Data commit

Task/Bitmap-Flood-fill/Scala/bitmap-flood-fill.scala

@@ -0,0 +1,43 @@
+import java.awt.Color
+import scala.collection.mutable
+
+object Flood {
+  def floodFillStack(bm:RgbBitmap, x: Int, y: Int, targetColor: Color): Unit = {
+    // validate
+    if (bm.getPixel(x,y) == targetColor) return
+
+    // vars
+    val oldColor = bm.getPixel(x,y)
+    val pixels = new mutable.Stack[(Int,Int)]
+
+    // candy coating methods
+    def paint(fx: Int, fy:Int) = bm.setPixel(fx,fy,targetColor)
+    def old(cx: Int, cy: Int): Boolean = bm.getPixel(cx,cy) == oldColor
+    def push(px: Int, py: Int) = pixels.push((px,py))
+
+    // starting point
+    push(x,y)
+
+    // work
+    while (pixels.nonEmpty) {
+      val (x, y) = pixels.pop()
+      var y1 = y
+      while (y1 >= 0 && old(x, y1)) y1 -= 1
+      y1 += 1
+      var spanLeft = false
+      var spanRight = false
+      while (y1 < bm.height && old(x, y1)) {
+        paint(x,y1)
+        if (x > 0 && spanLeft != old(x-1,y1)) {
+          if (old(x - 1, y1)) push(x - 1, y1)
+          spanLeft = !spanLeft
+        }
+        if (x < bm.width - 1 && spanRight != old(x+1,y1)) {
+          if (old(x + 1, y1)) push(x + 1, y1)
+          spanRight = !spanRight
+        }
+        y1 += 1
+      }
+    }
+  }
+}