Add a couple helpful methods

git-svn-id: https://zxing.googlecode.com/svn/trunk@1899 59b500cc-1b3d-0410-9834-0bbf25fbcc57

androidtest/src/com/google/zxing/client/androidtest/RGBLuminanceSource.java

@@ -55,13 +55,8 @@ public final class RGBLuminanceSource extends LuminanceSource {
         int r = (pixel >> 16) & 0xff;
         int g = (pixel >> 8) & 0xff;
         int b = pixel & 0xff;
-        if (r == g && g == b) {
+        // Calculate luminance cheaply, favoring green.
-          // Image is already greyscale, so pick any channel.
+        luminances[offset + x] = (byte) ((r + g + g + b) >> 2);
-          luminances[offset + x] = (byte) r;
-        } else {
-          // Calculate luminance cheaply, favoring green.
-          luminances[offset + x] = (byte) ((r + g + g + b) >> 2);
-        }
       }
     }
   }

core/src/com/google/zxing/LuminanceSource.java

@@ -110,4 +110,28 @@ public abstract class LuminanceSource {
     throw new RuntimeException("This luminance source does not support rotation.");
   }
 
+  public String toString() {
+    byte[] row = new byte[width];
+    StringBuffer result = new StringBuffer(height * (width + 1));
+    for (int y = 0; y < height; y++) {
+      row = getRow(y, row);
+      for (int x = 0; x < width; x++) {
+        int luminance = row[x] & 0xFF;
+        char c;
+        if (luminance < 0x40) {
+          c = '#';
+        } else if (luminance < 0x80) {
+          c = '+';
+        } else if (luminance < 0xC0) {
+          c = '.';
+        } else {
+          c = ' ';
+        }
+        result.append(c);
+      }
+      result.append('\n');
+    }
+    return result.toString();
+  }
+
 }

core/src/com/google/zxing/common/BitArray.java

@@ -92,6 +92,38 @@ public final class BitArray {
     bits[i >> 5] = newBits;
   }
 
+  /**
+   * Sets a range of bits.
+   *
+   * @param start start of range, inclusive.
+   * @param end end of range, exclusive
+   */
+  public void setRange(int start, int end) {
+    if (end < start) {
+      throw new IllegalArgumentException();
+    }
+    if (end == start) {
+      return;
+    }
+    end--; // will be easier to treat this as the last actually set bit -- inclusive
+    int firstInt = start >> 5;
+    int lastInt = end >> 5;
+    for (int i = firstInt; i <= lastInt; i++) {
+      int firstBit = i > firstInt ? 0 : start & 0x1F;
+      int lastBit = i < lastInt ? 31 : end & 0x1F;
+      int mask;
+      if (firstBit == 0 && lastBit == 31) {
+        mask = -1;
+      } else {
+        mask = 0;
+        for (int j = firstBit; j <= lastBit; j++) {
+          mask |= 1 << j;
+        }
+      }
+      bits[i] |= mask;
+    }
+  }
+
   /**
    * Clears all bits (sets to false).
    */