Move icon generation into dedicated files

idicon.go

@@ -1,130 +1,18 @@
 package main
 
 import (
-	"crypto/md5"
-	"encoding/hex"
 	"flag"
 	"fmt"
-	"image"
-	"image/color"
-	"image/draw"
+	"github.com/BurntSushi/toml"
+	"github.com/gorilla/mux"
+	"idicon/icons"
 	"image/png"
 	"log"
 	"net/http"
 	"os"
-	"regexp"
 	"strconv"
-	"strings"
-
-	"github.com/BurntSushi/toml"
-	"github.com/gorilla/mux"
 )
 
-// https://processing.org/reference/map_.html
-func remap(value uint32, vmin uint32, vmax uint32, dmin uint32, dmax uint32) float32 {
-	return float32((value-vmin)*(dmax-dmin)) / float32((vmax-vmin)+dmin)
-}
-
-func nibbles(hash [16]byte) []byte {
-	nibbles := make([]byte, 32)
-
-	for i := 0; i <= 15; i++ {
-		nibbles[i*2+1] = hash[i] & 0x0f
-		nibbles[i*2] = hash[i] & 0xf0 >> 4
-	}
-
-	return nibbles
-}
-
-// Based on https://github.com/dgraham/identicon
-func genGhIcon(id string, size int, f func([16]byte) color.RGBA) *image.NRGBA {
-	if size > 512 {
-		size = 512
-	}
-	blocks := 5
-
-	hash := hashBytes(id)
-	nibbles := nibbles(hash)
-	data := make([]bool, blocks*blocks)
-
-	for x := 0; x < blocks; x++ {
-		for y := 0; y < blocks; y++ {
-			ni := x + blocks*(blocks-y-1)
-			if x+blocks*y > 2*blocks {
-				di := (x + blocks*y) - 2*blocks
-				data[di] = nibbles[ni%32]%2 == 0
-			}
-		}
-	}
-
-	return drawImage(mirrorData(data, blocks), blocks, size, f(hash))
-}
-
-func genIdIcon(id string, size int, f func([16]byte) color.RGBA) *image.NRGBA {
-	id = strings.ToLower(id)
-	blocks := 5
-	if size > 512 {
-		size = 512
-	}
-
-	hash := hashBytes(id)
-	data := make([]bool, blocks*blocks)
-	for i := 0; i < len(hash)-1; i++ {
-		data[i] = hash[i]%2 != hash[i+1]%2
-	}
-	return drawImage(mirrorData(data, blocks), blocks, size, f(hash))
-}
-
-func hashBytes(id string) [16]byte {
-	hash := [16]byte{}
-	md5RegExp := regexp.MustCompile("[a-f0-9]{32}")
-	if !md5RegExp.Match([]byte(id)) {
-		hash = md5.Sum([]byte(id))
-	} else {
-		dec, _ := hex.DecodeString(id)
-		for idx, b := range dec {
-			hash[idx] = b
-		}
-	}
-	return hash
-}
-
-func mirrorData(data []bool, blocks int) []bool {
-	for x := 0; x < blocks; x++ {
-		min := x*blocks + 1
-		for y := 0; y < blocks; y++ {
-			a := ((blocks - x - 1) * blocks) + y
-			b := min + y - 1
-			if data[a] {
-				data[b] = true
-			}
-		}
-	}
-	return data
-}
-
-func drawImage(data []bool, blocks int, size int, c color.Color) *image.NRGBA {
-	img := image.NewNRGBA(image.Rect(0, 0, size, size))
-
-	draw.Draw(img, img.Bounds(), &image.Uniform{color.Gray{240}}, image.Point{0, 0}, draw.Src)
-
-	blockSize := size / (blocks + 1)
-	border := (size - (blocks * blockSize)) / 2
-
-	for x := border; x < blockSize*blocks+border; x++ {
-		bx := (x - border) / blockSize
-		for y := border; y < blockSize*blocks+border; y++ {
-			by := (y - border) / blockSize
-			idx := bx*blocks + by
-			if data[idx] && (bx < blocks || by < blocks) {
-				img.Set(x, y, c)
-			}
-		}
-	}
-
-	return img
-}
-
 func requestHandler(w http.ResponseWriter, r *http.Request) {
 	id := mux.Vars(r)["id"]
 
@@ -144,7 +32,7 @@ func requestHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	for _, userConfig := range config.Users {
-		if hashBytes(id) == hashBytes(userConfig.ID) {
+		if icons.HashBytes(id) == icons.HashBytes(userConfig.ID) {
 			id = userConfig.Alias
 			if len(userConfig.ColorScheme) > 0 {
 				colorScheme = userConfig.ColorScheme
@@ -156,19 +44,22 @@ func requestHandler(w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.Header().Add("Content-Type", "image/png")
-	cFunc := colorV2
+	cFunc := icons.ColorV2
 	if colorScheme == "v1" {
-		cFunc = colorV1
+		cFunc = icons.ColorV1
 	} else if colorScheme == "gh" {
-		cFunc = colorGh
+		cFunc = icons.ColorGh
 	}
 
+	var iconGenerator icons.IconGenerator
 	if pattern == "github" {
-		err = png.Encode(w, genGhIcon(id, size, cFunc))
+		iconGenerator = &icons.GhIconGenerator{}
+
 	} else {
-		err = png.Encode(w, genIdIcon(id, size, cFunc))
+		iconGenerator = &icons.IdIconGenerator{}
 	}
 
+	err = png.Encode(w, iconGenerator.GenIcon(id, size, cFunc))
 }
 
 var (