Playing around with images and drawing

mostly in preparation for doing image stuff in the Conway's Game of Life
implementation.

gotime/Makefile

@@ -15,7 +15,8 @@ TARGETS = \
 	github.com/meatballhat/box-o-sand/gotime/gotour-artifacts/ranges \
 	github.com/meatballhat/box-o-sand/gotime/gotour-artifacts/selects \
 	github.com/meatballhat/box-o-sand/gotime/junkdrawer/greppish \
-	github.com/meatballhat/box-o-sand/gotime/junkdrawer/reflectish
+	github.com/meatballhat/box-o-sand/gotime/junkdrawer/reflectish \
+	github.com/meatballhat/box-o-sand/gotime/junkdrawer/randimg
 
 
 test: build

gotime/junkdrawer/randimg/main.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+    "fmt"
+    "flag"
+    "image"
+    "image/color"
+    "image/draw"
+    "image/png"
+    "math/rand"
+    "os"
+    "time"
+)
+
+var (
+    outfile = flag.String("o", "randimg.png", "Output PNG file name")
+)
+
+func main() {
+    flag.Parse()
+    rand.Seed(time.Now().UTC().UnixNano())
+
+    out, err := os.Create(*outfile)
+    if err != nil {
+        fmt.Fprintf(os.Stderr, "ERROR: %v\n", err)
+        os.Exit(1)
+    }
+
+    imgRect := image.Rect(0, 0, 200, 200)
+    img := image.NewGray(imgRect)
+    draw.Draw(img, img.Bounds(), &image.Uniform{color.White}, image.ZP, draw.Src)
+
+    for y := 0; y < 200; y += 10 {
+        for x := 0; x < 200; x += 10 {
+            fill := &image.Uniform{color.Black}
+            if rand.Intn(10) % 2 == 0 {
+                fill = &image.Uniform{color.White}
+            }
+
+            draw.Draw(img, image.Rect(x, y, x+10, y+10), fill, image.ZP, draw.Src)
+        }
+    }
+
+    err = png.Encode(out, img)
+    if err != nil {
+        fmt.Fprintf(os.Stderr, "ERROR: %v\n", err)
+        os.Exit(2)
+    }
+
+    fmt.Printf("Wrote random image to \"%s\"\n", *outfile)
+    os.Exit(0)
+}