钟表程序(C语言+SDL2)（时钟程序编写）

/*

SDL2+C标准库写的时钟小程序

安卓系统下测试可行

以下是完整代码

*/

#include "SDL2/SDL.h"

#include "SDL2/SDL_thread.h"

#include<stdio.h>

#include<math.h>

#include<time.h>

#define PI 3.1415926536

//画可旋转矩形，围绕矩形中心旋转/顺时针旋转

//相对于数学坐标象限4/3/2/1

//参数分别是渲染器，矩形中心点坐标x0/y0坐标，矩形w宽/h高，A旋转角度/弧度值

int myRect(SDL_Renderer *render,int x0,int y0,int w,int h,double A)

{

//源矩形四个顶点坐标

double Ax,Ay,Bx,By,Cx,Cy,Dx,Dy;

//以矩形中心作为暂时坐标原点

Ax=-w/2.0;Ay=+h/2.0;

Bx=Ax;By=-h/2.0;

Cx=+w/2.0;Cy=By;

Dx=Cx;Dy=Ay;

SDL_Point p0[4]=

{

{Ax,Ay},//A

{Bx,By},//B

{Cx,Cy},//C

{Dx,Dy} //D

};

/*

逆时针旋转：

x'=x*cos(a)-y*sin(a);

y'=x*sin(a)+y*cos(a);

*/

//旋转A弧度后矩形ABCD四点新坐标

double A1x,A1y,B1x,B1y,C1x,C1y,D1x,D1y;

D1x=Dx*cos(A)-Dy*sin(A)+x0;

D1y=Dx*sin(A)+Dy*cos(A)+y0;

C1x=Cx*cos(A)-Cy*sin(A)+x0;

C1y=Cx*sin(A)+Cy*cos(A)+y0;

A1x=Ax*cos(A)-Ay*sin(A)+x0;

A1y=Ax*sin(A)+Ay*cos(A)+y0;

B1x=Bx*cos(A)-By*sin(A)+x0;

B1y=Bx*sin(A)+By*cos(A)+y0;

//旋转后的矩形四个点坐标

SDL_Point p1[5]=

{

{A1x,A1y},//A

{B1x,B1y},//B

{C1x,C1y},//C

{D1x,D1y}, //D

{A1x,A1y}//A

};

//画出旋转后矩形

SDL_RenderDrawLines(render,p1,5);

return 0;

}

//画圆函数

int myCircle(SDL_Renderer *render,int x0,int y0,int r)

{

double x1=0.0,y1=0.0;

static double TPI=6.2831853072;

double temp=0.0;

double step=0.0031415926536;

for(int i=0;temp<TPI;i++)

{

temp=i*step;

x1=x0-r*cos(temp);

y1=y0-r*sin(temp);

SDL_RenderDrawPoint(render, x1, y1);

}

return 0;

}

//画刻度

int myDraw(SDL_Renderer *render,int x0,int y0,int r)

{

double x1=0.0,y1=0.0;

static double TPI=6.2831853072;

double a1=0.1047197551;

double st=0.0,x2=0.0,y2=00;

//画刻度线60个 长度15像素

//夹角弧度

SDL_SetRenderDrawColor(render, 255, 255, 255, SDL_ALPHA_OPAQUE);

for(int j=0;j<60;j++)

{

st=j*a1;

x1=x0-r*cos(st);

y1=y0-r*sin(st);

x2=x1-15.0*cos(st);

y2=y1-15.0*sin(st);

if(j%5==0 && j!=0 && j!=15 && j!=30 && j!=45)

{

myRect(render,x1,y1,30,8,j*PI/30);

}

if(j==0) //9

{

SDL_Rect rect = {x1-15,y1-4,30 , 8 };

SDL_RenderFillRect(render, &rect);

}

else if(j==15) //12

{

SDL_Rect rect = {x1-4,y1-15,8 ,30 };

SDL_RenderFillRect(render, &rect);

}

else if(j==30) //3

{

SDL_Rect rect = {x1-10,y1-4,30, 8};

SDL_RenderFillRect(render, &rect);

}

else if(j==45) //6

{

SDL_Rect rect = {x1-4,y1-10,8 ,30};

SDL_RenderFillRect(render, &rect);

}

else

{

if(j!=5 && j!=10 && j!=20 && j!=25 && j!=35 && j!=40 &&j!=50 &&j!=55)

{

SDL_Point points[2]

{

{x1, y1},

{x2, y2}

};

//画线

SDL_RenderDrawLines(render, points, 2);

}

}

}

return 0;

}

//实时获取东8区时间

//获取时/分/秒

int getTime(int *hour,int *min,int *sec)

{

time_t now;

time(&now);

struct tm *info;

//获取GMT时间

info=gmtime(&now);

*hour=(info->tm_hour+8)%24;

*min=info->tm_min;

*sec=info->tm_sec;

return 0;

}

//动态画表针

int drawHand(SDL_Renderer *ren)

{

//时/分/秒

int h=0,m=0,s=0;

//对应弧度

float Ah,Am,As;

//获取时间

getTime(&h,&m,&s);

//当前时针偏转弧度

Ah=h*PI/6.0+m*PI/360.0;

//当前分针偏转弧度

Am=m*PI/30.0+s*PI/1800.0;

//当前秒针偏转弧度

As=s*PI/30.0;

//初始化时针在12时位置 时针长200宽12

//画时针

myRect(ren,360+100*sin(Ah),640-100*cos(Ah),12,200,Ah);

//画分针

myRect(ren,360+120*sin(Am),640-120*cos(Am),8,240,Am);

//画秒针

myRect(ren,360+140*sin(As),640-140*cos(As),4,280,As);

return 0;

}

int main(int agrs,char *argv[])

{

//定义窗口

SDL_Window *wnd=NULL;

//定义渲染器

SDL_Renderer *render=NULL;

//初始化所有子系统

SDL_Init(SDL_INIT_EVERYTHING);

// 创建窗口

wnd = SDL_CreateWindow(

// 标题

"我的SDL时钟",

// 居中

SDL_WINDOWPOS_CENTERED,

SDL_WINDOWPOS_CENTERED,

// 宽高

350, 350,

//状态

SDL_WINDOW_SHOWN);

//检查窗口是否创建成功

if (wnd == NULL)

{

printf("Could not create window: %s\n", SDL_GetError());

return 1;

}

//渲染器创建 render=SDL_CreateRenderer(wnd,1,1);

//背景色黑色 SDL_SetRenderDrawColor(render,0,0,0,255);

//刷新屏幕

SDL_RenderClear(render);

//选择绘制颜色

SDL_SetRenderDrawColor(render, 255, 0, 0, SDL_ALPHA_OPAQUE);

while(1){

//绘制钟盘

myDraw(render,360,640,300);

SDL_SetRenderDrawColor(render, 255, 0, 0, SDL_ALPHA_OPAQUE);

myCircle(render,360,640,3);

myCircle(render,360,640,4);

SDL_SetRenderDrawColor(render, 0, 0, 255, SDL_ALPHA_OPAQUE);

myCircle(render,360,640,11);

myCircle(render,360,640,12);

drawHand(render);

SDL_RenderPresent(render);

}

//清理

SDL_DestroyRenderer(render);

SDL_DestroyWindow(wnd);

SDL_Quit();

return 0;

}