Updates to handle textureless scenes during capture.

1) Starts stitching only when the camera sees a textured scene at the beginning.
2) If a texturess scene is encountered in the middle of a capture, the stitching continues with the intermediate frames translated using the pan velocity estimate.
3) Added more error codes and percolated them up to the java layer.
4) Fix a build error in Mosaic::addFrame() and added comments.
5) Update the javadoc in Mosaic.java to reflect the new returning codes.

Change-Id: I7727ace615ece22adefe313a19ac2cbe8c8d21a8

2 files changed, 15 insertions, 8 deletions

diff --git a/src/com/android/camera/panorama/Mosaic.java b/src/com/android/camera/panorama/Mosaic.java
index 9ad2c64..5064cec 100644
--- a/src/com/android/camera/panorama/Mosaic.java
+++ b/src/com/android/camera/panorama/Mosaic.java
@@ -88,6 +88,9 @@ public class Mosaic {
     public static final int MOSAIC_RET_OK = 1;
     public static final int MOSAIC_RET_ERROR = -1;
     public static final int MOSAIC_RET_CANCELLED = -2;
+    public static final int MOSAIC_RET_LOW_TEXTURE = -3;
+    public static final int MOSAIC_RET_FEW_INLIERS = 2;
+
 
     static {
         System.loadLibrary("jni_mosaic");
@@ -113,10 +116,11 @@ public class Mosaic {
      * image to t is computed and returned.
      *
      * @param pixels source image of NV21 format.
-     * @return Float array of length 10; first 9 entries correspond to the 3x3
-     *         transformation matrix between the first frame and the passed frame,
-     *         and the last entry is the number of the passed frame,
-     *         where the counting starts from 1.
+     * @return Float array of length 11; first 9 entries correspond to the 3x3
+     *         transformation matrix between the first frame and the passed frame;
+     *         the 10th entry is the number of the passed frame, where the counting
+     *         starts from 1; and the 11th entry is the returning code, whose value
+     *         is one of those MOSAIC_RET_* returning flags defined above.
      */
     public native float[] setSourceImage(byte[] pixels);
 
@@ -127,10 +131,11 @@ public class Mosaic {
      * using glReadPixels directly from GPU memory (where it is accessed by
      * an associated SurfaceTexture).
      *
-     * @return Float array of length 10; first 9 entries correspond to the 3x3
-     *         transformation matrix between the first frame and the passed frame,
-     *         and the last entry is the number of the passed frame,
-     *         where the counting starts from 1.
+     * @return Float array of length 11; first 9 entries correspond to the 3x3
+     *         transformation matrix between the first frame and the passed frame;
+     *         the 10th entry is the number of the passed frame, where the counting
+     *         starts from 1; and the 11th entry is the returning code, whose value
+     *         is one of those MOSAIC_RET_* returning flags defined above.
      */
     public native float[] setSourceImageFromGPU();
 
diff --git a/src/com/android/camera/panorama/MosaicFrameProcessor.java b/src/com/android/camera/panorama/MosaicFrameProcessor.java
index 54fc7b8..7660f5e 100644
--- a/src/com/android/camera/panorama/MosaicFrameProcessor.java
+++ b/src/com/android/camera/panorama/MosaicFrameProcessor.java
@@ -26,6 +26,7 @@ public class MosaicFrameProcessor {
     private static final String TAG = "MosaicFrameProcessor";
     private static final int NUM_FRAMES_IN_BUFFER = 2;
     private static final int MAX_NUMBER_OF_FRAMES = 100;
+    private static final int MOSAIC_RET_CODE_INDEX = 10;
     private static final int FRAME_COUNT_INDEX = 9;
     private static final int X_COORD_INDEX = 2;
     private static final int Y_COORD_INDEX = 5;
@@ -184,6 +185,7 @@ public class MosaicFrameProcessor {
 
     public void calculateTranslationRate(long now) {
         float[] frameData = mMosaicer.setSourceImageFromGPU();
+        int ret_code = (int) frameData[MOSAIC_RET_CODE_INDEX];
         mTotalFrameCount  = (int) frameData[FRAME_COUNT_INDEX];
         float translationCurrX = frameData[X_COORD_INDEX];
         float translationCurrY = frameData[Y_COORD_INDEX];