Handle zoom levels

README.md

@@ -1 +1,9 @@
 # slicerdicer
+
+Slice and dice an image, turning it into many equal sized tiles.
+
+## Usage
+
+slicerdicer -help
+
+slicerdicer --filename foo.png --tile-size 256

main.go

@@ -31,11 +31,30 @@ func main() {
 
   fmt.Println("starting tiling")
 
+  z := 0
+
+  // outer loop for zoom
+  for {
+    if (z == 0) {
+      // do nothing
+    } else {
+      // halve image size
+      src = imaging.Resize(src, size.X/2, 0, imaging.Linear)
+      // recalculate size
+      size = src.Bounds().Max
+      // we are done if we are now smaller then the tile
+      if (size.X < tile_size_x || size.Y < tile_size_y) {
+        break;
+      }
+    }
+
+    fmt.Print(fmt.Sprintf("zoom level: %d (%d x %d)\n", z, size.X, size.Y))
+
     for y := 0 ; y <= (size.Y / tile_size_y) ; y++ {
 
       for x := 0 ; x <= (size.X / tile_size_x) ; x++ {
  
-      output_filename := fmt.Sprintf("tile-0-%d-%d.png", x, y)
+        output_filename := fmt.Sprintf("tile-%d-%d-%d.png", z, x, y)
         cropped := imaging.Crop(src, image.Rect(tile_size_x*x, tile_size_y*y, tile_size_x*x+tile_size_x, tile_size_y*y+tile_size_y));
 
         fmt.Print("writing to: ", output_filename, "        ");
@@ -52,6 +71,9 @@ func main() {
     }
 
     fmt.Println()
+    z++
+  }
+
   fmt.Println("done")
 
 }