Opengl Performance issues , - c++

Question

So i'm making a game(something similar to a pong)using openGl in cpp , and when i try running the program , the image rendering is too slow ,i feel something is taking a huge toll on my GPU memory ,
(So far i have competed the drawing and movement of the paddle which works fine and the problem arises when the ball is set to motion on the press of a button , Everything slows down after this )
Here i have attached a portion of my code
Point out any deficiencies in my code
#include<stdlib.h>
#include<GL/glut.h>
#include<windows.h>
#include<iostream>
//#include<sstream>
#include<stdio.h>
#include<ctime>
#include<string.h>
typedef double point[3];
point a,b,c,d;
static float xmove=0.0;
static int release=0;
static float ii=0.00;
static int reac_top;
using namespace std;
//GLvoid player1_box();
GLfloat xangle=0.0;
float changeDir=1;// positive direction
double vv[4][3]={ {0.5,0.2,0.0},{ 0.5,0.25,0.0},{0.7,0.25,0.0},{0.7,0.2,0.0}};
void renderoutline()
{
glBegin(GL_LINE_LOOP);
glColor3f(1,0,0);
glVertex2f(0.0,0.0);
glColor3f(1,0,0);
glVertex2f(0,1.2);
glColor3f(1,0,0);
glVertex2f(1.2,1.2);
glColor3f(1,0,0);
glVertex2f(1.2,0);
glEnd();
}
void ball()
{
glBegin(GL_POLYGON);
glColor3f(0,0,1);
glVertex3f(0.6,0.25,0.0);
glColor3f(0,0,1);
glVertex3f(0.6,0.28,0.0);
glColor3f(0,0,1);
glVertex3f(0.62,0.28,0.0);
glColor3f(0,0,1);
glVertex3f(0.62,0.25,0.0);
glEnd();
}
void renderbox1( point a , point b , point c, point d)
{
glBegin(GL_POLYGON);
glColor3f(0,0,0);
glVertex3dv(a);
glColor3f(0,0,0);
glVertex3dv(b);
glColor3f(0,0,0);
glVertex3dv(c);
glColor3f(0,0,0);
glVertex3dv(d);
glEnd();
}
void keyboard(unsigned char key,int x,int y)
{
switch(key){
case 'a':xangle-=0.1;
++xmove;
while(xmove>5)
{
xmove=-5;
xangle=0.5;
continue;
}
break;
case 'd':xangle+=0.1;
--xmove;
while(xmove<-5)
{
xmove=5;
xangle =-0.5;
continue;
}
break;
case 'r':
release=1;
//printf("Inside switch r");
break;
}
glutPostRedisplay();
}
void display()
{
Sleep(2);
glClear(GL_COLOR_BUFFER_BIT);
glPushMatrix();
glLineWidth(3.0);
glLoadIdentity();
glTranslatef(xangle,0,0);
renderbox1(vv[0],vv[1],vv[2],vv[3]); // To draw the paddle
glPopMatrix();
//printf("x move in disp:%1f \n",xmove);
renderoutline();
glPushMatrix();
glTranslatef(0,ii,0);
ball(); //To draw the ball
glPopMatrix();
glFlush();
}
void moveBall(){ //glutidlefunction
if(release==1)
{ //Release becomes one when the key 'r' is pressed (glutkeyboardfunc)
Sleep(500);
if(ii>=0&&ii<=0.9 )
{
reac_top=false;
ii=ii+0.05;printf("1\n");//The ball which was intially on the paddle starts moving till it reaches the top edge of thescreen
}
else if(ii>=0.9)
{
//when the boll reaches top
ii=ii-0.05;
reac_top=3;
printf("2\n");
}
else if( (ii<0.9)&& (reac_top==3)&&(ii>0.05)) //The balls journey back to the paddle
{
printf("3\n");
ii=ii-0.05;
}
release=1;
}
}
void reshape(int w, int h)
{
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 1.2, 0, 1.2,-10.0,10.0);
glMatrixMode(GL_MODELVIEW);
glViewport(0,0,w,h);
//glutPostRedisplay();
//Use the whole window for rendering
}
int main(int argc ,char **argv)
{
//clock_t begin= clock();
char n1,n2;
int ack;
/*printf("The object of Tic Tac Toe is to get three in a row. \n . Players alternate placing Xs and Os(Traingles and Boxes in this version) \n on the game board until either opponent has three \n in a row or all nine squares are filled(Which would be a drawObviously). \n");
printf("\n Press 1 if acknowledged \n");
scanf("%d",&ack);*/
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
glutInitWindowSize(1000,500);
glutInitWindowPosition(200,0);
glutCreateWindow("3d Gasket");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutReshapeFunc(reshape);
glutIdleFunc(moveBall);
glClearColor(1,1,1,1);
glutMainLoop();
//clock_t end=clock();
}

Answer 1

You're using c++, use C++-style (stdlib.h -> cstdlib) headers.
Apply your projection/modelview matrices each time through display() instead of a reshape callback, helps prevent annoying matrix stack issues.
Don't Sleep(), use a timer/idle callback to glutPostRedisplay(). Bonus points for framerate-independent movement (you can use glutGet(GLUT_ELAPSED_TIME) to calculate delta-t).
Without Sleep() there's no reason to drag windows.h into things.
All together:
#include <GL/glut.h>
#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <ctime>
#include <cstring>
typedef double point[3];
point a,b,c,d;
static float xmove=0.0;
static int release=0;
static float ii=0.00;
static int reac_top;
using namespace std;
GLfloat xangle=0.0;
float changeDir=1;// positive direction
double vv[4][3]={ {0.5,0.2,0.0},{ 0.5,0.25,0.0},{0.7,0.25,0.0},{0.7,0.2,0.0}};
void renderoutline()
{
glBegin(GL_LINE_LOOP);
glColor3f(1,0,0);
glVertex2f(0.0,0.0);
glColor3f(1,0,0);
glVertex2f(0,1.2);
glColor3f(1,0,0);
glVertex2f(1.2,1.2);
glColor3f(1,0,0);
glVertex2f(1.2,0);
glEnd();
}
void ball()
{
glBegin(GL_POLYGON);
glColor3f(0,0,1);
glVertex3f(0.6,0.25,0.0);
glColor3f(0,0,1);
glVertex3f(0.6,0.28,0.0);
glColor3f(0,0,1);
glVertex3f(0.62,0.28,0.0);
glColor3f(0,0,1);
glVertex3f(0.62,0.25,0.0);
glEnd();
}
void renderbox1( point a , point b , point c, point d)
{
glBegin(GL_POLYGON);
glColor3f(0,0,0);
glVertex3dv(a);
glColor3f(0,0,0);
glVertex3dv(b);
glColor3f(0,0,0);
glVertex3dv(c);
glColor3f(0,0,0);
glVertex3dv(d);
glEnd();
}
void keyboard(unsigned char key,int x,int y)
{
switch(key)
{
case 'a':xangle-=0.1;
++xmove;
while(xmove>5)
{
xmove=-5;
xangle=0.5;
continue;
}
break;
case 'd':xangle+=0.1;
--xmove;
while(xmove<-5)
{
xmove=5;
xangle =-0.5;
continue;
}
break;
case 'r':
release=1;
break;
}
}
void display()
{
glClearColor(1,1,1,1);
glClear(GL_COLOR_BUFFER_BIT);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, 1.2, 0, 1.2,-10.0,10.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glPushMatrix();
glLineWidth(3.0);
glLoadIdentity();
glTranslatef(xangle,0,0);
renderbox1(vv[0],vv[1],vv[2],vv[3]); // To draw the paddle
glPopMatrix();
renderoutline();
glPushMatrix();
glTranslatef(0,ii,0);
ball();
glPopMatrix();
glFlush();
}
void moveBall()
{
if(release==1)
{
//Release becomes one when the key 'r' is pressed (glutkeyboardfunc)
if(ii>=0&&ii<=0.9 )
{
reac_top=false;
ii=ii+0.05;printf("1\n");//The ball which was intially on the paddle starts moving till it reaches the top edge of thescreen
}
else if(ii>=0.9)
{
//when the boll reaches top
ii=ii-0.05;
reac_top=3;
printf("2\n");
}
else if( (ii<0.9)&& (reac_top==3)&&(ii>0.05)) //The balls journey back to the paddle
{
printf("3\n");
ii=ii-0.05;
}
release=1;
}
}
void timer( int value )
{
moveBall();
glutTimerFunc( 16, timer, 0 );
glutPostRedisplay();
}
int main(int argc ,char **argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
glutInitWindowSize(1000,500);
glutInitWindowPosition(200,0);
glutCreateWindow("3d Gasket");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutTimerFunc( 0, timer, 0 );
glutMainLoop();
}