diff --git a/libs/hwui/AmbientShadow.cpp b/libs/hwui/AmbientShadow.cpp
index cb3a002..21c869b 100644
--- a/libs/hwui/AmbientShadow.cpp
+++ b/libs/hwui/AmbientShadow.cpp
@@ -326,9 +326,9 @@
     shadowVertexBuffer.updateVertexCount(vertexBufferIndex);
     shadowVertexBuffer.updateIndexCount(indexBufferIndex);
 
-    ShadowTessellator::checkOverflow(vertexBufferIndex, totalVertexCount, "Vertex Buffer");
-    ShadowTessellator::checkOverflow(indexBufferIndex, totalIndexCount, "Index Buffer");
-    ShadowTessellator::checkOverflow(umbraIndex, totalUmbraCount, "Umbra Buffer");
+    ShadowTessellator::checkOverflow(vertexBufferIndex, totalVertexCount, "Ambient Vertex Buffer");
+    ShadowTessellator::checkOverflow(indexBufferIndex, totalIndexCount, "Ambient Index Buffer");
+    ShadowTessellator::checkOverflow(umbraIndex, totalUmbraCount, "Ambient Umbra Buffer");
 
 #if DEBUG_SHADOW
     for (int i = 0; i < vertexBufferIndex; i++) {
diff --git a/libs/hwui/SpotShadow.cpp b/libs/hwui/SpotShadow.cpp
index df28ae8..e8f1b9a 100644
--- a/libs/hwui/SpotShadow.cpp
+++ b/libs/hwui/SpotShadow.cpp
@@ -618,68 +618,6 @@
 }
 
 /**
- * Converts a polygon specified with CW vertices into an array of distance-from-centroid values.
- *
- * Returns false in error conditions
- *
- * @param poly Array of vertices. Note that these *must* be CW.
- * @param polyLength The number of vertices in the polygon.
- * @param polyCentroid The centroid of the polygon, from which rays will be cast
- * @param rayDist The output array for the calculated distances, must be SHADOW_RAY_COUNT in size
- */
-bool convertPolyToRayDist(const Vector2* poly, int polyLength, const Vector2& polyCentroid,
-        float* rayDist) {
-    const int rays = SHADOW_RAY_COUNT;
-    const float step = M_PI * 2 / rays;
-
-    const Vector2* lastVertex = &(poly[polyLength - 1]);
-    float startAngle = angle(*lastVertex, polyCentroid);
-
-    // Start with the ray that's closest to and less than startAngle
-    int rayIndex = floor((startAngle - EPSILON) / step);
-    rayIndex = (rayIndex + rays) % rays; // ensure positive
-
-    for (int polyIndex = 0; polyIndex < polyLength; polyIndex++) {
-        /*
-         * For a given pair of vertices on the polygon, poly[i-1] and poly[i], the rays that
-         * intersect these will be those that are between the two angles from the centroid that the
-         * vertices define.
-         *
-         * Because the polygon vertices are stored clockwise, the closest ray with an angle
-         * *smaller* than that defined by angle(poly[i], centroid) will be the first ray that does
-         * not intersect with poly[i-1], poly[i].
-         */
-        float currentAngle = angle(poly[polyIndex], polyCentroid);
-
-        // find first ray that will not intersect the line segment poly[i-1] & poly[i]
-        int firstRayIndexOnNextSegment = floor((currentAngle - EPSILON) / step);
-        firstRayIndexOnNextSegment = (firstRayIndexOnNextSegment + rays) % rays; // ensure positive
-
-        // Iterate through all rays that intersect with poly[i-1], poly[i] line segment.
-        // This may be 0 rays.
-        while (rayIndex != firstRayIndexOnNextSegment) {
-            float distanceToIntersect = rayIntersectPoints(polyCentroid,
-                    cos(rayIndex * step),
-                    sin(rayIndex * step),
-                    *lastVertex, poly[polyIndex]);
-            if (distanceToIntersect < 0) {
-#if DEBUG_SHADOW
-                ALOGW("ERROR: convertPolyToRayDist failed");
-#endif
-                return false; // error case, abort
-            }
-
-            rayDist[rayIndex] = distanceToIntersect;
-
-            rayIndex = (rayIndex - 1 + rays) % rays;
-        }
-        lastVertex = &poly[polyIndex];
-    }
-
-    return true;
-}
-
-/**
  * This is only for experimental purpose.
  * After intersections are calculated, we could smooth the polygon if needed.
  * So far, we don't think it is more appealing yet.
@@ -700,490 +638,223 @@
     }
 }
 
-/**
- * Generate a array of the angleData for either umbra or penumbra vertices.
- *
- * This array will be merged and used to guide where to shoot the rays, in clockwise order.
- *
- * @param angleDataList The result array of angle data.
- *
- * @return int The maximum angle's index in the array.
- */
-int SpotShadow::setupAngleList(VertexAngleData* angleDataList,
-        int polyLength, const Vector2* polygon, const Vector2& centroid,
-        bool isPenumbra, const char* name) {
-    float maxAngle = FLT_MIN;
-    int maxAngleIndex = 0;
-    for (int i = 0; i < polyLength; i++) {
-        float currentAngle = angle(polygon[i], centroid);
-        if (currentAngle > maxAngle) {
-            maxAngle = currentAngle;
-            maxAngleIndex = i;
-        }
-        angleDataList[i].set(currentAngle, isPenumbra, i);
-#if DEBUG_SHADOW
-        ALOGD("%s AngleList i %d %f", name, i, currentAngle);
-#endif
-    }
-    return maxAngleIndex;
-}
+// Index pair is meant for storing the tessellation information for the penumbra
+// area. One index must come from exterior tangent of the circles, the other one
+// must come from the interior tangent of the circles.
+struct IndexPair {
+    int outerIndex;
+    int innerIndex;
+};
 
-/**
- * Make sure the polygons are indeed in clockwise order.
- *
- * Possible reasons to return false: 1. The input polygon is not setup properly. 2. The hull
- * algorithm is not able to generate it properly.
- *
- * Anyway, since the algorithm depends on the clockwise, when these kind of unexpected error
- * situation is found, we need to detect it and early return without corrupting the memory.
- *
- * @return bool True if the angle list is actually from big to small.
- */
-bool SpotShadow::checkClockwise(int indexOfMaxAngle, int listLength, VertexAngleData* angleList,
-        const char* name) {
-    int currentIndex = indexOfMaxAngle;
-#if DEBUG_SHADOW
-    ALOGD("max index %d", currentIndex);
-#endif
-    for (int i = 0; i < listLength - 1; i++) {
-        // TODO: Cache the last angle.
-        float currentAngle = angleList[currentIndex].mAngle;
-        float nextAngle = angleList[(currentIndex + 1) % listLength].mAngle;
-        if (currentAngle < nextAngle) {
-#if DEBUG_SHADOW
-            ALOGE("%s, is not CW, at index %d", name, currentIndex);
-#endif
-            return false;
-        }
-        currentIndex = (currentIndex + 1) % listLength;
-    }
-    return true;
-}
-
-/**
- * Check the polygon is clockwise.
- *
- * @return bool True is the polygon is clockwise.
- */
-bool SpotShadow::checkPolyClockwise(int polyAngleLength, int maxPolyAngleIndex,
-        const float* polyAngleList) {
-    bool isPolyCW = true;
-    // Starting from maxPolyAngleIndex , check around to make sure angle decrease.
-    for (int i = 0; i < polyAngleLength - 1; i++) {
-        float currentAngle = polyAngleList[(i + maxPolyAngleIndex) % polyAngleLength];
-        float nextAngle = polyAngleList[(i + maxPolyAngleIndex + 1) % polyAngleLength];
-        if (currentAngle < nextAngle) {
-            isPolyCW = false;
-        }
-    }
-    return isPolyCW;
-}
-
-/**
- * Given the sorted array of all the vertices angle data, calculate for each
- * vertices, the offset value to array element which represent the start edge
- * of the polygon we need to shoot the ray at.
- *
- * TODO: Calculate this for umbra and penumbra in one loop using one single array.
- *
- * @param distances The result of the array distance counter.
- */
-void SpotShadow::calculateDistanceCounter(bool needsOffsetToUmbra, int angleLength,
-        const VertexAngleData* allVerticesAngleData, int* distances) {
-
-    bool firstVertexIsPenumbra = allVerticesAngleData[0].mIsPenumbra;
-    // If we want distance to inner, then we just set to 0 when we see inner.
-    bool needsSearch = needsOffsetToUmbra ? firstVertexIsPenumbra : !firstVertexIsPenumbra;
-    int distanceCounter = 0;
-    if (needsSearch) {
-        int foundIndex = -1;
-        for (int i = (angleLength - 1); i >= 0; i--) {
-            bool currentIsOuter = allVerticesAngleData[i].mIsPenumbra;
-            // If we need distance to inner, then we need to find a inner vertex.
-            if (currentIsOuter != firstVertexIsPenumbra) {
-                foundIndex = i;
-                break;
-            }
-        }
-        LOG_ALWAYS_FATAL_IF(foundIndex == -1, "Wrong index found, means either"
-                " umbra or penumbra's length is 0");
-        distanceCounter = angleLength - foundIndex;
-    }
-#if DEBUG_SHADOW
-    ALOGD("distances[0] is %d", distanceCounter);
-#endif
-
-    distances[0] = distanceCounter; // means never see a target poly
-
-    for (int i = 1; i < angleLength; i++) {
-        bool firstVertexIsPenumbra = allVerticesAngleData[i].mIsPenumbra;
-        // When we needs for distance for each outer vertex to inner, then we
-        // increase the distance when seeing outer vertices. Otherwise, we clear
-        // to 0.
-        bool needsIncrement = needsOffsetToUmbra ? firstVertexIsPenumbra : !firstVertexIsPenumbra;
-        // If counter is not -1, that means we have seen an other polygon's vertex.
-        if (needsIncrement && distanceCounter != -1) {
-            distanceCounter++;
-        } else {
-            distanceCounter = 0;
-        }
-        distances[i] = distanceCounter;
-    }
-}
-
-/**
- * Given umbra and penumbra angle data list, merge them by sorting the angle
- * from the biggest to smallest.
- *
- * @param allVerticesAngleData The result array of merged angle data.
- */
-void SpotShadow::mergeAngleList(int maxUmbraAngleIndex, int maxPenumbraAngleIndex,
-        const VertexAngleData* umbraAngleList, int umbraLength,
-        const VertexAngleData* penumbraAngleList, int penumbraLength,
-        VertexAngleData* allVerticesAngleData) {
-
-    int totalRayNumber = umbraLength + penumbraLength;
-    int umbraIndex = maxUmbraAngleIndex;
-    int penumbraIndex = maxPenumbraAngleIndex;
-
-    float currentUmbraAngle = umbraAngleList[umbraIndex].mAngle;
-    float currentPenumbraAngle = penumbraAngleList[penumbraIndex].mAngle;
-
-    // TODO: Clean this up using a while loop with 2 iterators.
-    for (int i = 0; i < totalRayNumber; i++) {
-        if (currentUmbraAngle > currentPenumbraAngle) {
-            allVerticesAngleData[i] = umbraAngleList[umbraIndex];
-            umbraIndex = (umbraIndex + 1) % umbraLength;
-
-            // If umbraIndex round back, that means we are running out of
-            // umbra vertices to merge, so just copy all the penumbra leftover.
-            // Otherwise, we update the currentUmbraAngle.
-            if (umbraIndex != maxUmbraAngleIndex) {
-                currentUmbraAngle = umbraAngleList[umbraIndex].mAngle;
-            } else {
-                for (int j = i + 1; j < totalRayNumber; j++) {
-                    allVerticesAngleData[j] = penumbraAngleList[penumbraIndex];
-                    penumbraIndex = (penumbraIndex + 1) % penumbraLength;
-                }
-                break;
-            }
-        } else {
-            allVerticesAngleData[i] = penumbraAngleList[penumbraIndex];
-            penumbraIndex = (penumbraIndex + 1) % penumbraLength;
-            // If penumbraIndex round back, that means we are running out of
-            // penumbra vertices to merge, so just copy all the umbra leftover.
-            // Otherwise, we update the currentPenumbraAngle.
-            if (penumbraIndex != maxPenumbraAngleIndex) {
-                currentPenumbraAngle = penumbraAngleList[penumbraIndex].mAngle;
-            } else {
-                for (int j = i + 1; j < totalRayNumber; j++) {
-                    allVerticesAngleData[j] = umbraAngleList[umbraIndex];
-                    umbraIndex = (umbraIndex + 1) % umbraLength;
-                }
-                break;
-            }
-        }
-    }
-}
-
-#if DEBUG_SHADOW
-/**
- * DEBUG ONLY: Verify all the offset compuation is correctly done by examining
- * each vertex and its neighbor.
- */
-static void verifyDistanceCounter(const VertexAngleData* allVerticesAngleData,
-        const int* distances, int angleLength, const char* name) {
-    int currentDistance = distances[0];
-    for (int i = 1; i < angleLength; i++) {
-        if (distances[i] != INT_MIN) {
-            if (!((currentDistance + 1) == distances[i]
-                || distances[i] == 0)) {
-                ALOGE("Wrong distance found at i %d name %s", i, name);
-            }
-            currentDistance = distances[i];
-            if (currentDistance != 0) {
-                bool currentOuter = allVerticesAngleData[i].mIsPenumbra;
-                for (int j = 1; j <= (currentDistance - 1); j++) {
-                    bool neigborOuter =
-                            allVerticesAngleData[(i + angleLength - j) % angleLength].mIsPenumbra;
-                    if (neigborOuter != currentOuter) {
-                        ALOGE("Wrong distance found at i %d name %s", i, name);
-                    }
-                }
-                bool oppositeOuter =
-                    allVerticesAngleData[(i + angleLength - currentDistance) % angleLength].mIsPenumbra;
-                if (oppositeOuter == currentOuter) {
-                    ALOGE("Wrong distance found at i %d name %s", i, name);
-                }
-            }
-        }
-    }
-}
-
-/**
- * DEBUG ONLY: Verify all the angle data compuated are  is correctly done
- */
-static void verifyAngleData(int totalRayNumber, const VertexAngleData* allVerticesAngleData,
-        const int* distancesToInner, const int* distancesToOuter,
-        const VertexAngleData* umbraAngleList, int maxUmbraAngleIndex, int umbraLength,
-        const VertexAngleData* penumbraAngleList, int maxPenumbraAngleIndex,
-        int penumbraLength) {
-    for (int i = 0; i < totalRayNumber; i++) {
-        ALOGD("currentAngleList i %d, angle %f, isInner %d, index %d distancesToInner"
-              " %d distancesToOuter %d", i, allVerticesAngleData[i].mAngle,
-                !allVerticesAngleData[i].mIsPenumbra,
-                allVerticesAngleData[i].mVertexIndex, distancesToInner[i], distancesToOuter[i]);
-    }
-
-    verifyDistanceCounter(allVerticesAngleData, distancesToInner, totalRayNumber, "distancesToInner");
-    verifyDistanceCounter(allVerticesAngleData, distancesToOuter, totalRayNumber, "distancesToOuter");
-
-    for (int i = 0; i < totalRayNumber; i++) {
-        if ((distancesToInner[i] * distancesToOuter[i]) != 0) {
-            ALOGE("distancesToInner wrong at index %d distancesToInner[i] %d,"
-                    " distancesToOuter[i] %d", i, distancesToInner[i], distancesToOuter[i]);
-        }
-    }
-    int currentUmbraVertexIndex =
-            umbraAngleList[maxUmbraAngleIndex].mVertexIndex;
-    int currentPenumbraVertexIndex =
-            penumbraAngleList[maxPenumbraAngleIndex].mVertexIndex;
-    for (int i = 0; i < totalRayNumber; i++) {
-        if (allVerticesAngleData[i].mIsPenumbra == true) {
-            if (allVerticesAngleData[i].mVertexIndex != currentPenumbraVertexIndex) {
-                ALOGW("wrong penumbra indexing i %d allVerticesAngleData[i].mVertexIndex %d "
-                        "currentpenumbraVertexIndex %d", i,
-                        allVerticesAngleData[i].mVertexIndex, currentPenumbraVertexIndex);
-            }
-            currentPenumbraVertexIndex = (currentPenumbraVertexIndex + 1) % penumbraLength;
-        } else {
-            if (allVerticesAngleData[i].mVertexIndex != currentUmbraVertexIndex) {
-                ALOGW("wrong umbra indexing i %d allVerticesAngleData[i].mVertexIndex %d "
-                        "currentUmbraVertexIndex %d", i,
-                        allVerticesAngleData[i].mVertexIndex, currentUmbraVertexIndex);
-            }
-            currentUmbraVertexIndex = (currentUmbraVertexIndex + 1) % umbraLength;
-        }
-    }
-    for (int i = 0; i < totalRayNumber - 1; i++) {
-        float currentAngle = allVerticesAngleData[i].mAngle;
-        float nextAngle = allVerticesAngleData[(i + 1) % totalRayNumber].mAngle;
-        if (currentAngle < nextAngle) {
-            ALOGE("Unexpected angle values!, currentAngle nextAngle %f %f", currentAngle, nextAngle);
-        }
-    }
-}
-#endif
-
-/**
- * In order to compute the occluded umbra, we need to setup the angle data list
- * for the polygon data. Since we only store one poly vertex per polygon vertex,
- * this array only needs to be a float array which are the angles for each vertex.
- *
- * @param polyAngleList The result list
- *
- * @return int The index for the maximum angle in this array.
- */
-int SpotShadow::setupPolyAngleList(float* polyAngleList, int polyAngleLength,
-        const Vector2* poly2d, const Vector2& centroid) {
-    int maxPolyAngleIndex = -1;
-    float maxPolyAngle = -FLT_MAX;
-    for (int i = 0; i < polyAngleLength; i++) {
-        polyAngleList[i] = angle(poly2d[i], centroid);
-        if (polyAngleList[i] > maxPolyAngle) {
-            maxPolyAngle = polyAngleList[i];
-            maxPolyAngleIndex = i;
-        }
-    }
-    return maxPolyAngleIndex;
-}
-
-/**
- * For umbra and penumbra, given the offset info and the current ray number,
- * find the right edge index (the (starting vertex) for the ray to shoot at.
- *
- * @return int The index of the starting vertex of the edge.
- */
-inline int SpotShadow::getEdgeStartIndex(const int* offsets, int rayIndex, int totalRayNumber,
-        const VertexAngleData* allVerticesAngleData) {
-    int tempOffset = offsets[rayIndex];
-    int targetRayIndex = (rayIndex - tempOffset + totalRayNumber) % totalRayNumber;
-    return allVerticesAngleData[targetRayIndex].mVertexIndex;
-}
-
-/**
- * For the occluded umbra, given the array of angles, find the index of the
- * starting vertex of the edge, for the ray to shoo at.
- *
- * TODO: Save the last result to shorten the search distance.
- *
- * @return int The index of the starting vertex of the edge.
- */
-inline int SpotShadow::getPolyEdgeStartIndex(int maxPolyAngleIndex, int polyLength,
-        const float* polyAngleList, float rayAngle) {
-    int minPolyAngleIndex  = (maxPolyAngleIndex + polyLength - 1) % polyLength;
+// For one penumbra vertex, find the cloest umbra vertex and return its index.
+inline int getClosestUmbraIndex(const Vector2& pivot, const Vector2* polygon, int polygonLength) {
+    float minLengthSquared = FLT_MAX;
     int resultIndex = -1;
-    if (rayAngle > polyAngleList[maxPolyAngleIndex]
-        || rayAngle <= polyAngleList[minPolyAngleIndex]) {
-        resultIndex = minPolyAngleIndex;
-    } else {
-        for (int i = 0; i < polyLength - 1; i++) {
-            int currentIndex = (maxPolyAngleIndex + i) % polyLength;
-            int nextIndex = (maxPolyAngleIndex + i + 1) % polyLength;
-            if (rayAngle <= polyAngleList[currentIndex]
-                && rayAngle > polyAngleList[nextIndex]) {
-                resultIndex = currentIndex;
+    bool hasDecreased = false;
+    // Starting with some negative offset, assuming both umbra and penumbra are starting
+    // at the same angle, this can help to find the result faster.
+    // Normally, loop 3 times, we can find the closest point.
+    int offset = polygonLength - 2;
+    for (int i = 0; i < polygonLength; i++) {
+        int currentIndex = (i + offset) % polygonLength;
+        float currentLengthSquared = (pivot - polygon[currentIndex]).lengthSquared();
+        if (currentLengthSquared < minLengthSquared) {
+            if (minLengthSquared != FLT_MAX) {
+                hasDecreased = true;
             }
+            minLengthSquared = currentLengthSquared;
+            resultIndex = currentIndex;
+        } else if (currentLengthSquared > minLengthSquared && hasDecreased) {
+            // Early break b/c we have found the closet one and now the length
+            // is increasing again.
+            break;
         }
     }
-    if (CC_UNLIKELY(resultIndex == -1)) {
-        // TODO: Add more error handling here.
-        ALOGE("Wrong index found, means no edge can't be found for rayAngle %f", rayAngle);
+    if(resultIndex == -1) {
+        ALOGE("resultIndex is -1, the polygon must be invalid!");
+        resultIndex = 0;
     }
     return resultIndex;
 }
 
-/**
- * Convert the incoming polygons into arrays of vertices, for each ray.
- * Ray only shoots when there is one vertex either on penumbra on umbra.
- *
- * Finally, it will generate vertices per ray for umbra, penumbra and optionally
- * occludedUmbra.
- *
- * Return true (success) when all vertices are generated
- */
-int SpotShadow::convertPolysToVerticesPerRay(
-        bool hasOccludedUmbraArea, const Vector2* poly2d, int polyLength,
-        const Vector2* umbra, int umbraLength, const Vector2* penumbra,
-        int penumbraLength, const Vector2& centroid,
-        Vector2* umbraVerticesPerRay, Vector2* penumbraVerticesPerRay,
-        Vector2* occludedUmbraVerticesPerRay) {
-    int totalRayNumber = umbraLength + penumbraLength;
-
-    // For incoming umbra / penumbra polygons, we will build an intermediate data
-    // structure to help us sort all the vertices according to the vertices.
-    // Using this data structure, we can tell where (the angle) to shoot the ray,
-    // whether we shoot at penumbra edge or umbra edge, and which edge to shoot at.
-    //
-    // We first parse each vertices and generate a table of VertexAngleData.
-    // Based on that, we create 2 arrays telling us which edge to shoot at.
-    VertexAngleData allVerticesAngleData[totalRayNumber];
-    VertexAngleData umbraAngleList[umbraLength];
-    VertexAngleData penumbraAngleList[penumbraLength];
-
-    int polyAngleLength = hasOccludedUmbraArea ? polyLength : 0;
-    float polyAngleList[polyAngleLength];
-
-    const int maxUmbraAngleIndex =
-            setupAngleList(umbraAngleList, umbraLength, umbra, centroid, false, "umbra");
-    const int maxPenumbraAngleIndex =
-            setupAngleList(penumbraAngleList, penumbraLength, penumbra, centroid, true, "penumbra");
-    const int maxPolyAngleIndex = setupPolyAngleList(polyAngleList, polyAngleLength, poly2d, centroid);
-
-    // Check all the polygons here are CW.
-    bool isPolyCW = checkPolyClockwise(polyAngleLength, maxPolyAngleIndex, polyAngleList);
-    bool isUmbraCW = checkClockwise(maxUmbraAngleIndex, umbraLength,
-            umbraAngleList, "umbra");
-    bool isPenumbraCW = checkClockwise(maxPenumbraAngleIndex, penumbraLength,
-            penumbraAngleList, "penumbra");
-
-    if (!isUmbraCW || !isPenumbraCW || !isPolyCW) {
-#if DEBUG_SHADOW
-        ALOGE("One polygon is not CW isUmbraCW %d isPenumbraCW %d isPolyCW %d",
-                isUmbraCW, isPenumbraCW, isPolyCW);
-#endif
-        return false;
+inline bool sameDirections(bool isPositiveCross, float a, float b) {
+    if (isPositiveCross) {
+        return a >= 0 && b >= 0;
+    } else {
+        return a <= 0 && b <= 0;
     }
+}
 
-    mergeAngleList(maxUmbraAngleIndex, maxPenumbraAngleIndex,
-            umbraAngleList, umbraLength, penumbraAngleList, penumbraLength,
-            allVerticesAngleData);
+// Find the right polygon edge to shoot the ray at.
+inline int findPolyIndex(bool isPositiveCross, int startPolyIndex, const Vector2& umbraDir,
+        const Vector2* polyToCentroid, int polyLength) {
+    // Make sure we loop with a bound.
+    for (int i = 0; i < polyLength; i++) {
+        int currentIndex = (i + startPolyIndex) % polyLength;
+        const Vector2& currentToCentroid = polyToCentroid[currentIndex];
+        const Vector2& nextToCentroid = polyToCentroid[(currentIndex + 1) % polyLength];
 
-    // Calculate the offset to the left most Inner vertex for each outerVertex.
-    // Then the offset to the left most Outer vertex for each innerVertex.
-    int offsetToInner[totalRayNumber];
-    int offsetToOuter[totalRayNumber];
-    calculateDistanceCounter(true, totalRayNumber, allVerticesAngleData, offsetToInner);
-    calculateDistanceCounter(false, totalRayNumber, allVerticesAngleData, offsetToOuter);
-
-    // Generate both umbraVerticesPerRay and penumbraVerticesPerRay
-    for (int i = 0; i < totalRayNumber; i++) {
-        float rayAngle = allVerticesAngleData[i].mAngle;
-        bool isUmbraVertex = !allVerticesAngleData[i].mIsPenumbra;
-
-        float dx = cosf(rayAngle);
-        float dy = sinf(rayAngle);
-        float distanceToIntersectUmbra = -1;
-
-        if (isUmbraVertex) {
-            // We can just copy umbra easily, and calculate the distance for the
-            // occluded umbra computation.
-            int startUmbraIndex = allVerticesAngleData[i].mVertexIndex;
-            umbraVerticesPerRay[i] = umbra[startUmbraIndex];
-            if (hasOccludedUmbraArea) {
-                distanceToIntersectUmbra = (umbraVerticesPerRay[i] - centroid).length();
-            }
-
-            //shoot ray to penumbra only
-            int startPenumbraIndex = getEdgeStartIndex(offsetToOuter, i, totalRayNumber,
-                    allVerticesAngleData);
-            float distanceToIntersectPenumbra = rayIntersectPoints(centroid, dx, dy,
-                    penumbra[startPenumbraIndex],
-                    penumbra[(startPenumbraIndex + 1) % penumbraLength]);
-            if (distanceToIntersectPenumbra < 0) {
+        float currentCrossUmbra = currentToCentroid.cross(umbraDir);
+        float umbraCrossNext = umbraDir.cross(nextToCentroid);
+        if (sameDirections(isPositiveCross, currentCrossUmbra, umbraCrossNext)) {
 #if DEBUG_SHADOW
-                ALOGW("convertPolyToRayDist for penumbra failed rayAngle %f dx %f dy %f",
-                        rayAngle, dx, dy);
+            ALOGD("findPolyIndex loop %d times , index %d", i, currentIndex );
 #endif
-                distanceToIntersectPenumbra = 0;
-            }
-            penumbraVerticesPerRay[i].x = centroid.x + dx * distanceToIntersectPenumbra;
-            penumbraVerticesPerRay[i].y = centroid.y + dy * distanceToIntersectPenumbra;
-        } else {
-            // We can just copy the penumbra
-            int startPenumbraIndex = allVerticesAngleData[i].mVertexIndex;
-            penumbraVerticesPerRay[i] = penumbra[startPenumbraIndex];
-
-            // And shoot ray to umbra only
-            int startUmbraIndex = getEdgeStartIndex(offsetToInner, i, totalRayNumber,
-                    allVerticesAngleData);
-
-            distanceToIntersectUmbra = rayIntersectPoints(centroid, dx, dy,
-                    umbra[startUmbraIndex], umbra[(startUmbraIndex + 1) % umbraLength]);
-            if (distanceToIntersectUmbra < 0) {
-#if DEBUG_SHADOW
-                ALOGW("convertPolyToRayDist for umbra failed rayAngle %f dx %f dy %f",
-                        rayAngle, dx, dy);
-#endif
-                distanceToIntersectUmbra = 0;
-            }
-            umbraVerticesPerRay[i].x = centroid.x + dx * distanceToIntersectUmbra;
-            umbraVerticesPerRay[i].y = centroid.y + dy * distanceToIntersectUmbra;
+            return currentIndex;
         }
+    }
+    LOG_ALWAYS_FATAL("Can't find the right polygon's edge from startPolyIndex %d", startPolyIndex);
+    return -1;
+}
 
-        if (hasOccludedUmbraArea) {
-            // Shoot the same ray to the poly2d, and get the distance.
-            int startPolyIndex = getPolyEdgeStartIndex(maxPolyAngleIndex, polyLength,
-                    polyAngleList, rayAngle);
-
-            float distanceToIntersectPoly = rayIntersectPoints(centroid, dx, dy,
-                    poly2d[startPolyIndex], poly2d[(startPolyIndex + 1) % polyLength]);
-            if (distanceToIntersectPoly < 0) {
-                distanceToIntersectPoly = 0;
+// Generate the index pair for penumbra / umbra vertices, and more penumbra vertices
+// if needed.
+inline void genNewPenumbraAndPairWithUmbra(const Vector2* penumbra, int penumbraLength,
+        const Vector2* umbra, int umbraLength, Vector2* newPenumbra, int& newPenumbraIndex,
+        IndexPair* verticesPair, int& verticesPairIndex) {
+    // In order to keep everything in just one loop, we need to pre-compute the
+    // closest umbra vertex for the last penumbra vertex.
+    int previousClosestUmbraIndex = getClosestUmbraIndex(penumbra[penumbraLength - 1],
+            umbra, umbraLength);
+    for (int i = 0; i < penumbraLength; i++) {
+        const Vector2& currentPenumbraVertex = penumbra[i];
+        // For current penumbra vertex, starting from previousClosestUmbraIndex,
+        // then check the next one until the distance increase.
+        // The last one before the increase is the umbra vertex we need to pair with.
+        int currentUmbraIndex = previousClosestUmbraIndex;
+        float currentLengthSquared = (currentPenumbraVertex - umbra[currentUmbraIndex]).lengthSquared();
+        int currentClosestUmbraIndex = -1;
+        int indexDelta = 0;
+        for (int j = 1; j < umbraLength; j++) {
+            int newUmbraIndex = (previousClosestUmbraIndex + j) % umbraLength;
+            float newLengthSquared = (currentPenumbraVertex - umbra[newUmbraIndex]).lengthSquared();
+            if (newLengthSquared > currentLengthSquared) {
+                currentClosestUmbraIndex = (previousClosestUmbraIndex + j - 1) % umbraLength;
+                break;
+            } else {
+                currentLengthSquared = newLengthSquared;
+                indexDelta++;
             }
-            distanceToIntersectPoly = MathUtils::min(distanceToIntersectUmbra, distanceToIntersectPoly);
-            occludedUmbraVerticesPerRay[i].x = centroid.x + dx * distanceToIntersectPoly;
-            occludedUmbraVerticesPerRay[i].y = centroid.y + dy * distanceToIntersectPoly;
+        }
+        LOG_ALWAYS_FATAL_IF(currentClosestUmbraIndex == -1, "Can't find a closet umbra vertext at all");
+
+        if (indexDelta > 1) {
+            // For those umbra don't have  penumbra, generate new penumbra vertices by interpolation.
+            //
+            // Assuming Pi for penumbra vertices, and Ui for umbra vertices.
+            // In the case like below P1 paired with U1 and P2 paired with  U5.
+            // U2 to U4 are unpaired umbra vertices.
+            //
+            // P1                                        P2
+            // |                                          |
+            // U1     U2                   U3     U4     U5
+            //
+            // We will need to generate 3 more penumbra vertices P1.1, P1.2, P1.3
+            // to pair with U2 to U4.
+            //
+            // P1     P1.1                P1.2   P1.3    P2
+            // |       |                   |      |      |
+            // U1     U2                   U3     U4     U5
+            //
+            // That distance ratio b/t Ui to U1 and Ui to U5 decides its paired penumbra
+            // vertex's location.
+            int newPenumbraNumber = indexDelta - 1;
+
+            float accumulatedDeltaLength[newPenumbraNumber];
+            float totalDeltaLength = 0;
+
+            // To save time, cache the previous umbra vertex info outside the loop
+            // and update each loop.
+            Vector2 previousClosestUmbra = umbra[previousClosestUmbraIndex];
+            Vector2 skippedUmbra;
+            // Use umbra data to precompute the length b/t unpaired umbra vertices,
+            // and its ratio against the total length.
+            for (int k = 0; k < indexDelta; k++) {
+                int skippedUmbraIndex = (previousClosestUmbraIndex + k + 1) % umbraLength;
+                skippedUmbra = umbra[skippedUmbraIndex];
+                float currentDeltaLength = (skippedUmbra - previousClosestUmbra).length();
+
+                totalDeltaLength += currentDeltaLength;
+                accumulatedDeltaLength[k] = totalDeltaLength;
+
+                previousClosestUmbra = skippedUmbra;
+            }
+
+            const Vector2& previousPenumbra = penumbra[(i + penumbraLength - 1) % penumbraLength];
+            // Then for each unpaired umbra vertex, create a new penumbra by the ratio,
+            // and pair them togehter.
+            for (int k = 0; k < newPenumbraNumber; k++) {
+                float weightForCurrentPenumbra = 1.0f;
+                if (totalDeltaLength != 0.0f) {
+                    weightForCurrentPenumbra = accumulatedDeltaLength[k] / totalDeltaLength;
+                }
+                float weightForPreviousPenumbra = 1.0f - weightForCurrentPenumbra;
+
+                Vector2 interpolatedPenumbra = currentPenumbraVertex * weightForCurrentPenumbra +
+                    previousPenumbra * weightForPreviousPenumbra;
+
+                int skippedUmbraIndex = (previousClosestUmbraIndex + k + 1) % umbraLength;
+                verticesPair[verticesPairIndex++] = {newPenumbraIndex, skippedUmbraIndex};
+                newPenumbra[newPenumbraIndex++] = interpolatedPenumbra;
+            }
+        }
+        verticesPair[verticesPairIndex++] = {newPenumbraIndex, currentClosestUmbraIndex};
+        newPenumbra[newPenumbraIndex++] = currentPenumbraVertex;
+
+        previousClosestUmbraIndex = currentClosestUmbraIndex;
+    }
+}
+
+// Precompute all the polygon's vector, return true if the reference cross product is positive.
+inline bool genPolyToCentroid(const Vector2* poly2d, int polyLength,
+        const Vector2& centroid, Vector2* polyToCentroid) {
+    for (int j = 0; j < polyLength; j++) {
+        polyToCentroid[j] = poly2d[j] - centroid;
+    }
+    float refCrossProduct = 0;
+    for (int j = 0; j < polyLength; j++) {
+        refCrossProduct = polyToCentroid[j].cross(polyToCentroid[(j + 1) % polyLength]);
+        if (refCrossProduct != 0) {
+            break;
         }
     }
 
-#if DEBUG_SHADOW
-    verifyAngleData(totalRayNumber, allVerticesAngleData, offsetToInner,
-            offsetToOuter,  umbraAngleList, maxUmbraAngleIndex,  umbraLength,
-            penumbraAngleList,  maxPenumbraAngleIndex, penumbraLength);
-#endif
-    return true; // success
+    return refCrossProduct > 0;
+}
 
+// For one umbra vertex, shoot an ray from centroid to it.
+// If the ray hit the polygon first, then return the intersection point as the
+// closer vertex.
+inline Vector2 getCloserVertex(const Vector2& umbraVertex, const Vector2& centroid,
+        const Vector2* poly2d, int polyLength, const Vector2* polyToCentroid,
+        bool isPositiveCross, int& previousPolyIndex) {
+    Vector2 umbraToCentroid = umbraVertex - centroid;
+    float distanceToUmbra = umbraToCentroid.length();
+    umbraToCentroid = umbraToCentroid / distanceToUmbra;
+
+    // previousPolyIndex is updated for each item such that we can minimize the
+    // looping inside findPolyIndex();
+    previousPolyIndex = findPolyIndex(isPositiveCross, previousPolyIndex,
+            umbraToCentroid, polyToCentroid, polyLength);
+
+    float dx = umbraToCentroid.x;
+    float dy = umbraToCentroid.y;
+    float distanceToIntersectPoly = rayIntersectPoints(centroid, dx, dy,
+            poly2d[previousPolyIndex], poly2d[(previousPolyIndex + 1) % polyLength]);
+    if (distanceToIntersectPoly < 0) {
+        distanceToIntersectPoly = 0;
+    }
+
+    // Pick the closer one as the occluded area vertex.
+    Vector2 closerVertex;
+    if (distanceToIntersectPoly < distanceToUmbra) {
+        closerVertex.x = centroid.x + dx * distanceToIntersectPoly;
+        closerVertex.y = centroid.y + dy * distanceToIntersectPoly;
+    } else {
+        closerVertex = umbraVertex;
+    }
+
+    return closerVertex;
 }
 
 /**
@@ -1193,7 +864,6 @@
         Vector2* penumbra, int penumbraLength, Vector2* umbra, int umbraLength,
         const Vector3* poly, int polyLength, VertexBuffer& shadowTriangleStrip,
         const Vector2& centroid) {
-
     bool hasOccludedUmbraArea = false;
     Vector2 poly2d[polyLength];
 
@@ -1209,128 +879,140 @@
         }
     }
 
-    int totalRayNum = umbraLength + penumbraLength;
-    Vector2 umbraVertices[totalRayNum];
-    Vector2 penumbraVertices[totalRayNum];
-    Vector2 occludedUmbraVertices[totalRayNum];
-    bool convertSuccess = convertPolysToVerticesPerRay(hasOccludedUmbraArea, poly2d,
-            polyLength, umbra, umbraLength, penumbra, penumbraLength,
-            centroid, umbraVertices, penumbraVertices, occludedUmbraVertices);
-    if (!convertSuccess) {
-        return;
+    // For each penumbra vertex, find its corresponding closest umbra vertex index.
+    //
+    // Penumbra Vertices marked as Pi
+    // Umbra Vertices marked as Ui
+    //                                            (P3)
+    //          (P2)                               |     ' (P4)
+    //   (P1)'   |                                 |   '
+    //         ' |                                 | '
+    // (P0)  ------------------------------------------------(P5)
+    //           | (U0)                            |(U1)
+    //           |                                 |
+    //           |                                 |(U2)     (P5.1)
+    //           |                                 |
+    //           |                                 |
+    //           |                                 |
+    //           |                                 |
+    //           |                                 |
+    //           |                                 |
+    //       (U4)-----------------------------------(U3)      (P6)
+    //
+    // At least, like P0, P1, P2, they will find the matching umbra as U0.
+    // If we jump over some umbra vertex without matching penumbra vertex, then
+    // we will generate some new penumbra vertex by interpolation. Like P6 is
+    // matching U3, but U2 is not matched with any penumbra vertex.
+    // So interpolate P5.1 out and match U2.
+    // In this way, every umbra vertex will have a matching penumbra vertex.
+    //
+    // The total pair number can be as high as umbraLength + penumbraLength.
+    const int maxNewPenumbraLength = umbraLength + penumbraLength;
+    IndexPair verticesPair[maxNewPenumbraLength];
+    int verticesPairIndex = 0;
+
+    // Cache all the existing penumbra vertices and newly interpolated vertices into a
+    // a new array.
+    Vector2 newPenumbra[maxNewPenumbraLength];
+    int newPenumbraIndex = 0;
+
+    // For each penumbra vertex, find its closet umbra vertex by comparing the
+    // neighbor umbra vertices.
+    genNewPenumbraAndPairWithUmbra(penumbra, penumbraLength, umbra, umbraLength, newPenumbra,
+            newPenumbraIndex, verticesPair, verticesPairIndex);
+    ShadowTessellator::checkOverflow(verticesPairIndex, maxNewPenumbraLength, "Spot pair");
+    ShadowTessellator::checkOverflow(newPenumbraIndex, maxNewPenumbraLength, "Spot new penumbra");
+#if DEBUG_SHADOW
+    for (int i = 0; i < umbraLength; i++) {
+        ALOGD("umbra i %d,  [%f, %f]", i, umbra[i].x, umbra[i].y);
     }
+    for (int i = 0; i < newPenumbraIndex; i++) {
+        ALOGD("new penumbra i %d,  [%f, %f]", i, newPenumbra[i].x, newPenumbra[i].y);
+    }
+    for (int i = 0; i < verticesPairIndex; i++) {
+        ALOGD("index i %d,  [%d, %d]", i, verticesPair[i].outerIndex, verticesPair[i].innerIndex);
+    }
+#endif
 
-    // Minimal value is 1, for each vertex show up once.
-    // The bigger this value is , the smoother the look is, but more memory
-    // is consumed.
-    // When the ray number is high, that means the polygon has been fine
-    // tessellated, we don't need this extra slice, just keep it as 1.
-    int sliceNumberPerEdge = (totalRayNum > FINE_TESSELLATED_POLYGON_RAY_NUMBER) ? 1 : 2;
-
-    // For each polygon, we at most add (totalRayNum * sliceNumberPerEdge) vertices.
-    int slicedVertexCountPerPolygon = totalRayNum * sliceNumberPerEdge;
-    int totalVertexCount = slicedVertexCountPerPolygon * 2 + totalRayNum;
-    int totalIndexCount = 2 * (slicedVertexCountPerPolygon * 2 + 2);
+    // For the size of vertex buffer, we need 3 rings, one has newPenumbraSize,
+    // one has umbraLength, the last one has at most umbraLength.
+    //
+    // For the size of index buffer, the umbra area needs (2 * umbraLength + 2).
+    // The penumbra one can vary a bit, but it is bounded by (2 * verticesPairIndex + 2).
+    // And 2 more for jumping between penumbra to umbra.
+    const int newPenumbraLength = newPenumbraIndex;
+    const int totalVertexCount = newPenumbraLength + umbraLength * 2;
+    const int totalIndexCount = 2 * umbraLength + 2 * verticesPairIndex + 6;
     AlphaVertex* shadowVertices =
             shadowTriangleStrip.alloc<AlphaVertex>(totalVertexCount);
     uint16_t* indexBuffer =
             shadowTriangleStrip.allocIndices<uint16_t>(totalIndexCount);
-
-    int indexBufferIndex = 0;
     int vertexBufferIndex = 0;
+    int indexBufferIndex = 0;
 
-    uint16_t slicedUmbraVertexIndex[totalRayNum * sliceNumberPerEdge];
-    // Should be something like 0 0 0  1 1 1 2 3 3 3...
-    int rayNumberPerSlicedUmbra[totalRayNum * sliceNumberPerEdge];
-    int realUmbraVertexCount = 0;
-    for (int i = 0; i < totalRayNum; i++) {
-        Vector2 currentPenumbra = penumbraVertices[i];
-        Vector2 currentUmbra = umbraVertices[i];
-
-        Vector2 nextPenumbra = penumbraVertices[(i + 1) % totalRayNum];
-        Vector2 nextUmbra = umbraVertices[(i + 1) % totalRayNum];
-        // NextUmbra/Penumbra will be done in the next loop!!
-        for (int weight = 0; weight < sliceNumberPerEdge; weight++) {
-            const Vector2& slicedPenumbra = (currentPenumbra * (sliceNumberPerEdge - weight)
-                + nextPenumbra * weight) / sliceNumberPerEdge;
-
-            const Vector2& slicedUmbra = (currentUmbra * (sliceNumberPerEdge - weight)
-                + nextUmbra * weight) / sliceNumberPerEdge;
-
-            // In the vertex buffer, we fill the Penumbra first, then umbra.
-            indexBuffer[indexBufferIndex++] = vertexBufferIndex;
-            AlphaVertex::set(&shadowVertices[vertexBufferIndex++], slicedPenumbra.x,
-                    slicedPenumbra.y, 0.0f);
-
-            // When we add umbra vertex, we need to remember its current ray number.
-            // And its own vertexBufferIndex. This is for occluded umbra usage.
-            indexBuffer[indexBufferIndex++] = vertexBufferIndex;
-            rayNumberPerSlicedUmbra[realUmbraVertexCount] = i;
-            slicedUmbraVertexIndex[realUmbraVertexCount] = vertexBufferIndex;
-            realUmbraVertexCount++;
-            AlphaVertex::set(&shadowVertices[vertexBufferIndex++], slicedUmbra.x,
-                    slicedUmbra.y, M_PI);
-        }
+    // Fill the IB and VB for the penumbra area.
+    for (int i = 0; i < newPenumbraLength; i++) {
+        AlphaVertex::set(&shadowVertices[vertexBufferIndex++], newPenumbra[i].x,
+                newPenumbra[i].y, 0.0f);
+    }
+    for (int i = 0; i < umbraLength; i++) {
+        AlphaVertex::set(&shadowVertices[vertexBufferIndex++], umbra[i].x, umbra[i].y,
+                M_PI);
     }
 
-    indexBuffer[indexBufferIndex++] = 0;
-    //RealUmbraVertexIndex[0] must be 1, so we connect back well at the
-    //beginning of occluded area.
-    indexBuffer[indexBufferIndex++] = 1;
+    for (int i = 0; i < verticesPairIndex; i++) {
+        indexBuffer[indexBufferIndex++] = verticesPair[i].outerIndex;
+        // All umbra index need to be offseted by newPenumbraSize.
+        indexBuffer[indexBufferIndex++] = verticesPair[i].innerIndex + newPenumbraLength;
+    }
+    indexBuffer[indexBufferIndex++] = verticesPair[0].outerIndex;
+    indexBuffer[indexBufferIndex++] = verticesPair[0].innerIndex + newPenumbraLength;
 
-    float occludedUmbraAlpha = M_PI;
+    // Now fill the IB and VB for the umbra area.
+    // First duplicated the index from previous strip and the first one for the
+    // degenerated triangles.
+    indexBuffer[indexBufferIndex] = indexBuffer[indexBufferIndex - 1];
+    indexBufferIndex++;
+    indexBuffer[indexBufferIndex++] = newPenumbraLength + 0;
+    // Save the first VB index for umbra area in order to close the loop.
+    int savedStartIndex = vertexBufferIndex;
+
     if (hasOccludedUmbraArea) {
-        // Now the occludedUmbra area;
-        int currentRayNumber = -1;
-        int firstOccludedUmbraIndex = -1;
-        for (int i = 0; i < realUmbraVertexCount; i++) {
-            indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[i];
+        // Precompute all the polygon's vector, and the reference cross product,
+        // in order to find the right polygon edge for the ray to intersect.
+        Vector2 polyToCentroid[polyLength];
+        bool isPositiveCross = genPolyToCentroid(poly2d, polyLength, centroid, polyToCentroid);
 
-            // If the occludedUmbra vertex has not been added yet, then add it.
-            // Otherwise, just use the previously added occludedUmbra vertices.
-            if (rayNumberPerSlicedUmbra[i] != currentRayNumber) {
-                currentRayNumber++;
-                indexBuffer[indexBufferIndex++] = vertexBufferIndex;
-                // We need to remember the begining of the occludedUmbra vertices
-                // to close this loop.
-                if (currentRayNumber == 0) {
-                    firstOccludedUmbraIndex = vertexBufferIndex;
-                }
-                AlphaVertex::set(&shadowVertices[vertexBufferIndex++],
-                        occludedUmbraVertices[currentRayNumber].x,
-                        occludedUmbraVertices[currentRayNumber].y,
-                        occludedUmbraAlpha);
-            } else {
-                indexBuffer[indexBufferIndex++] = (vertexBufferIndex - 1);
-            }
+        // Because both the umbra and polygon are going in the same direction,
+        // we can save the previous polygon index to make sure we have less polygon
+        // vertex to compute for each ray.
+        int previousPolyIndex = 0;
+        for (int i = 0; i < umbraLength; i++) {
+            // Shoot a ray from centroid to each umbra vertices and pick the one with
+            // shorter distance to the centroid, b/t the umbra vertex or the intersection point.
+            Vector2 closerVertex = getCloserVertex(umbra[i], centroid, poly2d, polyLength,
+                    polyToCentroid, isPositiveCross, previousPolyIndex);
+
+            // We already stored the umbra vertices, just need to add the occlued umbra's ones.
+            indexBuffer[indexBufferIndex++] = newPenumbraLength + i;
+            indexBuffer[indexBufferIndex++] = vertexBufferIndex;
+            AlphaVertex::set(&shadowVertices[vertexBufferIndex++],
+                    closerVertex.x, closerVertex.y, M_PI);
         }
-        // Close the loop here!
-        indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[0];
-        indexBuffer[indexBufferIndex++] = firstOccludedUmbraIndex;
     } else {
+        // If there is no occluded umbra at all, then draw the triangle fan
+        // starting from the centroid to all umbra vertices.
         int lastCentroidIndex = vertexBufferIndex;
         AlphaVertex::set(&shadowVertices[vertexBufferIndex++], centroid.x,
-                centroid.y, occludedUmbraAlpha);
-        for (int i = 0; i < realUmbraVertexCount; i++) {
-            indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[i];
+                centroid.y, M_PI);
+        for (int i = 0; i < umbraLength; i++) {
+            indexBuffer[indexBufferIndex++] = newPenumbraLength + i;
             indexBuffer[indexBufferIndex++] = lastCentroidIndex;
         }
-        // Close the loop here!
-        indexBuffer[indexBufferIndex++] = slicedUmbraVertexIndex[0];
-        indexBuffer[indexBufferIndex++] = lastCentroidIndex;
     }
-
-#if DEBUG_SHADOW
-    ALOGD("allocated IB %d allocated VB is %d", totalIndexCount, totalVertexCount);
-    ALOGD("IB index %d VB index is %d", indexBufferIndex, vertexBufferIndex);
-    for (int i = 0; i < vertexBufferIndex; i++) {
-        ALOGD("vertexBuffer i %d, (%f, %f %f)", i, shadowVertices[i].x, shadowVertices[i].y,
-                shadowVertices[i].alpha);
-    }
-    for (int i = 0; i < indexBufferIndex; i++) {
-        ALOGD("indexBuffer i %d, indexBuffer[i] %d", i, indexBuffer[i]);
-    }
-#endif
+    // Closing the umbra area triangle's loop here.
+    indexBuffer[indexBufferIndex++] = newPenumbraLength;
+    indexBuffer[indexBufferIndex++] = savedStartIndex;
 
     // At the end, update the real index and vertex buffer size.
     shadowTriangleStrip.updateVertexCount(vertexBufferIndex);
diff --git a/libs/hwui/SpotShadow.h b/libs/hwui/SpotShadow.h
index 6fa2028f..e2d94f7 100644
--- a/libs/hwui/SpotShadow.h
+++ b/libs/hwui/SpotShadow.h
@@ -36,40 +36,6 @@
     static float projectCasterToOutline(Vector2& outline,
             const Vector3& lightCenter, const Vector3& polyVertex);
 
-    static int setupAngleList(VertexAngleData* angleDataList,
-            int polyLength, const Vector2* polygon, const Vector2& centroid,
-            bool isPenumbra, const char* name);
-
-    static int convertPolysToVerticesPerRay(
-            bool hasOccludedUmbraArea, const Vector2* poly2d, int polyLength,
-            const Vector2* umbra, int umbraLength, const Vector2* penumbra,
-            int penumbraLength, const Vector2& centroid,
-            Vector2* umbraVerticesPerRay, Vector2* penumbraVerticesPerRay,
-            Vector2* occludedUmbraVerticesPerRay);
-
-    static bool checkClockwise(int maxIndex, int listLength,
-            VertexAngleData* angleList, const char* name);
-
-    static void calculateDistanceCounter(bool needsOffsetToUmbra, int angleLength,
-            const VertexAngleData* allVerticesAngleData, int* distances);
-
-    static void mergeAngleList(int maxUmbraAngleIndex, int maxPenumbraAngleIndex,
-            const VertexAngleData* umbraAngleList, int umbraLength,
-            const VertexAngleData* penumbraAngleList, int penumbraLength,
-            VertexAngleData* allVerticesAngleData);
-
-    static int setupPolyAngleList(float* polyAngleList, int polyAngleLength,
-        const Vector2* poly2d, const Vector2& centroid);
-
-    static bool checkPolyClockwise(int polyAngleLength, int maxPolyAngleIndex,
-        const float* polyAngleList);
-
-    static int getEdgeStartIndex(const int* offsets, int rayIndex, int totalRayNumber,
-        const VertexAngleData* allVerticesAngleData);
-
-    static int getPolyEdgeStartIndex(int maxPolyAngleIndex, int polyLength,
-        const float* polyAngleList, float rayAngle);
-
     static void computeLightPolygon(int points, const Vector3& lightCenter,
             float size, Vector3* ret);
 
diff --git a/libs/hwui/Vector.h b/libs/hwui/Vector.h
index d033ed9..aa6acc9 100644
--- a/libs/hwui/Vector.h
+++ b/libs/hwui/Vector.h
@@ -99,6 +99,10 @@
         return x * v.x + y * v.y;
     }
 
+    float cross(const Vector2& v) const {
+        return x * v.y - y * v.x;
+    }
+
     void dump() {
         ALOGD("Vector2[%.2f, %.2f]", x, y);
     }