embedding files; better installation

Makefile

@@ -6,9 +6,9 @@ test:
 
 docs: build
 	cat charts/testdata/basic.json | ./calendarheatmap > docs/basic.png
-	cat charts/testdata/basic.json | ./calendarheatmap -colorscale=purple-blue-9.csv > docs/colorscale-1.png
-	cat charts/testdata/basic.json | ./calendarheatmap -colorscale=green-blue-9.csv > docs/colorscale-2.png
-	cat charts/testdata/basic.json | ./calendarheatmap -colorscale=yellow-green-9.csv > docs/colorscale-3.png
+	CALENDAR_HEATMAP_ASSETS_PATH=assets cat charts/testdata/basic.json | ./calendarheatmap -colorscale=purple-blue-9.csv > docs/colorscale-1.png
+	CALENDAR_HEATMAP_ASSETS_PATH=assets cat charts/testdata/basic.json | ./calendarheatmap -colorscale=green-blue-9.csv > docs/colorscale-2.png
+	CALENDAR_HEATMAP_ASSETS_PATH=assets cat charts/testdata/basic.json | ./calendarheatmap -colorscale=yellow-green-9.csv > docs/colorscale-3.png
 	cat charts/testdata/basic.json | ./calendarheatmap -locale=ko_KR > docs/korean.png
 	cat charts/testdata/basic.json | ./calendarheatmap -locale=ko_KR -output=svg > docs/korean.svg
 	cat charts/testdata/basic.json | ./calendarheatmap -labels=false > docs/nolabels.png

README.md

@@ -6,14 +6,14 @@
 Self-contained, plain Go implementation of calendar heatmap inspired by GitHub contribution activity.
 
 ```
-$ go build
+$ go install github.com/nikolaydubina/calendarheatmap@latest 
 $ echo '{
     "2020-05-16": 8,
     "2020-05-17": 13,
     "2020-05-18": 5,
     "2020-05-19": 8,
     "2020-05-20": 5
-}' | ./calendarheatmap > chart.png
+}' | calendarheatmap > chart.png
 ```
 
 Basic
@@ -21,6 +21,7 @@ Basic
 ![basic](docs/basic.png)
 
 Colorscales
+
 ![col1](docs/colorscale-1.png)
 ![col2](docs/colorscale-2.png)
 ![col2](docs/colorscale-3.png)
@@ -30,11 +31,8 @@ UTF-8
 
 SVG
 
-
 ![svg](docs/korean.svg)
 
-
-
 Without month separator
 ![nosep](docs/noseparator.png)
 
@@ -44,7 +42,6 @@ Without labels
 Without labels, without separator
 ![nosep_nolab](docs/noseparator_nolabels.png)
 
-
 ## GitHub stars over time
 
 [![GitHub stars over time](https://starchart.cc/nikolaydubina/calendarheatmap.svg)](https://starchart.cc/nikolaydubina/calendarheatmap)

charts/colorscale.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"image/color"
+	"io"
 	"math"
 	"os"
 	"strconv"
@@ -37,13 +38,9 @@ func uint8FromStr(s string) (uint8, error) {
 	return uint8(v), nil
 }
 
-// NewBasicColorscaleFromCSVFile loads basic colorscale from CSV file
-func NewBasicColorscaleFromCSVFile(path string) (BasicColorScale, error) {
-	colorscaleReader, err := os.Open(path)
-	if err != nil {
-		return nil, fmt.Errorf("can not open file: %w", err)
-	}
-	rows, err := csv.NewReader(colorscaleReader).ReadAll()
+// NewBasicColorscaleFromCSV creates colorscale from reader
+func NewBasicColorscaleFromCSV(reader io.Reader) (BasicColorScale, error) {
+	rows, err := csv.NewReader(reader).ReadAll()
 	if err != nil {
 		return nil, fmt.Errorf("can not read CSV: %w", err)
 	}
@@ -83,3 +80,12 @@ func NewBasicColorscaleFromCSVFile(path string) (BasicColorScale, error) {
 	}
 	return colorscale, nil
 }
+
+// NewBasicColorscaleFromCSVFile loads basic colorscale from CSV file
+func NewBasicColorscaleFromCSVFile(path string) (BasicColorScale, error) {
+	colorscaleReader, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("can not open file: %w", err)
+	}
+	return NewBasicColorscaleFromCSV(colorscaleReader)
+}

charts/text.go

@@ -11,12 +11,8 @@ import (
 	"golang.org/x/image/math/fixed"
 )
 
-// LoadFontFaceFromFile loads font face from file
-func LoadFontFaceFromFile(fontPath string) (font.Face, error) {
-	fontBytes, err := ioutil.ReadFile(fontPath)
-	if err != nil {
-		return nil, fmt.Errorf("can not open font file with error: %w", err)
-	}
+// LoadFontFace loads font face from bytes
+func LoadFontFace(fontBytes []byte) (font.Face, error) {
 	f, err := opentype.Parse(fontBytes)
 	if err != nil {
 		return nil, fmt.Errorf("can not parse font file: %w", err)
@@ -32,6 +28,15 @@ func LoadFontFaceFromFile(fontPath string) (font.Face, error) {
 	return face, nil
 }
 
+// LoadFontFaceFromFile loads font face from file
+func LoadFontFaceFromFile(fontPath string) (font.Face, error) {
+	fontBytes, err := ioutil.ReadFile(fontPath)
+	if err != nil {
+		return nil, fmt.Errorf("can not open font file with error: %w", err)
+	}
+	return LoadFontFace(fontBytes)
+}
+
 // drawText inserts text into provided image at bottom left coordinate
 func drawText(fontFace font.Face, img *image.RGBA, offset image.Point, text string, color color.RGBA) {
 	if fontFace == nil {

go.mod

@@ -1,5 +1,5 @@
 module github.com/nikolaydubina/calendarheatmap
 
-go 1.14
+go 1.16
 
 require golang.org/x/image v0.0.0-20200927104501-e162460cd6b5

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"encoding/json"
 	"flag"
 	"image/color"
@@ -10,9 +11,17 @@ import (
 	"path"
 	"time"
 
+	_ "embed"
+
 	"github.com/nikolaydubina/calendarheatmap/charts"
 )
 
+//go:embed assets/fonts/Sunflower-Medium.ttf
+var defaultFontFaceBytes []byte
+
+//go:embed assets/colorscales/green-blue-9.csv
+var defaultColorScaleBytes []byte
+
 func main() {
 	var (
 		colorScale   string
@@ -20,7 +29,6 @@ func main() {
 		locale       string
 		monthSep     bool
 		outputFormat string
-		assetsPath   string
 	)
 
 	flag.BoolVar(&labels, "labels", true, "labels for weekday and months")
@@ -28,14 +36,29 @@ func main() {
 	flag.StringVar(&colorScale, "colorscale", "green-blue-9.csv", "filename of colorscale")
 	flag.StringVar(&locale, "locale", "en_US", "locale of labels (en_US, ko_KR)")
 	flag.StringVar(&outputFormat, "output", "png", "output format (png, jpeg, gif, svg)")
-	flag.StringVar(&assetsPath, "assetspath", "", "absolute path, or relative path for executable, of calendarheatmap repo assets, if not set will try CALENDARHEATMAP_ASSETS env variable, if not will try 'assets'")
 	flag.Parse()
 
-	if assetsPath == "" {
-		assetsPath = os.Getenv("CALENDAR_HEATMAP_ASSETS_PATH")
-		if assetsPath == "" {
-			assetsPath = "assets"
+	var colorscale charts.BasicColorScale
+	if assetsPath := os.Getenv("CALENDAR_HEATMAP_ASSETS_PATH"); assetsPath != "" {
+		var err error
+		colorscale, err = charts.NewBasicColorscaleFromCSVFile(path.Join(assetsPath, "colorscales", colorScale))
+		if err != nil {
+			log.Fatal(err)
 		}
+	} else {
+		var err error
+		if colorScale != "green-blue-9.csv" {
+			log.Printf("defaulting to colorscale %s since CALENDAR_HEATMAP_ASSETS_PATH is not set", "green-blue-9.csv")
+		}
+		colorscale, err = charts.NewBasicColorscaleFromCSV(bytes.NewBuffer(defaultColorScaleBytes))
+		if err != nil {
+			log.Fatal(err)
+		}
+	}
+
+	fontFace, err := charts.LoadFontFace(defaultFontFaceBytes)
+	if err != nil {
+		log.Fatal(err)
 	}
 
 	data, err := ioutil.ReadAll(os.Stdin)
@@ -48,16 +71,6 @@ func main() {
 		log.Fatal(err)
 	}
 
-	colorscale, err := charts.NewBasicColorscaleFromCSVFile(path.Join(assetsPath, "colorscales", colorScale))
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	fontFace, err := charts.LoadFontFaceFromFile(path.Join(assetsPath, "fonts", "Sunflower-Medium.ttf"))
-	if err != nil {
-		log.Fatal(err)
-	}
-
 	conf := charts.HeatmapConfig{
 		Counts:             counts,
 		ColorScale:         colorscale,