OpenGL with two loops, one loop is not working - c++

Question

My OpenGL program is not working properly. Inside the drawScene() function I created two loops. One loop for GL_LINES another loop for GL_POINTS. The GL_LINES loop works fine but GL_POINTS loop doesn't work. Any help appreciated.
#include <iostream>
#include <stdlib.h>
#include <GL/glut.h>
#include <math.h>
#define PI 3.14159265
using namespace std;
//Called when a key is pressed
void handleKeypress(unsigned char key, int x, int y) {
switch (key) {
case 27: //Escape key
exit(0);
}
}
//Initializes 3D rendering
void initRendering() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_COLOR_MATERIAL); //Enable color
glClearColor(0.7f, 0.9f, 1.0f, 1.0f); //Change the background to sky blue
}
//Called when the window is resized
void handleResize(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (double)w / (double)h, 1.0, 200.0);
}
float _angle = 0.0f;
float _cameraAngle = 0.0f;
float x = -1.5;
float y = -0.5;
//Draws the 3D scene
void drawScene() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glLineWidth (9.0f);
glBegin(GL_LINES);
glColor3f(1.0f, 0.0f, 0.0f);
double r = 0.5;
for(int c = 0;c<=360;c++){
double y = r*cos (c*PI/180);
double x = r*sin (c*PI/180);
glVertex3d(x,y,-5.0);
glVertex3d(0.0,0.0,-5.0);
}
glEnd();
glPointSize (7.0f);
glBegin(GL_POINTS);
glColor3f(0.0f, 1.0f, 0.0f);
double r = 1.0;
for(int c = 0;c<=360;c++){
double y = r*cos (c*PI/180);
double x = r*sin (c*PI/180);
glVertex3d(x,y,-5.0);
//glVertex3d(0.0,0.0,-5.0);
}
glEnd();
glutSwapBuffers();
//glutPostRedisplay();
}
void update(int value) {
_angle += 2.0f;
if (_angle > 360) {
_angle -= 360;
}
glutPostRedisplay();
glutTimerFunc(60, update, 0);
}
int main(int argc, char** argv) {
//Initialize GLUT
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(400, 400);
//Create the window
glutCreateWindow("two circle");
initRendering();
//Set handler functions
glutDisplayFunc(drawScene);
glutKeyboardFunc(handleKeypress);
glutReshapeFunc(handleResize);
glutTimerFunc(25, update, 0); //Add a timer
glutMainLoop();
return 0;
}

Answer 1

Right now, you're declaring the variable r in two places: where you set double r = 0.5; and at double r = 1.0;
Try changing it to:
double r = 0.5;
//First loop
r = 1.0;
//Second loop