commit 47d86230823de5d372688dff2b6e363a607009a8
author Chris Craik <ccraik@google.com> Thu Aug 14 17:26:21 2014 -0700
committer Chris Craik <ccraik@google.com> Fri Aug 15 00:41:09 2014 +0000
tree 206ec39f118a5b89ba42cfc3b4c318ea6b8da616
parent 1e1a01b0e44ab7a948265a78070937d2022d7abd

Fix nine patch outline radius computation

bug:16852714
Change-Id: I475154c0f324fd2e2c8991415e0d8240c75663d8

tools/aapt/Images.cpp

diff --git a/tools/aapt/Images.cpp b/tools/aapt/Images.cpp
index cf3dd0a..137c85c 100644
--- a/tools/aapt/Images.cpp
+++ b/tools/aapt/Images.cpp
@@ -485,9 +485,13 @@
     find_max_opacity(image->rows, innerStartX, innerStartY, innerMidX, innerMidY, 1, 1,
             &diagonalInset);
 
-    // Determine source radius based upon inset
-    // radius = 1 / (sqrt(2) - 1) * inset
-    image->outlineRadius = 2.4142f * diagonalInset;
+    /* Determine source radius based upon inset:
+     *     sqrt(r^2 + r^2) = sqrt(i^2 + i^2) + r
+     *     sqrt(2) * r = sqrt(2) * i + r
+     *     (sqrt(2) - 1) * r = sqrt(2) * i
+     *     r = sqrt(2) / (sqrt(2) - 1) * i
+     */
+    image->outlineRadius = 3.4142f * diagonalInset;
 
     NOISY(printf("outline insets %d %d %d %d, rad %f, alpha %x\n",
             image->outlineInsetsLeft,