Fix Android build

Fix several CMake and cxx issues when building VTK for Android.

CMake/vtkAndroid.cmake

@@ -27,7 +27,7 @@ set(ANDROID_NDK ${_ANDROID_NDK_DEFAULT} CACHE PATH
 if (NOT EXISTS "${ANDROID_NDK}/platforms")
   message(FATAL_ERROR "Please set a valid ANDROID_NDK path")
 endif()
-set(ANDROID_NATIVE_API_LEVEL "21" CACHE STRING "Android Native API Level")
+set(ANDROID_NATIVE_API_LEVEL "27" CACHE STRING "Android Native API Level")
 set(ANDROID_ARCH_ABI "armeabi" CACHE STRING "Target Android architecture/abi")
 
 # find android

CMake/vtkMobileDevices.cmake

@@ -21,12 +21,15 @@ if (ANDROID OR APPLE_IOS)
        )
   elseif (ANDROID)
     unset(OPENGL_INCLUDE_DIR CACHE)
-    unset(OPENGL_gl_LIBRARY CACHE)
+    unset(OPENGL_gles3_LIBRARY CACHE)
     unset(OPENGL_egl_LIBRARY CACHE)
 
-    find_path(OPENGL_INCLUDE_DIR GLES3/gl3.h)
-    find_library(OPENGL_gl_LIBRARY NAMES GLESv3)
-    find_library(OPENGL_egl_LIBRARY NAMES EGL)
+    set(_ANDROID_INC_PATH ${CMAKE_ANDROID_NDK}/sysroot/usr/include)
+    set(_ANDROID_LIB_PATH ${CMAKE_ANDROID_NDK}/platforms/android-${CMAKE_SYSTEM_VERSION}/arch-${CMAKE_ANDROID_ARCH}/usr/lib)
+
+    find_path(OPENGL_INCLUDE_DIR GLES3/gl3.h ${_ANDROID_INC_PATH})
+    find_library(OPENGL_gles3_LIBRARY NAMES GLESv3 PATHS ${_ANDROID_LIB_PATH})
+    find_library(OPENGL_egl_LIBRARY NAMES EGL PATHS ${_ANDROID_LIB_PATH})
   endif()
 else()
   # Choose static or shared libraries.

Common/Core/vtkAndroidOutputWindow.h

@@ -48,12 +48,12 @@ public:
    * New lines are converted to carriage return new lines.
    */
   void DisplayText(const char*) override;
-  virtual void DisplayErrorText(const char*);
-  virtual void DisplayWarningText(const char*);
-  virtual void DisplayGenericWarningText(const char*);
+  void DisplayErrorText(const char*) override;
+  void DisplayWarningText(const char*) override;
+  void DisplayGenericWarningText(const char*) override;
   ///@}
 
-  virtual void DisplayDebugText(const char*);
+  void DisplayDebugText(const char*) override;
 
 protected:
   vtkAndroidOutputWindow();

Common/Core/vtkOutputWindow.cxx

@@ -17,7 +17,7 @@
 #if defined(_WIN32) && !defined(VTK_USE_X)
 #include "vtkWin32OutputWindow.h"
 #endif
-#if defined(ANDROID)
+#if defined(__ANDROID__) || defined(ANDROID)
 #include "vtkAndroidOutputWindow.h"
 #endif
 

Rendering/OpenGL2/vtkEGLRenderWindow.cxx

@@ -31,8 +31,9 @@
 #include <cassert>
 #include <sstream>
 
-#ifdef ANDROID
+#if defined(__ANDROID__) || defined(ANDROID)
 #include <android/native_window.h>
+#include <vtkAndroidRenderWindowInteractor.h>
 #endif
 
 namespace
@@ -139,7 +140,7 @@ struct vtkEGLRenderWindow::vtkInternals
 vtkEGLRenderWindow::vtkEGLRenderWindow()
 {
   this->Internals = new vtkInternals();
-  this->OwnWindow = 1;
+  this->OwnWindow = true;
   this->ScreenSize[0] = 1920;
   this->ScreenSize[1] = 1080;
 
@@ -338,7 +339,7 @@ void vtkEGLRenderWindow::ResizeWindow(int width, int height)
    */
   EGLint surfaceType, clientAPI;
   const EGLint* contextAttribs;
-#ifdef ANDROID
+#if defined(__ANDROID__) || defined(ANDROID)
   surfaceType = EGL_WINDOW_BIT;
   clientAPI = EGL_OPENGL_ES2_BIT;
   const EGLint contextES2[] = { EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE };
@@ -354,7 +355,7 @@ void vtkEGLRenderWindow::ResizeWindow(int width, int height)
     EGL_RED_SIZE, 8, EGL_ALPHA_SIZE, 8, EGL_DEPTH_SIZE, 8, EGL_RENDERABLE_TYPE, clientAPI,
     EGL_NONE };
 
-#if !defined(ANDROID)
+#if !defined(__ANDROID__) && !defined(ANDROID)
   const EGLint surface_attribs[] = { EGL_WIDTH, width, EGL_HEIGHT, height, EGL_NONE };
 #endif
 
@@ -375,7 +376,7 @@ void vtkEGLRenderWindow::ResizeWindow(int width, int height)
 
     EGLint major = 0, minor = 0;
     vtkEGLDisplayInitializationHelper::Initialize(impl->Display, &major, &minor);
-#if !defined(ANDROID)
+#if !defined(__ANDROID__) && !defined(ANDROID)
     if (major <= 1 && minor < 4)
     {
       vtkErrorMacro("Only EGL 1.4 and greater allows OpenGL as client API. "
@@ -396,7 +397,7 @@ void vtkEGLRenderWindow::ResizeWindow(int width, int height)
     return;
   }
 
-#ifdef ANDROID
+#if defined(__ANDROID__) || defined(ANDROID)
   EGLint format = 0;
   /* EGL_NATIVE_VISUAL_ID is an attribute of the EGLConfig that is
    * guaranteed to be accepted by ANativeWindow_setBuffersGeometry().
@@ -417,13 +418,22 @@ void vtkEGLRenderWindow::ResizeWindow(int width, int height)
     eglDestroySurface(impl->Display, impl->Surface);
   }
 
-#ifdef ANDROID
+#if defined(__ANDROID__) || defined(ANDROID)
   impl->Surface = eglCreateWindowSurface(impl->Display, config, impl->Window, nullptr);
 #else
   impl->Surface = eglCreatePbufferSurface(impl->Display, config, surface_attribs);
 #endif
   this->Mapped = this->ShowWindow;
-  this->OwnWindow = 1;
+  this->OwnWindow = true;
+
+#if defined(__ANDROID__) || defined(ANDROID)
+  vtkAndroidRenderWindowInteractor* interactor =
+    vtkAndroidRenderWindowInteractor::SafeDownCast(this->Interactor);
+  if (interactor)
+  {
+    interactor->SetOwnWindow(this->OwnWindow);
+  }
+#endif
 
   this->MakeCurrent();
 
@@ -485,9 +495,18 @@ void vtkEGLRenderWindow::WindowInitialize(void)
   this->OpenGLInit();
 
   // for offscreen EGL always turn on point sprites
-#if !defined(ANDROID) && defined(GL_POINT_SPRITE)
+#if !defined(__ANDROID__) && !defined(ANDROID) && defined(GL_POINT_SPRITE)
   glEnable(GL_POINT_SPRITE);
 #endif
+
+#if defined(__ANDROID__) || defined(ANDROID)
+  vtkAndroidRenderWindowInteractor* interactor =
+    vtkAndroidRenderWindowInteractor::SafeDownCast(this->Interactor);
+  if (interactor)
+  {
+    interactor->SetOwnWindow(this->OwnWindow);
+  }
+#endif
 }
 
 // Initialize the rendering window.
@@ -608,8 +627,17 @@ void vtkEGLRenderWindow::SetPosition(int x, int y)
 // Set this RenderWindow to a pre-existing window.
 void vtkEGLRenderWindow::SetWindowInfo(const char*)
 {
-  this->OwnWindow = 0;
   this->Mapped = 1;
+  this->OwnWindow = false;
+
+#if defined(__ANDROID__) || defined(ANDROID)
+  vtkAndroidRenderWindowInteractor* interactor =
+    vtkAndroidRenderWindowInteractor::SafeDownCast(this->Interactor);
+  if (interactor)
+  {
+    interactor->SetOwnWindow(this->OwnWindow);
+  }
+#endif
 }
 
 void vtkEGLRenderWindow::SetWindowName(const char* name)

Rendering/UI/vtkAndroidRenderWindowInteractor.cxx

@@ -537,7 +537,7 @@ void vtkAndroidRenderWindowInteractor::Initialize()
   // get the info we need from the RenderingWindow
   ren = this->RenderWindow;
 
-  if (ren->GetOwnWindow())
+  if (this->GetOwnWindow())
   {
     this->AndroidApplication->userData = this;
     this->AndroidApplication->onAppCmd = android_handle_cmd;

Rendering/UI/vtkAndroidRenderWindowInteractor.h

@@ -44,12 +44,12 @@ public:
   static vtkAndroidRenderWindowInteractor* New();
 
   vtkTypeMacro(vtkAndroidRenderWindowInteractor, vtkRenderWindowInteractor);
-  void PrintSelf(ostream& os, vtkIndent indent);
+  void PrintSelf(ostream& os, vtkIndent indent) override;
 
   /**
    * Initialize the event handler
    */
-  virtual void Initialize();
+  void Initialize() override;
 
   ///@{
   /**
@@ -61,8 +61,8 @@ public:
    * and all other interactors associated with the widget are disabled
    * when their data is not displayed.
    */
-  virtual void Enable();
-  virtual void Disable();
+  void Enable() override;
+  void Disable() override;
   ///@}
 
   /**
@@ -70,7 +70,7 @@ public:
    * calls PostQuitMessage(0) to terminate the application. An application can Specify
    * ExitMethod for alternative behavior (i.e. suppression of keyboard exit)
    */
-  void TerminateApp(void);
+  void TerminateApp(void) override;
 
   ///@{
   /**
@@ -87,7 +87,7 @@ public:
    * These methods correspond to the Exit, User and Pick
    * callbacks. They allow for the Style to invoke them.
    */
-  virtual void ExitCallback();
+  void ExitCallback() override;
 
   virtual void SetAndroidApplication(struct android_app* app) { this->AndroidApplication = app; }
 
@@ -110,6 +110,14 @@ public:
   void HandleCommand(int32_t cmd);
   int32_t HandleInput(AInputEvent* event);
 
+  ///@{
+  /**
+   * Returns true if the window is owned by VTK.
+   */
+  vtkSetMacro(OwnWindow, bool);
+  vtkGetMacro(OwnWindow, bool);
+  ///@}
+
 protected:
   vtkAndroidRenderWindowInteractor();
   ~vtkAndroidRenderWindowInteractor() override;
@@ -138,8 +146,8 @@ protected:
    * Win32-specific internal timer methods. See the superclass for detailed
    * documentation.
    */
-  virtual int InternalCreateTimer(int timerId, int timerType, unsigned long duration);
-  virtual int InternalDestroyTimer(int platformTimerId);
+  int InternalCreateTimer(int timerId, int timerType, unsigned long duration) override;
+  int InternalDestroyTimer(int platformTimerId) override;
   ///@}
 
   /**
@@ -147,7 +155,9 @@ protected:
    * call this method it will loop processing events until the
    * application is exited.
    */
-  virtual void StartEventLoop();
+  void StartEventLoop() override;
+
+  vtkTypeBool OwnWindow;
 
 private:
   vtkAndroidRenderWindowInteractor(const vtkAndroidRenderWindowInteractor&) = delete;