正弦曲线

pwnmelife

#include <Windows.h>
#include <strsafe.h>
#include "SysMets.h"
#include <math.h>

#define NUM 1000
#define TWOPI (2 * 3.14159)
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);


int WINAPI WinMain(HINSTANCE hInstance,
        HINSTANCE hPrevInstance,
        LPSTR lpCmdLine,
        int nShowCmd) {
        static TCHAR szAppName[] = TEXT("Bill");
        HWND hwnd;
        WNDCLASS wndclass;
        MSG msg;
        
        wndclass.cbClsExtra = 0;
        wndclass.cbWndExtra = 0;

        wndclass.hInstance = hInstance;
        wndclass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
        wndclass.hCursor = LoadCursor(NULL, IDC_ARROW);
        wndclass.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
        wndclass.lpszClassName = szAppName;
        wndclass.lpszMenuName = NULL;
        wndclass.lpfnWndProc = WndProc;
        wndclass.style = CS_HREDRAW | CS_VREDRAW;

        RegisterClass(&wndclass);
        hwnd = CreateWindow(TEXT("Bill"), TEXT("Tip"), WS_OVERLAPPEDWINDOW | WS_HSCROLL | WS_VSCROLL,
                CW_USEDEFAULT, 40, CW_USEDEFAULT, 100,
                NULL, NULL, hInstance, NULL);

        ShowWindow(hwnd, nShowCmd);
        UpdateWindow(hwnd);
        while (GetMessage(&msg, NULL, 0, 0)) {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
        }
        return 0;

}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message,
        WPARAM wParam, LPARAM lParam) {
        HDC hdc;
        static int cxClient, cyClient;
        int i;
        PAINTSTRUCT ps;
        POINT apt[NUM];
        
        switch (message) {
        case WM_CREATE:
                return 0;
        case WM_PAINT:
                hdc = BeginPaint(hwnd, &ps);
                MoveToEx(hdc, 0, cyClient/2, NULL);
                LineTo(hdc, cxClient, cyClient / 2); //画一条直线
                for (i = 0; i < NUM; i++) {
                        apt[i].x = i * cxClient / NUM;
                        apt[i].y = (int)(cyClient / 2 * (1 - sin(TWOPI * i / NUM))); // (y/2 (1 - sin(2π(x/NUM))))
                }
                Polyline(hdc, apt, NUM);
                EndPaint(hwnd, &ps);
                return 0;
        case WM_SIZE:
                cxClient = LOWORD(lParam);
                cyClient = HIWORD(lParam);
                return 0;
        case WM_DESTROY:
                PostQuitMessage(0);
                return 0;
        default:
                return DefWindowProc(hwnd, message, wParam, lParam);
        }
}