Android platform support (#1)

## What's new?
- Added Android platform support to PhysX 5.1.
- New build preset `android-arm64-v8a` added. Initial support focused on 64-bit arm8 architecture with NEON SIMD instructions.
- Support for generating PhysX as either static or dynamic libraries.
- New android platform readme.
        
## Out of Scope
The following points are considered out of scope, they can be added in the future:
- Support for PhysX Snippets.
- Support for Omniverse Visual Debugger (OmniPVD) .
- Support for other architectures: arm7, x86, x86_64.
- Support for other SIMD instructions set: SSE.
        
## Known Errors/Limitations
- The name of the bin folder for android will appear as `bin\UNKNOWN`. **To fix this nVidia has to modify the CMakeModules package it's downloaded from packman when building PhysX** (NVIDIA-Omniverse#59). The file that needs to be modified is `GetCompilerAndPlatform.cmake`, adding the following lines to the `if` condition inside `GetPlatformBinName` function:
````
	ELSEIF(TARGET_BUILD_PLATFORM STREQUAL "android")
		SET(RETVAL "android.${ANDROID_ABI}")
````
- PhysX Systems that require a CUDA capable GPU are not supported in Android, for example particle system or cloth simulation.
            
## Testing
- Built PhysX 5.1 successfully on android in debug, checked, profile and release using `PX_GENERATE_STATIC_LIBRARIES` set to both true and false. The right output binaries were generated in `bin/android.arm64-v8a`
- Built cmake `install` target successfully. It generated the correct output for Android under `install/android-29` folder, only including necessary headers for Android.
- Runtime tested using `Open 3D Engine (O3DE)` with an early integration [branch](https://github.com/aws-lumberyard-dev/o3de/tree/PhysX5Support). The following video shows O3DE running PhysX 5.1 on Android.
https://user-images.githubusercontent.com/27999040/203624867-6ed19905-d0dc-4dfe-943a-46e584fd9983.mp4

Signed-off-by: moraaar <[email protected]>

Author: moraaar

physx/.gitignore

@@ -1,4 +1,6 @@
 bin/
 compiler/linux-*
 compiler/vc*
+compiler/android*
 include/PxConfig.h
+install/

physx/buildtools/cmake_generate_projects.py

@@ -20,7 +20,7 @@ def cmakeExt():
 
 
 def filterPreset(presetName):
-    winPresetFilter = ['win','switch','crosscompile']
+    winPresetFilter = ['win','switch','crosscompile','android']
     if sys.platform == 'win32':        
         if any(presetName.find(elem) != -1 for elem in winPresetFilter):
             return True
@@ -101,6 +101,14 @@ def __init__(self, presetName):
                 cmParam = '-D' + cmakeParam.attrib['name'] + '=\"' + \
                     os.environ['PHYSX_ROOT_DIR'] + '/' + \
                     cmakeParam.attrib['value'] + '\"'
+            elif cmakeParam.attrib['name'] == 'ANDROID_ABI':
+                cmParam = '-D' + \
+                    cmakeParam.attrib['name'] + '=\"' + \
+                    cmakeParam.attrib['value'] + '\"'
+                if cmakeParam.attrib['value'].startswith('arm'):
+                    cmParam = cmParam + ' -DPX_OUTPUT_ARCH=arm'
+                elif cmakeParam.attrib['value'].startswith('x86'):
+                    cmParam = cmParam + ' -DPX_OUTPUT_ARCH=x86'
             else:
                 cmParam = '-D' + \
                     cmakeParam.attrib['name'] + '=' + \
@@ -113,6 +121,8 @@ def isMultiConfigPlatform(self):
             return False
         elif self.targetPlatform == 'linuxAarch64':
             return False
+        elif self.targetPlatform == 'android':
+            return False
         return True
 
     def getCMakeSwitches(self):
@@ -152,6 +162,8 @@ def getPlatformCMakeParams(self):
             outString = outString + '-G \"Visual Studio 16 2019\"'
         elif self.compiler == 'xcode':
             outString = outString + '-G Xcode'
+        elif self.targetPlatform == 'android':
+            outString = outString + '-G \"MinGW Makefiles\"'
         elif self.targetPlatform == 'linux':
             outString = outString + '-G \"Unix Makefiles\"'
         elif self.targetPlatform == 'linuxAarch64':
@@ -181,6 +193,22 @@ def getPlatformCMakeParams(self):
                 '/switch/NX64Toolchain.txt'
             outString = outString + ' -DCMAKE_GENERATOR_PLATFORM=NX64'
             return outString
+        elif self.targetPlatform == 'android':
+            outString = outString + ' -DTARGET_BUILD_PLATFORM=android'
+            if os.environ.get('ANDROID_NDK_HOME') is None:
+                print('Please provide path to android NDK in environment variable ANDROID_NDK_HOME.')
+                exit(-1)
+            else:
+                outString = outString + ' -DCMAKE_TOOLCHAIN_FILE=' + \
+                    os.environ['ANDROID_NDK_HOME'] + \
+                    '/build/cmake/android.toolchain.cmake'
+                outString = outString + ' -DANDROID_STL=\"c++_static\"'
+                outString = outString + ' -DCM_ANDROID_FP=\"softfp\"'
+                outString = outString + ' -DANDROID_NDK=' + \
+                    os.environ['ANDROID_NDK_HOME']
+                outString = outString + ' -DCMAKE_MAKE_PROGRAM=\"' + \
+                    os.environ['ANDROID_NDK_HOME'] + '\\prebuilt\\windows-x86_64\\bin\\make.exe\"'
+            return outString
         elif self.targetPlatform == 'linux':
             outString = outString + ' -DTARGET_BUILD_PLATFORM=linux'
             outString = outString + ' -DPX_OUTPUT_ARCH=x86'

physx/buildtools/presets/public/android-arm64-v8a.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<preset name="android-arm64-v8a" comment="Android-29, arm64-v8a PhysX SDK ">
+  <platform targetPlatform="android" compiler="clang" />
+  <CMakeSwitches>
+    <cmakeSwitch name="PX_GENERATE_STATIC_LIBRARIES" value="True" comment="Generate static libs" />  
+  </CMakeSwitches>
+  <CMakeParams>
+    <cmakeParam name="CMAKE_INSTALL_PREFIX" value="install/android-29/PhysX" comment="Install path relative to PhysX SDK root" />
+    <cmakeParam name="ANDROID_NATIVE_API_LEVEL" value="android-29" comment="Android platform API level" />
+    <cmakeParam name="ANDROID_ABI" value="arm64-v8a" comment="Android arm 64 ABI" />
+  </CMakeParams>
+</preset>

physx/documentation/platformreadme/android/README_ANDROID.md

@@ -0,0 +1,34 @@
+# NVIDIA PhysX SDK for Android
+
+## Location of Binaries:
+
+* SDK libraries: bin/android.arm64-v8a
+
+
+## Required packages to generate projects:
+
+* CMake, minimum version 3.14
+* Python, minimum version 3.5
+* Android SDK, minimum version 29
+* Android NDK, minimum version 22
+
+
+## Generating Makefiles:
+
+* Set the environment variable ANDROID_NDK_HOME to the path to Android NDK.
+* Makefiles are generated through a script in physx root directory: generate_projects.bat
+* Script generate_projects.bat expects a preset name as a parameter, if a parameter is not provided it does list the available presets and you can select one.
+* Supported preset for android platform is: android-arm64-v8a.
+* Generated solutions are in folder compiler/android-arm64-v8a-debug, compiler/android-arm64-v8a-checked, compiler/android-arm64-v8a-profile, compiler/android-arm64-v8a-release.
+
+
+## Building SDK:
+
+* Makefiles are in compiler/android-arm64-v8a-debug, etc.
+* Build solution: cmake --build .
+
+## Limitations:
+
+* PhysX Snippets are not supported.
+* PhysX Systems that require a CUDA capable GPU are not supported, for example particle system or cloth simulation.
+* Omniverse Visual Debugger (OmniPVD) is not supported.

physx/include/foundation/PxAlloca.h

@@ -62,7 +62,7 @@ class PxScopedPointer : private Alloc
 #if PX_WINDOWS_FAMILY
 #include <malloc.h>
 #define PxAlloca(x) _alloca(x)
-#elif PX_LINUX
+#elif PX_LINUX || PX_ANDROID
 #include <malloc.h>
 #define PxAlloca(x) alloca(x)
 #elif PX_APPLE_FAMILY

physx/include/foundation/PxIntrinsics.h

@@ -33,7 +33,7 @@
 
 #if PX_WINDOWS_FAMILY
 #include "windows/PxWindowsIntrinsics.h"
-#elif(PX_LINUX || PX_APPLE_FAMILY)
+#elif(PX_LINUX || PX_ANDROID || PX_APPLE_FAMILY)
 #include "unix/PxUnixIntrinsics.h"
 #elif PX_SWITCH
 #include "switch/PxSwitchIntrinsics.h"

physx/include/foundation/PxMathIntrinsics.h

@@ -33,7 +33,7 @@
 
 #if PX_WINDOWS_FAMILY
 #include "foundation/windows/PxWindowsMathIntrinsics.h"
-#elif(PX_LINUX || PX_APPLE_FAMILY)
+#elif(PX_LINUX || PX_ANDROID || PX_APPLE_FAMILY)
 #include "foundation/unix/PxUnixMathIntrinsics.h"
 #elif PX_SWITCH
 #include "foundation/switch/PxSwitchMathIntrinsics.h"

physx/include/foundation/PxPreprocessor.h

@@ -95,7 +95,9 @@ Operating system defines, see http://sourceforge.net/p/predef/wiki/OperatingSyst
 	#define PX_WIN64 1
 #elif defined(_WIN32) // note: _M_PPC implies _WIN32
 	#define PX_WIN32 1
-#elif defined(__linux__) || defined (__EMSCRIPTEN__)
+#elif defined(__ANDROID__)
+	#define PX_ANDROID 1
+#elif defined(__linux__) || defined (__EMSCRIPTEN__) // note: __ANDROID__ implies __linux__
 	#define PX_LINUX 1
 #elif defined(__APPLE__)
 	#define PX_OSX 1
@@ -155,6 +157,9 @@ define anything not defined on this platform to 0
 #ifndef PX_WIN32
 	#define PX_WIN32 0
 #endif
+#ifndef PX_ANDROID
+	#define PX_ANDROID 0
+#endif
 #ifndef PX_LINUX
 	#define PX_LINUX 0
 #endif
@@ -218,7 +223,7 @@ family shortcuts
 #define PX_GCC_FAMILY (PX_CLANG || PX_GCC)
 // os
 #define PX_WINDOWS_FAMILY (PX_WIN32 || PX_WIN64)
-#define PX_LINUX_FAMILY PX_LINUX
+#define PX_LINUX_FAMILY (PX_LINUX || PX_ANDROID)
 #define PX_APPLE_FAMILY PX_OSX                              // equivalent to #if __APPLE__
 #define PX_UNIX_FAMILY (PX_LINUX_FAMILY || PX_APPLE_FAMILY) // shortcut for unix/posix platforms
 #if defined(__EMSCRIPTEN__)
@@ -461,7 +466,7 @@ PX_CUDA_CALLABLE PX_INLINE void PX_UNUSED(T const&)
 		char _;
 		long a;
 	};
-#elif PX_CLANG && PX_ARM
+#elif PX_ANDROID || (PX_CLANG && PX_ARM)
 	struct PxPackValidation
 	{
 		char _;
@@ -512,7 +517,7 @@ protected:                  \
 #endif
 
 #ifndef PX_SUPPORT_EXTERN_TEMPLATE
-	#define PX_SUPPORT_EXTERN_TEMPLATE (PX_VC != 11)
+	#define PX_SUPPORT_EXTERN_TEMPLATE ((!PX_ANDROID) && (PX_VC != 11))
 #else
 	#define PX_SUPPORT_EXTERN_TEMPLATE 0
 #endif

physx/include/foundation/PxThread.h

@@ -36,7 +36,7 @@
 
 #if PX_WINDOWS_FAMILY
 #define PxSpinLockPause() __asm pause
-#elif PX_LINUX || PX_APPLE_FAMILY || PX_SWITCH
+#elif PX_LINUX || PX_ANDROID || PX_APPLE_FAMILY || PX_SWITCH
 #define PxSpinLockPause() asm("nop")
 #else
 #error "Platform not supported!"

physx/include/foundation/PxTime.h

@@ -32,7 +32,7 @@
 #include "foundation/PxSimpleTypes.h"
 #include "foundation/PxFoundationConfig.h"
 
-#if PX_LINUX
+#if PX_LINUX || PX_ANDROID
 #include <time.h>
 #endif
 
@@ -83,7 +83,7 @@ class PX_FOUNDATION_API PxTime
 	Second getLastTime() const;
 
   private:
-#if PX_LINUX || PX_APPLE_FAMILY
+#if PX_LINUX || PX_ANDROID || PX_APPLE_FAMILY
 	Second mLastTime;
 #else
 	PxI64 mTickCount;