[vsg-dev#1035] glslang support

psi29a · Nov 28, 2023 · 97ed759 · 97ed759
1 parent 8d8acf9
commit 97ed759
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Showing 4 changed files with 32 additions and 48 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -37,29 +37,35 @@ find_package(Vulkan ${Vulkan_MIN_VERSION} REQUIRED)
 
 find_package(Threads REQUIRED)
 
-# Enable/disable shader compilation support that pulls in glslang
-set(VSG_SUPPORTS_ShaderCompiler  1 CACHE STRING "Optional shader compiler support, 0 for off, 1 for enabled." )
-if (VSG_SUPPORTS_ShaderCompiler)
-    if (NOT EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/src/glslang/build_vars.cmake)
-
-        if (Git_FOUND)
-
-            set(glslang_URL "https://github.com/vsg-dev/glslang.git" CACHE STRING "URL of the glslang git repository")
-            set(glslang_branch "VSG-1.0.x" CACHE STRING "branch/tag of the glslang git repository")
-
-            execute_process(COMMAND ${GIT_EXECUTABLE} clone --depth 1 --branch ${glslang_branch} ${glslang_URL}
-                            WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/src
-                            RESULT_VARIABLE GIT_SUBMOD_RESULT)
-
-            if(NOT GIT_SUBMOD_RESULT EQUAL "0")
-                message(WARNING "git clone of glslang failed. ShaderCompile support disabled.")
-                set(VSG_SUPPORTS_ShaderCompiler 0)
+set(VSG_USE_SYSTEM_GLSLANG 1 CACHE STRING "Use system installed glslang, 0 for off, 1 for enabled." )
+set(GLSLANG_VERSION 13.1.1)
+if (VSG_USE_SYSTEM_GLSLANG)
+    find_package(glslang REQUIRED ${GLSLANG_VERSION})
+else ()
+    cmake_policy(SET CMP0135 NEW) # use DOWNLOAD_EXTRACT_TIMESTAMP
+    set(ENABLE_OPT OFF CACHE BOOL "")
+    include(FetchContent)
+    FetchContent_Declare(glslang
+            URL https://github.com/KhronosGroup/glslang/archive/refs/tags/${GLSLANG_VERSION}.zip
+            URL_HASH SHA3_256=4b01f8b92754eb6ea2aee3747fba25a9439a37d69c24058222ec920b132a172a
+            SOURCE_DIR fetched/glslang
+    )
+    # Like `FetchContent_MakeAvailable` but passes EXCLUDE_FROM_ALL to `add_subdirectory`.
+    macro(FetchContent_MakeAvailableExcludeFromAll)
+        foreach(contentName IN ITEMS ${ARGV})
+            string(TOLOWER ${contentName} contentNameLower)
+            FetchContent_GetProperties(${contentName})
+            if(NOT ${contentNameLower}_POPULATED)
+                FetchContent_Populate(${contentName})
+                if(EXISTS ${${contentNameLower}_SOURCE_DIR}/CMakeLists.txt)
+                    add_subdirectory(${${contentNameLower}_SOURCE_DIR}
+                            ${${contentNameLower}_BINARY_DIR} EXCLUDE_FROM_ALL)
+                endif()
             endif()
-        else()
-                message(WARNING "git clone of glslang failed. ShaderCompile support disabled.")
-                set(VSG_SUPPORTS_ShaderCompiler 0)
-        endif()
-    endif()
+        endforeach()
+    endmacro()
+    FetchContent_MakeAvailableExcludeFromAll(glslang)
+
 endif()
 
 set(VSG_SUPPORTS_Windowing  1 CACHE STRING "Optional native windowing support providing a default implementation of vsg::Window::create(), 0 for off, 1 for enabled." )

diff --git a/src/vsg/CMakeLists.txt b/src/vsg/CMakeLists.txt
@@ -236,6 +236,7 @@ endif()
 set(LIBRARIES PUBLIC
         Vulkan::Vulkan
         Threads::Threads
+        glslang
 )
 
 # Check for std::atomic

diff --git a/src/vsg/utils/ShaderCompiler.cpp b/src/vsg/utils/ShaderCompiler.cpp
@@ -19,11 +19,9 @@ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLI
 #include <vsg/state/GraphicsPipeline.h>
 #include <vsg/utils/ShaderCompiler.h>
 
-#if VSG_SUPPORTS_ShaderCompiler
-#    include <SPIRV/GlslangToSpv.h>
-#    include <glslang/Public/ResourceLimits.h>
-#    include <glslang/Public/ShaderLang.h>
-#endif
+#include <SPIRV/GlslangToSpv.h>
+#include <glslang/Public/ResourceLimits.h>
+#include <glslang/Public/ShaderLang.h>
 
 #include <algorithm>
 #include <iomanip>
@@ -35,7 +33,6 @@ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLI
 
 using namespace vsg;
 
-#if VSG_SUPPORTS_ShaderCompiler
 static std::atomic_uint s_initialized = 0;
 
 static void s_initializeProcess()
@@ -54,8 +51,6 @@ static void s_finalizeProcess()
     }
 }
 
-#endif
-
 std::string debugFormatShaderSource(const std::string& source)
 {
     std::istringstream iss(source);
@@ -79,17 +74,9 @@ ShaderCompiler::ShaderCompiler() :
 
 ShaderCompiler::~ShaderCompiler()
 {
-#if VSG_SUPPORTS_ShaderCompiler
     s_finalizeProcess();
-#endif
-}
-
-bool ShaderCompiler::supported() const
-{
-    return VSG_SUPPORTS_ShaderCompiler == 1;
 }
 
-#if VSG_SUPPORTS_ShaderCompiler
 bool ShaderCompiler::compile(ShaderStages& shaders, const std::vector<std::string>& defines, ref_ptr<const Options> options)
 {
     // need to balance the inits.
@@ -290,13 +277,6 @@ bool ShaderCompiler::compile(ShaderStages& shaders, const std::vector<std::strin
 
     return true;
 }
-#else
-bool ShaderCompiler::compile(ShaderStages&, const std::vector<std::string>&, ref_ptr<const Options> /*options*/)
-{
-    warn("ShaderCompile::compile(..) not supported,");
-    return false;
-}
-#endif
 
 bool ShaderCompiler::compile(ref_ptr<ShaderStage> shaderStage, const std::vector<std::string>& defines, ref_ptr<const Options> options)
 {

diff --git a/src/vsg/vk/Context.cpp b/src/vsg/vk/Context.cpp
@@ -143,16 +143,13 @@ ShaderCompiler* Context::getOrCreateShaderCompiler()
 {
     if (shaderCompiler) return shaderCompiler;
 
-#if VSG_SUPPORTS_ShaderCompiler
     shaderCompiler = ShaderCompiler::create();
 
     if (device && device->getInstance())
     {
         shaderCompiler->defaults->vulkanVersion = device->getInstance()->apiVersion;
     }
 
-#endif
-
     return shaderCompiler;
 }