// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies).

 // All rights reserved.

 // This component and the accompanying materials are made available

 // under the terms of "Eclipse Public License v1.0"

 // which accompanies this distribution, and is available

 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 // For the Winscw Emulator only, selects between REF, GCE and non-GCE version of EGL.

 // Notes:

 //   The default is the non-GCE based version.

 //   To use the REF version GCE needs to be enabled. 

 //

 // To select the GCE version do one of:

 // 1. Add a line to the epoc.ini file in \epoc32\data like this:

 // symbian_graphics_use_gce ON

 // or

 // 2. Start epoc.exe with these parameters, (the "--" IS necessary):

 // -Dsymbian_graphics_use_gce=ON --

 // or

 // 3. epoc.exe can be told to switch to a different initialisation file than epoc.ini, with the -M parameter.

 // Progress chaining to the real libEGL is logged in epocwind.out.

 // 

 // To select the REF version do one of the steps above, adding 

 // symbian_graphics_use_egl_ref in addition to symbian_graphics_use_gce. 

 //

 //

 #include <emulator.h>

 #include <e32svr.h>

 #include <u32hal.h>

 extern "C" {

 #include "egl_stubs.h"

 FARPROC vector[MAX_ORDINAL+1];		// 1 additional entry: vector[0] to set the initialised state

 #ifdef _DEBUG

 void Stop(char* aErrorMessage)

 #else

 void Stop(char* /*aErrorMessage*/)

 #endif

 	{

 	int err = GetLastError();

 #ifdef _DEBUG

 	RDebug::Printf("%S, (last error = %i)", aErrorMessage, err);

 #endif

 	_asm int 3;

 	}

 void fill_vector(HINSTANCE aDll)

 	{

 	FARPROC address = NULL;

 	for (int i=1;i<=MAX_ORDINAL;i++)

 		{

 		address = GetProcAddress(aDll, (LPCSTR)i);

 		if (address == NULL)

 			{

 			Stop("... has too few exported functions");

 			}

 		vector[i] = address;

 		}

 	// There's an additional _E32Dll entry point after last ordinal position.

 	// Read it, but no need to store it

 	address = GetProcAddress(aDll, (LPCSTR)(MAX_ORDINAL+1));

 	if (address == NULL)

 		{

 		Stop("... has too few exported functions");

 		}

   // next position should be empty

 	address = GetProcAddress(aDll, (LPCSTR)(MAX_ORDINAL+2));

 	if (address != NULL)

 		{

 		Stop("... has too many exported functions");

 		}

 	// Set initialised

 	vector[0] = (FARPROC)1;	

 	}

 // redirects DLL calls to GCE or non-GCE implementation

 void init_vector()

 	{

 	// ask HAL which configuration to use

 	TBool gce = EFalse;

 	UserSvr::HalFunction(EHalGroupEmulator, EEmulatorHalBoolProperty,  (TAny*)"symbian_graphics_use_gce",  &gce);

     const char* library = "";

     if (gce)

         {

 		// reference EGL is for NGA only

 		TBool ref = EFalse;

         UserSvr::HalFunction(EHalGroupEmulator, EEmulatorHalBoolProperty,  (TAny*)"symbian_graphics_use_egl_ref",  &ref);

         library = ref ? "libegl_ref.dll" : "libegl_gce.dll";

         }

 	else

 		{

 		library = "libegl_nongce.dll";

 		}

 #ifdef _DEBUG

 	RDebug::Printf("Redirecting libEGL.dll to \"%s\" ...\n", library);

 #endif

 	Emulator::Escape();		// prevent deadlock between EKA2 scheduler and MS kernel

 	// try to load selected DLL

 	HINSTANCE instance = LoadLibraryA(library);

 	Emulator::Reenter();

 	if (instance == NULL)

 		{

 		Stop("... unable to load");

 		}

 	else

 		{

 		fill_vector(instance);

 #ifdef _DEBUG

 		RDebug::Printf("... DLL loaded successfully");

 #endif

 		}

 	}

 __declspec(naked) void common_dispatch()

 	{

 	_asm cmp	dword ptr vector,0		// initialised?

 	_asm je  	do_init_vector

 call_though_vector:

 	_asm jmp	[vector+eax*4]

 do_init_vector:

 	_asm push	eax

 	_asm push	ecx

 	_asm push	edx

 	_asm call	init_vector

 	_asm pop	edx

 	_asm pop 	ecx

 	_asm pop 	eax

 	_asm jmp	call_though_vector

 	}

 }