bugfix and added text mode

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"image"
 	"image/color"
@@ -114,8 +115,7 @@ func max(i int) int {
 	return i
 }
 
-func (g *GOL) check(x, y int) {
-	n := 0
+func (g *GOL) n(x, y int) (n int) {
 	for i := min(x - 1); i <= max(x+1); i++ {
 		for j := min(y - 1); j <= max(y+1); j++ {
 			if g.grid1.G[i][j] {
@@ -123,6 +123,11 @@ func (g *GOL) check(x, y int) {
 			}
 		}
 	}
+	return
+}
+
+func (g *GOL) check(x, y int) {
+	n := g.n(x, y)
 	if g.grid1.G[x][y] {
 		n--
 		switch n {
@@ -136,6 +141,8 @@ func (g *GOL) check(x, y int) {
 	} else {
 		if n == 3 {
 			g.grid2.G[x][y] = true
+		} else {
+			g.grid2.G[x][y] = false
 		}
 	}
 }
@@ -158,9 +165,57 @@ func (g *GOL) Calc() (gr *Grid) {
 	g.Gen++
 	return g.grid()
 }
+
+var text bool
+
 func main() {
+	flag.BoolVar(&text, "text", false, "text mode")
+	flag.Parse()
 	gol := NewGOL()
 	gc := make(chan *Grid, 10)
+	if text {
+		go func() {
+			buf := make([]byte, (size*size)+size*6)
+			for {
+				buf[0] = '+'
+				c := 1
+				for ; c < size+1; c++ {
+					buf[c] = '-'
+				}
+				buf[c] = '+'
+				c++
+				buf[c] = '\n'
+				c++
+				grid := <-gc
+				for i := 0; i < size; i++ {
+					buf[c] = '|'
+					c++
+					for j := 0; j < size; j++ {
+						if grid.G[j][i] {
+							buf[c] = '#'
+						} else {
+							buf[c] = ' '
+						}
+						c++
+					}
+					buf[c] = '|'
+					c++
+					buf[c] = '\n'
+					c++
+				}
+				buf[c] = '+'
+				c++
+				for i := 0; i < size; i++ {
+					buf[c] = '-'
+					c++
+				}
+				buf[c] = '+'
+				c++
+				buf[c] = '\n'
+				fmt.Printf("\r%s", string(buf))
+			}
+		}()
+	} else {
 		ic := make(chan image.Image, 10)
 		go func() {
 			o := jpeg.Options{100}
@@ -205,10 +260,13 @@ func main() {
 				ic <- img
 			}
 		}()
+	}
 
 	for {
 		gc <- gol.Calc()
+		if !text {
 			fmt.Fprintf(os.Stderr, "\rGeneration: %d", gol.Gen)
+		}
 		time.Sleep(time.Second / gps)
 	}
 }