Fetching DirectX 9 Device

This tutorial shows how to fetch the DirectX 9 Device in 64-bit games on the Team Fortress 2 branch. This method works on both Windows and Linux platforms.

Access to the low-level DirectX 9 device allows the creation of effects that Source has no support for, such as rendering cubemaps in real-time.

Warning:This is intended for advanced users. Low level access to the DirectX 9 device is very powerful, but also comes with great responsibility.

Tutorial

Open the client initialization code in game/client/cdll_client_int.cpp, and it's corresponding header file cdll_client_int.h.

In the cpp file, following the big wall of #includes, add this:

#include "shaderapi/IShaderDevice.h"

Scrolling further down, you will see a list of interface pointers, below the comment that says this:

// IF YOU ADD AN INTERFACE, EXTERN IT IN THE HEADER FILE.

Add these interfaces:

IShaderDevice* g_pShaderDevice = NULL;
IDirect3DDevice9* g_pDirect3DDevice9 = NULL;

Now go to the header file, where the device will be forward declared and externed.

First, add this forward declaration below the list of class forwards:

struct IDirect3DDevice9;

Then scroll down and add this in, below the list of interfaces, to expose it for the rest of the client code.

extern IDirect3DDevice9* g_pDirect3DDevice9;

Back to the .cpp file, go to the CHLClient::Init function and add the following after the if (!g_pMatSystemSurface) check:

	g_pShaderDevice = (IShaderDevice*)appSystemFactory( SHADER_DEVICE_INTERFACE_VERSION, NULL );
	if ( !g_pShaderDevice )
		return false;

Next comes the fun part. The IShaderDevice class has a public function that checks whether the DirectX 9 device exists, named IsUsingGraphics. We can abuse this to fetch the actual pointer to the device.

Copy the following function into the file somewhere above. You don't need to worry about the specific details of how this works.

IDirect3DDevice9* GetDX9Device()
{
    // Dereference the virtual table and access the IsUsingGraphics method
	byte* pIShaderDevice_IsUsingGraphics = ( byte* )( *( void*** )g_pShaderDevice)[5];
    // Resolve the RIP instruction to get the absolute address
	byte* ppDirect3DDevice9 = pIShaderDevice_IsUsingGraphics + 8 + *( int32* )( pIShaderDevice_IsUsingGraphics + 3 );
	return *( IDirect3DDevice9** )ppDirect3DDevice9;
}

Now go back to where you added the code to fetch the g_pShaderDevice interface, and add the following below:

	g_pDirect3DDevice9 = GetDX9Device();
	if ( !g_pDirect3DDevice9 )
	{
		Error( "Failed to get DirectX9 device pointer" );
		return false;
	}

And that's all! You can now call the raw DirectX9 API using the g_pDirect3DDevice9 interface.

Usage

To call functions on the DirectX 9 device, you will need to download the DirectX 9 SDK.

After you download it, extract it to a place in your mod's folder. The convention is to make a dx9sdk directory in the top-level folder of your source code.

You can then include the DirectX 9 API like-so in client code:

#include "../../dx9sdk/include/d3d9.h"

// ...
void ExampleToFetchSwapChain()
{
	IDirect3DSwapChain9* pSwapChain = NULL;
	g_pDirect3DDevice9->GetSwapChain( 0, &pSwapChain );
}