From 186ea1218ee5dcb7650d0759a2af4b61af166cbe Mon Sep 17 00:00:00 2001
From: Derek Sollenberger <djsollen@google.com>
Date: Wed, 14 Mar 2018 13:26:47 -0400
Subject: [PATCH] Document the byte packing order of the current Bitmap.Configs

This CL documents the byte order for 585, 8888, and fp16 buffers.

Test: documenting existing behavior
Bug: 71518511
Change-Id: I128344db318eb4597b6eb00f0ae317e369145152
---
 graphics/java/android/graphics/Bitmap.java | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/graphics/java/android/graphics/Bitmap.java b/graphics/java/android/graphics/Bitmap.java
index 44e7066c5c661..52d29e32e4642 100644
--- a/graphics/java/android/graphics/Bitmap.java
+++ b/graphics/java/android/graphics/Bitmap.java
@@ -461,6 +461,11 @@ public final class Bitmap implements Parcelable {
          *
          * This configuration may be useful when using opaque bitmaps
          * that do not require high color fidelity.
+         *
+         * <p>Use this formula to pack into 16 bits:</p>
+         * <pre class="prettyprint">
+         * short color = (R & 0x1f) << 11 | (G & 0x3f) << 5 | (B & 0x1f);
+         * </pre>
          */
         RGB_565     (3),
 
@@ -493,6 +498,11 @@ public final class Bitmap implements Parcelable {
          *
          * This configuration is very flexible and offers the best
          * quality. It should be used whenever possible.
+         *
+         * <p>Use this formula to pack into 32 bits:</p>
+         * <pre class="prettyprint">
+         * int color = (A & 0xff) << 24 | (B & 0xff) << 16 | (G & 0xff) << 8 | (R & 0xff);
+         * </pre>
          */
         ARGB_8888   (5),
 
@@ -503,6 +513,11 @@ public final class Bitmap implements Parcelable {
          *
          * This configuration is particularly suited for wide-gamut and
          * HDR content.
+         *
+         * <p>Use this formula to pack into 64 bits:</p>
+         * <pre class="prettyprint">
+         * long color = (A & 0xffff) << 48 | (B & 0xffff) << 32 | (G & 0xffff) << 16 | (R & 0xffff);
+         * </pre>
          */
         RGBA_F16    (6),