Changed the order of the BaseMonochromeBitmapSource constructor arguments to be width...

[zxing.git] / javame / src / com / google / zxing / client / j2me / LCDUIImageMonochromeBitmapSource.java

diff --git a/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java b/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java
index 7527230..b65b715 100644 (file)
--- a/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java
+++ b/javame/src/com/google/zxing/client/j2me/LCDUIImageMonochromeBitmapSource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2007 Google Inc.
+ * Copyright 2007 ZXing authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,31 +23,32 @@ import javax.microedition.lcdui.Image;
 /**
  * <p>An implementation based on Java ME's {@link Image} representation.</p>
  *
- * @author Sean Owen (srowen@google.com), Daniel Switkin (dswitkin@google.com)
+ * @author Sean Owen
+ * @author Daniel Switkin (dswitkin@google.com)
  */
 public final class LCDUIImageMonochromeBitmapSource extends BaseMonochromeBitmapSource {
 
-  private final int[] rgbPixels;
-  private final int width;
-  private final int height;
+  private final Image image;
+  private final int[] pixelHolder;
 
   public LCDUIImageMonochromeBitmapSource(Image image) {
-    width = image.getWidth();
-    height = image.getHeight();
-    rgbPixels = new int[width * height];
-    image.getRGB(rgbPixels, 0, width, 0, 0, width, height);
+    super(image.getWidth(), image.getHeight());
+    this.image = image;
+    pixelHolder = new int[1];
   }
 
-  public int getHeight() {
-    return height;
+  public final int getHeight() {
+    return image.getHeight();
   }
 
-  public int getWidth() {
-    return width;
+  public final int getWidth() {
+    return image.getWidth();
   }
 
-  public int getLuminance(int x, int y) {
-    int pixel = rgbPixels[y * width + x];
+  // This is expensive and should be used very sparingly.
+  protected int getLuminance(int x, int y) {
+    image.getRGB(pixelHolder, 0, getWidth(), x, y, 1, 1);
+    int pixel = pixelHolder[0];
 
     // Instead of multiplying by 306, 601, 117, we multiply by 256, 512, 256, so that
     // the multiplies can be implemented as shifts.
@@ -66,9 +67,35 @@ public final class LCDUIImageMonochromeBitmapSource extends BaseMonochromeBitmap
              (pixel & 0x000000FF       )) >> 2;
   }
 
-  // Nothing to do, since we have direct access to the image data.
-  public void cacheRowForLuminance(int y) {
+  // For efficiency, the RGB data and the luminance data share the same array.
+  protected int[] getLuminanceRow(int y, int[] row) {
+    int width = getWidth();
+    if (row == null || row.length < width) {
+      row = new int[width];
+    }
+    image.getRGB(row, 0, width, 0, y, width, 1);
+    for (int x = 0; x < width; x++) {
+      int pixel = row[x];
+      row[x] = (((pixel & 0x00FF0000) >> 16) +
+                ((pixel & 0x0000FF00) >>  7) +
+                 (pixel & 0x000000FF       )) >> 2;
+    }
+    return row;
+  }
 
+  protected int[] getLuminanceColumn(int x, int[] column) {
+    int height = getHeight();
+    if (column == null || column.length < height) {
+      column = new int[height];
+    }
+    image.getRGB(column, 0, 1, x, 0, 1, height);
+    for (int y = 0; y < height; y++) {
+      int pixel = column[y];
+      column[y] = (((pixel & 0x00FF0000) >> 16) +
+                   ((pixel & 0x0000FF00) >>  7) +
+                    (pixel & 0x000000FF       )) >> 2;
+    }
+    return column;
   }
 
-}
\ No newline at end of file
+}