From 72715369dda902ae2ae7407693603cbc6e23e5d8 Mon Sep 17 00:00:00 2001
From: Brad Davis <bdavis@saintandreas.org>
Date: Mon, 6 Jun 2016 01:39:56 -0700
Subject: [PATCH] Make inclusion into external projects easier

---
 CMakeLists.txt | 78 +++++++++++++++++++++++++++++---------------------
 1 file changed, 46 insertions(+), 32 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7685410..5a210b3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,42 +28,56 @@ cmake_minimum_required(VERSION 3.2)
 
 project(VulkanHppGenerator)
 
-file(TO_NATIVE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/Vulkan-Docs/src/spec/vk.xml vk_spec)
-string(REPLACE "\\" "\\\\" vk_spec ${vk_spec})
-add_definitions(-DVK_SPEC="${vk_spec}")
+# If you wish to target a specific version of the spec, override this value like so 
+# cmake -DVK_SPEC_URL:STRING=https://example.com/some/other/url/vk.xml
+set(VK_SPEC_URL "https://raw.githubusercontent.com/KhronosGroup/Vulkan-Docs/1.0/src/spec/vk.xml" CACHE STRING "URL from which to fetch the Vulkan Spec XML")
 
-file(TO_NATIVE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/vulkan/vulkan.hpp vulkan_hpp)
+# Download the request URL specification
+file(DOWNLOAD ${VK_SPEC_URL} ${CMAKE_CURRENT_BINARY_DIR}/vk.xml )
+
+# Populate a preprocessor define with the location of the spec
+file(TO_NATIVE_PATH ${CMAKE_CURRENT_BINARY_DIR}/vk.xml VK_SPEC)
+string(REPLACE "\\" "\\\\" VK_SPEC ${VK_SPEC})
+add_definitions(-DVK_SPEC="${VK_SPEC}")
+
+# Populate a preprocessor define with the desire output location
+file(TO_NATIVE_PATH ${CMAKE_CURRENT_BINARY_DIR}/vulkan.hpp vulkan_hpp)
 string(REPLACE "\\" "\\\\" vulkan_hpp ${vulkan_hpp})
 add_definitions(-DVULKAN_HPP="${vulkan_hpp}")
 
-set(HEADERS
-)
-
-set(SOURCES
-  VulkanHppGenerator.cpp
-)
-
-set(TINYXML2_SOURCES
-  tinyxml2/tinyxml2.cpp
-)
-
-set(TINYXML2_HEADERS
-  tinyxml2/tinyxml2.h
-)
-
-source_group(headers FILES ${HEADERS})
+# Create the executable project
+set(SOURCES VulkanHppGenerator.cpp)
 source_group(sources FILES ${SOURCES})
-
-source_group(TinyXML2\\headers FILES ${TINYXML2_HEADERS})
-source_group(TinyXML2\\sources FILES ${TINYXML2_SOURCES})
-
-add_executable(VulkanHppGenerator
-  ${HEADERS}
-  ${SOURCES}
-  ${TINYXML2_SOURCES}
-  ${TINYXML2_HEADERS}
-)
-
+add_executable(VulkanHppGenerator ${SOURCES} )
 set_property(TARGET VulkanHppGenerator PROPERTY CXX_STANDARD 11)
 
-target_include_directories(VulkanHppGenerator PRIVATE "${CMAKE_SOURCE_DIR}/tinyxml2")
+if (WIN32)
+	include(ExternalProject)
+	# Fetch and build tinyxml in order to parse the specification
+	ExternalProject_Add(
+	    tinyxml2
+	    DOWNLOAD_NAME tinyxml2-c8dad95d4488663c0381d502b3274df7dbf2fc55.zip
+	    URL https://codeload.github.com/leethomason/tinyxml2/zip/c8dad95d4488663c0381d502b3274df7dbf2fc55
+	    URL_MD5 6984b655cae1cd4b54fccaebfe23b35c
+	    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX:PATH=<INSTALL_DIR> -DBUILD_SHARED_LIBS:BOOL=OFF -DBUILD_STATIC_LIBS:BOOL=ON
+	    LOG_DOWNLOAD 1
+	)
+	# Grab the include path and library and store them  
+	ExternalProject_Get_Property(tinyxml2 INSTALL_DIR)
+	# Make sure tinyxml build first, and is available to the generator
+	add_dependencies(VulkanHppGenerator tinyxml2)
+	target_include_directories(VulkanHppGenerator PRIVATE ${INSTALL_DIR}/include)
+	target_link_libraries(VulkanHppGenerator ${INSTALL_DIR}/lib/tinyxml2.lib)
+else()
+	include(FindPkgConfig)
+	pkg_check_modules(TINYXML2 REQUIRED tinyxml2)
+	link_directories(${TINYXML2_LIBDIR})
+	target_include_directories(VulkanHppGenerator PRIVATE ${TINYXML2_INCLUDEDIR})
+	target_link_libraries(VulkanHppGenerator ${TINYXML2_LIBRARIES})
+endif()
+
+# Execute the generator
+add_custom_command(TARGET VulkanHppGenerator POST_BUILD COMMAND VulkanHppGenerator)
+
+# Install the output file to the destination
+install(FILES "${CMAKE_CURRENT_BINARY_DIR}/vulkan.hpp" DESTINATION "include/vulkan")