accept a number and return always the same symmetric grid avatar (a7744096) · Commits · blackheaven / tinygraphs

app-backend/main.go

+2 −1

Original line number	Diff line number	Diff line
		@@ -22,7 +22,8 @@ func main() {
		r.HandleFunc("/red/?", colors.Red)

		r.HandleFunc("/grid/?", grid.H6X6)
		r.HandleFunc("/grid/[0-8]?", grid.Color)
		r.HandleFunc("/grid/[0-8]/?", grid.Color)
		r.HandleFunc("/grid/square/[0-9]+/?", grid.Square)

		r.HandleFunc("/grid/random/?", grid.Random)
		r.HandleFunc("/grid/random/[0-8]/?", grid.RandomColor)

0 → 100644

+33 −0

Original line number	Diff line number	Diff line
		package grid

		import (
		"crypto/md5"
		"fmt"
		"github.com/taironas/tinygraphs/colors"
		"github.com/taironas/tinygraphs/draw"
		"github.com/taironas/tinygraphs/misc"
		"github.com/taironas/tinygraphs/write"
		"image"
		"io"
		"log"
		"net/http"
		)

		// gridColorHandler is the handler for /grid/square/[0-9]+/?
		// build a 6x6 grid with alternate colors based on the number passed in the url
		func Square(w http.ResponseWriter, r *http.Request) {
		intID, err := misc.PermalinkID(r, 3)
		if err != nil {
		log.Printf("error when extracting permalink id: %v", err)
		} else {
		m := image.NewRGBA(image.Rect(0, 0, 240, 240))
		colorMap := colors.MapOfColorPatterns()
		h := md5.New()
		io.WriteString(h, string(intID))
		log.Printf("md5: %x", h.Sum(nil))
		key := fmt.Sprintf("%x", h.Sum(nil)[:])
		draw.Square(m, key, colorMap[0][0], colorMap[0][1])
		var img image.Image = m
		write.Image(w, &img)
		}
		}

+44 −0

Original line number	Diff line number	Diff line
		package draw

		import (
		"encoding/hex"
		"image"
		"image/color"
		"log"
		"math"
		"math/rand"
		"strconv"
		)

		//drawGrid6X6 builds an image with 6X6 quadrants of alternate colors.
		@@ -126,3 +129,44 @@ func RandomSymetricInXGrid6X6(m *image.RGBA, color1, color2 color.RGBA) {
		}
		}
		}

		func Square(m *image.RGBA, key string, color1, color2 color.RGBA) {
		size := m.Bounds().Size()
		squares := 6
		quad := size.X / squares
		middle := math.Ceil(float64(squares) / float64(2))
		colorMap := make(map[int]color.RGBA)
		var currentYQuadrand = 0
		for y := 0; y < size.Y; y++ {
		yQuadrant := y / quad
		if yQuadrant != currentYQuadrand {
		// when y quadrant changes, clear map
		colorMap = make(map[int]color.RGBA)
		currentYQuadrand = yQuadrant
		}
		for x := 0; x < size.X; x++ {
		xQuadrant := x / quad
		if _, ok := colorMap[xQuadrant]; !ok {
		if float64(xQuadrant) < middle {
		colorMap[xQuadrant] = colorFromKey(key, color1, color2, xQuadrant+3*yQuadrant)
		} else {
		colorMap[xQuadrant] = colorMap[squares-xQuadrant-1]
		}
		}
		m.Set(x, y, colorMap[xQuadrant])
		}
		}
		}

		func colorFromKey(key string, color1, color2 color.RGBA, index int) color.RGBA {
		s := hex.EncodeToString([]byte{key[index]})
		if r, err := strconv.ParseInt(s, 16, 0); err == nil {
		if r%2 == 0 {
		return color1
		}
		return color2
		} else {
		log.Println("Error calling ParseInt(%v, 16, 0)", s, err)
		}
		return color1
		}