#include <windows.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>

const char szClassName[] = "WinDZ";
const char szWindowName[] = "Windows DZ";

LRESULT CALLBACK WndProc(HWND hWnd, UINT iMessage, WPARAM wParam, LPARAM lParam);

bool isVisible = false;
HWND buttonHwnd;
void DrawGraph(HWND hWnd, HDC hDC)
{
    RECT rect;
    GetClientRect(hWnd, &rect);
    const int xVE=rect.right-rect.left;
    const int yVE=rect.bottom-rect.top;

    SetBkMode(hDC, TRANSPARENT);

    SetMapMode(hDC, MM_ISOTROPIC);
    SetWindowExtEx(hDC, xVE, yVE, NULL);
    SetViewportExtEx(hDC, xVE, -yVE, NULL);
    SetViewportOrgEx(hDC, xVE/2, yVE/2, NULL);


    HPEN hPen = CreatePen(PS_SOLID, 1, RGB(0, 0, 0));
    HPEN hOldPen = (HPEN)SelectObject (hDC, hPen);

    HFONT hOldFont, hFont;
    hFont = CreateFont(15,0,0,0,FW_NORMAL,0,0,0,ANSI_CHARSET,OUT_DEFAULT_PRECIS,CLIP_DEFAULT_PRECIS,DEFAULT_QUALITY,DEFAULT_PITCH|FF_DONTCARE,"Times New Roman Cyr");
    hOldFont=(HFONT)SelectObject(hDC,hFont);

    TextOut(hDC, 5, -5, "0", 1);

    MoveToEx(hDC, 0, -yVE/2, NULL);
    LineTo(hDC, 0, yVE/2);
    MoveToEx(hDC, -xVE/2, 0, NULL);
    LineTo(hDC, xVE/2, 0);

    double maxY = -999999.0;
    double ax[21], ay[21];
    int x;
    double xVal = -1.0;
    int pointX, pointY;

    for (x = 0; x <= 20; x++)
    {
        ax[x] = xVal;
        ay[x] = sin(xVal);

        if (ay[x] > maxY)
            maxY = ay[x];

        xVal += 0.1;
    }
    double mx = xVE/2;
    double my = yVE/2;

    char fStr[100];
    int len;
    MoveToEx(hDC, ax[0]*mx, ay[0]*my, NULL);
    for (x = 0; x <= 20; x++)
    {

        pointX = ax[x]*mx;
        pointY = ay[x]*my;

        if (!(x % 2) && x != 10)
        {
            len = sprintf(fStr, "%.1f", ax[x]);
            TextOut(hDC, x < 10 ? pointX : pointX - 20, 0, fStr, len);

            len = sprintf(fStr, "%.1f", ay[x]);
            TextOut(hDC, 5, pointY, fStr, len);
        }

        LineTo(hDC, pointX, pointY);
    }

    SelectObject(hDC, hOldPen);
    SelectObject(hDC, hOldFont);
    DeleteObject (hPen);
}

int PASCAL WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpszCmdLine,
           int nCmdShow)
{

    HWND hWnd;


    WNDCLASS wndclass;
    wndclass.style         = (CS_HREDRAW | CS_VREDRAW);
    wndclass.lpfnWndProc   = WndProc;
    wndclass.hInstance     = hInstance;
    wndclass.cbClsExtra = 0;
    wndclass.cbWndExtra = 0;
    wndclass.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
    wndclass.hCursor       = LoadCursor(NULL, IDC_ARROW);
    wndclass.hbrBackground = (HBRUSH)GetStockObject(0);
    wndclass.lpszMenuName  = NULL;
    wndclass.lpszClassName = szClassName;

    if (!RegisterClass(&wndclass))
            exit(FALSE);


    hWnd = CreateWindow(szClassName,
        szWindowName,
        WS_OVERLAPPEDWINDOW,
        250,
        250,
        800,
        600,
        NULL,
        0,
        hInstance,
        NULL);

    if (!hWnd)
        exit(FALSE);

    buttonHwnd = CreateWindow("button", "Показать/Скрыть", WS_CHILD|WS_VISIBLE, 0, 0, 150, 30, hWnd, (HMENU)333, hInstance, NULL);

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


    MSG msg;
    while(GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    return (int)msg.wParam;
}


LRESULT CALLBACK WndProc(HWND hWnd, UINT iMessage, WPARAM wParam, LPARAM lParam)
{
    HDC hDC;
    PAINTSTRUCT ps;
    RECT rct;
    switch (iMessage)
    {
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        case WM_PAINT:
            if (isVisible)
            {
                hDC=BeginPaint(hWnd, &ps);
                DrawGraph(hWnd, hDC);
                EndPaint(hWnd, &ps);
            }

        case WM_COMMAND:
            if (wParam == 333)
            {
                if (!(isVisible = !isVisible))
                {
                    GetClientRect(hWnd, &rct);
                    InvalidateRect(hWnd, &rct, true);
                    UpdateWindow(buttonHwnd);
                }
            }
            break;

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