[PIU] Wykresy

#include <windows.h>
#include <time.h>
#include <string>
#include <vector>

using namespace std;

LRESULT CALLBACK WinProc(HWND, UINT, WPARAM, LPARAM);
bool createWinClass(HINSTANCE&, TCHAR*);

class CWykres
{
    public:
        CWykres();
        void paint(const HWND);
        short int getVal() const;
        short int getCount() const;

    private:
        void randBars();
        short int maxval, count, minval;
        vector<int> bars;
};

CWykres::CWykres()
{
    srand((unsigned int)time(NULL));
    maxval = (rand() % 11) + 5;
    count = (rand() % 21) + 5;

    if(maxval % 2) maxval = maxval - 1;
    bars.reserve(count);
    randBars();
}

void CWykres::randBars()
{
    srand((unsigned int)time(NULL));
    for(unsigned int i = 0; i < (unsigned int)count; i++)
    {
        int val = (rand() % (maxval + 1));
        int sign = rand() % 2;

        if(sign) val = -val;

        bars.push_back(val);
    }
}

short int CWykres::getVal() const
{
    return maxval;
}

short int CWykres::getCount() const
{
    return count;
}

void CWykres::paint(const HWND hwnd)
{
    PAINTSTRUCT paintdata;
    RECT window_size, window_margin;
    POINT position;

    HDC hdc = BeginPaint(hwnd, &paintdata);
    HPEN emptyPen = (HPEN) SelectObject(hdc, GetStockObject(NULL_PEN));
    HBRUSH emptyBrush = (HBRUSH) SelectObject(hdc, GetStockObject(NULL_BRUSH));

    HPEN standardPen = CreatePen(PS_SOLID, 1, RGB(0, 0, 0));
    HBRUSH standardBrush = CreateSolidBrush(RGB(255, 0, 0));
    HPEN redPen = CreatePen(PS_SOLID, 1, RGB(0, 0, 0));

    SelectObject(hdc, standardBrush);
    SelectObject(hdc, standardPen);
    GetClientRect(hwnd, &window_size);

    // window for axis
    window_margin = window_size;
    window_margin.left = static_cast<LONG>(window_margin.right * 0.1);
    window_margin.right = static_cast<LONG>(window_margin.right * 0.9);
    window_margin.top = static_cast<LONG>(window_margin.bottom * 0.1);
    window_margin.bottom = static_cast<LONG>(window_margin.bottom * 0.9);

    // y axis
    MoveToEx(hdc, window_margin.left, window_margin.top, &position);
    LineTo(hdc, window_margin.left, window_margin.bottom);

    // y axis triangle
    POINT yTriangle[4];
    yTriangle[0].x = window_margin.left - 10;
    yTriangle[1].x = window_margin.left + 10;
    yTriangle[0].y = yTriangle[1].y = window_margin.top;
    yTriangle[2].x = window_margin.left;
    yTriangle[2].y = window_margin.top - 10;
    yTriangle[3] = yTriangle[0];
    Polyline(hdc,  yTriangle, 4);

    // x axis
    int halftop = static_cast<int>((window_margin.bottom - window_margin.top)/2 + window_margin.top);
    MoveToEx(hdc, window_margin.left, halftop, &position);
    LineTo(hdc, window_margin.right, halftop);

    // x axis triangle
    POINT xTriangle[4];
    xTriangle[0].x = xTriangle[1].x = window_margin.right;
    xTriangle[0].y = halftop - 10;
    xTriangle[1].y = halftop + 10;
    xTriangle[2].x = window_margin.right + 10;
    xTriangle[2].y = halftop;
    xTriangle[3] = xTriangle[0];
    Polyline(hdc,  xTriangle, 4);

    // describe y axis
    int maxval = getVal();
    int copy = maxval + 1;
    int spacing = (window_margin.bottom - window_margin.top) / (copy + 1);

    for(unsigned int i = 1; i <= (unsigned int)copy; i++, maxval = (maxval - 2))
    {
        if(maxval == 0)
            continue;

        unsigned int top = window_margin.top + (i * spacing);
        std::wstring s = to_wstring(maxval) + L".0";
        TextOut(hdc, window_margin.left - 40, top - 5, s.c_str(), s.size());

        MoveToEx(hdc, window_margin.left - 5, top, &position);
        LineTo(hdc, window_margin.left + 5, top);
    }

    // describe x axis
    maxval = getCount();
    spacing = (window_margin.right - window_margin.left - 20) / maxval;
    int spacingY = (window_margin.bottom - window_margin.top) / 2;

    SelectObject(hdc, redPen);
    // make rectangles
    for(unsigned int i = 1; i <= (unsigned int)maxval; i++)
    {
        unsigned int left = window_margin.left + (i * spacing);
        float rectSize = (float)bars[i - 1];
        float max = (float)getVal();

        if(rectSize > 0)
        {
            float top = (rectSize / (max + 2)) * (float)spacingY;
            Rectangle(hdc, left - (spacing / 4), halftop - (int)top, left + (spacing / 4), halftop);
        }
        else
        {
            float top = ((-rectSize) / (max + 2)) * (float)spacingY;
            Rectangle(hdc, left - (spacing / 4), halftop + (int)top, left + (spacing / 4), halftop);
        }
    }
    SelectObject(hdc, standardPen);

    // make descriptions
    for(unsigned int i = 1; i <= (unsigned int)maxval; i++)
    {
        unsigned int left = window_margin.left + (i * spacing);
        std::wstring s = to_wstring(i);

        SetBkMode(hdc, TRANSPARENT);
        TextOut(hdc, left - 5, halftop + 5, s.c_str(), s.size());

        MoveToEx(hdc, left, halftop - 5, &position);
        LineTo(hdc, left, halftop + 5);
    }

    SelectObject(hdc, emptyPen);
    SelectObject(hdc, emptyBrush);

    EndPaint(hwnd, &paintdata);
    DeleteObject(standardPen);
    DeleteObject(standardBrush);
    DeleteObject(redPen);
}

CWykres Wykres;
TCHAR APPName[] = TEXT("Moja aplikacja");
TCHAR ClassName[] = TEXT("Nazwa klasy");

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    if(!createWinClass(hInstance, ClassName))
        return 0;

    HWND window = CreateWindowEx(0, ClassName, APPName, WS_OVERLAPPEDWINDOW, 200, 200, 500, 400, 0, 0, 0, 0);
    if(window) {
        MSG msg;
        ShowWindow(window, nShowCmd);

        while(GetMessage(&msg, 0, 0, 0) > 0) {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
    else MessageBox(0, TEXT("Inicjalizacja okna nie powiodła się."), APPName, MB_OK | MB_ICONERROR);

    UnregisterClass(ClassName, hInstance);
    return 0;
}

static LRESULT CALLBACK WinProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    switch(msg)
    {
        case WM_PAINT:
            Wykres.paint(hwnd);
            break;
        case WM_MOVE:
        case WM_SIZE:
            InvalidateRect(hwnd, 0, TRUE);
            break;
        case WM_CLOSE:
            DestroyWindow(hwnd);
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hwnd, msg, wParam, lParam);
    }
    return 0;
}

static bool createWinClass(HINSTANCE& hInstance, TCHAR* ClassName)
{
    WNDCLASSEX wc;
    wc.cbClsExtra = wc.cbWndExtra = 0;
    wc.cbSize = sizeof(WNDCLASSEX);
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
    wc.hCursor = LoadCursor(0, IDC_ARROW);
    wc.hIconSm = wc.hIcon = LoadIcon(0, IDI_APPLICATION);
    wc.hInstance = hInstance;
    wc.lpfnWndProc = WinProc;
    wc.lpszClassName = ClassName;
    wc.lpszMenuName = 0;
    wc.style = 0;
    return (RegisterClassEx(&wc) != 0);
}