Sphere generation and calculating indices windings

Math and Physics Programming

Started by MARS_999 August 02, 2012 04:18 AM

0 comments, last by MARS_999 11 years, 8 months ago

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August 02, 2012 04:18 AM

Here is the code I am using, it produces a sphere, but the indices are not correct as I have a rendering error with a quad tearing off the sphere and can only assume the indices are incorrect?

Thanks!



class SolidSphere

{

protected:

	std::vector<GLfloat> vertices, normals, texcoords;

	std::vector<GLuint> indices;

public:

SolidSphere(){}

~SolidSphere(){}

	void Generate(float radius, int rings, int sectors)

	{

		float const R = 1.0f/(float)(rings-1);

		float const S = 1.0f/(float)(sectors-1);

		int r, s;

		vertices.resize(rings  * sectors * 3);

		normals.resize(rings   * sectors * 3);

		texcoords.resize(rings * sectors * 2);

		std::vector<GLfloat>::iterator v = vertices.begin();

		std::vector<GLfloat>::iterator n = normals.begin();

		std::vector<GLfloat>::iterator t = texcoords.begin();

		for(r = 0; r < rings; ++r)

   for(s = 0; s < sectors; ++s)

   {

				float const y = sinf( -M_PI_2 + M_PI * r * R);

				float const x = cosf(2*M_PI * s * S) * sinf(M_PI * r * R);

				float const z = sinf(2*M_PI * s * S) * sinf(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;

   }

		indices.resize(rings * sectors * 4);

		std::vector<GLuint>::iterator i = 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)

	{

  //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

  glEnable(GL_TEXTURE_2D);

  //glEnable(GL_LIGHT0);

  //glEnable(GL_LIGHTING);

  glPushMatrix();

   glTranslatef(x, y, z);

   glEnableClientState(GL_VERTEX_ARRAY);

   glEnableClientState(GL_NORMAL_ARRAY);

   glEnableClientState(GL_TEXTURE_COORD_ARRAY);

   glVertexPointer(3, GL_FLOAT, 0, &vertices[0]);

   glNormalPointer(GL_FLOAT, 0, &normals[0]);

   glTexCoordPointer(2, GL_FLOAT, 0, &texcoords[0]);

	glDrawElements(GL_QUADS, indices.size(), GL_UNSIGNED_INT, &indices[0]);

   glDisableClientState(GL_TEXTURE_COORD_ARRAY);

   glDisableClientState(GL_NORMAL_ARRAY);

   glDisableClientState(GL_VERTEX_ARRAY);

		glPopMatrix();

  glDisable(GL_TEXTURE_2D);

	}

};