Re: [Visualpython-users] new version crashed on Windows XP

[CL <clc...@gm...>]

Hi Bruce

I have built vpython and found that the following code can fix the
problem on my PC:

The first crash is at ShowWindow in display::create() in windisplay.cpp

I've modifed it to:
	if (!wglMakeCurrent( dev_context, gl_context))
		WIN32_CRITICAL_ERROR( "wglMakeCurrent failed");
	ShowWindow( widget_handle, SW_SHOW);
	wglMakeCurrent( NULL, NULL );
Look like my video driver insist to have wglMakeCurrent called before ShowWindow

The second crash is at gl_extensions.cpp

template <class PFN>
void getPFN( PFN& func, display_kernel& d, const char* name ) {
	func = reinterpret_cast<PFN>( d.getProcAddress( name ) );
	if (!func)
		throw std::runtime_error(
			("Unable to get extension function: " +
			(std::string)name + " even though the extension is advertised.").c_str() );
}

When it is loading GL_ARB_multitexture
	if ( ARB_multitexture = d.hasExtension( "GL_ARB_multitexture" ) ) {
		F( glActiveTexture );
	}

The entry point glActiveTexture is not defined in my driver. I believe
it is also not defined in most old drivers. Since it is not defined,
an exception is flew. The exception is not handled.

I've changed it to:

	if ( ARB_multitexture = d.hasExtension( "GL_ARB_multitexture" ) ) {
		getPFN( glActiveTexture, d, "glActiveTextureARB" );
	}


After that, it is working fine. Textures are not supported, as vpython
seems requires shader extensions in order to support texture.