#include "dxm.h"

void DXM::initD3D(HWND hwnd)
{
    //Create device & swap chain
    DXGI_SWAP_CHAIN_DESC scd;
    memset(&scd, 0, sizeof(DXGI_SWAP_CHAIN_DESC));

    scd.BufferCount = 1;
    scd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    scd.BufferDesc.Width = 800;
    scd.BufferDesc.Height = 600;
    scd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
    scd.OutputWindow = hwnd;
    scd.SampleDesc.Count = 1;
    scd.SampleDesc.Quality = 0;
    scd.Windowed = TRUE;

    D3D10CreateDeviceAndSwapChain(NULL, D3D10_DRIVER_TYPE_HARDWARE,
        NULL, 0, D3D10_SDK_VERSION, &scd, &swapchain, &device);

    ID3D10Texture2D *backBuffer;
    swapchain->GetBuffer(0, __uuidof(ID3D10Texture2D),
        (LPVOID*)&backBuffer);
    device->CreateRenderTargetView(backBuffer, NULL, &rtv);
    backBuffer->Release();

    device->OMSetRenderTargets(1, &rtv, NULL);

    //Viewport
    D3D10_VIEWPORT viewport;
    memset(&viewport, 0, sizeof(D3D10_VIEWPORT));

    viewport.TopLeftX = 0;
    viewport.TopLeftY = 0;
    viewport.Width = 800;
    viewport.Height = 600;

    device->RSSetViewports(1, &viewport);

    //Create effect
    D3DX10CreateEffectFromFile(L"effect1.fx", NULL, NULL, "fx_4_0",
        D3D10_SHADER_ENABLE_STRICTNESS, 0, device, 0, 0, &effect, 0, 0);

    technique = effect->GetTechniqueByName("Render");

    //Define input layout
    D3D10_INPUT_ELEMENT_DESC elementDesc[] = {
        {"POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D10_INPUT_PER_VERTEX_DATA, 0},
        {"COLOR", 0, DXGI_FORMAT_R8G8B8A8_UNORM, 0, 12, D3D10_INPUT_PER_VERTEX_DATA, 0}
    };
    UINT numElements = arrysize(elementDesc);

    //Create input layout
    ID3D10InputLayout *vertexLayout = NULL;
    D3D10_PASS_DESC passdesc;
    technique->GetPassByIndex(0)->GetDesc(&passdesc);
    device->CreateInputLayout(elementDesc, numElements, passdesc.pIAInputSignature,
        passdesc.IAInputSignatureSize, &vertexLayout);

    device->IASetInputLayout(vertexLayout);

    //Create vertex buffer
    cvertex verts[4];
    verts[0].position = D3DXVECTOR3(-1.0f, -1.0f, 0.0f);
    verts[0].color = 0xffff0000;
    verts[1].position = D3DXVECTOR3(-1.0f, 1.0f, 0.0f);
    verts[1].color = 0xff0000ff;
    verts[2].position = D3DXVECTOR3(1.0f, -1.0f, 0.0f);
    verts[2].color = 0xff00ff00;
    verts[3].position = D3DXVECTOR3(1.0f, 1.0f, 0.0f);
    verts[3].color = 0xffffffff;

    //Fill buffer description
    D3D10_BUFFER_DESC bd;
    bd.Usage = D3D10_USAGE_DEFAULT;
    bd.ByteWidth = sizeof(cvertex)*4;
    bd.BindFlags = D3D10_BIND_VERTEX_BUFFER;
    bd.CPUAccessFlags = 0;
    bd.MiscFlags = 0;

    D3D10_SUBRESOURCE_DATA initData;
    initData.pSysMem = verts;
    device->CreateBuffer(&bd, &initData, &vertexBuffer);

    //Set vertex buffer
    UINT stride = sizeof(cvertex);
    UINT offset = 0;
    device->IASetVertexBuffers(0, 1, &vertexBuffer, &stride, &offset);

    //Set prim topology
    device->IASetPrimitiveTopology(D3D10_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);
}

void DXM::render()
{
    device->ClearRenderTargetView(rtv, D3DXCOLOR(0.0f, 0.2f, 0.4f, 1.0f));

    D3D10_TECHNIQUE_DESC techDesc;
    technique->GetDesc(&techDesc);
    for (UINT p = 0; p < techDesc.Passes; ++p)
    {
        technique->GetPassByIndex(p)->Apply(0);
        device->Draw(4, 0);
    }

    swapchain->Present(0, 0);
}

void DXM::cleanD3D()
{
    swapchain->SetFullscreenState(FALSE, NULL);
    swapchain->Release();
    rtv->Release();

    effect->Release();
    vertexBuffer->Release();

    device->Release();
}