Update build to allow setting more external paths (#7044)

* Update build to allow setting more external paths

Update the build to allow setting user-specific paths for the external
modules: glm, imgui, slang-rhi, and tinyobjloader.

8 files changed, 85 insertions, 17 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8fa900d83..a933d0ab6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -203,6 +203,26 @@ advanced_option(
     "Build using user defined path for glslang"
     OFF
 )
+advanced_option(
+    SLANG_OVERRIDE_GLM_PATH
+    "Build using user defined path for glm"
+    OFF
+)
+advanced_option(
+    SLANG_OVERRIDE_IMGUI_PATH
+    "Build using user defined path for imgui"
+    OFF
+)
+advanced_option(
+    SLANG_OVERRIDE_SLANG_RHI_PATH
+    "Build using user defined path for slang-rhi"
+    OFF
+)
+advanced_option(
+    SLANG_OVERRIDE_TINYOBJLOADER_PATH
+    "Build using user defined path for tinyobjloader"
+    OFF
+)
 
 advanced_option(
     SLANG_EXCLUDE_DAWN
diff --git a/external/CMakeLists.txt b/external/CMakeLists.txt
index afab86a9d..55d9e4941 100644
--- a/external/CMakeLists.txt
+++ b/external/CMakeLists.txt
@@ -157,11 +157,19 @@ endif()
 
 # imgui
 add_library(imgui INTERFACE)
-target_include_directories(
-    imgui
-    ${system}
-    INTERFACE "${CMAKE_CURRENT_LIST_DIR}/imgui"
-)
+if(NOT SLANG_OVERRIDE_IMGUI_PATH)
+    target_include_directories(
+        imgui
+        ${system}
+        INTERFACE "${CMAKE_CURRENT_LIST_DIR}/imgui"
+    )
+else()
+    target_include_directories(
+        imgui
+        ${system}
+        INTERFACE "${SLANG_OVERRIDE_IMGUI_PATH}"
+    )
+endif()
 
 # stb
 add_library(stb INTERFACE)
@@ -196,7 +204,16 @@ if(SLANG_ENABLE_SLANG_RHI)
         set(SLANG_RHI_ENABLE_D3D11 OFF)
         set(SLANG_RHI_ENABLE_D3D12 OFF)
     endif()
-    add_subdirectory(slang-rhi)
+    if(NOT SLANG_OVERRIDE_SLANG_RHI_PATH)
+        add_subdirectory(slang-rhi)
+    else()
+        add_subdirectory(
+            ${SLANG_OVERRIDE_SLANG_RHI_PATH}
+            slang-rhi
+            EXCLUDE_FROM_ALL
+            ${system}
+        )
+    endif()
 endif()
 
 # Tidy things up:
diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
index 53698726b..d871f91f2 100644
--- a/tools/CMakeLists.txt
+++ b/tools/CMakeLists.txt
@@ -164,6 +164,37 @@ if(SLANG_ENABLE_GFX)
         INCLUDE_DIRECTORIES_PUBLIC
             ${slang_SOURCE_DIR}
             ${slang_SOURCE_DIR}/include
+            if
+            (not ${SLANG_OVERRIDE_SPIRV_TOOLS_PATH})
+        INCLUDE_DIRECTORIES_PUBLIC
+            ${slang_SOURCE_DIR}/external/spirv-tools
+            else
+            ()
+        INCLUDE_DIRECTORIES_PUBLIC
+            ${SLANG_OVERRIDE_SPIRV_TOOLS_PATH}
+            endif
+            ()
+            if
+            (not ${SLANG_OVERRIDE_GLM_PATH})
+        INCLUDE_DIRECTORIES_PUBLIC ${slang_SOURCE_DIR}/external/glm else ()
+        INCLUDE_DIRECTORIES_PUBLIC
+            ${SLANG_OVERRIDE_GLM_PATH}
+            endif
+            ()
+            if
+            (not ${SLANG_OVERRIDE_IMGUI_PATH})
+        INCLUDE_DIRECTORIES_PUBLIC ${slang_SOURCE_DIR}/external/imgui else ()
+        INCLUDE_DIRECTORIES_PUBLIC
+            ${SLANG_OVERRIDE_IMGUI_PATH}
+            endif
+            ()
+            if
+            (not ${SLANG_OVERRIDE_TINYOBJLOADER_PATH})
+        INCLUDE_DIRECTORIES_PUBLIC
+            ${slang_SOURCE_DIR}/external/tinyobjloader
+            else
+            ()
+        INCLUDE_DIRECTORIES_PUBLIC ${SLANG_OVERRIDE_TINYOBJLOADER_PATH} endif ()
         INCLUDE_DIRECTORIES_PRIVATE ${NVAPI_INCLUDE_DIRS}
         INSTALL
         EXPORT_SET_NAME SlangTargets
diff --git a/tools/gfx/vulkan/glslang-module.h b/tools/gfx/vulkan/glslang-module.h
index cda903577..fc3e2861d 100644
--- a/tools/gfx/vulkan/glslang-module.h
+++ b/tools/gfx/vulkan/glslang-module.h
@@ -2,7 +2,7 @@
 #pragma once
 
 #include "core/slang-list.h"
-#include "external/spirv-tools/include/spirv-tools/linker.hpp"
+#include "include/spirv-tools/linker.hpp"
 #include "slang-com-helper.h"
 #include "slang-com-ptr.h"
 #include "slang-glslang/slang-glslang.h"
diff --git a/tools/gfx/vulkan/vk-shader-program.cpp b/tools/gfx/vulkan/vk-shader-program.cpp
index 2dd9b0326..a7e754b6c 100644
--- a/tools/gfx/vulkan/vk-shader-program.cpp
+++ b/tools/gfx/vulkan/vk-shader-program.cpp
@@ -1,7 +1,7 @@
 // vk-shader-program.cpp
 #include "vk-shader-program.h"
 
-#include "external/spirv-tools/include/spirv-tools/linker.hpp"
+#include "include/spirv-tools/linker.hpp"
 #include "vk-device.h"
 #include "vk-util.h"
 
diff --git a/tools/platform/gui.h b/tools/platform/gui.h
index eea9aa4f0..7e2a12ffe 100644
--- a/tools/platform/gui.h
+++ b/tools/platform/gui.h
@@ -2,7 +2,7 @@
 #pragma once
 
 #include "core/slang-basic.h"
-#include "external/imgui/imgui.h"
+#include "imgui.h"
 #include "slang-com-ptr.h"
 #include "slang-gfx.h"
 #include "vector-math.h"
diff --git a/tools/platform/model.cpp b/tools/platform/model.cpp
index 18a7ad641..a0786d8da 100644
--- a/tools/platform/model.cpp
+++ b/tools/platform/model.cpp
@@ -4,15 +4,15 @@
 #include "window.h"
 
 #define TINYOBJLOADER_IMPLEMENTATION
-#include "../../external/tinyobjloader/tiny_obj_loader.h"
+#include "tiny_obj_loader.h"
 
 #define STB_IMAGE_IMPLEMENTATION
 #include "stb_image.h"
 
 #define STB_IMAGE_RESIZE_IMPLEMENTATION
-#include "../../external/glm/glm/glm.hpp"
-#include "../../external/glm/glm/gtc/constants.hpp"
-#include "../../external/glm/glm/gtc/matrix_transform.hpp"
+#include "glm/glm.hpp"
+#include "glm/gtc/constants.hpp"
+#include "glm/gtc/matrix_transform.hpp"
 #include "stb_image_resize.h"
 
 #include <memory>
diff --git a/tools/platform/vector-math.h b/tools/platform/vector-math.h
index 2e24833eb..de84fe09f 100644
--- a/tools/platform/vector-math.h
+++ b/tools/platform/vector-math.h
@@ -3,10 +3,10 @@
 
 // We will use the GLM library for our vector math types, just for simplicity.
 
-#include "../../external/glm/glm/glm.hpp"
-#include "../../external/glm/glm/gtc/constants.hpp"
-#include "../../external/glm/glm/gtc/matrix_transform.hpp"
-#include "../../external/glm/glm/gtc/quaternion.hpp"
+#include "glm/glm.hpp"
+#include "glm/gtc/constants.hpp"
+#include "glm/gtc/matrix_transform.hpp"
+#include "glm/gtc/quaternion.hpp"
 
 namespace gfx
 {