Improve nine patch scaling
Apply separate coefficient for X and Y, when scaling nine patch
lattice dividers. This is reducing rounding error and fixing
a nine patch issue in Clock app alarm background.
There are other issues in nine patch scaling (see ag/3378768).
Test: Ran clock app
Bug: 70353853
Change-Id: Ibbbfddc47767fb3314cdb88820e520b3f472e727
diff --git a/core/jni/android/graphics/BitmapFactory.cpp b/core/jni/android/graphics/BitmapFactory.cpp
index 79c5a34..79aa5ac 100644
--- a/core/jni/android/graphics/BitmapFactory.cpp
+++ b/core/jni/android/graphics/BitmapFactory.cpp
@@ -385,10 +385,18 @@
return nullObjectReturn("codec->getAndroidPixels() failed.");
}
+ // This is weird so let me explain: we could use the scale parameter
+ // directly, but for historical reasons this is how the corresponding
+ // Dalvik code has always behaved. We simply recreate the behavior here.
+ // The result is slightly different from simply using scale because of
+ // the 0.5f rounding bias applied when computing the target image size
+ const float scaleX = scaledWidth / float(decodingBitmap.width());
+ const float scaleY = scaledHeight / float(decodingBitmap.height());
+
jbyteArray ninePatchChunk = NULL;
if (peeker.mPatch != NULL) {
if (willScale) {
- peeker.scale(scale, scale, scaledWidth, scaledHeight);
+ peeker.scale(scaleX, scaleY, scaledWidth, scaledHeight);
}
size_t ninePatchArraySize = peeker.mPatch->serializedSize();
@@ -419,14 +427,6 @@
SkBitmap outputBitmap;
if (willScale) {
- // This is weird so let me explain: we could use the scale parameter
- // directly, but for historical reasons this is how the corresponding
- // Dalvik code has always behaved. We simply recreate the behavior here.
- // The result is slightly different from simply using scale because of
- // the 0.5f rounding bias applied when computing the target image size
- const float sx = scaledWidth / float(decodingBitmap.width());
- const float sy = scaledHeight / float(decodingBitmap.height());
-
// Set the allocator for the outputBitmap.
SkBitmap::Allocator* outputAllocator;
if (javaBitmap != nullptr) {
@@ -456,7 +456,7 @@
paint.setFilterQuality(kLow_SkFilterQuality); // bilinear filtering
SkCanvas canvas(outputBitmap, SkCanvas::ColorBehavior::kLegacy);
- canvas.scale(sx, sy);
+ canvas.scale(scaleX, scaleY);
canvas.drawBitmap(decodingBitmap, 0.0f, 0.0f, &paint);
} else {
outputBitmap.swap(decodingBitmap);
diff --git a/core/jni/android/graphics/NinePatchPeeker.cpp b/core/jni/android/graphics/NinePatchPeeker.cpp
index 066d47b..9171fc6 100644
--- a/core/jni/android/graphics/NinePatchPeeker.cpp
+++ b/core/jni/android/graphics/NinePatchPeeker.cpp
@@ -76,13 +76,18 @@
if (!mPatch) {
return;
}
- mPatch->paddingLeft = int(mPatch->paddingLeft * scaleX + 0.5f);
- mPatch->paddingTop = int(mPatch->paddingTop * scaleY + 0.5f);
- mPatch->paddingRight = int(mPatch->paddingRight * scaleX + 0.5f);
- mPatch->paddingBottom = int(mPatch->paddingBottom * scaleY + 0.5f);
// The max value for the divRange is one pixel less than the actual max to ensure that the size
// of the last div is not zero. A div of size 0 is considered invalid input and will not render.
- scaleDivRange(mPatch->getXDivs(), mPatch->numXDivs, scaleX, scaledWidth - 1);
- scaleDivRange(mPatch->getYDivs(), mPatch->numYDivs, scaleY, scaledHeight - 1);
+ if (!SkScalarNearlyEqual(scaleX, 1.0f)) {
+ mPatch->paddingLeft = int(mPatch->paddingLeft * scaleX + 0.5f);
+ mPatch->paddingRight = int(mPatch->paddingRight * scaleX + 0.5f);
+ scaleDivRange(mPatch->getXDivs(), mPatch->numXDivs, scaleX, scaledWidth - 1);
+ }
+
+ if (!SkScalarNearlyEqual(scaleY, 1.0f)) {
+ mPatch->paddingTop = int(mPatch->paddingTop * scaleY + 0.5f);
+ mPatch->paddingBottom = int(mPatch->paddingBottom * scaleY + 0.5f);
+ scaleDivRange(mPatch->getYDivs(), mPatch->numYDivs, scaleY, scaledHeight - 1);
+ }
}