Performance Optimization: Align texture dirty rect

Align x offset and width to 32, y offset and height to 4.
It improves the font texture upload performance.

Change-Id: I967eeed90658f2ce1eb08cb2740d5dc34c72f40b

1 files changed, 10 insertions, 4 deletions

diff --git a/libs/hwui/font/CacheTexture.cpp b/libs/hwui/font/CacheTexture.cpp
index d2685da..a767a4e 100644
--- a/libs/hwui/font/CacheTexture.cpp
+++ b/libs/hwui/font/CacheTexture.cpp
@@ -204,15 +204,21 @@ void CacheTexture::allocatePixelBuffer() {
 bool CacheTexture::upload() {
     const Rect& dirtyRect = mDirtyRect;
 
-    uint32_t x = mHasUnpackRowLength ? dirtyRect.left : 0;
-    uint32_t y = dirtyRect.top;
-    uint32_t width = mHasUnpackRowLength ? dirtyRect.getWidth() : getWidth();
-    uint32_t height = dirtyRect.getHeight();
+    // align the x direction to 32 and y direction to 4 for better performance
+    uint32_t x = (((uint32_t)dirtyRect.left) & (~0x1F));
+    uint32_t y = (((uint32_t)dirtyRect.top) & (~0x3));
+    uint32_t r = ((((uint32_t)dirtyRect.right) + 0x1F) & (~0x1F));
+    uint32_t b = ((((uint32_t)dirtyRect.bottom) + 0x3) & (~0x3));
+    uint32_t width = (r > getWidth() ? getWidth() : r) - x;
+    uint32_t height = (b > getHeight() ? getHeight() : b) - y;
 
     // The unpack row length only needs to be specified when a new
     // texture is bound
     if (mHasUnpackRowLength) {
         glPixelStorei(GL_UNPACK_ROW_LENGTH, getWidth());
+    } else {
+        x = 0;
+        width = getWidth();
     }
 
     mPixelBuffer->upload(x, y, width, height);