macOS Apple Silicon support

BUILDING.md

@@ -18,7 +18,7 @@ KTX consist of the following parts
 Supported platforms (please to through their specific requirements first)
 
 - [GNU/Linux](#gnulinux)
-- [iOS and macOS](#ios-and-macos)
+- [Apple macOS/iOS](#apple-macosios)
 - [Web/Emscripten](#webemscripten)
 - [Windows 64-bit](#windows-x64)
 
@@ -98,7 +98,7 @@ cmake . -G Ninja -B build -DCMAKE_BUILD_TYPE=Release -DKTX_FEATURE_LOADTEST_APPS
 cmake --build build
 ```
 
-### iOS and macOS
+### Apple macOS/iOS
 
 You need to install the following
 
@@ -110,6 +110,10 @@ For the load tests applications you need to install the [Vulkan SDK](#vulkan-sdk
 
 Other dependencies (like zstd, SDL2 or the assimp library are included in this repository or come with Xcode).
 
+**NOTE:** the `iphoneos` or `MacOSX` SDK version gets hardwired into the generated projects. After installing an Xcode update that has the SDK for a new version of iOS, builds will fail. The only way to remedy this is to delete the build folder and regenerate from scratch.
+
+#### macOS
+
 To build for macOS:
 
 ```bash
@@ -123,6 +127,37 @@ cmake -GXcode -Bbuild/mac -DKTX_FEATURE_LOADTEST_APPS=ON -DVULKAN_INSTALL_DIR="$
 # Compile the project
 cmake --build build/mac
 ```
+##### Apple Silicon and Universal Binaries
+
+Macs are either based on Intel or the newer Apple Silicon architecture. By default CMake configures to build for your host's platform, whichever it is. If you want to cross compile universal binaries (that support both platforms), add the parameter `-DCMAKE_OSX_ARCHITECTURES="\$(ARCHS_STANDARD)"` to cmake.
+
+> **Known limitations:**
+> - Load tests apps are not supported on native Apple Silicon and cannot be cross compiled for Intel either
+> - Intel Macs have support for SSE, but if you're building universal binaries, you have to disable SSE or the build will fail
+
+Example how to build universal binaries
+
+```bash
+# Configure universal binaries and disable SSE 
+cmake -G Xcode -B build-macos-universal -DCMAKE_OSX_ARCHITECTURES="\$(ARCHS_STANDARD)" -DBASISU_SUPPORT_SSE=OFF
+# Build 
+cmake --build build-macos-universal
+# Easy way to check if the resulting binaries are universal
+
+file build-macos-universal/Debug/libktx.dylib
+# outputs:
+# build-macos-universal/Debug/libktx.dylib: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit dynamically linked shared library x86_64] [arm64]
+# build-macos-universal/Debug/libktx.dylib (for architecture x86_64):	Mach-O 64-bit dynamically linked shared library x86_64
+# build-macos-universal/Debug/libktx.dylib (for architecture arm64):	Mach-O 64-bit dynamically linked shared library arm64
+
+file build-macos-universal/Debug/toktx
+# outputs:
+# build-macos-universal/Debug/toktx: Mach-O universal binary with 2 architectures: [x86_64:Mach-O 64-bit executable x86_64] [arm64:Mach-O 64-bit executable arm64]
+# build-macos-universal/Debug/toktx (for architecture x86_64):	Mach-O 64-bit executable x86_64
+# build-macos-universal/Debug/toktx (for architecture arm64):	Mach-O 64-bit executable arm64
+```
+
+##### macOS signing
 
 To sign the applications you need to set the following CMake variables:
 
@@ -138,6 +173,8 @@ To sign the installation package you need to set the following variables:
 | PRODUCTBUILD\_IDENTITY\_NAME | Owner of the _Developer ID Installer_ certificate to use for signing |
 | PRODUCTBUILD\_KEYCHAIN\_PATH | Path to the keychain file with the certificate. Blank if its in the default keychain.
 
+#### iOS
+
 To build for iOS:
 
 ```bash
@@ -151,8 +188,11 @@ cmake -G Xcode -B build/ios -DKTX_FEATURE_LOADTEST_APPS=ON -DVULKAN_INSTALL_DIR=
 # Compile the project
 cmake --build build -- -sdk iphoneos
 ```
+
 If using the CMake GUI, when it asks you to specify the generator for the project, you need to check _Specify options for cross-compiling_ and on the next screen make sure _Operating System_ is set to `iOS`.
 
+##### iOS signing
+
 To sign the applications you need to set the following CMake variables:
 
 | Name | Value |
@@ -161,8 +201,6 @@ To sign the applications you need to set the following CMake variables:
 | XCODE\_DEVELOPMENT\_TEAM | Development team of the certificate owner
 | XCODE\_PROVISIONING\_PROFILE | Name of the profile to use.
 
-**NOTE:** the `iphoneos` SDK version gets hardwired into the generated projects. After installing an Xcode update that has the SDK for a new version of iOS, builds will fail. The only way to remedy this is to delete the build folder and regenerate from scratch.
-
 ### Web/Emscripten
 
 There are two ways to build the Web version of the software: using Docker or using your own Emscripten installation.

CMakeLists.txt

@@ -601,7 +601,7 @@ if(EMSCRIPTEN)
     )
 endif()
 
-add_library( objUtil OBJECT
+add_library( objUtil STATIC
     utils/argparser.cpp
     utils/argparser.h
     utils/ktxapp.h

ci_scripts/build_macos.sh

@@ -22,14 +22,19 @@ echo "Configure KTX-Software (macOS)"
 if [ -n "$MACOS_CERTIFICATES_P12" ]; then
   cmake -GXcode -Bbuild-macos \
   -DKTX_FEATURE_DOC=ON \
+  -DCMAKE_OSX_ARCHITECTURES="\$(ARCHS_STANDARD)" \
+  -DBASISU_SUPPORT_SSE=OFF \
   -DKTX_FEATURE_LOADTEST_APPS=ON -DVULKAN_INSTALL_DIR="${VULKAN_INSTALL_DIR}" \
   -DXCODE_CODE_SIGN_IDENTITY="${CODE_SIGN_IDENTITY}" \
   -DXCODE_DEVELOPMENT_TEAM="${DEVELOPMENT_TEAM}" \
   -DPRODUCTBUILD_IDENTITY_NAME="${PKG_SIGN_IDENTITY}"
 else # No secure variables means a PR or fork build.
   cmake -GXcode -Bbuild-macos \
   -DKTX_FEATURE_DOC=ON \
-  -DKTX_FEATURE_LOADTEST_APPS=ON -DVULKAN_INSTALL_DIR="${VULKAN_INSTALL_DIR}"
+  -DCMAKE_OSX_ARCHITECTURES="\$(ARCHS_STANDARD)" \
+  -DBASISU_SUPPORT_SSE=OFF \
+  -DKTX_FEATURE_LOADTEST_APPS=ON \
+  -DVULKAN_INSTALL_DIR="${VULKAN_INSTALL_DIR}"
 fi
 
 echo "Configure KTX-Software (macOS) without SSE support"

cmake/cputypetest.cmake

@@ -52,9 +52,20 @@ armv8
         #endif
     #elif TARGET_OS_MAC
 
+        #if defined __x86_64__
+
 #undef x86_64
 x86_64
 
+        #elif defined __aarch64__
+
+#undef arm64
+arm64
+
+        #else
+            #error Unsupported platform
+        #endif
+
     #else
         #error Unsupported platform
     #endif

interface/basisu_c_binding/CMakeLists.txt

@@ -1,20 +1,11 @@
 # Copyright 2017-2020 The Khronos Group Inc.
 # SPDX-License-Identifier: Apache-2.0
 
-add_library(obj_basisu_cbind OBJECT
+add_library(obj_basisu_cbind STATIC
     inc/basisu_c_binding.h
     src/basisu_c_binding.cpp
 )
 
-if(WIN32)
-    # The Windows ktx.dll seem to not include needed symbols from basisu_transcoder.cpp
-    # This is a workaround to get it linking
-    target_sources(obj_basisu_cbind
-    PRIVATE
-        ${PROJECT_SOURCE_DIR}/lib/basisu/transcoder/basisu_transcoder.cpp
-    )
-endif()
-
 target_compile_features(obj_basisu_cbind PUBLIC c_std_99 cxx_std_11)
 
 target_include_directories(

tests/CMakeLists.txt

@@ -3,7 +3,11 @@
 
 if(KTX_FEATURE_LOADTEST_APPS)
     # Test apps that load and display various KTX textures
-    add_subdirectory(loadtests)
+    if(APPLE AND CPU_ARCHITECTURE STREQUAL arm64)
+        message(WARNING "Building load test apps is not supported on Apple Silicon as host platform, so they are skipped")
+    else()
+        add_subdirectory(loadtests)
+    endif()
 endif()
 
 # gtest based unit-tests

tests/loadtests/CMakeLists.txt

@@ -59,7 +59,7 @@ function( ensure_runtime_dependencies_windows target )
     )
 endfunction()
 
-add_library( appfwSDL OBJECT
+add_library( appfwSDL STATIC
     appfwSDL/AppBaseSDL.cpp
     appfwSDL/AppBaseSDL.h
     appfwSDL/main.cpp
@@ -97,7 +97,7 @@ PUBLIC
     geom
 )
 
-add_library( GLAppSDL OBJECT
+add_library( GLAppSDL STATIC
     appfwSDL/GLAppSDL.cpp
     appfwSDL/GLAppSDL.h
     glloadtests/GLLoadTests.cpp

tests/loadtests/glloadtests.cmake

@@ -172,6 +172,8 @@ function( create_gl_target target sources KTX_GL_CONTEXT_PROFILE KTX_GL_CONTEXT_
         if(NOT IOS)
             set_target_properties( ${target} PROPERTIES
                 INSTALL_RPATH "@executable_path/../Frameworks"
+                # No Apple silicon support yet, so restrict archs to Intel
+                XCODE_ATTRIBUTE_ARCHS x86_64
             )
             add_custom_command( TARGET ${target} POST_BUILD
                 COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:ktx> "$<TARGET_BUNDLE_CONTENT_DIR:${target}>/Frameworks/$<TARGET_FILE_NAME:ktx>"

tests/loadtests/vkloadtests.cmake

@@ -75,8 +75,6 @@ add_custom_target(
 
 add_executable( vkloadtests
     ${EXE_FLAG}
-    $<TARGET_OBJECTS:appfwSDL>
-    $<TARGET_OBJECTS:objUtil>
     appfwSDL/VulkanAppSDL/VulkanAppSDL.cpp
     appfwSDL/VulkanAppSDL/VulkanAppSDL.h
     appfwSDL/VulkanAppSDL/vulkancheckres.h
@@ -132,6 +130,8 @@ target_link_libraries(
     vkloadtests
     ktx
     ${KTX_ZLIB_LIBRARIES}
+    objUtil
+    appfwSDL
 )
 
 if(IOS)
@@ -245,6 +245,8 @@ if(APPLE)
     if(NOT IOS)
         set_target_properties( vkloadtests PROPERTIES
             INSTALL_RPATH "@executable_path/../Frameworks"
+            # No Apple silicon support yet, so restrict archs to Intel
+            XCODE_ATTRIBUTE_ARCHS x86_64
         )
         add_custom_command( TARGET vkloadtests POST_BUILD
             COMMAND ${CMAKE_COMMAND} -E copy "${VULKAN_SDK}/lib/libMoltenVK.dylib" "$<TARGET_BUNDLE_CONTENT_DIR:vkloadtests>/Frameworks/libMoltenVK.dylib"

tests/transcodetests/CMakeLists.txt

@@ -3,7 +3,6 @@
 
 add_executable( transcodetests
     transcodetests.cc
-    $<TARGET_OBJECTS:obj_basisu_cbind>
 )
 
 target_include_directories(
@@ -19,6 +18,7 @@ target_link_libraries(
     transcodetests
     gtest
     ktx
+    obj_basisu_cbind
     ${CMAKE_THREAD_LIBS_INIT}
 )
 
@@ -33,3 +33,18 @@ gtest_discover_tests( transcodetests
     TEST_PREFIX transcodetest
     EXTRA_ARGS "${PROJECT_SOURCE_DIR}/tests/testimages/"
 )
+
+if(WIN32)
+    # The Windows ktx.dll seem to not include needed symbols from basisu_transcoder.cpp
+    # This is a workaround to get it linking
+    add_library(obj_tmp_basisu OBJECT
+        ${PROJECT_SOURCE_DIR}/lib/basisu/transcoder/basisu_transcoder.cpp
+        ${PROJECT_SOURCE_DIR}/lib/basisu/zstd/zstd.c
+        )
+    target_compile_definitions(
+        obj_tmp_basisu
+        PUBLIC # only for basisu_c_binding.
+            BASISU_NO_ITERATOR_DEBUG_LEVEL
+        )
+    target_link_libraries(transcodetests obj_tmp_basisu)
+endif()

tools/ktx2check/CMakeLists.txt

@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_executable( ktx2check
-    $<TARGET_OBJECTS:objUtil>
     ktx2check.cpp
     stdafx.h
 )
@@ -21,6 +20,7 @@ PRIVATE
 target_link_libraries(
     ktx2check
     ktx
+    objUtil
 )
 set_tool_properties(ktx2check)
 set_xcode_code_sign(ktx2check)

tools/ktx2ktx2/CMakeLists.txt

@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_executable( ktx2ktx2
-    $<TARGET_OBJECTS:objUtil>
     ktx2ktx2.cpp
     stdafx.h
 )
@@ -21,6 +20,7 @@ PRIVATE
 target_link_libraries(
     ktx2ktx2
     ktx
+    objUtil
 )
 
 set_tool_properties(ktx2ktx2)

tools/ktxinfo/CMakeLists.txt

@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_executable( ktxinfo
-    $<TARGET_OBJECTS:objUtil>
     ktxinfo.cpp
     stdafx.h
 )
@@ -20,6 +19,7 @@ PRIVATE
 target_link_libraries(
     ktxinfo
     ktx
+    objUtil
 )
 
 set_tool_properties(ktxinfo)

tools/ktxsc/CMakeLists.txt

@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_executable( ktxsc
-    $<TARGET_OBJECTS:objUtil>
     ktxsc.cpp
     stdafx.h
 )
@@ -21,6 +20,7 @@ PRIVATE
 target_link_libraries(
     ktxsc
     ktx
+    objUtil
 )
 
 set_tool_properties(ktxsc)

tools/toktx/CMakeLists.txt

@@ -2,7 +2,6 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_executable( toktx
-    $<TARGET_OBJECTS:objUtil>
     image.cc
     image.hpp
     jpgimage.cc
@@ -28,6 +27,7 @@ PRIVATE
 target_link_libraries(
     toktx
     ktx
+    objUtil
 )
 
 target_compile_definitions(