Analog Clock using C(++)

analogclock.cpp

#include <SDL2/SDL.h>
#include <cmath>
#include <ctime>
#include <iostream>

#define S_WIDTH 1024
#define S_HEIGHT 768




void drawCircle(SDL_Renderer *renderer, float radius, float center_x=S_WIDTH/2, float center_y=S_HEIGHT/2 ){
	int x, y;
	for(int i=0; i<=360; i=i+1) {
		x= center_x + radius*cos(i*M_PI/180);
		y=  center_y + radius*sin(i*M_PI/180);
		//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
		SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
	}
	for(int i=0; i<=360; i=i+1) {
		x= center_x + (radius-1)*cos(i*M_PI/180);
		y=  center_y + (radius-1)*sin(i*M_PI/180);
		//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
		SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
	}
	for(int i=0; i<=360; i=i+1) {
		x= center_x + (radius-2)*cos(i*M_PI/180);
		y=  center_y + (radius-2)*sin(i*M_PI/180);
		//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
		SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
	}

}

void drawLine(SDL_Renderer *renderer, float distance, float angle_in_degree, float center_x=S_WIDTH/2, float center_y=S_HEIGHT/2){
	int x,y;
	y =  center_y + distance * sin(angle_in_degree*3.14/180);
	x =  center_x + distance * cos(angle_in_degree*3.14/180);
	SDL_RenderDrawLine(renderer, S_WIDTH/2, S_HEIGHT/2,x,y);
}
int main(int argc, char *argv[])
{
	SDL_Window *window;
	SDL_Renderer *renderer;
	SDL_Event event;
	SDL_CreateWindowAndRenderer(S_WIDTH, S_HEIGHT, 0, &window, &renderer);
	//SDL_Surface *s = SDL_GetWindowSurface(window); //Declaring the surface.
	//s = SDL_CreateRGBSurface(SDL_HWSURFACE, width, height, 32, 0, 0, 0, 0); //Creating the surface.
	//SDL_FillRect(s, NULL, SDL_MapRGB(s->format, 255, 0, 0)); //Filling the surface with red colour.
	SDL_SetRenderDrawColor(renderer, 255, 0, 0, 55);
	
	SDL_RenderFillRect(renderer, NULL);
	SDL_RenderPresent(renderer);

	//Probably on a loop
	SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
	SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_BLEND);

	drawCircle(renderer,160);
	//drawLine(renderer,150,62);
	SDL_RenderPresent(renderer); //back buffer to front buffer? :D	
	SDL_Delay(2000);	
	
	while (true)
	{
		

    	
		//Get system Time
		time_t rawtime;
 		struct tm * timeinfo;
  		time (&rawtime);
  		timeinfo = localtime (&rawtime);
  		int hr = timeinfo->tm_hour;
  		int min = timeinfo->tm_min;
  		int sec = timeinfo->tm_sec;
  		//int ap = (hr>=12) 1 : 0 ; //1=> pm, 0 =>am 
  		hr = (hr>=12) ? (hr-12) : hr;
  		std::cout<<min;
  		SDL_SetRenderDrawColor(renderer, 255, 0, 0, 255);
    	SDL_RenderClear(renderer);
    	SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255);
		SDL_SetRenderDrawBlendMode(renderer, SDL_BLENDMODE_BLEND);
    	drawCircle(renderer,160);
  		SDL_RenderPresent(renderer);
  		drawLine(renderer, 150, (-90 + sec*6));
  		drawLine(renderer, 100, (-90 + min*6));
  		drawLine(renderer, 50,  (-90 +  hr*360/12));
  		SDL_RenderPresent(renderer);
  		SDL_PollEvent(&event);
       	if (event.type == SDL_QUIT) break;
		if (event.type == SDL_KEYUP && event.key.keysym.sym == SDLK_ESCAPE) break;	

    }
    SDL_Quit();
	return 0;
}

analogclockObjects.cpp

#include <SDL2/SDL.h>
#include <SDL2/SDL_ttf.h>
#include <cmath>
#include <ctime>
#include <iostream>
#include <cstring>

#define S_WIDTH 1024
#define S_HEIGHT 768


/*class Exception{
private:
	int exCode;
	char* exDesc;
public:
	Exception(char* ex, int cd){
		exCode = cd;
		exDesc = new char[strlen(ex)+1];
		strcpy(exDesc, ex);
	}
	~Exception(){
		delete[] exDesc;
	}
};*/

class rgba{
private:
	int r,g,b,a;
public:
	rgba(int rr = 0, int gg = 0, int bb = 0, int aa = 0):r(rr),g(gg),b(bb),a(aa){}
	int getR(){return r;}
	int getG(){return g;}
	int getB(){return b;}
	int getA(){return a;}
};

class graphics{
private:
	SDL_Window *window;
	SDL_Renderer *renderer;
	rgba forecolor;
public:
	SDL_Event event;
	graphics(){
		SDL_CreateWindowAndRenderer(S_WIDTH, S_HEIGHT, 0, &window, &renderer);
		forecolor = rgba(255,255,255,255);
	}
	~graphics(){
		SDL_Quit();
	}


	void clearWithColor(rgba color){
		SDL_SetRenderDrawColor(renderer, color.getR(), color.getG(), color.getB(), color.getA());
		SDL_RenderClear(renderer);
		SDL_SetRenderDrawColor(renderer, forecolor.getR(), forecolor.getG(), forecolor.getB(), forecolor.getA());
	}
	void plotGraph(float x, float y){
		SDL_RenderDrawPoint(renderer, x, y);
	}
	void drawLine(float orX, float orY, float distX, float distY){
		SDL_RenderDrawLine(renderer, orX, orY,distX,distY);
	}
	void setBlendMode(SDL_BlendMode mode){
		SDL_SetRenderDrawBlendMode(renderer, mode);
	}
	void render(){
		SDL_RenderPresent(renderer);
	}
	bool poll(bool (*pollfunc)(SDL_Event&)){
		SDL_PollEvent(&event);
		return pollfunc(event); //Passing by reference
	}
	void setDrawColor(rgba r){
		SDL_SetRenderDrawColor(renderer, r.getR(), r.getG(), r.getB(), r.getA());
	}
	void bilt(){
		TTF_Font *font;
		font=TTF_OpenFont("font.ttf", 16);
		SDL_Surface *txtSurface;
		SDL_Color color = {0,0,255,0};
		txtSurface=TTF_RenderText_Solid(font,"Hello World!",color);
		SDL_Delay(2000);
		SDL_BlitSurface(txtSurface, NULL, SDL_GetWindowSurface(window), NULL);
		SDL_Delay(2000);
		}
	/*void mainLoop(void (*logic)(graphics& g), bool(*poll)(SDL_Event&)){
		while(1) {
			logic(this);
			if(pollFunction(poll)) break;
		}
	}*/
};


class shape{
protected:
	char *shapeName;
public:
	shape(char *name){
		shapeName = new char[strlen(name)+1];
		strcpy(shapeName, name);
	}
	virtual void draw(){
	};
};

class circle:public shape{
public:
	circle():shape("Circle"){}
	using shape::draw; //Just for overriding 
	
	void draw(graphics& graph, float radius, float center_x=S_WIDTH/2, float center_y=S_HEIGHT/2){
		float x, y;
		for(int i=0; i<=360; i=i+1) {
			x= center_x + radius*cos(i*M_PI/180);
			y=  center_y + radius*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}
		for(int i=0; i<=360; i=i+1) {
			x= center_x + (radius-1)*cos(i*M_PI/180);
			y=  center_y + (radius-1)*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}
		for(int i=0; i<=360; i=i+1) {
			x= center_x + (radius-2)*cos(i*M_PI/180);
			y=  center_y + (radius-2)*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}	
	}
	void drawAnim(graphics& graph, float radius, float center_x=S_WIDTH/2, float center_y=S_HEIGHT/2){
		float x, y;
		for(int i=0; i<=360; i=i+1) {
			x= center_x + radius*cos(i*M_PI/180);
			y=  center_y + radius*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			SDL_Delay(2);
			graph.render();
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}
		for(int i=0; i<=360; i=i+1) {
			x= center_x + (radius+1)*cos(i*M_PI/180);
			y=  center_y + (radius+1)*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}
		for(int i=0; i<=360; i=i+1) {
			x= center_x + (radius+2)*cos(i*M_PI/180);
			y=  center_y + (radius+2)*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}	
	}
	void drawAnimSemi(graphics& graph, float radius, float center_x=S_WIDTH/2, float center_y=S_HEIGHT/2){
		float x, y;
		for(int i=90; i<=270; i=i+1) {
			x= center_x + radius*cos(i*M_PI/180);
			y=  center_y + radius*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			SDL_Delay(2);
			graph.render();
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}
		for(int i=90; i<=270; i=i+1) {
			x= center_x + (radius-1)*cos(i*M_PI/180);
			y=  center_y + (radius-1)*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}
		for(int i=90; i<=270; i=i+1) {
			x= center_x + (radius-2)*cos(i*M_PI/180);
			y=  center_y + (radius-2)*sin(i*M_PI/180);
			//SDL_SetRenderDrawColor(renderer,1.0,1.0,1.0,0.4);
			graph.plotGraph(x,y);
			//SDL_RenderDrawPoint(renderer, x, y); //Renders on middle of screen.
		}	
	}

};

class line:public shape{
public:
	line():shape("Line"){}
	using shape::draw;
	void draw(graphics& g, float distance, float angle_in_degree, float center_x=S_WIDTH/2, float center_y=S_HEIGHT/2){
		float x,y;
		y =  center_y + distance * sin(angle_in_degree*3.14/180);
		x =  center_x + distance * cos(angle_in_degree*3.14/180);	
		g.drawLine(center_x, center_y, x,y);
		g.drawLine(center_x, center_y,x+1,y+1);
		g.drawLine(center_x, center_y,x+2,y+2);
	}
};

/* The Poll Function -- Checks for event and indicates whether to end or not!*/
bool poll(SDL_Event& event){
	if (event.type == SDL_QUIT) return false;
	if (event.type == SDL_KEYUP && event.key.keysym.sym == SDLK_ESCAPE) return false;	
	return true;
}

int main(int argc, char *argv[]) {
	graphics g;
	circle c1;
	circle dot;
	line hour, minute, second;
	//TTF_Init();
	// load font.ttf at size 16 into font
	//g.clearWithColor(rgba(255,150,0,255));
	//g.bilt();
	//g.render();  
	//SDL_Delay(4000);
	g.clearWithColor(rgba(255,150,0,255));
	c1.drawAnimSemi(g,20,300,400);
	hour.draw(g,50,-90,350,420);
	hour.draw(g,50,-90,351,420);
	hour.draw(g,50,-90,352,420);
	c1.drawAnim(g,20,400,400);
	c1.drawAnimSemi(g,20,450,400);
	g.render();
	SDL_Delay(1500);
	while(1){

		/* Get Time from System */
		time_t rawtime;
 		struct tm * timeinfo;
  		time (&rawtime);
  		timeinfo = localtime (&rawtime);
  		int hr = timeinfo->tm_hour;
  		int min = timeinfo->tm_min;
  		int sec = timeinfo->tm_sec;
  		//int ap = (hr>=12) 1 : 0 ; //1=> pm, 0 =>am 
  		hr = (hr>=12) ? (hr-12) : hr;
  		std::cout<<hr;

  		/* BackBuffer: Clear Screen, and Plot on (unseen) screen */
  		g.clearWithColor(rgba(255,150,0,255));
  		g.setBlendMode(SDL_BLENDMODE_BLEND);
  		dot.draw(g,5);
  		c1.draw(g, 160); 
  		second.draw(g, 150, (-90 + sec*6));
  		minute.draw(g, 100, (-90 + min*6));
  		hour.draw  (g, 50,  (-90 + hr*360/12 ));

  		/* The magic: Put the changes on screen */
  		g.render();

  		/* Check for Event!*/
		if(!g.poll(poll)) break;
	}
	//TTF_Quit();
	return 0;
}

Compiling this will be PITA, but you can try configuring SDL in your computer :D

First line errors, file not found. Does this have some files to download?

This is a very old code, and I don't have standard C/C++ setup at the moment.

But you NEED to install libsdl to be able to use these header files. Also, when compiling you have to provide some flags.

Does these links help?

• https://glusoft.com/sdl2-tutorials/install-sdl-linux/
• https://thenumb.at/cpp-course/index.html#sdl
• https://wiki.libsdl.org/SDL2/Tutorials