's/\.mp4$//')
+
+        ffmpeg -i "${basename}.mp4" -vf "fps=10,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 "${basename}.gif"
+    done
+}
+
+main

examples/demo/scripts/rename.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+func main() {
+	var sim bool
+	var glob string
+
+	flag.BoolVar(&sim, "sim", false, "simulate")
+	flag.StringVar(&glob, "glob", "", "glob to use for matching files, must end in *.gif")
+	flag.Parse()
+
+	if !strings.HasSuffix(glob, "*.gif") {
+		fmt.Fprintln(os.Stderr, "-glob flag required and must end in *.gif")
+		os.Exit(int(syscall.EINVAL))
+	}
+
+	m, err := filepath.Glob(glob)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "failed to glob %s: %v\n", glob, err)
+		os.Exit(1)
+	}
+
+	if len(m) == 0 {
+		fmt.Fprintf(os.Stderr, "no files matched glob %s\n", glob)
+		os.Exit(1)
+	}
+
+	idx := strings.Index(glob, "*")
+
+	for _, match := range m {
+		num := strings.TrimSuffix(match[idx:], ".gif")
+
+		ni, err := strconv.Atoi(num)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "failed to convert number in %s to integer: %v\n", match, err)
+			os.Exit(1)
+		}
+
+		ni--
+
+		newName := fmt.Sprintf("%d.gif", ni)
+
+		if sim {
+			fmt.Printf("would rename %s to %s\n", match, newName)
+			continue
+		}
+
+		if err := os.Rename(match, newName); err != nil {
+			fmt.Fprintf(os.Stderr, "failed to rename %s to %s\n", match, newName)
+			os.Exit(1)
+		}
+	}
+}