/* * 绘图 * * SetPiexl(HDC, int, int ,COLORREF); * GetPiexl(HDC, int, int); * * MoveToEx(HDC, int, int, LPPOINT); * * LineTo(HDC, int, int); 绘制直线 * * Polyline 绘制折线 * PolylineTo * * GetCurrentPositionEx(HDC, LPPOINT); * * GetClientRect(HWND, LPRECT); */#include "stdafx.h"#include "HelloWnd.h"#include <math.h>// 绘制网格void DrawGrid(HDC hdc){RECT rt;GetClientRect(hwnd, &rt);for(int x=0; x < rt.right; x+=100){MoveToEx(hdc, x, 0, NULL);LineTo(hdc, x, rt.bottom);}for(int y=0; y < rt.bottom; y+=100){MoveToEx(hdc,0,y,NULL);LineTo(hdc, rt.right, y);}}// 绘制矩形void DrawRectangle(HDC hdc){POINT apt[5] = {100, 100, 200, 100, 200, 200, 100, 200, 100, 100};MoveToEx(hdc, apt[0].x, apt[0].y, NULL);for(int i=1; i<5;i++){LineTo(hdc, apt[i].x, apt[i].y);}}// 绘制折线void DrawPolyline(HDC hdc){POINT apt[5] = {100, 100, 200, 100, 200, 200, 100, 200, 100, 100};Polyline(hdc, apt, 5);}void DrawPolylineTo(HDC hdc){POINT apt[5] = {100, 100, 200, 100, 200, 200, 100, 200, 100, 100};MoveToEx(hdc, apt[0].x, apt[0].y, NULL);PolylineTo(hdc, apt+1, 4);}#define NUM 1000#define PI 3.1415926535// 绘制正弦波void DrawSinewave(HDC hdc, int cx, int cy){POINT apt[NUM];MoveToEx(hdc, 0, cy/2, NULL);LineTo(hdc, cx, cy/2);/*sin(x),cos(x)等，这里的x都是弧度，而不是直接的角度。因此，在计算对应角度的三角函数时，需要先将角度转换成弧度再计算。弧度和角度的转换公式是：角度=弧度*180.0f/PI弧度=角度*PI/180.0fsin(30) = 1/2 sin(45) = sqrt(2)/2 sin(60) = sqrt(3)/2sin(90) = 1*/double b = 0;for(int i=0;i<NUM;++i){b = i * PI / 180; /* 把角度转化为弧度 */apt[i].y = sin(b) * cy / 2 + cy / 2;apt[i].x = (cx / NUM) * i;}Polyline(hdc, apt, NUM);}
