From cd2b8cc822b341a714fc6fbca15fddef80d2ee95 Mon Sep 17 00:00:00 2001
From: Georg Hagen <georg.hagen.git@madvoxel.com>
Date: Wed, 22 May 2024 14:38:51 +0200
Subject: [PATCH] Make assimp optional

---
 3rdParty/CMakeLists.txt        |  2 +-
 3rdParty/assimp/CMakeLists.txt | 52 ++++++++++++++++++++++------------
 CMakeLists.txt                 |  9 ++++--
 3 files changed, 42 insertions(+), 21 deletions(-)

diff --git a/3rdParty/CMakeLists.txt b/3rdParty/CMakeLists.txt
index a40f3d2..0c733a3 100644
--- a/3rdParty/CMakeLists.txt
+++ b/3rdParty/CMakeLists.txt
@@ -2,8 +2,8 @@ add_subdirectory(glm)
 if (NOT ANDROID AND NOT IOS)
     add_subdirectory(glfw)
     add_subdirectory(ftxui)
-    add_subdirectory(assimp)
 endif()
+add_subdirectory(assimp)
 add_subdirectory(fmt)
 add_subdirectory(spdlog)
 add_subdirectory(yaml-cpp)
diff --git a/3rdParty/assimp/CMakeLists.txt b/3rdParty/assimp/CMakeLists.txt
index aa65379..6c32a3d 100644
--- a/3rdParty/assimp/CMakeLists.txt
+++ b/3rdParty/assimp/CMakeLists.txt
@@ -1,23 +1,39 @@
 include(FetchContent)
 
-if(NOT DEFINED ASSIMP_REPO)
-    set(ASSIMP_REPO https://github.com/assimp/assimp.git)
+find_package(assimp QUIET)
+if (assimp_FOUND)
+    message("Using system assimp")
+elseif (USE_ASSIMP)
+    if(NOT DEFINED ASSIMP_REPO)
+        set(ASSIMP_REPO https://github.com/assimp/assimp.git)
+    endif ()
+    FetchContent_Declare(
+            assimp
+            EXCLUDE_FROM_ALL
+            GIT_REPOSITORY ${ASSIMP_REPO}
+            GIT_TAG v5.0.1
+            GIT_SHALLOW TRUE
+    )
+
+    set(BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
+    set(ASSIMP_BUILD_TESTS OFF CACHE BOOL "" FORCE)
+    set(ASSIMP_BUILD_SAMPLES OFF CACHE BOOL "" FORCE)
+    set(ASSIMP_INJECT_DEBUG_POSTFIX OFF CACHE BOOL "" FORCE)
+    set(ASSIMP_INSTALL OFF CACHE BOOL "" FORCE)
+    set(ASSIMP_BUILD_ASSIMP_TOOLS OFF CACHE BOOL "" FORCE)
+    set(ASSIMP_BUILD_SAMPLES OFF CACHE BOOL "" FORCE)
+
+    FetchContent_MakeAvailable(assimp)
+
+    set(assimp_FOUND ON PARENT_SCOPE)
 endif ()
 
-FetchContent_Declare(
-        assimp
-        EXCLUDE_FROM_ALL
-        GIT_REPOSITORY ${ASSIMP_REPO}
-        GIT_TAG v5.0.1
-        GIT_SHALLOW TRUE
-)
 
-set(BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
-set(ASSIMP_BUILD_TESTS OFF CACHE BOOL "" FORCE)
-set(ASSIMP_BUILD_SAMPLES OFF CACHE BOOL "" FORCE)
-set(ASSIMP_INJECT_DEBUG_POSTFIX OFF CACHE BOOL "" FORCE)
-set(ASSIMP_INSTALL OFF CACHE BOOL "" FORCE)
-set(ASSIMP_BUILD_ASSIMP_TOOLS OFF CACHE BOOL "" FORCE)
-set(ASSIMP_BUILD_SAMPLES OFF CACHE BOOL "" FORCE)
-
-FetchContent_MakeAvailable(assimp)
\ No newline at end of file
+function(LinkAssimp TARGET)
+    if (NOT assimp_FOUND)
+        find_package(assimp QUIET)
+    endif ()
+    if (assimp_FOUND)
+        target_link_libraries(${TARGET} PUBLIC assimp)
+    endif ()
+endfunction()
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 62d4b29..189ab09 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,10 +1,14 @@
 cmake_minimum_required(VERSION 3.28 FATAL_ERROR)
 
+option(USE_ASSIMP "If assimp should be used" ON)
+
 include(cmake/VarsFromFile.cmake)
 include(cmake/SetCompilerSettings.cmake)
 include(cmake/SetupVulkan.cmake)
 include(cmake/Filter.cmake)
 
+VarsFromFile("DependencyMirrors.txt") # Load mirror list (for CICD)
+
 set(CMAKE_POLICY_DEFAULT_CMP0077 NEW)
 
 if(LINUX)
@@ -84,7 +88,6 @@ if (NOT ANDROID AND NOT IOS)
     if (libjpeg-turbo_FOUND)
         target_link_libraries(openVulkanoCpp PRIVATE libjpeg-turbo::turbojpeg)
     endif()
-    target_link_libraries(openVulkanoCpp PRIVATE assimp)
     target_link_libraries(openVulkanoCpp PRIVATE ftxui::screen ftxui::dom ftxui::component)
 endif()
 
@@ -106,4 +109,6 @@ if(CMAKE_BUILD_TYPE STREQUAL "Debug")
     add_compile_definitions(DEBUG)
 endif()
 
-SetGlmDefines(openVulkanoCpp)
\ No newline at end of file
+SetGlmDefines(openVulkanoCpp)
+
+LinkAssimp(openVulkanoCpp)
\ No newline at end of file