Add pdsg (palladium spirv-generator)

- remove glslang from pd-system
- use spirv blobs instead of glsl 460
- Use Legacy shaders for OpenGL2 backend
- add devnotes

vendor/CMakeLists.txt

@@ -5,15 +5,18 @@ if(${CMAKE_SYSTEM_NAME} STREQUAL "Nintendo3DS")
 else()
     # GLAD
     add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/glad)
-    # GLSLANG
-    set(ENABLE_OPT OFF CACHE BOOL "" FORCE)
-    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/glslang)
     # SPIRV-Cross
     set(SPIRV_CROSS_CLI OFF CACHE BOOL "" FORCE)
     set(SPIRV_CROSS_ENABLE_TESTS OFF CACHE BOOL "" FORCE)
     add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/spirv-cross)
 endif()
 
+if(PD_BUILD_TOOLS)
+    # GLSLANG
+    set(ENABLE_OPT OFF CACHE BOOL "" FORCE)
+    add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/glslang)
+endif()
+
 # STB
 add_library(stb INTERFACE)
 target_include_directories(stb INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/stb)