CSVを読み込んでグラフを描画したい>Win32サンプル1 - プログラムの部屋

#ifndef UNICODE
#define UNICODE
#endif

#include <windows.h>

#include <vector>
#include <algorithm>

std::[[vector]]<unsigned short> g_array;

void OnPaint(HWND hWnd)
{
    HDC hdc;
    PAINTSTRUCT ps;

    RECT rc;
    ::GetClientRect(hWnd, &rc);

    int nPts = static_cast<int>(g_array.size());
    int iWinW = rc.right - rc.left;
    int iWinH = rc.bottom - rc.top;

    int iMaxY = *(std::max_element(g_array.begin(), g_array.end()));

    double iGapX = iWinW / (nPts - 1);
    double iGapY = iWinH / iMaxY;

    int nCurX = 0;

    hdc = BeginPaint(hWnd, &ps);

    while(nCurX < nPts) {
        int x = static_cast<int>(nCurX * iGapX);
        int y = static_cast<int>(g_array.at(nCurX) * iGapY);

        ::LineTo(hdc, x, y);
        nCurX++;
    }

    EndPaint(hWnd, &ps);
}

void OnSize(HWND hWnd)
{
    ::InvalidateRect(hWnd, NULL, TRUE);
}

LRESULT CALLBACK WindowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch(uMsg)
    {
    case WM_PAINT:
        OnPaint(hWnd);
        break;

    case WM_SIZE:
        OnSize(hWnd);
        break;

    case WM_DESTROY:
        PostQuitMessage(0);
        break;

    default:
        return(::DefWindowProc(hWnd, uMsg, wParam, lParam));
    }
    return (0L);
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   LPSTR lpCmdLine, int nCmdShow)
{
    int ar[10] = {5, 9, 4, 3, 8, 1, 1, 0, 9, 6};
    g_array.assign(ar, ar + 10);

    HWND hWnd;
    MSG msg;
    WNDCLASSEX wndClass;

    const wchar_t* szClassName = L"Win32PaintSample";

    wndClass.cbSize = sizeof(WNDCLASSEX);
    wndClass.style = CS_HREDRAW | CS_VREDRAW;
    wndClass.lpfnWndProc = (WNDPROC)WindowProc;
    wndClass.cbClsExtra = 0;
    wndClass.cbWndExtra = 0;
    wndClass.hInstance = hInstance;
    wndClass.hIcon = NULL;
    wndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    wndClass.hbrBackground = static_cast<HBRUSH>(GetStockObject(WHITE_BRUSH));
    wndClass.lpszMenuName = NULL;
    wndClass.lpszClassName = szClassName;
    wndClass.hIconSm = NULL;

    if(::RegisterClassEx(&wndClass) == 0) { return FALSE; }

    hWnd = ::CreateWindowEx(WS_EX_APPWINDOW, szClassName, szClassName,
        WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
        CW_USEDEFAULT, NULL, NULL, hInstance, NULL);

    ::ShowWindow(hWnd, nCmdShow);
    ::UpdateWindow(hWnd);

    while(::GetMessage(&msg, NULL, 0, 0)) {
        ::TranslateMessage(&msg);
        ::DispatchMessage(&msg);
    }

    return (int)msg.wParam;
}