Make default vertex program correctly track surface size.
diff --git a/rsProgramVertex.cpp b/rsProgramVertex.cpp
index eea8b3b..68f589f 100644
--- a/rsProgramVertex.cpp
+++ b/rsProgramVertex.cpp
@@ -157,12 +157,17 @@
 
     pv->bindAllocation(alloc);
 
+    updateSize(rsc, w, h);
+}
+
+void ProgramVertexState::updateSize(Context *rsc, int32_t w, int32_t h)
+{
     Matrix m;
     m.loadOrtho(0,w, h,0, -1,1);
-    alloc->subData(RS_PROGRAM_VERTEX_PROJECTION_OFFSET, 16, &m.m[0], 16*4);
+    mDefaultAlloc->subData(RS_PROGRAM_VERTEX_PROJECTION_OFFSET, 16, &m.m[0], 16*4);
 
     m.loadIdentity();
-    alloc->subData(RS_PROGRAM_VERTEX_MODELVIEW_OFFSET, 16, &m.m[0], 16*4);
+    mDefaultAlloc->subData(RS_PROGRAM_VERTEX_MODELVIEW_OFFSET, 16, &m.m[0], 16*4);
 }
 
 void ProgramVertexState::deinit(Context *rsc)