# How to make it fully functional

**URL:** <https://discourse.glfw.org/t/how-to-make-it-fully-functional/1775>\
**Category:** support\
**Created:** [February 24, 2021, 1:36pm UTC](https://discourse.glfw.org/t/how-to-make-it-fully-functional/1775 "2021-02-24T13:36:32Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Night](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@Night](https://discourse.glfw.org/u/Night)\
**Post date:** [February 24, 2021, 1:36pm UTC](https://discourse.glfw.org/t/how-to-make-it-fully-functional/1775/1 "2021-02-24T13:36:32Z")

</div>

Hello guys I am just a beginner I saw this code on the internet since then I am trying to complete it but I haven’t made any progress .I took this code from [Original Code](http://www.cplusplus.com/forum/general/117629/). I was just wondering how to make it working currently its output can be seen in the picture. Rod only moves when I minimize and maximize the screen of the game. The code modified by me is as under. I am making it on Ubuntu.  
 ![152825359_1787728978069006_3668532226206467644_n](https://canada1.discourse-cdn.com/flex035/uploads/glfw/original/1X/3bb95e80ebb1541548babd91a1dbf154e669535c.jpeg)

```auto
#ifndef BSLAYER_CPP_
#define BSLAYER_CPP_
#include <GL/gl.h>
#include <GL/glut.h>
#include <iostream>
#include<string>
#include<cmath> // for basic math functions such as cos, sin, sqrt
using namespace std;
 int q=0;
        int w=0;
//defining some MACROS

#define MAX(A,B) ((A) > (B) ? (A):(B)) // finds max of two numbers
#define MIN(A,B) ((A) < (B) ? (A):(B)) // find min of two numbers
#define ABS(A) ((A) < (0) ? -(A):(A)) // find ABS of a given number

// define some constants
// constant FPS (Frame per second) is used to specify
// number of frames per second in your game.. if FPS is small 
// your objects will move slowly and if large your objects
// will move faster, see the Timer function below for further help

#define FPS 80 // frame per seconds

// define another constant to hold ASCII for Escape key.
#define KEY_ESC 27 // A

// define some colors as 2D arrays, we have five pre-defined colors here..
// you can add many more if you wish..

float colors[5][3] = { { 1 / 255.0, 164 / 255.0, 164 / 255.0 }, { 215 / 255.0, 0
		/ 255.0, 96 / 255.0 }, { 208 / 255.0, 209 / 255.0, 2 / 255.0 }, { 0
		/ 255.0, 161 / 255.0, 203 / 255.0 }, { 50 / 255.0, 116 / 255.0, 44
		/ 255.0 } };

// defining some utility functions...
/*
 * This function converts an input angle from degree to radians */
float Deg2rad(float degree) {
	return (degree / 180.0) * M_PI;
}
// seed the random numbers generator by current time (see the documentation of srand for further help)...
void InitRandomizer() {
	srand((unsigned int) time(0)); // time(0) returns number of seconds elapsed since January 1, 1970.
}
//This function returns a random value within the specified range of [rmin, rmax] ...
long GetRandInRange(const long &rmin, const long &rmax) {
	long range = rmax - rmin; // find the range
	long value = (rand() % (long) range) + rmin; // translate the generated number ...
//	cout << value << endl << flush;
	return value;
}

/*To draw a triangle we need three vertices with each vertex having 2-coordinates [x, y] and a color for the triangle.
 * This function takes 4 arguments first three arguments (3 vertices + 1 color) to
 * draw the triangle with the given color.
 * */
void DrawTriangle(int x1, int y1, int x2, int y2, int x3, int y3,
		float color[]) {
	glColor3fv(color); // Set the triangle colour
	// ask library to draw triangle at given position...

	glBegin(GL_TRIANGLES);
	/*Draw triangle using given three vertices...*/
	glVertex4i(x1, y1, 0, 1);
	glVertex4i(x2, y2, 0, 1);
	glVertex4i(x3, y3, 0, 1);
	glEnd();
}
/*
 * Write two functions DrawRectangle and DrawSphere
 * */

/*
 * Main Canvas drawing function.
 * */

void Display()/**/{
	// set the background color using function glClearColor.
	// to change the background play with the red, green and blue values below.
	// Note that r, g and b values must be in the range [0,1] where 0 means dim rid and 1 means pure red and so on.

	glClearColor(0/*Red Component*/, 0.0/*Green Component*/,
			0.0/*Blue Component*/, 0 /*Alpha component*/); // Red==Green==Blue==1 --> White Colour
	glClear(GL_COLOR_BUFFER_BIT); //Update the colors

	//write your drawing commands here or call your drawing functions...

	// Drawing set of three triangles at different points of a circle using simple trignometry...
	
		
	int i=100;
	int u=850;
	int a=3;	
	
	while(u>260)
	{
		if(a==3)	// to insert colour
			a=4;
		else if(a==4)
			a=3;
		while(i<950) //to draw the bricks
		{
			DrawTriangle(i, u, i, u-29, i+70, u, colors[a]);
			DrawTriangle(i+70, u, i, u-29, i+70, u-29, colors[a]);
			i=i+71;
		}
		i=100;
		u=u-31;
	}
//to draw a ball	
 int midx = 110;
	      int midy = 50;
		//for ( float theta = Deg2rad(100); theta != 360 ; theta++ )
		 float theta = Deg2rad(10);
		float theta2 = Deg2rad(30);
	while ( theta <=13720 )
		{  
			
		
		DrawTriangle(midx, midy, midx + 10 * cos(theta),
				midy + 10* sin(theta), midx + 10 * cos(theta2),
				midy + 10 * sin(theta2), colors[2]); 
		theta=theta+10;
		theta2=theta2+10;
	}
       
//to draw rod

              DrawTriangle(30+w, 15, 30+w, 5, 120+w, 15, colors[3]); 
	      DrawTriangle(120+w, 15, 30+w, 5, 120+w, 5, colors[3]);
              // do not modify this line..
              glutSwapBuffers();
}
/* Function sets canvas size (drawing area) in pixels...
 * that is what dimensions (x and y) your game will have
 * Note that the bottom-left coordinate has value (0,0) and top-right coordinate has value (width-1,height-1)
 * */
void SetCanvasSize(int width, int height) {
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(0, width, 0, height, -1, 1); // set the screen size to given width and height.
}

/*This function is called (automatically) whenever any non-printable key (such as up-arrow, down-arraw)
 * is pressed from the keyboard
 *
 * You will have to add the necessary code here when the arrow keys are pressed or any other key is pressed...
 *
 * This function has three argument variable key contains the ASCII of the key pressed, while x and y tells the
 * program coordinates of mouse pointer when key was pressed.
 *
 * */

void NonPrintableKeys(int key, int x, int y) {

	if (key == GLUT_KEY_LEFT /*GLUT_KEY_LEFT is constant and contains ASCII for left arrow key*/) {
	// what to do when left key is pressed...
       
       
	q=q-5;
        w=q;
	             	
	
	} else if (key == GLUT_KEY_RIGHT /*GLUT_KEY_RIGHT is constant and contains ASCII for right arrow key*/) {
       
        q=q+5;
        w=q;

	} else if (key == GLUT_KEY_UP/*GLUT_KEY_UP is constant and contains ASCII for up arrow key*/) {

	}

	else if (key == GLUT_KEY_DOWN/*GLUT_KEY_DOWN is constant and contains ASCII for down arrow key*/) {

	}

	/* This function calls the Display function to redo the drawing. Whenever you need to redraw just call
	 * this function*/
	/*
	 glutPostRedisplay();
	 */
}

/*This function is called (automatically) whenever any printable key (such as x,b, enter, etc.)
 * is pressed from the keyboard
 * This function has three argument variable key contains the ASCII of the key pressed, while x and y tells the
 * program coordinates of mouse pointer when key was pressed.
 * */
void PrintableKeys(unsigned char key, int x, int y) {
	if (key == KEY_ESC/* Escape key ASCII*/) {
		exit(1); // exit the program when escape key is pressed.
	}
}

/*
 * This function is called after every 1000.0/FPS milliseconds 
 * (FPS is defined on in the beginning).
 * You can use this function to animate objects and control the
 * speed of different moving objects by varying the constant FPS.
 *
 * */
void Timer(int m) {

	// implement your functionality here
    

	// once again we tell the library to call our Timer function after next 1000/FPS
	glutTimerFunc(1000.0 / FPS, Timer, 0);
}

/*
 * our gateway main function
 * */
int main(int argc, char*argv[]) {
	int width = 1000, height = 900; // i have set my window size to be 800 x 600
	InitRandomizer(); // seed the random number generator...
	glutInit(&argc, argv); // initialize the graphics library...

	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA); // we will be using color display mode
	glutInitWindowPosition(50, 50); // set the initial position of our window
	glutInitWindowSize(width, height); // set the size of our window
	glutCreateWindow("ITCs Brick Slayer"); // set the title of our game window
	SetCanvasSize(width, height); // set the number of pixels...

	// Register your functions to the library,
	// you are telling the library names of function to call for different tasks.
	glutDisplayFunc(Display); // tell library which function to call for drawing Canvas.
	glutSpecialFunc(NonPrintableKeys); // tell library which function to call for non-printable ASCII characters
	glutKeyboardFunc(PrintableKeys); // tell library which function to call for printable ASCII characters
	// This function tells the library to call our Timer function after 1000.0/FPS milliseconds...
	glutTimerFunc(1000.0 / FPS, Timer, 0);

	// now handle the control to library and it will call our registered functions when
	// it deems necessary...
	glutMainLoop();
	return 1;
}

#endif /* BSLAYER_CPP_ */

```

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<div class="post-metadata">

**Author:** ![dougbinks](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.glfw.org/dougbinks/32/39_2.png) [@dougbinks](https://discourse.glfw.org/u/dougbinks)\
**Post date:** [February 25, 2021, 1:07pm UTC](https://discourse.glfw.org/t/how-to-make-it-fully-functional/1775/2 "2021-02-25T13:07:12Z")

</div>

Hi @Night,

Welcome to the GLFW forum. As the name states this forum is for assistance in using the [GLFW library](https://www.glfw.org/), rather than for general OpenGL questions (or indeed GLUT which you are using instead of GLFW).

Your question is a little open-ended, and I think you would be better off following an online tutorial such as the one here: [LearnOpenGL - Hello Window](https://learnopengl.com/Getting-started/Hello-Window)

Good luck learning!

Doug

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<div class="post-metadata">

**Author:** ![Night](https://avatars.discourse-cdn.com/v4/letter/n/90db22/32.png) [@Night](https://discourse.glfw.org/u/Night)\
**Post date:** [February 26, 2021, 7:38pm UTC](https://discourse.glfw.org/t/how-to-make-it-fully-functional/1775/3 "2021-02-26T19:38:24Z")

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Thanks a lot as I am a beginner so don’t know a lot…Thanks again!