#include "Direct3D.h"
#include "Utilities.h"

#include <random>

INT Direct3D::init(HWND hWnd, UINT width, UINT height, BOOL isFullscreen)
{
	// 1. create connection to Direct3D API
	IDirect3D9* pD3D = Direct3DCreate9(D3D_SDK_VERSION);
	if (pD3D == nullptr) return 200;

	// 2. check compatibility
	UINT adapter = D3DADAPTER_DEFAULT; // graphic card index
	D3DDEVTYPE devType = D3DDEVTYPE_HAL; // hardware type, hardware or software renderer
	D3DCAPS9 caps = {};
	HRESULT hr = pD3D->GetDeviceCaps(adapter, devType, &caps);
	CheckFailed(hr, 210);

	// support for fixed functiuon pipeline
	DWORD vertexProcessing = D3DCREATE_SOFTWARE_VERTEXPROCESSING; // fallback
	if (caps.VertexProcessingCaps & D3DDEVCAPS_HWTRANSFORMANDLIGHT)
	{
		// hardware support for fixed function pipeline
		vertexProcessing = D3DCREATE_HARDWARE_VERTEXPROCESSING;
	}

	// 3. define presentation parameters
	D3DPRESENT_PARAMETERS d3dpp = {};
	d3dpp.hDeviceWindow = hWnd; // target window to draw into
	d3dpp.Windowed = !isFullscreen; // fullscreen window?
	d3dpp.BackBufferCount = 1; // at least 1
	d3dpp.BackBufferWidth = width;
	d3dpp.BackBufferHeight = height;
	d3dpp.BackBufferFormat = D3DFMT_A8R8G8B8; // back buffer pixel format
	d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD; // what happen to front buffer after swap

	// 4. create Direct3D device
	hr = pD3D->CreateDevice(
		adapter, // graphic adapter index
		devType, // hardware device type
		hWnd, // target window handle
		vertexProcessing, // optional flags, here important for fixed function pipeline support
		&d3dpp, &_pD3DDevice
	);
	CheckFailed(hr, 220);

	// 5. tidy up
	safeRelease(pD3D);

	return 0;
}

void Direct3D::beginScene()
{
	_pD3DDevice->BeginScene(); // draw calls only after this call

	// clear back buffer
	static std::default_random_engine e;
	static std::uniform_int_distribution<UINT> d(0, 255);

	_pD3DDevice->Clear(
		0, nullptr, // clear specific areas only
		D3DCLEAR_TARGET, // what to clear
		D3DCOLOR_XRGB(0, 0, 0), 1.0f, 0xFFFFFFFF // how to clear
	);
}

void Direct3D::endScene()
{
	_pD3DDevice->EndScene(); // draw calls only before this call

	// swap front with back buffer
	_pD3DDevice->Present(nullptr, nullptr, nullptr, nullptr);
}

void Direct3D::deInit()
{
	safeRelease(_pD3DDevice);
}