eglDestroyContext example c c++ java objc

Name

eglDestroyContext - destroy an EGL rendering context

C Specification

EGLBoolean eglDestroyContext(EGLDisplay display,
    EGLContext context)

Parameters

display

Specifies the EGL display connection.

context

Specifies the EGL rendering context to be destroyed.

Description

If the EGL rendering context context is not current to any thread, eglDestroyContext destroys it immediately. Otherwise, context is destroyed when it becomes not current to any thread.

Errors of eglDestroyContext

EGL_FALSE is returned if destruction of the context fails, EGL_TRUE otherwise.
EGL_BAD_DISPLAY is generated if display is not an EGL display connection.
EGL_NOT_INITIALIZED is generated if display has not been initialized.
EGL_BAD_CONTEXT is generated if context is not an EGL rendering context.

Copyright

Copyright © 2003 Silicon Graphics, Inc.
This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

See Also

eglCreateContext, eglMakeCurrent

Example of eglDestroyContext

void CXXXView::OnInitialUpdate()

{

 CView::OnInitialUpdate();

 // TODO: Add your specialized code here and/or call the base class

 if (m_eglDisplay != EGL_NO_DISPLAY)

  return;

 const EGLint attrs[] = {

  EGL_LEVEL, 0,

  EGL_SURFACE_TYPE, EGL_WINDOW_BIT,

  EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,

  EGL_NATIVE_RENDERABLE, EGL_FALSE,

  EGL_DEPTH_SIZE, EGL_DONT_CARE,

  EGL_NONE

 };

 EGLint numConfig =0;

 m_eglDisplay = eglGetDisplay(GetDC()->GetSafeHdc());

 if (m_eglDisplay == EGL_NO_DISPLAY)

  if ((m_eglDisplay = eglGetDisplay((EGLNativeDisplayType) EGL_DEFAULT_DISPLAY)) == EGL_NO_DISPLAY)

   return;

 // Initialize the display

 EGLint major = 0;

 EGLint minor = 0;

 if (!eglInitialize(m_eglDisplay, &major, &minor))

  return;

 if (major < 1 || minor < 3)

 {

  // Does not support EGL 1.3

  printf("System does not support at least EGL 1.3 \n");

  return;

 }

 EGLConfig eglConfig;

 // Obtain the first configuration with a depth buffer

 if (!eglChooseConfig(m_eglDisplay, attrs, &eglConfig, 1, &numConfig))

  return;

 // Create a surface for the main window

 if ((m_eglSurface = eglCreateWindowSurface(m_eglDisplay, eglConfig, (EGLNativeWindowType) GetSafeHwnd(), NULL)) == EGL_NO_SURFACE)

  return;

 // Bind the API (It could be OpenGLES or OpenVG)

 // eglBindAPI(EGL_OPENGL_ES_API);

 EGLint ai32ContextAttribs[] = { EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE };

 // Create an OpenGL ES context

 if ((m_eglContext = eglCreateContext(m_eglDisplay, eglConfig, EGL_NO_CONTEXT, ai32ContextAttribs)) == EGL_NO_CONTEXT)

  return;

 // Make the context and surface current

 if (!eglMakeCurrent(m_eglDisplay, m_eglSurface, m_eglSurface, m_eglContext))

  return;

 ///

 glClearColor(0.5f, 0.5f, 0.5f, 0.0f);

}

void CXXXView::PostNcDestroy()

{

 // TODO: Add your specialized code here and/or call the base class

 eglMakeCurrent(EGL_NO_DISPLAY, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);

 eglDestroyContext(m_eglDisplay, m_eglContext);

 eglDestroySurface(m_eglDisplay, m_eglSurface);

 eglTerminate(m_eglDisplay);

 CView::PostNcDestroy();

}

void CXXXView::onDraw(void)

{

 glClear(GL_COLOR_BUFFER_BIT);

 ///

 IGameImporter * gameImport = NULL;

 auto pDoc = GetDocument();

 if (pDoc && pDoc->IsKindOf(RUNTIME_CLASS(CXXXDoc)))

  gameImport = dynamic_cast<cxxxdoc *=""> (pDoc)->getGameImport();

 ///

 eglSwapBuffers(m_eglDisplay, m_eglSurface);

}

BOOL CXXXView::OnEraseBkgnd(CDC* pDC)

{

 // TODO: Add your message handler code here and/or call default

 /// return CView::OnEraseBkgnd(pDC);

 return FALSE;

}

void CXXXView::OnSize(UINT nType, int cx, int cy)

{

 CView::OnSize(nType, cx, cy);

 // TODO: Add your message handler code here

 glViewport(0, 0, cx, cy);

}

/// CXXXApp.cpp

BOOL CXXXApp::OnIdle(LONG lCount)

{

 // TODO: Add your specialized code here and/or call the base class

// return CWinAppEx::OnIdle(lCount);

 CMainFrame * pFrame = (CMainFrame *) AfxGetMainWnd();

 CView * pView = pFrame->GetActiveView();

 if (pView && pView->IsKindOf(RUNTIME_CLASS(CXXXView)))

  dynamic_cast<cxxxview *=""> (pView)->onDraw();

 return TRUE;

}

/// CViewTree.h

#define WM_TVN_SELCHANGED (WM_USER+3)

class CViewTree : public CTreeCtrl

{

public:

 afx_msg void OnTvnSelchanged(NMHDR *pNMHDR, LRESULT *pResult);

};

/// CViewTree.cpp

BEGIN_MESSAGE_MAP(CViewTree, CTreeCtrl)

 ON_NOTIFY_REFLECT(TVN_SELCHANGED, &CViewTree::OnTvnSelchanged)

END_MESSAGE_MAP()

void CViewTree::OnTvnSelchanged(NMHDR *pNMHDR, LRESULT *pResult)

{

 LPNMTREEVIEW pNMTreeView = reinterpret_cast<lpnmtreeview>(pNMHDR);

 // TODO: Add your control notification handler code here

 GetParent()->SendNotifyMessage(WM_TVN_SELCHANGED, (WPARAM) pNMTreeView, (LPARAM) pResult);

 *pResult = 0;

}