Some optimizations in blur outline generator

1) Using ALPHA_8 as the start and end bitmap. This removes one extra
   bitmap generation step
2) Using ByteBuffer on ALPHA_8 bitmap for clipAlpha. This allows us
   to use byteArray instead of intArray for representing pixels

Change-Id: I1b654c439fd491b6b91180ddc562bb97fad857aa

5 files changed, 37 insertions, 41 deletions

diff --git a/src/com/android/launcher3/CellLayout.java b/src/com/android/launcher3/CellLayout.java
index baccfd157..6714d9f17 100644
--- a/src/com/android/launcher3/CellLayout.java
+++ b/src/com/android/launcher3/CellLayout.java
@@ -236,6 +236,7 @@ public class CellLayout extends ViewGroup implements BubbleTextShadowHandler {
         for (int i = 0; i < mDragOutlines.length; i++) {
             mDragOutlines[i] = new Rect(-1, -1, -1, -1);
         }
+        mDragOutlinePaint.setColor(getResources().getColor(R.color.outline_color));
 
         // When dragging things around the home screens, we show a green outline of
         // where the item will land. The outlines gradually fade out, leaving a trail
diff --git a/src/com/android/launcher3/HolographicOutlineHelper.java b/src/com/android/launcher3/HolographicOutlineHelper.java
index 682231198..9dec7d9e4 100644
--- a/src/com/android/launcher3/HolographicOutlineHelper.java
+++ b/src/com/android/launcher3/HolographicOutlineHelper.java
@@ -29,6 +29,10 @@ import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.util.SparseArray;
 
+import com.android.launcher3.config.ProviderConfig;
+
+import java.nio.ByteBuffer;
+
 /**
  * Utility class to generate shadow and outline effect, which are used for click feedback
  * and drag-n-drop respectively.
@@ -79,50 +83,53 @@ public class HolographicOutlineHelper {
      * Applies a more expensive and accurate outline to whatever is currently drawn in a specified
      * bitmap.
      */
-    public void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
-            int outlineColor) {
-        applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, color, outlineColor, true);
+    public void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas) {
+        applyExpensiveOutlineWithBlur(srcDst, srcDstCanvas, true);
     }
 
-    public void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas, int color,
-            int outlineColor, boolean clipAlpha) {
+    public void applyExpensiveOutlineWithBlur(Bitmap srcDst, Canvas srcDstCanvas,
+            boolean clipAlpha) {
+        if (ProviderConfig.IS_DOGFOOD_BUILD && srcDst.getConfig() != Bitmap.Config.ALPHA_8) {
+            throw new RuntimeException("Outline blue is only supported on alpha bitmaps");
+        }
 
         // We start by removing most of the alpha channel so as to ignore shadows, and
         // other types of partial transparency when defining the shape of the object
         if (clipAlpha) {
-            int[] srcBuffer = new int[srcDst.getWidth() * srcDst.getHeight()];
-            srcDst.getPixels(srcBuffer,
-                    0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
-            for (int i = 0; i < srcBuffer.length; i++) {
-                final int alpha = srcBuffer[i] >>> 24;
-                if (alpha < 188) {
-                    srcBuffer[i] = 0;
+            byte[] pixels = new byte[srcDst.getWidth() * srcDst.getHeight()];
+            ByteBuffer buffer = ByteBuffer.wrap(pixels);
+            buffer.rewind();
+            srcDst.copyPixelsToBuffer(buffer);
+
+            for (int i = 0; i < pixels.length; i++) {
+                if ((pixels[i] & 0xFF) < 188) {
+                    pixels[i] = 0;
                 }
             }
-            srcDst.setPixels(srcBuffer,
-                    0, srcDst.getWidth(), 0, 0, srcDst.getWidth(), srcDst.getHeight());
+
+            buffer.rewind();
+            srcDst.copyPixelsFromBuffer(buffer);
         }
-        Bitmap glowShape = srcDst.extractAlpha();
 
         // calculate the outer blur first
         mBlurPaint.setMaskFilter(mMediumOuterBlurMaskFilter);
         int[] outerBlurOffset = new int[2];
-        Bitmap thickOuterBlur = glowShape.extractAlpha(mBlurPaint, outerBlurOffset);
+        Bitmap thickOuterBlur = srcDst.extractAlpha(mBlurPaint, outerBlurOffset);
 
         mBlurPaint.setMaskFilter(mThinOuterBlurMaskFilter);
         int[] brightOutlineOffset = new int[2];
-        Bitmap brightOutline = glowShape.extractAlpha(mBlurPaint, brightOutlineOffset);
+        Bitmap brightOutline = srcDst.extractAlpha(mBlurPaint, brightOutlineOffset);
 
         // calculate the inner blur
-        srcDstCanvas.setBitmap(glowShape);
+        srcDstCanvas.setBitmap(srcDst);
         srcDstCanvas.drawColor(0xFF000000, PorterDuff.Mode.SRC_OUT);
         mBlurPaint.setMaskFilter(mMediumInnerBlurMaskFilter);
         int[] thickInnerBlurOffset = new int[2];
-        Bitmap thickInnerBlur = glowShape.extractAlpha(mBlurPaint, thickInnerBlurOffset);
+        Bitmap thickInnerBlur = srcDst.extractAlpha(mBlurPaint, thickInnerBlurOffset);
 
         // mask out the inner blur
         srcDstCanvas.setBitmap(thickInnerBlur);
-        srcDstCanvas.drawBitmap(glowShape, -thickInnerBlurOffset[0],
+        srcDstCanvas.drawBitmap(srcDst, -thickInnerBlurOffset[0],
                 -thickInnerBlurOffset[1], mErasePaint);
         srcDstCanvas.drawRect(0, 0, -thickInnerBlurOffset[0], thickInnerBlur.getHeight(),
                 mErasePaint);
@@ -132,14 +139,12 @@ public class HolographicOutlineHelper {
         // draw the inner and outer blur
         srcDstCanvas.setBitmap(srcDst);
         srcDstCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
-        mDrawPaint.setColor(color);
         srcDstCanvas.drawBitmap(thickInnerBlur, thickInnerBlurOffset[0], thickInnerBlurOffset[1],
                 mDrawPaint);
         srcDstCanvas.drawBitmap(thickOuterBlur, outerBlurOffset[0], outerBlurOffset[1],
                 mDrawPaint);
 
         // draw the bright outline
-        mDrawPaint.setColor(outlineColor);
         srcDstCanvas.drawBitmap(brightOutline, brightOutlineOffset[0], brightOutlineOffset[1],
                 mDrawPaint);
 
@@ -148,7 +153,6 @@ public class HolographicOutlineHelper {
         brightOutline.recycle();
         thickOuterBlur.recycle();
         thickInnerBlur.recycle();
-        glowShape.recycle();
     }
 
     Bitmap createMediumDropShadow(BubbleTextView view) {
diff --git a/src/com/android/launcher3/graphics/DragPreviewProvider.java b/src/com/android/launcher3/graphics/DragPreviewProvider.java
index e078d9b15..bc91c15be 100644
--- a/src/com/android/launcher3/graphics/DragPreviewProvider.java
+++ b/src/com/android/launcher3/graphics/DragPreviewProvider.java
@@ -27,7 +27,6 @@ import android.widget.TextView;
 import com.android.launcher3.HolographicOutlineHelper;
 import com.android.launcher3.Launcher;
 import com.android.launcher3.PreloadIconDrawable;
-import com.android.launcher3.R;
 import com.android.launcher3.Workspace;
 import com.android.launcher3.config.ProviderConfig;
 import com.android.launcher3.folder.FolderIcon;
@@ -134,14 +133,12 @@ public class DragPreviewProvider {
      * Responsibility for the bitmap is transferred to the caller.
      */
     public Bitmap createDragOutline(Canvas canvas) {
-        final int outlineColor = mView.getResources().getColor(R.color.outline_color);
         final Bitmap b = Bitmap.createBitmap(mView.getWidth() + DRAG_BITMAP_PADDING,
-                mView.getHeight() + DRAG_BITMAP_PADDING, Bitmap.Config.ARGB_8888);
-
+                mView.getHeight() + DRAG_BITMAP_PADDING, Bitmap.Config.ALPHA_8);
         canvas.setBitmap(b);
         drawDragView(canvas);
         HolographicOutlineHelper.obtain(mView.getContext())
-                .applyExpensiveOutlineWithBlur(b, canvas, outlineColor, outlineColor);
+                .applyExpensiveOutlineWithBlur(b, canvas);
         canvas.setBitmap(null);
         return b;
     }
diff --git a/src/com/android/launcher3/shortcuts/ShortcutDragPreviewProvider.java b/src/com/android/launcher3/shortcuts/ShortcutDragPreviewProvider.java
index a25e475d4..2adb82e2d 100644
--- a/src/com/android/launcher3/shortcuts/ShortcutDragPreviewProvider.java
+++ b/src/com/android/launcher3/shortcuts/ShortcutDragPreviewProvider.java
@@ -22,12 +22,9 @@ import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.view.View;
-import android.widget.ImageView;
 
-import com.android.launcher3.BubbleTextView;
 import com.android.launcher3.HolographicOutlineHelper;
 import com.android.launcher3.Launcher;
-import com.android.launcher3.R;
 import com.android.launcher3.Utilities;
 import com.android.launcher3.graphics.DragPreviewProvider;
 
@@ -45,23 +42,22 @@ public class ShortcutDragPreviewProvider extends DragPreviewProvider {
 
     @Override
     public Bitmap createDragOutline(Canvas canvas) {
-        Bitmap b = drawScaledPreview(canvas);
+        Bitmap b = drawScaledPreview(canvas, Bitmap.Config.ALPHA_8);
 
-        final int outlineColor = mView.getResources().getColor(R.color.outline_color);
         HolographicOutlineHelper.obtain(mView.getContext())
-                .applyExpensiveOutlineWithBlur(b, canvas, outlineColor, outlineColor);
+                .applyExpensiveOutlineWithBlur(b, canvas);
         canvas.setBitmap(null);
         return b;
     }
 
     @Override
     public Bitmap createDragBitmap(Canvas canvas) {
-        Bitmap b = drawScaledPreview(canvas);
+        Bitmap b = drawScaledPreview(canvas, Bitmap.Config.ARGB_8888);
         canvas.setBitmap(null);
         return b;
     }
 
-    private Bitmap drawScaledPreview(Canvas canvas) {
+    private Bitmap drawScaledPreview(Canvas canvas, Bitmap.Config config) {
         Drawable d = mView.getBackground();
         Rect bounds = getDrawableBounds(d);
 
@@ -70,7 +66,7 @@ public class ShortcutDragPreviewProvider extends DragPreviewProvider {
         final Bitmap b = Bitmap.createBitmap(
                 size + DRAG_BITMAP_PADDING,
                 size + DRAG_BITMAP_PADDING,
-                Bitmap.Config.ARGB_8888);
+                config);
 
         canvas.setBitmap(b);
         canvas.save(Canvas.MATRIX_SAVE_FLAG);
diff --git a/src/com/android/launcher3/widget/PendingItemPreviewProvider.java b/src/com/android/launcher3/widget/PendingItemPreviewProvider.java
index 8739390c4..eaa0bb3d5 100644
--- a/src/com/android/launcher3/widget/PendingItemPreviewProvider.java
+++ b/src/com/android/launcher3/widget/PendingItemPreviewProvider.java
@@ -24,7 +24,6 @@ import android.view.View;
 import com.android.launcher3.HolographicOutlineHelper;
 import com.android.launcher3.Launcher;
 import com.android.launcher3.PendingAddItemInfo;
-import com.android.launcher3.R;
 import com.android.launcher3.Workspace;
 import com.android.launcher3.graphics.DragPreviewProvider;
 
@@ -50,7 +49,7 @@ public class PendingItemPreviewProvider extends DragPreviewProvider {
 
         int w = size[0];
         int h = size[1];
-        final Bitmap b = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
+        final Bitmap b = Bitmap.createBitmap(w, h, Bitmap.Config.ALPHA_8);
         canvas.setBitmap(b);
 
         Rect src = new Rect(0, 0, mPreviewBitmap.getWidth(), mPreviewBitmap.getHeight());
@@ -68,9 +67,8 @@ public class PendingItemPreviewProvider extends DragPreviewProvider {
         // Don't clip alpha values for the drag outline if we're using the default widget preview
         boolean clipAlpha = !(mAddInfo instanceof PendingAddWidgetInfo &&
                 (((PendingAddWidgetInfo) mAddInfo).previewImage == 0));
-        final int outlineColor = mView.getResources().getColor(R.color.outline_color);
         HolographicOutlineHelper.obtain(mView.getContext())
-                .applyExpensiveOutlineWithBlur(b, canvas, outlineColor, outlineColor, clipAlpha);
+                .applyExpensiveOutlineWithBlur(b, canvas, clipAlpha);
         canvas.setBitmap(null);
 
         return b;