Added Gamma library (#2957)

ports/gamma/CMakeLists.txt

@@ -0,0 +1,44 @@
+cmake_minimum_required (VERSION 3.0)
+
+project (gamma)
+
+# dependent on libsndfile and portaudio
+find_path(LIBSNDFILE_H sndfile.h)
+find_library(LIBSNDFILE_LIB NAMES libsndfile-1 libsndfile)
+find_path(PORTAUDIO_H portaudio.h)
+find_library(PORTAUDIO_LIB NAMES portaudio)
+
+set(CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS ON)
+
+set(SOURCEFILES
+        src/arr.cpp
+        src/AudioIO.cpp
+        src/Conversion.cpp
+        src/Domain.cpp
+        src/DFT.cpp
+        src/FFT_fftpack.cpp
+        src/fftpack++1.cpp
+        src/fftpack++2.cpp
+        src/SoundFile.cpp
+        src/Print.cpp
+        src/Recorder.cpp
+        src/scl.cpp
+        src/Scheduler.cpp
+        src/Timer.cpp
+        src/SoundFile.cpp)
+
+include_directories(. Gamma ${CMAKE_INSTALL_FULL_INCLUDEDIR} ${PORTAUDIO_H} ${LIBSNDFILE_H})
+
+add_library (gamma ${SOURCEFILES})
+target_link_libraries(gamma PUBLIC ${LIBSNDFILE_LIB} ${PORTAUDIO_LIB})
+
+install(
+  TARGETS gamma
+  RUNTIME DESTINATION bin
+  LIBRARY DESTINATION lib
+  ARCHIVE DESTINATION lib
+)
+
+if(NOT DISABLE_INSTALL_HEADERS)
+    install(DIRECTORY Gamma DESTINATION include FILES_MATCHING PATTERN "*.h")
+endif()

ports/gamma/CONTROL

@@ -0,0 +1,4 @@
+Source: gamma
+Version: gamma-2018-01-27
+Build-Depends: libsndfile, portaudio
+Description: Gamma is a cross-platform, C++ library for doing generic synthesis and filtering of signals. It is oriented towards real-time sound and graphics applications, but is equally useful for non-real-time tasks. Gamma is designed to be "light-footed" in terms of memory and processing making it highly suitable for plug-in development or embedding in other C++ projects.

ports/gamma/portfile.cmake

@@ -0,0 +1,27 @@
+# Instead of official release, base on commit hash for now.
+set(GAMMA_RELEASE_TAG "cc442ad0c5da369966cd937a96925c7b9a04e9e5")
+
+include(vcpkg_common_functions)
+
+set(SOURCE_PATH ${CURRENT_BUILDTREES_DIR}/src/Gamma-${GAMMA_RELEASE_TAG})
+
+vcpkg_download_distfile(ARCHIVE
+    URLS "https://github.com/LancePutnam/Gamma/archive/cc442ad0c5da369966cd937a96925c7b9a04e9e5.zip"
+    FILENAME "gamma-${GAMMA_RELEASE_TAG}.zip"
+    SHA512 de44f4d07db0b2cf09e77508d993273d09788dfa919d549393bb77534922b65e9d8a1b8193b4b02c72e6bc4dd060b41b18ff3520a36d4c28f6e2fb4b1e859ee7
+)
+vcpkg_extract_source_archive(${ARCHIVE})
+
+file(COPY ${CMAKE_CURRENT_LIST_DIR}/CMakeLists.txt DESTINATION ${SOURCE_PATH})
+
+vcpkg_configure_cmake(
+    SOURCE_PATH ${SOURCE_PATH}
+    PREFER_NINJA
+    OPTIONS_DEBUG -DDISABLE_INSTALL_HEADERS=1
+)
+
+vcpkg_install_cmake()
+vcpkg_copy_pdbs()
+
+# Handle copyright
+file(INSTALL ${SOURCE_PATH}/COPYRIGHT DESTINATION ${CURRENT_PACKAGES_DIR}/share/gamma RENAME copyright)