Vẽ bông hoa

[anbinhtrong]

// BongHoa.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "resource.h"
#include "math.h"
#define MAX_LOADSTRING 100
#define MAX_MARKERS 100
#define MARKER_SIZE 5
struct BongHoa{
    POINT Tam;
    POINT DiemDieuKhien;
    COLORREF MauVien;
    COLORREF MauTo;
};
void DrawMarker(HDC hdc,POINT pt,int size);
void DrawFlower(HDC hdc,BongHoa phoa,int SoCanh,int GocNghieng);
POINT QuayDiem(POINT Tam,POINT p,int GocQuay);
// Global Variables:
HINSTANCE hInst;                                // current instance
TCHAR szTitle[MAX_LOADSTRING];                                // The title bar text
TCHAR szWindowClass[MAX_LOADSTRING];                                // The title bar text

// Foward declarations of functions included in this code module:
ATOM                MyRegisterClass(HINSTANCE hInstance);
BOOL                InitInstance(HINSTANCE, int);
LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
LRESULT CALLBACK    About(HWND, UINT, WPARAM, LPARAM);

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
     // TODO: Place code here.
    MSG msg;
    HACCEL hAccelTable;

    // Initialize global strings
    LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
    LoadString(hInstance, IDC_BONGHOA, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

    // Perform application initialization:
    if (!InitInstance (hInstance, nCmdShow)) 
    {
        return FALSE;
    }

    hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_BONGHOA);

    // Main message loop:
    while (GetMessage(&msg, NULL, 0, 0)) 
    {
        if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg)) 
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }

    return msg.wParam;
}



//
//  FUNCTION: MyRegisterClass()
//
//  PURPOSE: Registers the window class.
//
//  COMMENTS:
//
//    This function and its usage is only necessary if you want this code
//    to be compatible with Win32 systems prior to the 'RegisterClassEx'
//    function that was added to Windows 95. It is important to call this function
//    so that the application will get 'well formed' small icons associated
//    with it.
//
ATOM MyRegisterClass(HINSTANCE hInstance)
{
    WNDCLASSEX wcex;

    wcex.cbSize = sizeof(WNDCLASSEX); 

    wcex.style            = CS_HREDRAW | CS_VREDRAW;
    wcex.lpfnWndProc    = (WNDPROC)WndProc;
    wcex.cbClsExtra        = 0;
    wcex.cbWndExtra        = 0;
    wcex.hInstance        = hInstance;
    wcex.hIcon            = LoadIcon(hInstance, (LPCTSTR)IDI_BONGHOA);
    wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground    = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName    = (LPCSTR)IDC_BONGHOA;
    wcex.lpszClassName    = szWindowClass;
    wcex.hIconSm        = LoadIcon(wcex.hInstance, (LPCTSTR)IDI_SMALL);

    return RegisterClassEx(&wcex);
}

//
//   FUNCTION: InitInstance(HANDLE, int)
//
//   PURPOSE: Saves instance handle and creates main window
//
//   COMMENTS:
//
//        In this function, we save the instance handle in a global variable and
//        create and display the main program window.
//
BOOL InitInstance(HINSTANCE hInstance, int nCmdShow)
{
   HWND hWnd;

   hInst = hInstance; // Store instance handle in our global variable

   hWnd = CreateWindow(szWindowClass, szTitle, WS_OVERLAPPEDWINDOW,
      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);

   if (!hWnd)
   {
      return FALSE;
   }

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

   return TRUE;
}

//
//  FUNCTION: WndProc(HWND, unsigned, WORD, LONG)
//
//  PURPOSE:  Processes messages for the main window.
//
//  WM_COMMAND    - process the application menu
//  WM_PAINT    - Paint the main window
//  WM_DESTROY    - post a quit message and return
//
//
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    int wmId, wmEvent;
    PAINTSTRUCT ps;
    HDC hdc;
    TCHAR szHello[MAX_LOADSTRING];
    LoadString(hInst, IDS_HELLO, szHello, MAX_LOADSTRING);
    static BongHoa bh[100];
    static int sbh=0;
    static    POINT Marker[MAX_MARKERS];
    static int nMarker=0;
    int i;
    double pi=3.1415926;
    switch(message) 
    {
        case WM_COMMAND:
            wmId    = LOWORD(wParam); 
            wmEvent = HIWORD(wParam); 
            // Parse the menu selections:
            switch (wmId)
            {
                case IDM_ABOUT:
                   DialogBox(hInst, (LPCTSTR)IDD_ABOUTBOX, hWnd, (DLGPROC)About);
                   break;
                case IDM_EXIT:
                   DestroyWindow(hWnd);
                   break;
                default:
                   return DefWindowProc(hWnd, message, wParam, lParam);
            }
            break;
        case WM_LBUTTONDOWN:
            Marker[nMarker].x=LOWORD(lParam);
            Marker[nMarker].y=HIWORD(lParam);
            if((nMarker%2)==1)
            {
                bh[sbh].Tam=Marker[nMarker-1];
                bh[sbh].DiemDieuKhien=Marker[nMarker];
                bh[sbh].MauTo=RGB(rand()%255,rand()%255,rand()%255);
                bh[sbh].MauVien=RGB(rand()%255,rand()%255,rand()%255);
                sbh++;
            }
            nMarker++;
            InvalidateRect(hWnd,NULL,TRUE);
            break;
        case WM_RBUTTONDOWN:
            sbh=0;
            nMarker=0;
            InvalidateRect(hWnd, NULL, TRUE);
            break;
        case WM_PAINT:
            
            hdc = BeginPaint(hWnd, &ps);
            // TODO: Add any drawing code here...
            RECT rt;
            GetClientRect(hWnd, &rt);
            DrawText(hdc, szHello, strlen(szHello), &rt, DT_CENTER);
            for(i=0;i<sbh;i++)
                DrawFlower(hdc,bh[i],4,0);
            for(i=0;i<nMarker;i++)
                DrawMarker(hdc,Marker[i],MARKER_SIZE);
            EndPaint(hWnd, &ps);
            break;
        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
   }
   return 0;
}

// Mesage handler for about box.
LRESULT CALLBACK About(HWND hDlg, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
        case WM_INITDIALOG:
                return TRUE;

        case WM_COMMAND:
            if (LOWORD(wParam) == IDOK || LOWORD(wParam) == IDCANCEL) 
            {
                EndDialog(hDlg, LOWORD(wParam));
                return TRUE;
            }
            break;
    }
    return FALSE;
}
void DrawMarker(HDC hdc,POINT pt,int size)
{
    SetPixel(hdc,pt.x,pt.y,RGB(255,0,0));
    for(int i=0;i<size;i++)
    {
        SetPixel(hdc,pt.x+i,pt.y,RGB(255,0,0));
        SetPixel(hdc,pt.x-i,pt.y,RGB(255,0,0));
        SetPixel(hdc,pt.x,pt.y+i,RGB(255,0,0));
        SetPixel(hdc,pt.x,pt.y-i,RGB(255,0,0));
    }
}
//quay diem ko sai
POINT QuayDiem(POINT Tam,POINT p,int GocQuay)
{
    double pi=3.1415926;
    POINT a;
    double R=sqrt(pow(p.x-Tam.x,2)+pow(p.y-Tam.y,2));
    double goc=acos((double)(p.x-Tam.x)/R);
    goc=(p.y<=Tam.y)?2*pi-goc:goc;
    goc=goc+GocQuay*pi/180;
    a.x=Tam.x+(long)(R*cos(goc));
    a.y=Tam.y+(long)(R*sin(goc));
    return a;
}
void DrawFlower(HDC hdc,BongHoa phoa,int SoCanh,int GocNghieng)
{
    HBRUSH hbr;
    HPEN hp;
    int i;
    hp=CreatePen(PS_SOLID,2,phoa.MauVien);
    hbr=CreateSolidBrush(phoa.MauTo);
    SelectObject(hdc,hp);
    SelectObject(hdc,hbr);
    BeginPath(hdc);
    double pi=3.1415926;
    POINT *b;
    b=new POINT[3*SoCanh];
    b[2]=phoa.Tam;
    b[0]=phoa.DiemDieuKhien;
    b[1].x=(2*phoa.Tam.x-phoa.DiemDieuKhien.x);
    b[1].y=b[0].y;

    int GocQuay=360/SoCanh;
    int j=1;
    for(i=3;i<3*SoCanh;i+=3,j++)
    {
        b[i]=QuayDiem(phoa.Tam,b[0],j*GocQuay);
        b[i+1]=QuayDiem(phoa.Tam,b[1],j*GocQuay);
        b[i+2]=QuayDiem(phoa.Tam,b[2],j*GocQuay);
    }
    for(i=0;i<3*SoCanh;i++)
        b[i]=QuayDiem(phoa.Tam,b[i],GocNghieng);
    MoveToEx(hdc,phoa.Tam.x,phoa.Tam.y,NULL);
    PolyBezierTo(hdc,b,3*SoCanh);
    CloseFigure(hdc);
    EndPath(hdc);
    StrokeAndFillPath(hdc);
    DeleteObject(hp);
    DeleteObject(hbr);
}

[anbinhtrong]

Trường hợp thêm góc nghiêng và tăng số cánh hoa, bạn bổ sung:

case WM_KEYDOWN:
            switch(wParam)
            {
                case VK_LEFT: 
                    if(socanh>3) socanh--;
                    break;
                case VK_RIGHT: 
                    if(socanh<15) socanh++;
                    break;
                case VK_UP:
                    GocNghieng+=10;
                    break;
                case VK_DOWN:
                    GocNghieng-=10;
                    break;
            }
            InvalidateRect(hWnd,NULL,TRUE);
            break;

Lưu ý: bạn nên sửa lại tham số hàm WM_PAINT cho phù hợp.