Thread: Creating a 3D Solid Sphere in OpenGL

Hi guys!


I'm working on a new OpenGL problem today: Creating a 3D Solid Sphere in OpenGL.

I've used the following code to define a class '3DSphere.cpp' (according to Link).

Code:

/*
 * 3DSphere.cpp
 *
 *  Created on: Oct 30, 2012
 *      Author: guptaa
 */



#include <stdio.h>
#include <stdlib.h>

#include <gl.h>
#include <glu.h>
#include <glut.h>

#include <math.h>
#include <vector.h>


class 3DSphere
{

protected:
    vector<GLfloat> vertices;
    vector<GLfloat> normals;
    vector<GLfloat> texcoords;
    vector<GLushort> indices;

public:
    void SolidSphere(float radius, unsigned int rings, unsigned int sectors)
    {
        float const R = 1./(float)(rings-1);
        float const S = 1./(float)(sectors-1);
        int r, s;

        sphere_vertices.resize(rings * sectors * 3);
        sphere_normals.resize(rings * sectors * 3);
        sphere_texcoords.resize(rings * sectors * 2);
        vector<GLfloat>::iterator v = sphere_vertices.begin();
        vector<GLfloat>::iterator n = sphere_normals.begin();
        vector<GLfloat>::iterator t = sphere_texcoords.begin();
        for(r = 0; r < rings; r++) for(s = 0; s < sectors; s++) {
                float const y = sin( -M_PI_2 + M_PI * r * R );
                float const x = cos(2*M_PI * s * S) * sin( M_PI * r * R );
                float const z = sin(2*M_PI * s * S) * sin( M_PI * r * R );

                *t++ = s*S;
                *t++ = r*R;

                *v++ = x * radius;
                *v++ = y * radius;
                *v++ = z * radius;

                *n++ = x;
                *n++ = y;
                *n++ = z;
        }

        sphere_indices.resize(rings * sectors * 4);
        std:vector<GLushort>::iterator i = sphere_indices.begin();
        for(r = 0; r < rings; r++) for(s = 0; s < sectors; s++) {
                *i++ = r * sectors + s;
                *i++ = r * sectors + (s+1);
                *i++ = (r+1) * sectors + (s+1);
                *i++ = (r+1) * sectors + s;
        }
    }

    void draw(GLfloat x, GLfloat y, GLfloat z)
    {
        glMatrixMode(GL_MODELVIEW);
        glPushMatrix();
        glTranslatef(x,y,z);

        glEnableClientState(GL_VERTEX_ARRAY);
        glEnableClientState(GL_NORMAL_ARRAY);
        glEnableClientState(GL_TEXTURE_COORD_ARRAY);

        glVertexPointer(3, GL_FLOAT, 0, &sphere_vertices[0]);
        glNormalPointer(GL_FLOAT, 0, &sphere_normals[0]);
        glTexCoordPointer(2, GL_FLOAT, 0, &sphere_texcoords[0]);
        glDrawElements(GL_QUADS, sphere_indices.size()/4, GL_UNSIGNED_SHORT, sphere_indices);
        glPopMatrix();
    }
}

However, I receive the following error (ref: line 21 - opening of 3DSphere class):

invalid suffix "DSphere" on integer constant

It seems a C error rather than an OpenGL one.

Also - where does the actual drawing take place? There is no main function here!

First, this is C++ code, so this post should be moved to the C++ board.

Second, you cannot start an identifier with a digit. Only A-Za-z_ (and I think $) are allowed for the first character of an identifier.

Originally Posted by christop

First, this is C++ code, so this post should be moved to the C++ board.

Second, you cannot start an identifier with a digit. Only A-Za-z_ (and I think $) are allowed for the first character of an identifier.

Thanks for letting me know. I hope someone can shift this thread into another section.

I changed the name to just 'Sphere.cpp'. And now the rest of the error have started appearing:

Code:

expected identifier before numeric constant    Sphere.cpp    /CreateSyntheticObjects    line 21    C/C++ Problem
expected unqualified-id before numeric constant    Sphere.cpp    /CreateSyntheticObjects    line 21    C/C++ Problem
Invalid arguments '
Candidates are:
void glDrawElements(unsigned int, int, unsigned int, const void *)

invalid suffix "DSphere" on integer constant    Sphere.cpp    /CreateSyntheticObjects    line 21    C/C++ Problem
Method 'begin' could not be resolved    Sphere.cpp    /CreateSyntheticObjects    line 40    Semantic Error

Method 'resize' could not be resolved    Sphere.cpp    /CreateSyntheticObjects    line 37    Semantic Error
Method 'size' could not be resolved    Sphere.cpp    /CreateSyntheticObjects    line 83    Semantic Error
Symbol 'sphere_indices' could not be resolved    Sphere.cpp    /CreateSyntheticObjects    line 60    Semantic Error
Symbol 'sphere_normals' could not be resolved    Sphere.cpp    /CreateSyntheticObjects    line 38    Semantic Error
Symbol 'sphere_texcoords' could not be resolved    Sphere.cpp    /CreateSyntheticObjects    line 39    Semantic Error
Symbol 'sphere_vertices' could not be resolved    Sphere.cpp    /CreateSyntheticObjects    line 37    Semantic Error