IntPtr TryInitEglDisplay(IWindowInfo window, ref int major, ref int minor, ref GraphicsContextFlags flags)
{
//see https://github.com/Microsoft/angle/wiki/Initializing-ANGLE-on-D3D11-Feature-Level-9
//IntPtr egl_display1 = Egl.GetPlatformDisplayEXT(Egl.PLATFORM_ANGLE_ANGLE, IntPtr.Zero, new int[]{
// Egl.PLATFORM_ANGLE_TYPE_ANGLE,
// Egl.PLATFORM_ANGLE_TYPE_D3D11_ANGLE,
// Egl.PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE, 9,
// Egl.PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE, 3,
// Egl.NONE,
//});
//if (!Egl.Initialize(egl_display1, out int m1, out int m2))
//{
//}
//1. use default openTK default
WinWindowInfo win_win = (WinWindowInfo)window;
bool success = false;
int eglMajor, eglMinor;
IntPtr egl_display = IntPtr.Zero;
if (isFirstTimeEval)
{
isFirstTimeEval = false;
egl_display = GetDisplay(win_win.DeviceContext);
success = Egl.Initialize(egl_display, out eglMajor, out eglMinor);
//-------------------
//we found that some old machine can't init with D3D11
//so ... we use D3D9 instead
if (!success)
{
egl_display = Egl.GetPlatformDisplayEXT(Egl.PLATFORM_ANGLE_ANGLE, IntPtr.Zero, new int[] {
Egl.PLATFORM_ANGLE_TYPE_ANGLE,
Egl.PLATFORM_ANGLE_TYPE_D3D9_ANGLE,
Egl.NONE,
});
if (Egl.Initialize(egl_display, out eglMajor, out eglMinor))
{
useD3D9Only = true;
success = true;
//in this case
major = 2; //GLES2
minor = 1;
flags = flags & ~GraphicsContextFlags.AngleD3D11; //can't use D3D11
}
else
{
throw new GraphicsContextException(String.Format("Failed to initialize EGL, error {0}.", Egl.GetError()));
}
}
}
else
{
//not first time
if (useD3D9Only)
{
//no D3D11
egl_display = Egl.GetPlatformDisplayEXT(Egl.PLATFORM_ANGLE_ANGLE, IntPtr.Zero, new int[] {
Egl.PLATFORM_ANGLE_TYPE_ANGLE,
Egl.PLATFORM_ANGLE_TYPE_D3D9_ANGLE,
Egl.NONE,
});
if (Egl.Initialize(egl_display, out eglMajor, out eglMinor))
{
useD3D9Only = true;
success = true;
//in this case
major = 2; //GLES2
minor = 1;
flags = flags & ~GraphicsContextFlags.AngleD3D11; //can't use D3D11
}
else
{
throw new GraphicsContextException(String.Format("Failed to initialize EGL, error {0}.", Egl.GetError()));
}
}
else
{
//use D3D11
egl_display = GetDisplay(win_win.DeviceContext);
success = Egl.Initialize(egl_display, out eglMajor, out eglMinor);
//-------------------
//we found that some old machine can't init with D3D11
//so ... we use D3D9 instead
if (!success)
{
//???
throw new GraphicsContextException(String.Format("Failed to initialize EGL, error {0}.", Egl.GetError()));
}
}
}
return(egl_display);
}