Add implementations for saveLayerAlpha() and textured rects.

Even though there's an implementation for textured rects, drawBitmap() is not
hooked up yet as it will require a good texture cache.

This method is implemented using FBOs. There's currently an issue either in the
driver or in the Canvas renderer that forces the FBO to be fullscreen, which is
extremely expensive and yields terrible performance.

Change-Id: I148419195e12d45653c60186938aa78c23a68e2c
diff --git a/libs/hwui/Matrix.cpp b/libs/hwui/Matrix.cpp
index c772f00..e9c7791 100644
--- a/libs/hwui/Matrix.cpp
+++ b/libs/hwui/Matrix.cpp
@@ -97,6 +97,14 @@
     memcpy(v, data, sizeof(data));
 }
 
+float Matrix4::getTranslateX() {
+    return data[12];
+}
+
+float Matrix4::getTranslateY() {
+    return data[13];
+}
+
 void Matrix4::loadTranslate(float x, float y, float z) {
     loadIdentity();
     data[12] = x;