Hi Graham,
First thx for your reply. They are on the same adapter. As I'm using MS Windows XP the EGLDisplays are in this case just two different windows. I forgot to mention the adapter itself, it's a Radeon HD 4350.
This is just a small test application to confirm if nothing else was the reason,
i've encapsuled the Display creation and context creation in one class:
class DisplayContext{
public:
DisplayContext():
hwnd(0),hInstance(0),disp(0),windowConfig(0), context(0)
{
}
~DisplayContext()
{
}
bool OpenWindow(int width, int height, const TCHAR* wndClass, const TCHAR* wndName)
{
hInstance = GetModuleHandle(NULL);
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_OWNDC;
wcex.lpfnWndProc = &DefWindowProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = hInstance;
wcex.hIcon = NULL;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.hbrBackground = 0; //(HBRUSH)(COLOR_WINDOW+1);
wcex.lpszMenuName = NULL;
wcex.lpszClassName = wndClass;
wcex.hIconSm = NULL;
RegisterClassEx(&wcex);
RECT rect = {0,0, width, height};
int style = WS_BORDER | WS_CAPTION;
AdjustWindowRect(&rect, style, FALSE);
hwnd = CreateWindow(wndClass, wndName, style,
CW_USEDEFAULT, CW_USEDEFAULT, rect.right - rect.left, rect.bottom - rect.top, NULL, NULL, GetModuleHandle(NULL), NULL);
ShowWindow(hwnd, SW_SHOW);
return hwnd != 0;
}
bool CreateEGLContext(EGLContext share)
{
if(hwnd != 0) {
HDC hdc = GetDC(hwnd);
disp = eglGetDisplay(hdc);
EGLint major, minor;
eglInitialize(disp,&major, &minor);
eglBindAPI(EGL_OPENGL_ES_API);
EGLint attributes[] =
{
EGL_BUFFER_SIZE, 0,
EGL_RED_SIZE, 5,
EGL_GREEN_SIZE, 6,
EGL_BLUE_SIZE, 5,
// EGL_LUMINANCE_SIZE, 0,
EGL_ALPHA_SIZE, 0,
//EGL_ALPHA_MASK_SIZE, 0,
EGL_COLOR_BUFFER_TYPE, EGL_RGB_BUFFER,
EGL_CONFIG_CAVEAT, EGL_DONT_CARE,
EGL_CONFIG_ID, EGL_DONT_CARE,
//EGL_CONFORMANT, 0,
EGL_DEPTH_SIZE, 24,
EGL_LEVEL, 0,
EGL_MAX_SWAP_INTERVAL, EGL_DONT_CARE,
EGL_MIN_SWAP_INTERVAL, EGL_DONT_CARE,
EGL_NATIVE_RENDERABLE, EGL_DONT_CARE,
EGL_NATIVE_VISUAL_TYPE, EGL_DONT_CARE,
EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL_SAMPLE_BUFFERS, 0,
EGL_SAMPLES, 0,
EGL_STENCIL_SIZE, 0,
EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
EGL_TRANSPARENT_TYPE, EGL_NONE,
EGL_TRANSPARENT_RED_VALUE, EGL_DONT_CARE,
EGL_TRANSPARENT_GREEN_VALUE, EGL_DONT_CARE,
EGL_TRANSPARENT_BLUE_VALUE, EGL_DONT_CARE,
EGL_NONE
};
EGLint surfaceAttributes[] = {EGL_NONE};
EGLint contextAttributes[] = {EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE};
EGLint nrOfConfigs;
eglChooseConfig(disp, attributes,&windowConfig,1,&nrOfConfigs);
surface = eglCreateWindowSurface(disp, windowConfig, hwnd,surfaceAttributes);
context = eglCreateContext(disp, windowConfig, share,contextAttributes);
return context != EGL_NO_CONTEXT;
}
}
EGLContext GetContext(){
return context;
}
private:
WNDCLASSEX wcex;
HINSTANCE hInstance;
HWND hwnd;
EGLDisplay disp;
EGLConfig windowConfig;
EGLContext context;
EGLSurface surface;
};
They are called an instatiated as follows:
DisplayContext context1;
DisplayContext context2;
bool res = context1.OpenWindow(640,480, "TEST1", "TEST1");
res = context1.CreateEGLContext(EGL_NO_CONTEXT);
res = context2.OpenWindow(640,480, "TEST2", "TEST2");
res = context2.CreateEGLContext(context1.GetContext());
while res always gets false after the second CreateEGLContext. When checking EGLGetError EGL_BAD_CONTEXT is returned after the second call to eglCreateContext.
The functions from atioglxx.dll are called analogous to the existing egl demo.
First the dll is loaded with
HINSTANCE atioglxxDll = LoadLibrary(_T("atioglxx.dll"));
The function pointers are declared as showed on the example of eglGetError:
typedef EGLint EGLAPIENTRY eglGetError(void);
EglFunctions::eglGetError* eglGetErrorPointer;
Then the pointers are queried from the Dll:
result = result & ((eglGetErrorPointer = (EglFunctions::eglGetError*)GetProcAddress(atioglxxDll, "eglGetError")) != 0);
Finally a dll wrapper that implements the EGL interface itself calls the functions:
EGLint EGLAPIENTRY eglGetError(void)
{
return eglGetErrorPointer();
}
If you need any more information please tell me.
Cheers, Georg
