Vẽ ngôi sao

[anbinhtrong]

// win_2_4.cpp : Defines the entry point for the application.
//

#include "stdafx.h"
#include "resource.h"
#include <math.h>
#include <time.h>

#define MAX_LOADSTRING 100
#define max_marker 1000
#define marker_size 5
#define MAX_RGB 255

//-----Dinh nghia struct Ngoi sao---------

struct NgoiSao{
    POINT Tam;
    double bk;
    COLORREF PenColor;
    COLORREF BrushColor;
};

void InvertPixel(HDC hdc, int  x, int y);
void Drawmarker(HDC hdc,POINT p, int sixe);
void VeNgoiSao(HDC hdc, NgoiSao ns, int SoCanhNgoiSao, int GocNghieng);

// 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_WIN_2_4, szWindowClass, MAX_LOADSTRING);
    MyRegisterClass(hInstance);

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

    hAccelTable = LoadAccelerators(hInstance, (LPCTSTR)IDC_WIN_2_4);

    // 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_WIN_2_4);
    wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
    wcex.hbrBackground    = (HBRUSH)(COLOR_WINDOW+1);
    wcex.lpszMenuName    = (LPCSTR)IDC_WIN_2_4;
    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)
{
    PAINTSTRUCT ps;
    HDC hdc;
    int i,r;
    static POINT apt[max_marker];
    static int nmarkers=0;
    //----------Mang chua cac ngoi sao------
    static NgoiSao ns[100];
    static int nns;

    switch (message) 
    {
        case WM_CREATE:
            srand(time(NULL));
            break;
        case WM_LBUTTONDOWN:
            if(nmarkers <= max_marker)
            {
                apt[nmarkers].x=LOWORD(lParam);
                apt[nmarkers].y=HIWORD(lParam);
                if((nmarkers+1)%2==0)    // Tinh ban kinh
                {
                    r=(int)sqrt(pow(apt[nmarkers].x-apt[nmarkers-1].x,2)
                        +
                        pow(apt[nmarkers].y-apt[nmarkers-1].y,2));                    
                    ns[nns].bk=r;
                    ns[nns].PenColor=RGB(rand()%MAX_RGB,rand()%MAX_RGB,rand()%MAX_RGB);
                    ns[nns].BrushColor=RGB(rand()%MAX_RGB,rand()%MAX_RGB,rand()%MAX_RGB);
                    nns++;
                }
                else
                    ns[nns].Tam=apt[nmarkers];
                nmarkers++;                
                InvalidateRect(hWnd, NULL, TRUE);
            }
            break;

        case WM_RBUTTONDOWN:
            nmarkers=0;
            nns=0;
            InvalidateRect(hWnd, NULL, TRUE);
            break;

        case WM_PAINT:
            hdc=BeginPaint(hWnd, &ps);
            for(i=0; i<nmarkers; i++)
                Drawmarker(hdc, apt[i], marker_size);
            for(i=0;i<nns;i++)
                VeNgoiSao(hdc,ns[i],5,0);
            EndPaint(hWnd, &ps);
            break;

        case WM_DESTROY:
            PostQuitMessage(0);
            break;
        default:
            return DefWindowProc(hWnd, message, wParam, lParam);
   }
   return 0;
}

void VeNgoiSao(HDC hdc, NgoiSao ns, int SoCanhNgoiSao, int GocNghieng)
{
    HBRUSH hbr;
    HPEN hpen;
    hpen=CreatePen(PS_SOLID,3,ns.PenColor);
    hbr=CreateSolidBrush(ns.BrushColor);
    SelectObject(hdc,hpen);
    SelectObject(hdc,hbr);
    SetPolyFillMode(hdc,WINDING);
    int Angle=360/SoCanhNgoiSao;
    int i;
    double PI=3.14;
    double RAD=PI/180;
    POINT *P,*Q;
    P=new POINT[SoCanhNgoiSao];
    Q=new POINT[SoCanhNgoiSao+1];
    for(i=0;i<SoCanhNgoiSao;i++)
    {
        P[i].x=(long)(ns.Tam.x + cos((i*Angle-90-GocNghieng)*RAD)*ns.bk);
        P[i].y=(long)(ns.Tam.y + sin((i*Angle-90-GocNghieng)*RAD)*ns.bk);
    }
//    Drawmarker(hdc,P[0],5);
    int OrderDraw[6]={3,0,2,4,1,3};
    for(i=0;i<6;i++)
        Q[i]=P[OrderDraw[i]];
    Polygon(hdc,Q,SoCanhNgoiSao+1);
    DeleteObject(hpen);
    DeleteObject(hbr);
}

void InvertPixel(HDC hdc, int  x, int y)
{
    COLORREF crColor=GetPixel(hdc, x, y);
    SetPixel(hdc, x, y, ~crColor &RGB(255,255,255));
}

void Drawmarker(HDC hdc, POINT pt, int size)
{
    int i, x=pt.x, y=pt.y;
    InvertPixel(hdc, x, y);
    for(i=1; i<size; i++)
    {
        InvertPixel(hdc, x-i, y);
        InvertPixel(hdc, x+i, y);
        InvertPixel(hdc, x, y-i);
        InvertPixel(hdc, x, y+i);
    }
}

// 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;
}

[anbinhtrong]

Dùng ALTERNATE: tô theo dòng kẻ quét

SetPolyFillMode(hdc,ALTERNATE);