Use system packages for Corrosion, stb and nlohmann

cmake/Findstb.cmake

@@ -0,0 +1,12 @@
+find_path(
+        STB_INCLUDE_DIR
+        NAMES stb_image.h
+        PATH_SUFFIXES stb
+)
+find_package_handle_standard_args(stb DEFAULT_MSG STB_INCLUDE_DIR)
+if(STB_FOUND)
+    mark_as_advanced(STB_INCLUDE_DIR)
+    add_library(stb INTERFACE)
+    target_include_directories(stb SYSTEM INTERFACE ${STB_INCLUDE_DIR})
+    add_library(stb::stb ALIAS stb)
+endif()

extern/CMakeLists.txt

@@ -1,13 +1,7 @@
 # SPDX-FileCopyrightText: 2023 Joshua Goins <josh@redstrate.com>
 # SPDX-License-Identifier: CC0-1.0
 
-FetchContent_Declare(
-        Corrosion
-        GIT_REPOSITORY https://github.com/corrosion-rs/corrosion.git
-        GIT_TAG v0.3.5
-)
-
-FetchContent_MakeAvailable(Corrosion)
+find_package(Corrosion REQUIRED)
 
 FetchContent_Declare(
         libphysis

extern/tinygltf/CMakeLists.txt

@@ -1,3 +1,7 @@
+find_package(nlohmann_json REQUIRED)
+find_package(stb REQUIRED)
+
 add_library(tinygltf STATIC)
 target_sources(tinygltf PRIVATE src/tiny_gltf.cc)
-target_include_directories(tinygltf PUBLIC include)
+target_include_directories(tinygltf PUBLIC include)
+target_link_libraries(tinygltf PUBLIC nlohmann_json::nlohmann_json)

extern/tinygltf/include/tiny_gltf.h

@@ -1691,7 +1691,7 @@ class TinyGLTF {
 
 #ifndef TINYGLTF_NO_INCLUDE_JSON
 #ifndef TINYGLTF_USE_RAPIDJSON
-#include "json.hpp"
+#include <nlohmann/json.hpp>
 #else
 #ifndef TINYGLTF_NO_INCLUDE_RAPIDJSON
 #include "document.h"
@@ -1710,13 +1710,13 @@ class TinyGLTF {
 
 #ifndef TINYGLTF_NO_STB_IMAGE
 #ifndef TINYGLTF_NO_INCLUDE_STB_IMAGE
-#include "stb_image.h"
+#include <stb/stb_image.h>
 #endif
 #endif
 
 #ifndef TINYGLTF_NO_STB_IMAGE_WRITE
 #ifndef TINYGLTF_NO_INCLUDE_STB_IMAGE_WRITE
-#include "stb_image_write.h"
+#include <stb/stb_image_write.h>
 #endif
 #endif