Exporting C++ headers from system/core

Moved headers from include/libutils and include/libsysutils to
libutils/include and libsysutils/include respectively, so they can be
exported via these libs. They needed to be moved since Soong does
not allow export from external folder.

Added symlink from old locations. They are needed since Soong
includes system/core/include by default. Once all modules are
cleaned up to explicitly add the required libs, the symlinks will be
removed.

Moved headers of libutils to libutils_headers. They should be used
by modules for header-only inlines. Added libutils_headers as
dependency of libutils.

Split of C++ headers into those that have no dependency and those that
have dependency on libutils.so will be handled in a later CL.

Test: Add above libs to shared lib of local module
Change-Id: I122db72056b26b1f39bad1d9a0c2a1c5efda3550

1 files changed, 64 insertions, 0 deletions

diff --git a/libutils/include/utils/LinearTransform.h b/libutils/include/utils/LinearTransform.h
new file mode 100644
index 000000000..04cb355c7
--- /dev/null
+++ b/libutils/include/utils/LinearTransform.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _LIBS_UTILS_LINEAR_TRANSFORM_H
+#define _LIBS_UTILS_LINEAR_TRANSFORM_H
+
+#include <stdint.h>
+
+namespace android {
+
+// LinearTransform defines a structure which hold the definition of a
+// transformation from single dimensional coordinate system A into coordinate
+// system B (and back again).  Values in A and in B are 64 bit, the linear
+// scale factor is expressed as a rational number using two 32 bit values.
+//
+// Specifically, let
+// f(a) = b
+// F(b) = f^-1(b) = a
+// then
+//
+// f(a) = (((a - a_zero) * a_to_b_numer) / a_to_b_denom) + b_zero;
+//
+// and
+//
+// F(b) = (((b - b_zero) * a_to_b_denom) / a_to_b_numer) + a_zero;
+//
+struct LinearTransform {
+  int64_t  a_zero;
+  int64_t  b_zero;
+  int32_t  a_to_b_numer;
+  uint32_t a_to_b_denom;
+
+  // Transform from A->B
+  // Returns true on success, or false in the case of a singularity or an
+  // overflow.
+  bool doForwardTransform(int64_t a_in, int64_t* b_out) const;
+
+  // Transform from B->A
+  // Returns true on success, or false in the case of a singularity or an
+  // overflow.
+  bool doReverseTransform(int64_t b_in, int64_t* a_out) const;
+
+  // Helpers which will reduce the fraction N/D using Euclid's method.
+  template <class T> static void reduce(T* N, T* D);
+  static void reduce(int32_t* N, uint32_t* D);
+};
+
+
+}
+
+#endif  // _LIBS_UTILS_LINEAR_TRANSFORM_H