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

INT Direct3D::init(HWND hWnd, UINT width, UINT height, BOOL isFullscreen)
{
	HRESULT hr = {};

	// 1. define swap chain description
	DXGI_SWAP_CHAIN_DESC swapChainDesc = {};
	swapChainDesc.OutputWindow = hWnd; // target window instance handle
	swapChainDesc.Windowed = !isFullscreen; // windowed or fullscreen
	swapChainDesc.BufferCount = 1; // amount of backbuffers, minimum 1
	swapChainDesc.BufferDesc.Width = width;
	swapChainDesc.BufferDesc.Height = height;
	swapChainDesc.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM; // pixel format, here 4 channels (red, green, blue, alpha) with 8bit depth each and unsigned normalized floating points
	swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT; // which technique is used to render to back buffer
	swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_DISCARD; // what happens to front buffer after swap
	swapChainDesc.SampleDesc.Count = 1; // have to be at least one

	// 2. create Direct3D device, device context & swap chain
	D3D_FEATURE_LEVEL featureLevels[] = {
		D3D_FEATURE_LEVEL_11_1,
		D3D_FEATURE_LEVEL_11_0,
		D3D_FEATURE_LEVEL_10_1,
		D3D_FEATURE_LEVEL_10_0
	};

	D3D_FEATURE_LEVEL chosenFeatureLevel = {};

	hr = D3D11CreateDeviceAndSwapChain(
		nullptr, // graphic card, nullptr -> default adapter
		D3D_DRIVER_TYPE_HARDWARE, // rendering with hard- or software renderer
		nullptr, // software renderer module reference
		0, // optional flags
		featureLevels, std::size(featureLevels), // which api features are supported
		D3D11_SDK_VERSION, &swapChainDesc, &_pDXGISwapChain, &_pD3DDevice, &chosenFeatureLevel, &_pD3DDeviceContext);
	CheckFailed(hr, 20);

	// 3. create render target
	ID3D11Texture2D* pBackBuffer = nullptr;
	hr = _pDXGISwapChain->GetBuffer(0, IID_PPV_ARGS(&pBackBuffer));
	CheckFailed(hr, 22);

	hr = _pD3DDevice->CreateRenderTargetView(pBackBuffer, nullptr, &_pD3DRenderTargetView);
	CheckFailed(hr, 24);

	safeRelease(pBackBuffer);

	// 4. create depth stencil buffer

	// 5. create rasterizer state
	//d3d.getDevice()->SetRenderState(D3DRS_LIGHTING, TRUE);
//d3d.getDevice()->SetRenderState(D3DRS_FILLMODE, D3DFILL_SOLID);
//d3d.getDevice()->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);
//d3d.getDevice()->SetRenderState(D3DRS_DIFFUSEMATERIALSOURCE, D3DMCS_MATERIAL);
//d3d.getDevice()->SetRenderState(D3DRS_SPECULARMATERIALSOURCE, D3DMCS_MATERIAL);
//d3d.getDevice()->SetRenderState(D3DRS_SPECULARENABLE, TRUE);

	// 6. describe viewport
	D3D11_VIEWPORT viewport = {};
	viewport.TopLeftX = 0.0f;
	viewport.TopLeftY = 0.0f;
	viewport.Width = width;
	viewport.Height = height;

	// 7. setup render pipeline (device context)
	_pD3DDeviceContext->OMSetRenderTargets(1, &_pD3DRenderTargetView, nullptr);
	_pD3DDeviceContext->RSSetViewports(1, &viewport);

	return 0;
}

void Direct3D::beginScene(FLOAT r, FLOAT g, FLOAT b)
{
	// clear back buffer with a solid color
	FLOAT backgroundColor[] = { r, g, b, 1.0f };
	_pD3DDeviceContext->ClearRenderTargetView(_pD3DRenderTargetView, backgroundColor);
}

void Direct3D::endScene()
{
	_pDXGISwapChain->Present(
		0, // sync interval, 0,1,2,3,4 -> (de-)active vsync setting and how often should be synced
		0 // optional flags
	);
}

void Direct3D::deInit()
{
	safeRelease(_pD3DRenderTargetView);
	safeRelease(_pDXGISwapChain);
	safeRelease(_pD3DDeviceContext);
	safeRelease(_pD3DDevice);
}