Object not showing (c++ )

[Pedrosanchez87]

I am trying to make a lunar lander type game to start off opengl with, but i cant get get the object to show, if anyone could help out to why this isnt showing, it would be greatly appreciated . This is the code i have

main

#include <iostream>
#include <GL/glut.h>
#include "Lander.h"
#include "random.h"
 
using namespace std;
float startx = rnd(100, 600); float starty = rnd(350, 450); int startradius = 10;
 
Lander lander(startx, starty, startradius);
 
void display(void)
{
	glClear(GL_COLOR_BUFFER_BIT);
	lander.show();
	glutSwapBuffers();
}
 
void main(int argc, char **argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA);
	glutInitWindowSize(1000, 600);
	glutInitWindowPosition(100, 100);
	glutCreateWindow("Animation Example");
	glClearColor(1.0, 1.0, 1.0, 0.0);
	glutDisplayFunc(display);
	glutMainLoop();
 
}

Lander.h

#ifndef Lander_H
#define Lander_H
 
class Lander
{
public:
	Lander(float ix, float iy, int iradius);
	void show();
	void draw();
private:
	float x, y, radius;
};
#endif

Lander.cpp

#include "Lander.h"
#include<gl/glut.h>
#include <cmath>
 
 
Lander::Lander(float ix, float iy, int iradius)
{
	x = ix; y = iy; radius = iradius;
}
 
void Lander::show()
{
	glPushMatrix();
	glTranslatef(x, y, 0);
	glRotatef(22, 0, 0, 1);
	glTranslatef(-x, -y, 0);
	draw();
	glPopMatrix();
}
 
void Lander::draw()
{
	glBegin(GL_POLYGON);		
	const int NPOINTS = 8;
	const float TWOPI = 2 * 3.1415927;
	const float STEP = TWOPI / NPOINTS;
	glColor3f(1.0, 0.0, 0.0);
	for (float angle = 0; angle<TWOPI; angle += STEP)
		glVertex2f(x + radius*cos(angle), y + radius*sin(angle));
	glEnd();
 
	glBegin(GL_LINE_LOOP);		
	glColor3f(1.0, 0.0, 0.0);
	glVertex2f(x - 6, y - 6);
	glColor3f(1.0, 0.0, 0.0);
	glVertex2f(x - 12, y - 12);
	glEnd();
 
	glBegin(GL_LINE_LOOP);		
	glColor3f(1.0, 0.0, 0.0);
	glVertex2f(x, y - 8);
	glColor3f(1.0, 0.0, 0.0);
	glVertex2f(x, y - 17);
	glEnd();
}

[Loonywx]

I think you need to clear the depth buffer also:

glClearColor(color[0], color[1], color[2], color[3]);
glClearDepth(static_cast<GLclampd>(depth));
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

[mhagain]

Try creating a double-buffered context rather than single-buffered; i.e. replace this:

glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA);

With this:

glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);

Tutorials that create single-buffered contexts should be mercilessly wiped from the face of the earth. You see - double-buffered is not actually more difficult, it's more compatible, and weird errors like this that might put people off from continuing just won't happen.