add text rendering via repl

io.go

@@ -1,44 +0,0 @@
-package main
-
-import (
-	"image"
-	_ "image/gif"
-	_ "image/jpeg"
-	"image/png"
-	"log"
-	"os"
-)
-
-func readImage(path string) (img image.Image) {
-	reader, err := os.Open(path)
-	if err != nil {
-		log.Fatal(err)
-	}
-	img, _, err2 := image.Decode(reader)
-	if err2 != nil {
-		log.Fatal(err2)
-	}
-	return img
-}
-
-func writeImage(path string, img image.Image) {
-	f, err := os.Create(path)
-	if err != nil {
-		log.Fatal(err)
-	}
-	if err := png.Encode(f, img); err != nil {
-		f.Close()
-		log.Fatal(err)
-	}
-}
-
-func imgToNRGBA(img image.Image) *image.NRGBA {
-	b := img.Bounds()
-	r := image.NewNRGBA(b)
-	for x := b.Min.X; x < b.Max.X; x++ {
-		for y := b.Min.Y; y < b.Max.Y; y++ {
-			r.Set(x, y, img.At(x, y))
-		}
-	}
-	return r
-}

main.go

@@ -11,6 +11,7 @@ import (
 	"sync"
 
 	"github.com/SpeckiJ/Hochwasser/pixelflut"
+	"github.com/SpeckiJ/Hochwasser/render"
 	"github.com/SpeckiJ/Hochwasser/rpc"
 )
 
@@ -50,7 +51,12 @@ func main() {
 
 	if *imgPath != "" {
 		offset := image.Pt(*x, *y)
-		img := imgToNRGBA(readImage(*imgPath))
+		imgTmp, err := render.ReadImage(*imgPath)
+		if err != nil {
+			log.Println(err)
+			return
+		}
+		img := render.ImgToNRGBA(imgTmp)
 
 		// check connectivity by opening one test connection
 		conn, err := net.Dial("tcp", *address)
@@ -71,7 +77,7 @@ func main() {
 			if *fetchImgPath != "" {
 				fetchedImg := pixelflut.FetchImage(img.Bounds().Add(offset), *address, 1, stopChan)
 				*connections -= 1
-				defer writeImage(*fetchImgPath, fetchedImg)
+				defer render.WriteImage(*fetchImgPath, fetchedImg)
 			}
 
 			// local 🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊🌊

render/image.go

@@ -0,0 +1,54 @@
+package render
+
+import (
+	"image"
+	_ "image/gif" // register gif, jpeg, png format handlers
+	_ "image/jpeg"
+	"image/png"
+	"os"
+
+	"golang.org/x/image/draw"
+)
+
+func ReadImage(path string) (image.Image, error) {
+	reader, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	img, _, err := image.Decode(reader)
+	if err != nil {
+		return nil, err
+	}
+	return img, nil
+}
+
+func WriteImage(path string, img image.Image) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	if err := png.Encode(f, img); err != nil {
+		f.Close()
+		return err
+	}
+	return nil
+}
+
+func ImgToNRGBA(img image.Image) *image.NRGBA {
+	b := img.Bounds()
+	r := image.NewNRGBA(b)
+	for x := b.Min.X; x < b.Max.X; x++ {
+		for y := b.Min.Y; y < b.Max.Y; y++ {
+			r.Set(x, y, img.At(x, y))
+		}
+	}
+	return r
+}
+
+func ScaleImage(img image.Image, factor int) (scaled *image.NRGBA) {
+	b := img.Bounds()
+	scaledBounds := image.Rect(0, 0, b.Max.X*factor, b.Max.Y*factor)
+	scaledImg := image.NewNRGBA(scaledBounds)
+	draw.NearestNeighbor.Scale(scaledImg, scaledBounds, img, b, draw.Src, nil)
+	return scaledImg
+}

render/text.go

@@ -0,0 +1,42 @@
+package render
+
+import (
+	"image"
+	"image/color"
+
+	"golang.org/x/image/draw"
+	"golang.org/x/image/font"
+	"golang.org/x/image/font/basicfont"
+	"golang.org/x/image/math/fixed"
+)
+
+func pt(p fixed.Point26_6) image.Point {
+	return image.Point{
+		X: int(p.X+32) >> 6,
+		Y: int(p.Y+32) >> 6,
+	}
+}
+
+func RenderText(text string, scale int, col color.Color) *image.NRGBA {
+	// @incomplete: draw with texture via Drawer.Src
+	face := basicfont.Face7x13
+	stringBounds, _ := font.BoundString(face, text)
+
+	b := image.Rectangle{pt(stringBounds.Min), pt(stringBounds.Max)}
+	img := image.NewNRGBA(b)
+
+	draw.Draw(img, b, image.Black, image.Point{}, draw.Src) // fill with black bg
+
+	d := font.Drawer{
+		Dst:  img,
+		Src:  image.NewUniform(col),
+		Face: face,
+	}
+	d.DrawString(text)
+
+	// normalize bounds to start at 0,0
+	img.Rect = img.Bounds().Sub(img.Bounds().Min)
+
+	// scale up, as this font is quite small
+	return ScaleImage(img, scale)
+}

rpc/dottir.go

@@ -46,11 +46,9 @@ type FlutStatus struct {
 }
 
 func (h *Hevring) Flut(task FlutTask, reply *FlutAck) error {
-	if (h.task != FlutTask{}) {
+	// stop old task if new task is received
-		// @incomplete: stop old task if new task is received
+	if h.taskQuit != nil {
-		fmt.Println("[hevring] already have a task")
+		close(h.taskQuit)
-		reply.Ok = false
-		return nil
 	}
 
 	fmt.Printf("[hevring] Rán gave us /w o r k/! %v\n", task)
@@ -71,7 +69,7 @@ func (h *Hevring) Status(metrics bool, reply *FlutStatus) error {
 }
 
 func (h *Hevring) Stop(x int, reply *FlutAck) error {
-	if (h.task != FlutTask{}) {
+	if h.taskQuit != nil {
 		fmt.Println("[hevring] stopping task")
 		h.task = FlutTask{}
 		close(h.taskQuit)
@@ -82,7 +80,9 @@ func (h *Hevring) Stop(x int, reply *FlutAck) error {
 }
 
 func (h *Hevring) Die(x int, reply *FlutAck) error {
-	go func() { // @cleanup: hacky
+	// @robustness: waiting for reply to be sent via timeout
+	// @incomplete: should try to reconnect for a bit first
+	go func() {
 		time.Sleep(100 * time.Millisecond)
 		fmt.Println("[hevring] Rán disconnected, stopping")
 		os.Exit(0)

rpc/ran.go

@@ -1,20 +1,19 @@
 package rpc
 
 import (
-	"bufio"
 	"fmt"
 	"image"
 	"log"
 	"net"
 	"net/rpc"
-	"os"
-	"strings"
 	"sync"
 	"time"
 
 	"github.com/SpeckiJ/Hochwasser/pixelflut"
 )
 
+// Rán represents the RPC hub, used to coordinate `Hevring` clients.
+// Implements `Fluter`
 type Rán struct {
 	clients []*rpc.Client
 	task    FlutTask
@@ -93,70 +92,23 @@ func SummonRán(address string, stopChan chan bool, wg *sync.WaitGroup) *Rán {
 		}
 	}()
 
-	// REPL to change tasks without loosing clients
+	go RunREPL(r)
-	go func() {
+	go r.killClients(stopChan, wg)
-		scanner := bufio.NewScanner(os.Stdin)
-		for scanner.Scan() {
-			input := strings.Split(scanner.Text(), " ")
-			cmd := strings.ToLower(input[0])
-			args := input[1:]
-			if cmd == "stop" {
-				for _, c := range r.clients {
-					ack := FlutAck{}
-					c.Call("Hevring.Stop", 0, &ack) // @speed: async
-				}
-
-			} else if cmd == "start" {
-				if (r.task != FlutTask{}) {
-					for _, c := range r.clients {
-						ack := FlutAck{}
-						// @speed: should send tasks async
-						err := c.Call("Hevring.Flut", r.task, &ack)
-						if err != nil || !ack.Ok {
-							log.Printf("[rán] client didn't accept task")
-						}
-					}
-				}
-
-			} else if cmd == "img" && len(args) > 0 {
-				// // @incomplete
-				// path := args[0]
-				// img := readImage(path)
-				// offset := image.Pt(0, 0)
-				// if len(args) == 3 {
-				// 	x := strconv.Atoi(args[1])
-				// 	y := strconv.Atoi(args[2])
-				// 	offset = image.Pt(x, y)
-				// }
-				// task := FlutTask{}
-
-			} else if cmd == "metrics" {
-				r.metrics.Enabled = !r.metrics.Enabled
-
-			}
-		}
-	}()
-
-	// kill clients on exit
-	go func() {
-		<-stopChan
-		for _, c := range r.clients {
-			ack := FlutAck{}
-			c.Call("Hevring.Die", 0, &ack) // @speed: async
-		}
-		wg.Done()
-	}()
 
 	return r
 }
 
-// SetTask assigns a FlutTask to Rán, distributing it to all clients
+func (r *Rán) getTask() FlutTask { return r.task }
-func (r *Rán) SetTask(img *image.NRGBA, offset image.Point, address string, maxConns int) {
-	// @incomplete: smart task creation:
-	//   fetch server state & sample foreign activity in image regions. assign
-	//   subregions to clients (per connection), considering their bandwidth.
 
-	r.task = FlutTask{address, maxConns, img, offset, true}
+func (r *Rán) toggleMetrics() {
+	r.metrics.Enabled = !r.metrics.Enabled
+}
+
+func (r *Rán) applyTask(t FlutTask) {
+	if (t == FlutTask{}) { // @robustness: FlutTask should provide .IsValid()
+		return
+	}
+	r.task = t
 	for _, c := range r.clients {
 		ack := FlutAck{}
 		// @speed: should send tasks async
@@ -166,3 +118,29 @@ func (r *Rán) SetTask(img *image.NRGBA, offset image.Point, address string, max
 		}
 	}
 }
+
+func (r *Rán) stopTask() {
+	// @robustness: errorchecking
+	for _, c := range r.clients {
+		ack := FlutAck{}
+		c.Call("Hevring.Stop", 0, &ack) // @speed: async
+	}
+}
+
+func (r *Rán) killClients(stopChan <-chan bool, wg *sync.WaitGroup) {
+	<-stopChan
+	for _, c := range r.clients {
+		ack := FlutAck{}
+		c.Call("Hevring.Die", 0, &ack) // @speed: async
+	}
+	wg.Done()
+}
+
+// SetTask assigns a FlutTask to Rán, distributing it to all clients
+func (r *Rán) SetTask(img *image.NRGBA, offset image.Point, address string, maxConns int) {
+	// @incomplete: smart task creation:
+	//   fetch server state & sample foreign activity in image regions. assign
+	//   subregions to clients (per connection), considering their bandwidth.
+
+	r.applyTask(FlutTask{address, maxConns, img, offset, true})
+}

rpc/repl.go

@@ -0,0 +1,116 @@
+package rpc
+
+import (
+	"bufio"
+	"encoding/hex"
+	"fmt"
+	"image"
+	"image/color"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/SpeckiJ/Hochwasser/render"
+)
+
+// Fluter implements flut operations that can be triggered via a REPL
+type Fluter interface {
+	getTask() FlutTask
+	applyTask(FlutTask)
+	stopTask()
+	toggleMetrics()
+}
+
+const commandMode = "CMD"
+const textMode = "TXT"
+
+// RunREPL starts reading os.Stdin for commands to apply to the given Fluter
+func RunREPL(f Fluter) {
+	mode := commandMode
+	textSize := 4
+	textCol := color.NRGBA{0xff, 0xff, 0xff, 0xff}
+
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		inputStr := scanner.Text()
+
+		switch mode {
+		case textMode:
+			if inputStr == commandMode {
+				fmt.Println("[rán] command mode")
+				mode = commandMode
+				continue
+			}
+			t := f.getTask()
+			t.Img = render.RenderText(inputStr, textSize, textCol)
+			f.applyTask(t)
+
+		case commandMode:
+			input := strings.Split(inputStr, " ")
+			cmd := strings.ToLower(input[0])
+			args := input[1:]
+			switch cmd {
+			case "stop":
+				f.stopTask()
+
+			case "start":
+				f.applyTask(f.getTask())
+
+			case "offset":
+				if len(args) == 2 {
+					x, err := strconv.Atoi(args[0])
+					y, err2 := strconv.Atoi(args[1])
+					if err == nil && err2 == nil {
+						t := f.getTask()
+						t.Offset = image.Pt(x, y)
+						f.applyTask(t)
+					}
+				}
+
+			case "conns":
+				if len(args) == 1 {
+					if conns, err := strconv.Atoi(args[0]); err == nil {
+						t := f.getTask()
+						t.MaxConns = conns
+						f.applyTask(t)
+					}
+				}
+
+			case "shuffle":
+				t := f.getTask()
+				t.Shuffle = !t.Shuffle
+				f.applyTask(t)
+
+			case "txt":
+				fmt.Printf("[rán] text mode, return via %v\n", commandMode)
+				mode = textMode
+				if len(args) > 0 {
+					if size, err := strconv.Atoi(args[0]); err == nil {
+						textSize = size
+					}
+				}
+				if len(args) > 1 {
+					if col, err := hex.DecodeString(args[1]); err == nil {
+						textCol = color.NRGBA{col[0], col[1], col[2], 0xff}
+					}
+				}
+
+			case "img":
+				if len(args) > 0 {
+					path := strings.Join(args, " ")
+					t := f.getTask()
+					if img, err := render.ReadImage(path); err != nil {
+						fmt.Println(err)
+					} else {
+						t.Img = render.ImgToNRGBA(img)
+						f.applyTask(t)
+					}
+				}
+
+			case "metrics":
+				f.toggleMetrics()
+
+			}
+		}
+	}
+}